ENH220 011/021 Pathophysiology Final Exam Review PDF

NH220 011/021 - Pathophysiology Final Exam Review What is on the Exam? Section 1. Anatomy, Function, and Structure 16 questions in this section include basic cell structure, heart, respiratory system, urinary system, gastrointestinal tract and liver, ocular, auditory, and nervous system anatomy. T...

NH220 011/021 - Pathophysiology Final Exam Review What is on the Exam? Section 1. Anatomy, Function, and Structure 16 questions in this section include basic cell structure, heart, respiratory system, urinary system, gastrointestinal tract and liver, ocular, auditory, and nervous system anatomy. This section includes diagrams. Section 2. Physiology There are 11 questions in this section that include cell physiology, heart function, urinary system, gastrointestinal tract, liver or pancreas, and nervous system physiology. Section 3. Pathophysiology There are 15 questions in this section that include cell pathophysiology, cardiovascular system, respiratory system pathology, renal system, ocular system, gastrointestinal tract, liver or pancreas, and nervous system pathology. Section 4. Application Scenarios There are 3 questions in this section which are meant to assess your ability to apply what you have learned in this course and select the most appropriate answer; each question will appear as a scenario. No information is given about these questions as they are meant to test true understanding of the material. Questions that were on term one and two tests Answers Below Questions Test 1 1. In cases of transport failure, what is a likely consequence of the impairment of passive transport processes? A) Enhanced cellular energy production to compensate for the loss of passive transport. B) Facilitated movement of substances against their concentration gradient. C) An increase in the rate of substance movement across the membrane out of the cell. D) Accumulation of substances outside the cell. E) Reduced reliance on active transport mechanisms to maintain homeostasis. 2. Which of the following is LEAST likely to be directly affected on an ECG during a heart attack? A) T wave B) Q wave C) P wave D) R wave E) ST segment 3. The heart receives deoxygenated blood from the body through which two major blood vessels? A) Pulmonary arteries Aorta and pulmonary vein Coronary veins Superior and inferior vena cava Pulmonary veins Which term describes a condition where there is a sudden, severe restriction of blood flow to the tissues, often due to a blockage in an artery? schemia Hypoxia Myocardial Infarction Stenosis Angina Which of the following is a common human fungal infection caused by Candida species? Thrush Ringworm Malaria ) Aspergillosis Histoplasmosis What is the term for the process of programmed cell death that helps control the growth of neoplastic cells? Apoptosis Metastasis Angiogenesis ) Hyperplasia Mutagenesis Systemic inflammation can have widespread effects on the body. Which of the following statements accurately describes systemic inflammation? Systemic inflammation is characterized by the release of pro-inflammatory molecules into the bloodstream. Systemic inflammation is primarily a psychological response and does not involve physiological changes in the body. Systemic inflammation is exclusive to autoimmune diseases and does not occur in response to infections. Systemic inflammation is always a healthy response to infections. Systemic inflammation is limited to a specific area of the body and does not affect other organs or tissues. Which type of Immune cell is responsible for coordinating the adaptive immune response and producing cytokines? Eosinophils T Cells Neutroph B cells Macrophages Which complement pathway is initiated by the binding of antibodies to antigens on the surface of pathogens? Classical pathway Alternative pathway Lectin pathway Primary pathway Primary complement pathway What is the primary function of IgE antibodies in the immune system? Opsonization of pathogens Allergic responses and defense against parasites Neutralization of toxins Activation of complement ) Memory cell formation Which of the following is a potential underlying mechanism for autoimmune diseases? ) Increased production of foreign antigens Inactivation of T cells Overproduction of self- antigens Suppression of the immune system Alteration of self-antigens Which organelle is responsible for maintaining cell shape and providing structural support? Cytoplasm Peroxisome Nucleus ) Chloroplast Cytoskeleton Which of the following is a common arrhy mia characterized by disorganized atrial electrical activity with an irregularly irregula entricular response? First-degree AV block Atrial fibrillation Atrial flutter Ventricular tachycardia Supraventricular tachycardia In which organelle do individuals with cystic fibrosis experience malfunction, resulting in the production of thick and sticky mucus, leading to piratory and digestive problems? Golgi Apparatus Cell membrane (Plasma membrane) Nucleus Mitochondria Endoplasmic Reticulum What are the primary lo or infection? Saved effects of acute inflammation at the site of tissue injury Localized muscle contractio. Increased blood flow Tissue hardening Decreased blood flow and tissue cool, heightened tissue sensitivity: formation of granulomas. ) Swelling Which of the following statements is true regarding Mycoplasma pneumoniae infection in young adults? Mycoplasma pneumoniae only affects children. Mycoplasma pneumoniae is associated with skin infections in young adults. Mycoplasma pneumoniae commonly causes respiratory infections in young adults. Mycoplasma pneumoniae primarily affects older adults and the elderly. Young adults are not susceptible to Mycoplasma pneumoniae infection. Which of the following statements accurately distinguishes between necrosis and apoptosis it. / biology? Necrosis is a fu of cell death assoclated with inflammation and celtular damage and is chai. erized by cell swelling and membrane rupture. Apoptosis is a programmed cell deal.ocess marked by cell shrinkage and fragmentation. Necrosis is a common outcons SE fissue repair while apoptosis is a protective mechanism to maintain damaged c Min a dormant state until they can be repaired, Necrosis is a highly regulated process that occu uring tissue development Necrosis is a programmed cell death process charac. ed by cell shrinkage and fragmentation Necrosis and apoptosis are terms used interchangeably to des. a the same cellular process of cell death. Maria, a 62-year-old patient, has been diagnosed with advanced lung cancer. Maria has been undergoing chemotherapy for several months, and the initial response to treatment was positive. However, during a recent follow-up scan, their oncologist noticed signs of disease progression. What is a potential reason for the observed disease progression in Maria's case? Maria has another type of cancer that has metastasized. The testing revealed the wrong subtype. Tumor heterogeneity may have led to the emergence of treatment-resistant cancer cell populations. Maria's immune system has become more effective at fighting the cancer. Maria's cancer is not lung cancer but a different type of malignancy. In Tetralogy of Fallot, why does right ventricular hypertrophy occur? Due to chronic mitral valve regurgitation Because of increased blood flow through the pulmonary valve Because of increased pressure to eject blood due to pulmonary stenosis As a result of pulmonary valve insufficiency Due to increased preload from left-to-right shunting  Sarah has recently been diagnosed with a disorder that destroys red blood cells by hemolysis. Their doctor suspects that her condition falls under one of the hypersensitivity reactions. Based only on the given information, which type of hypersensitivity reaction is most likely responsible for Sarah's disorder? Туре I Type 1I Type III Type IV Type V Which condition, due to systemic hypertension, is characterized by a high-pressure load on the ventricle responsible for blood flow to the body? ) Tricuspid regurgitation Left ventricular hypertrophy Mitralva valve prolpse Atrial septal defect Ventricular septal defect Which organelle is responsible for detoxifying harmful substances in the cell? Endoplasmic Reticulum Peroxisome © Vacuole Nucleus Lysosome Mark recently received a blood transfusion due to a medical procedure. A few hours after the transfusion, they developed symptoms of fever, chills, and pain in their lower back. Mark's medical team suspects a transfusion reaction causing red blood cell hemolysis. Which type of hypersensitivity reaction is most likely responsible for Mark's symptoms? Type I Type I| Type III ) Type IV Type V Which of the following is a primary function of the complement system in innate immunity? Cytokine release Pathogen lysis and opsonization Phagocytosis Antibody production Cell-mediated immunity What is the potential consequence of regulatory T lymphocyte dysfunction in autoimmune diseases? Decreased inflammation Enhanced immune response control Reduced autoimmune reactions Malfunctioning immune response Increased production of foreign antigens Which immunoglobulin isotype is the most abundant in serum and is responsible for the secondary immune response following antigen exposure? IgG IgA IgD IgM IgE The pacemaker of the heart, responsible for setting the rhythm of the heartbeat, is known as: Bundle of His AV node Purkinje fibers Sinoatrial (SA) node Endocardium This condition results from a decrease in cellular energy production and muscle weakness in many parts of the body, especially the eyes, where it can cause paralysis of the eye muscles. Which organelle does this condition affect? ) Nucleus Ribosomes Peroxisome Mitochondrion Rough endoplasmic reticulum In Tetralogy of Fallot, why does right ventricular hypertrophy occur? Because of increased pressure to eject blood due to pulmonary stenosis ) Because of increased blood flow through the pulmonary valve Due to chronic mitral valve regurgitation ) Due to increased preload from left-to-right shunting ) As a result of pulmonary valve insufficiency In the context of COVID-19, the interaction between the SARS-CoV-2 virus and ACE2 involves a multi-step process. Which of the following accurately describes a key step in this interaction? ACE2 directly destroys the viral particles upon contact. The SARS-CoV-2 spike protein binds to ACE2 and enters the cell via endocytosis.  ACE activates an immune response that eliminates the virus before it can enter host cells. ACE2 inhibits the viral replication process once the virus is inside the host cell. The SARS-CoV-2 virus directly fuses with the host cell membrane without any specific receptors. Which of the following best defines a benign neoplasm? A neoplasm that is always life-threatening A neoplasm that originates from blood cells A neoplasm that primarily affects the nervous system A neoplasm that is slow growing and localized A neoplasm that spreads to other parts of the body Which condition is the result of the heart's inability to pump sufficient blood to meet the body's needs? Hypertension Cardiomyopathy Heart failure Aortic regurgitation Myocarditis Which of the following is an example of a physical barrier in innate immunity? OT cells Antibodies Mucus Memory cells Cytokines Test 2 What mechanism allows Helicobacter pylori to survive in the acidic environment of the stomach? Secretion of proteases to digest gastric cells Production of urease to neutralize stomach acid Formation of biofilm on the gastric lining an Inhibition of mucus production by epithelial cells Activation of gastric acid pumps Why is an individual with an incompetent cardiac sphincter at risk for Barrett esophagus? an Increased gastric acid secretion Proliferation of smooth muscle cells in the esophagus Increased production of gastric mucus (Loss of protective mucosal lining in the esophagus Chronic reflux leading to squamous-to-columnar metaplasia What is a common clinical feature of pneumonia? (Rash I Fever and cough I Muscle stiffness I Hypertension Weight gain Which microorganism causes tuberculosis? Influenza virus SARS-CoV-2 Mycobacterium tuberculosis _ Streptococcus pneumoniae ) Legionella Pneumocystis pneumonia mainly affects which group of people? Immunocompromised individuals Athletes Smokers Elderly individuals Children under 5 During an asthma attack, the primary limitation to airflow is caused by which of the following processes? I Constriction of bronchial smooth muscle I Inflammatory cell infiltration into alveoli (ID Swelling of bronchial mucosa I Accumulation of fibrotic tissue in bronchioles (I Reduced alveolar surface area In a case of miliary tuberculosis, the spread of infection is facilitated through which of the following processes? * Dissemination via erosion into a large blood vessel I Activation of dormant bacteria in lymph nodes ( Lymphatic transmission to peripheral tissues I Bronchogenic spread across lobes ® Direct invasion of lung parenchyma In hepatic encephalopathy, which toxic substance typically accumulates, leading to neurological symptoms? Ammonia Urea Cholesterol OGlucose Bilirubin Why does cirrhosis of the liver often lead to esophageal varices? Hepatic stellate cells cause constriction of esophageal veins Increased blood volume causes direct vessel rupture The liver secretes excess bile, leading to vascular inflammation Portal hypertension causes blood to be redirected through collateral veins, including those in the esophagus Increased bilirubin levels weaken blood vessels What is the main function of the kidneys? Excrete waste products Store urine I Secrete digestive enzymes Produce insulin I Generate blood cells Which type of urinary stone often leads to the formation of large branching structures in the renal pelvis? Staghorn calculus Bilirubin stone Struvite stone Urinary calculi Calcium oxalate stone Which condition is an inflammation of the bladder often causing a burning sensation during urination? Nephrolithiasis Nephrosis O Glomerulonephritis Hepatitis Cystitis Which condition is characterized by inflammation of the large intestine and rectum, often leading to bloody diarrhea? (Celiac disease Diverticulitis Ibs Crohn's disease Ulcerative colitis Lesson 1 Introduction to the Course, Cells and Tissues, and Inflammation and Repair 1. Preamble 2. The Course 3. Cells - Structure - Organelles - Dysfunction 4. Tissues - Major classes - Tissue Types - Dysfunction 5. Inflammation - Process - Effects - Repair - Dysfunction 6. Postamble What is pathophysiology? pathos- physis- logos Pathophysiology is a branch of study, at the intersection of pathology and physiology, concerning disordered physiological processes that cause, result from, or are otherwise associated with a disease or injury. Cells In biology, the smallest unit can live on its own, and that makes up all living organisms and the tissues of the body. A cell has three main parts: the cell membrane, the nucleus, and the cytoplasm. The cell membrane surrounds the cell and controls the substances that enter and exit the cell. Somatic cells In cellular biology, a somatic or vegetal cell is any biological cell forming the body of a multicellular organism other than a gamete, germ cell, gametocyte, or undifferentiated stem cell. Somatic cells compose the body of an organism and divide through mitosis. We are not using anything else. All the different parts of the cell 1. Nucleus Description: Large, round structure often located in the center of the cell. Function: The control center of the cell, containing the cell's genetic material (DNA). It regulates gene expression and mediates the replication of DNA during the cell cycle. 2. Mitochondria Description: Oval-shaped, double-membraned organelles with an inner membrane folded into cristae. Function: Known as the powerhouse of the cell, mitochondria generate ATP (adenosine triphosphate), the energy currency of the cell, through cellular respiration. 3. Endoplasmic Reticulum (ER) Rough ER: ○ Description: Network of membranes covered in ribosomes. ○ Function: Synthesizes and packages proteins, which are transported out of the cell or to the Golgi apparatus for further modification. Smooth ER: ○ Description: Network of membranes without ribosomes. ○ Function: Synthesizes lipids, metabolizes carbohydrates, and detoxifies drugs and toxins. 4. Golgi Apparatus Description: Stacked, flattened membrane sacs. Function: Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles. 5. Ribosomes Description: Small, spherical structures composed of RNA and proteins, either floating freely in the cytoplasm or attached to the rough ER. Function: Synthesizes proteins by translating mRNA into amino acid sequences. 6. Lysosomes Description: Membrane-bound organelles containing digestive enzymes. Function: Break down waste materials, cellular debris, and foreign invaders like bacteria. They act as the cell’s waste disposal system. 7. Peroxisomes Description: Small, membrane-bound organelles containing enzymes. Function: Break down fatty acids and detoxify harmful substances like hydrogen peroxide (H₂O₂). 8. Cytoskeleton Description: A network of protein fibers, including microtubules, microfilaments, and intermediate filaments. Function: Provides structural support, maintains the shape of the cell, and facilitates cell movement and intracellular transport. 9. Cytoplasm Description: Gel-like fluid that fills the cell. Function: The medium in which organelles are suspended, allowing for the movement of materials around the cell. Many cellular processes also occur here. 10. Plasma Membrane (Cell Membrane) Description: A phospholipid bilayer with embedded proteins. Function: Controls the movement of substances in and out of the cell, providing a selective barrier and maintaining homeostasis. 11. Centrosome and Centrioles Description: Centrosomes contain a pair of centrioles, made of microtubules. Function: Play a role in organizing microtubules during cell division (mitosis), ensuring proper chromosome separation. 12. Vesicles Description: Small membrane-bound sacs. Function: Transport materials within the cell and to the cell membrane for export. 13. Chloroplasts (in plant cells) Description: Green, double-membraned organelles containing chlorophyll. Function: Carry out photosynthesis by converting sunlight, water, and carbon dioxide into glucose and oxygen. 14. Cell Wall (in plant cells) Description: A rigid outer layer made of cellulose. Function: Provides structural support and protection, helping maintain the cell’s shape. 15. Vacuole In plant cells: ○ Description: Large, central organelle filled with fluid. ○ Function: Stores water, nutrients, and waste products, and helps maintain cell turgor (pressure) for structural support. In animal cells: ○ Description: Smaller, more numerous vacuoles. ○ Function: Store substances like nutrients and waste, though they are less prominent compared to those in plant cells. The lipid bilayer is a fundamental component of all cell membranes. It forms a two-layered structure made primarily of phospholipids, which have a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. This dual nature causes the phospholipids to arrange themselves into two layers: 1. Outer Layer: The hydrophilic heads face outward, toward the watery environments inside and outside of the cell. 2. Inner Layer: The hydrophobic tails face inward, away from the water, interacting with each other. Key Features: Selective Permeability: The lipid bilayer controls what substances can enter and leave the cell. Small, non-polar molecules (like oxygen and carbon dioxide) can pass through, while large or charged molecules need specialized proteins to help them cross.  Fluidity: The bilayer is not rigid. The phospholipids can move sideways within the layer, providing the membrane with flexibility. This is influenced by temperature and the presence of cholesterol molecules within the bilayer. Proteins and Carbohydrates: Embedded in the lipid bilayer are various proteins and carbohydrates that play roles in cell communication, transport, and signaling. Structure of the Lipid Bilayer: Phospholipids: The main building blocks, with their hydrophilic head and hydrophobic tails. Cholesterol: Found between the phospholipids, helps to maintain membrane fluidity. Membrane Proteins: These can be peripheral (on the surface) or integral (spanning across the membrane), and they serve various functions such as transport, enzymatic activity, or signal transduction. Cellular transport Osmosis Osmosis is the spontaneous net movement or diffusion of solvent molecules through a selectively permeable membrane from a region of high water potential to a region of low water potential, in the direction that tends to equalize the solute concentrations on the two sides. Endocytosis and Exocytosis Endocytosis is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane and bringing it into the cell. Exocytosis describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell. Pinocytosis and Phagocytosis Pinocytosis primarily refers to the uptake of extracellular fluids and small molecules by a cell, whereas phagocytosis is a process by which the cell membrane invaginates around large macromolecular structures (e.g., proteins and viruses) that are otherwise unable to diffuse into the cell. Hyperplasia Hyperplasia, or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of organic tissue that results from cell proliferation. It may lead to the gross enlargement of an organ, and the term is sometimes confused with benign neoplasia or benign tumor. Hypertrophy Hypertrophy is the increase in the volume of an organ or tissue due to the enlargement of its component cells. It is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number. Metaplasia 'Metaplasia' is defined as the conversion of one cell type to another, and it can include conversions between tissue-specific stem cells. 'Transdifferentiation,' on the other hand, refers to the conversion of one differentiated cell type to another, and should therefore be considered a subset of metaplasia. Dysplasia A term used to describe the presence of abnormal cells within a tissue or organ. Dysplasia is not cancer, but it may sometimes become cancer. Dysplasia can be mild, moderate, or severe, depending on how abnormal the cells look under a microscope and how much of the tissue or organ is affected. Necrosis Necrosis is the death of body tissue. It occurs when too little blood flows to the tissue. This can be from injury, radiation, or chemicals. Necrosis cannot be reversed. When large areas of tissue die due to a lack of blood supply, the condition is called gangrene. Apoptosis A type of cell death in which a series of molecular steps in a cell lead to its death. This is one method the body uses to get rid of unneeded or abnormal cells. The process of apoptosis may be blocked in cancer cells. Also called programmed cell death. Mitochondria Dysfunction Leber’s Hereditary Optic Neuropathy (LHON) Symptoms: Sudden vision loss, usually in young adults. Genetic mutations in mitochondrial DNA (mtDNA) are responsible. Impaired ATP production in retinal cells leads to cell death. Treatment options are limited; no cure exists. Endoplasmic Reticulum Dysfunction Cystic Fibrosis is a genetic disorder affecting the respiratory and digestive systems. Mutation in the CFTR gene leads to defective CFTR protein. Misfolded CFTR accumulates in the ER. Lysosome Dysfunction Gaucher’s Disease Caused by a deficiency of the enzyme glucocerebrosidase. Symptoms include enlarged spleen and liver, anemia, and bone pain. Various forms of the disease, including a severe neurological form. Tissues Epithelium Epithelial cells help to protect or enclose organs. Most produce mucus or other secretions. Certain types of epithelial cells have tiny hairs called cilia, which help remove foreign substances. Epithelial cells are arranged in single, or multiple layers, depending on the organ and location. Connective and Supporting Provides structural support Connects and anchors different tissues Types: Fibrous (e.g., tendons, ligaments) Cartilage (e.g., nose, joints) Elastic (e.g., blood vessels) Bone (e.g., skeletal framework) Reticular (e.g., lymph nodes, spleen) Hematopoietic (e.g., bone marrow) Adipose (e.g., fat cells) Lymphatic (e.g., lymph nodes) Types of Connective Tissue Fibers - Collagen fibers Connect and support tissues - Elastic fibers Responsible for distensibility of arteries - Reticular fibers Form supporting framework of organs Muscle Tissue Nervous tissue Nerve - Transmits electrical signals - Coordinates and controls body functions - Components: Neurons and supporting cells (glia) Tissue Disorders Ehlers-Danlos Syndrome Ehlers–Danlos syndromes are a group of 13 genetic connective-tissue disorders. Symptoms often include loose joints, joint pain, stretchy velvety skin, and abnormal scar formation. These may be noticed at birth or in early childhood. Osteoarthritis Osteoarthritis is a degenerative joint condition. It causes pain, swelling, and stiffness, affecting a person’s ability to move freely. Osteoarthritis affects the entire joint, including the tissues around it. It is most common in the knees, hips, spine, and hands. Many factors can contribute to developing osteoarthritis. Some include a history of joint injury or overuse, older age, and being overweight. It affects women more than men. Exercise and healthy eating to build strong muscles and keep a healthy weight can reduce symptoms. Surgery to replace joints is used in severe cases to reduce pain and regain mobility. Inflammation Inflammation is a complex response to tissue injury or infection that is local and systemic and increases capillary permeability plays a crucial role in immune response and tissue repair inflammation is part of the body's defense mechanism. It is the process by which the immune system recognizes and removes harmful and foreign stimuli and begins the healing process. Inflammation can be either acute or chronic. Acute Inflammatory Process Acute inflammation is a component of the innate immune system and is typified by the movement of fluid, plasma proteins, and leukocytes (i.e., neutrophils, eosinophils, and macrophages) from surrounding vasculature into the tissue at the site of injury or infection Local Effects of Inflammation - Capillary Dilatation - Increased Blood Flow and Redness - Increased Capillary Permeability - Swelling - Attraction of Leukocytes - Leukocyte Migration - Adhesion to Endothelium Systemic Effects of Inflammation - Fever - Leukocytes - Immune Activation - Cytokine Release - Tissue Repair Cellular Reaction and Inflammation - Monocytes Monocytes are a type of white blood cell. They play a key role in the immune response and inflammation. - Chemical Mediators Chemical mediators are signaling molecules involved in the inflammatory process. Chemical Agents and Cell-Derived Mediators - Chemical Agents Intensifying Inflammation These agents enhance the inflammatory process and contribute to tissue injury. - Cell-Derived Mediators Mast cells are specialized connective tissue cells with granules containing histamine, a vasodilator. Prostaglandins and leukotrienes are synthesized from arachidonic acid. Lesson 2 Immunity, Hypersensitivity, Allergy, Autoimmune, and Neoplastic disease 1. Objectives 2. Immunity - Innate - Adaptive - Antibodies - Allergies - Disease 3. Neoplastic Disease - Benign - Malignant - Classification - Genetics - Diagnosis 4. Next Class Objectives - Basic features of cell-mediated and humoral immunity. - Five classes of antibodies and their differences. - Four types of hypersensitivity and allergicpathogenesis. - Immune response suppression and methods. - Causes and clinical manifestations ofimmunodeficiency. - Benign vs. malignant tumor characteristics and naming.Role of oncogenes and suppressor genes in tumorpathogenesis. - Inherited susceptibility to cancer. - Immunologic defenses against tumors -. Innate Immunity Innate immunity is the body’s first line of defense, providing immediate and non-specific protection against various pathogens, such as bacteria, viruses, and fungi. We have: - Physical Barriers - Cellular Defenses - Chemical Defenses Components of Innate Immunity Physical Barriers: Skin: The skin acts as a tough, physical barrier that prevents the entry of pathogens into the body. Mucous Membranes: Mucous membranes line various entry points into the body, such as the respiratory and digestive tracts. Cellular Defenses: Phagocytic Cells: Neutrophils and macrophages are white blood cells that patrol tissues and engulf invading pathogens. Natural Killer (NK) Cells: NK cells are specialized immune cells that can identify and destroy infected or abnormal host cells, such as those infected by viruses or cancer cells. Chemical Defenses: Complement System: Complement proteins are a group of circulating proteins that help in the opsonization of pathogens. Antimicrobial Peptides: These small proteins are released by cells at sites of infection and can disrupt microbial structures, including cell membranes, effectively killing pathogens. Opsonization Opsonization is an immune process that uses opsonins to tag foreign pathogens for elimination by phagocytes. Without an opsonin, such as an antibody, the negatively charged cell walls of the pathogen and phagocyte repel each other. Functions of Innate Immunity Rapid Response: Innate immunity provides immediate protection upon encountering a pathogen. Non-Specific Defense: Innate immunity does not differentiate between different types of pathogens. Inflammation: When tissues are injured or infected, innate immunity triggers inflammation as a response. Fever: Innate immunity can induce fever in response to infection. Activation of Adaptive Immunity: Innate immunity is also crucial in initiating and guiding the adaptive immune response. Limitations of Innate Immunity While innate immunity is vital for immediate protection, it has certain limitations: - It lacks specificity and memory - Some pathogens have evolved mechanisms - It may not be sufficient to eliminate certain pathogens Adaptive Immunity - It provides specific, long-lasting protection against pathogens. - Adaptive immunity involves the actions of T cells and B cells. - Memory cells in adaptive immunity lead to immunological memory. Humoral Immunity - Also known as antibody-mediated immunity, primarily revolves around the production and action of antibodies. - Antibodies neutralize bacteria by various means, such as preventing them from attaching to host cells or marking them for destruction by other immune cells. Cell-Mediated Immunity - Cell-mediated immunity is centered around the actions of T cells, another type of lymphocyte. - Vital in combating a broader range of threats (e.g., viruses, fungi, parasites, some bacteria) - Crucial when dealing with intracellular pathogens because it enables the immune system to recognize and eliminate infected cells, preventing the pathogen from spreading. - Rejects organs in some cases as the transplanted organ is foreign Interaction of Humoral and Cell-Mediated Immunity Antigen Processing and Presentation: - Antigens are foreign substances that trigger immune responses and undergo crucial processing. - Antigen-presenting cells (e.g., dendritic cells, macrophages, and B cells) capture and process antigens. - These cells break down antigens into smaller fragments and display them on their cell membranes using major histocompatibility complexes (MHC). Lymphocyte Interaction: - Lymphocytes, such as B cells (for humoral immunity) and T cells (for cell-mediated immunity), recognize displayed antigens via MHC molecules. - This interaction is a critical step in initiating the immune response. Lymphocyte Activation: - B cells, when exposed to their target antigen, proliferate into antibody-producing plasma cells. - T cells, once activated, give rise to helper T cells (regulators) and cytotoxic T cells (cell-mediated immunity). Lag Phase: - After initial antigen exposure, there’s a lag phase lasting a week or more. - This delay is due to lymphocyte activation, proliferation, and the buildup of an effective immune response. Immune Memory: - After the initial immune response to a foreign antigen, some lymphoid cells retain antigen memory. - This memory is vital for quicker and stronger immune responses upon subsequent encounters with the same antigen. T Cell Response to Antigen: - T lymphocytes (T cells) require specific conditions to respond effectively. - Antigen presentation by antigen-processing cells is essential for T-cell activation. Antigen Presentation: - Antigen-processing cells like macrophages phagocytose foreign antigens. T Lymphocyte Response to Antigen - T cells have specific receptors, called T cell receptors (TCRs), on their cell membranes. - Interaction between TCR and antigen-MHC triggers the activation of T cells. - Helper T cells (CD4+ T cells) are responsible for regulating the immune response - Cytotoxic T cells (CD8+ T cells) are primarily involved in eliminating infected host cells or abnormal cells B Lymphocyte Response to Antigen - B lymphocytes (B cells) are another integral part of the immune system. - Response to antigens differs from that of T cells. - B cells have immunoglobulin (Ig) molecules, also known as antibodies, on their cell membranes. - Function as antigen receptors. - B cells internalize it and process it within their cytoplasm. The antigen is broken down into smaller fragments. - Fragments of the antigen are then displayed on the B cell’s membrane in conjunction with MHC class II molecules. - Once activated, B cells can differentiate into plasma cells. - Each plasma cell secretes antibodies specifically tailored to recognize and neutralize the antigen that initiated the immune response. Development of T and B Lymphocytes Antibodies IgG: This is a smaller antibody and is the principal antibody type produced in response to the majority of infectious agents. IgM: IgM is a larger antibody and is particularly efficient at binding to and neutralizing fungi. IgE: IgE concentrations are increased in individuals with allergies. IgA: helps prevent the absorption of harmful ingested or inhaled antigens by forming antigen-antibody complexes. IgD: present in small quantities in the blood. Hypersensitivity Reactions and Immunity - Hypersensitivity reactions refer to exaggerated or abnormal immune responses to antigens. - A display of hypersensitivity to an organism or its products indicates immunity. - However, diseases can be associated with the development of acquired immunity. Allergies Types of Hypersensitivity Reactions Immune Response Genes - Immune response genes relate to HLA complex on chromosome 6. - They regulate immune responses via T and B cell function. - Impact infection resistance, tumor defense, and autoimmune susceptibility. Control of Immune Response - Immune response genes control immune reactions.They manage reaction intensity and duration. - Ensures efficient targeting of pathogens. Immunity and Vaccination - “Immunity debt” vs. “Immunity theft” - Vaccines strengthen your defenses. Resistance - Gene variations influence susceptibility to infections. - Some genes boost resistance, others increase susceptibility. Autoimmune Disease Susceptibility - Genetic variations can predispose to autoimmune diseases. - Autoimmune diseases involve self-attacks by the immune system. Suppression of Immune Response - Immune system requires regulation. - Immune suppression prevents unwanted effects. - Various reasons for immune suppression. Methods of Immune Suppression Immunosuppressive Drugs: Impede cell function, and reduce immune cell activity. Common drugs: corticosteroids, calcineurin inhibitors (e.g., cyclosporine), and antimetabolites (e.g., methotrexate). Radiation: Used to suppress immune responses in specific tissues. Corticosteroids: Potent anti-inflammatory drugs inhibit inflammation, phagocytosis, and protein synthesis. Gamma Globulin Preparations: Contains antibodies, prevents response to specific antigens, useful for immune-related conditions. Autoimmune Diseases - Autoimmune diseases involve self-antigen alteration. - Cross-reactive antibodies - Regulatory T-cell dysfunction contributes to autoimmune reactions. Autoimmune Diseases Summary Neoplastic Disease Benign Versus Malignant Benign Tumors: - Grow slowly over time. - Expand within their local confines, exerting pressure on nearby structures. - Remain localized and do not invade nearby tissues or organs. - Cell Differentiation Malignant Tumors: - Grow rapidly, posing a more immediate threat. - Infiltrate surrounding tissues, breaking through boundaries. - May metastasize - Poorly differentiated cells Tumor Classification: Carcinoma, Sarcoma, and Leukemia Carcinoma Carcinoma is a cancer that forms in epithelial tissue. Epithelial tissue lines most of your organs, the internal passageways in your body (like your esophagus), and your skin. Most cancers affecting your skin, breasts, kidneys, liver, lungs, pancreas, prostate gland, head, and neck are carcinomas. Sarcoma A sarcoma is a malignant tumor, a type of cancer that arises from cells of mesenchymal origin. Connective tissue is a broad term that includes bone, cartilage, muscle, fat, vascular, or other structural tissues, and sarcomas can arise in any of these types of tissues Leukemia Leukemia is a broad term for cancers of the blood cells. The type of leukemia depends on the type of blood cell that becomes cancer and whether it grows quickly or slowly. Leukemia occurs most often in adults older than 55, but it is also the most common cancer in children younger than 15. Growth of Neoplasms - Derivation from a Single Cell (Stem Cell): - Neoplasms originate from a single abnormal cell. - Cells have undergone genetic changes. - Gives rise to a population of cells with similar characteristics. Tumor Heterogeneity - Neoplasms exhibit a high degree of heterogeneity. - Genetic mutations and microenvironmental factors. - Mixture of cell types within the same tumor. Multistep Progression of Genetic Changes Leading to Cancer - Development of cancer→multistep process. - Key aspects include: - Activation of Oncogenes. - Loss of Function of Tumor Suppressor Genes. - Additional Random Genetic Changes. Necrosis in Tumors - Tumor Blood Supply: Often derived from invaded tissues, with angiogenesis promoting expansion. - Outgrowing Blood Supply: Faster growth than vascular support - Necrosis: Tissue death in poorly perfused regions, associated with pain and inflammation. Genetic Change in Neoplastic Disease - Genetic changes in neoplastic diseases disrupt normal cell control mechanisms. - Cells no longer respond to growth-regulating signals, bypassing checks and balances. - This allows uncontrolled proliferation. - Tumor suppressor genes prevent uncontrolled DNA replication and mitosis, acting as checks on cell growth. - Mutations in these genes lead to loss of function, unrestrained cell growth, and the development of cancer. Etiologic Factors in Neoplastic Disease Chemical Carcinogens: Chemical substances, both natural and synthetic, can act as carcinogens, increasing the risk of cancer. Failure of Immunologic Defenses - The immune system recognizes and eliminates abnormal cells, but sometimes it fails, allowing transformed cells to evade detection and proliferate. - Immunotherapy, such as immune checkpoint inhibitors, enhances the immune response against cancer cells. Heredity - Genetic factors inherited from parents influence susceptibility to certain cancers. - Specific gene mutations or variations increase the risk of neoplastic diseases. Viruses - Some viruses are etiological factors in human cancers. - Integrate genetic material into the host’s DNA. - Examples: HTLV-1, HHV-8, Papillomavirus, Hepatitis B and C Viruses, Epstein-Barr Virus. HPV and Cervical Cancer Regulation - Apoptosis! - Dysfunctional → accumulation of abnormal cells. Oncogenes Oncogenes are a group of genetic mutations that may cause cancer. They're a mutated form of genes that manage cell growth. When these genes change into oncogenes, they cause cells to grow and divide uncontrollably. Oncogenes are powerful. Cancer typically happens when several genes mutate. Tumor Suppressor Genes - Tumor suppressor genes prevent uncontrolled DNA replication and mitosis, acting as checks on cell growth. - Mutations in these genes lead to loss of function, unrestrained cell growth, and the development of cancer. DNA Repair Genes Heredity and Tumors  - Heredity can influence susceptibility to specific cancers due to inherited genetic factors. - Examples: BRCA1 and BRCA2 mutations in breast cancer, various syndromes predisposing to tumors. Diagnosis of Tumors - Early recognition and diagnosis are crucial for effective tumor treatment. - Early detection is vital for improved prognosis and treatment outcomes. - Recognizing warning signs, symptoms, and risk factors aids in early tumor identification. - Precancerous conditions have the potential to transform into cancerous lesions. - Examples include: Actinic Keratoses Lentigo Maligna Leukoplakia - Timely intervention is crucial to prevent malignant transformation in precancerous conditions. - Proper treatment reduces the risk of progression to cancer. - Various laboratory procedures and diagnostic tests are used: Colonoscopy Vaginal examinations and Pap smears Endoscopic examination X-ray studies Cytologic and laboratory tests are essential:  - Examination of abnormal cells on slides - Cytologic diagnosis from smears, needle aspirations, or biopsies - Frozen section for rapid histologic diagnosis during surgery Tumor-associated antigen tests help detect certain cancers. Examples include: - Carcinoembryonic Antigen (CEA) - Alpha Fetoprotein - Human Chorionic Gonadotropin (hCG) - Acid Phosphatase Lesson 3 Pathogens, Parasites, and Communicable Diseases 1 Objective 2 Bacteria - Gram stain - Staphylococci - Streptococci - Pneumococci - Spore-forming 3 Viruses - Types of Viruses - COVID-19 4 Fungi - Types of Fungal Infections 5 Parasites - Protozoal Infections 6 Comm. Diseases Objectives - Explain how bacteria are classified. List and describe the major groups of pathogenic bacteria. - Explain the mode of action in virus infections, and describe how the body’s response to viral infection leads to recovery. - Discuss the spectrum of infections caused by fungi. - Explain the factors that predispose to systemic infections. Describe the methods used to treat fungal infections. - Describe a typical parasite life cycle. - Explain how parasitic infections are acquired. - Explain how communicable diseases are transmitted and controlled. Pathogenic Microorganisms - Bacteria - Chlamydiae - Rickettsiae and ehrlichiae - Mycoplasmata - Viruses - Fungi Classification of Bacteria - Previously classified according to major characteristics: - Shape and arrangement - Gram stain reaction - Biochemical and growth characteristics - Aerobic and anaerobic - Spore formation - Biochemical profile - Antigenic structure Modern Bacterial Classification Major Classes of Pathologic Bacteria Major Classes of Pathologic Bacteria Gram Staining Bacteria are classified as either gram-positive or gram-negative based on their ability to resist or retain certain dyes Gram-positive Resists decolorization and retains purple stain Gram-Negative Organisms Can be decolorized and stained red Gram-Negative Organisms Non-obligate intracellular parasites Mycobacterium Mycoplasma Treponema Leptospira Obligate intracellular parasites Chlamydia Rickettsia Important Pathogenic Bacteria Gram-positive Gram-Negative Staphylococci - Gram-positive cocci arranged in grapelike clusters - Normal inhabitants - Skin (Staphylococcus epidermidis) - Nasal cavity (Staphylococcus aureus) Staphylococci Infections Streptococci Classification Group A (Streptococcus pyogenes): Causes pharyngitis Group B (Streptococcus agalactiae): Genital tract of women, neonatal meningitis, sepsis Group D (Streptococcus bovis): Urinary, biliary, and cardiovascular infections - Nonbeta hemolysis - Alpha hemolysis: Incomplete lysis of red cells (Streptococcus pneumoniae) - Gamma hemolysis: Nonhemolytic, no lysis Pathogenic Bacteria Pneumococci - Common cause of bacterial pneumonia - Gram-positive cocci Gram-positive bacilli - Corynebacteria - Listeria - Bacilli - Clostridia - Aerobic - Listeria monocytogenes Aerobic spore-forming gram-positive organisms - Bacillus anthracis - Anaerobic spore-forming gram-positive organisms - Clostridia - Gas gangrene - Tetanus - Botulism Spiral organisms - Syphilis - Lyme disease - Acid-fast bacteria - Tuberculosis - Leprosy Chlamydiae - Gram-negative, nonmotile bacteria - Form inclusion bodies in infected cells - Obligate intracellular parasites - Psittacosis (pneumonia) - Trachoma (Chlamydia trachomatis) - Nongonococcal urethritis - Cervicitis - Neonatal inclusion conjunctivitis Rickettsiae - Disease: Damage to small blood vessels of skin; leakage of blood into surrounding tissues (rash and edema) - Rocky Mountain Spotted Fever (ticks) Mycoplasma - Primary atypical pneumonia: Mycoplasma pneumoniae - Most common in winter, young adults, outbreaks in groups - Resolves spontaneously in 10 to 14 days - Responds to antibiotics Viruses Classification - Nucleic acid structure: Either DNA or RNA, with an outer envelope made of lipoprotein - Size and complexity of the genome varies - Nucleoid - Capsid - Obligate intracellular parasites - Lack metabolic enzymes Viral Reproduction - Viruses replicate by infecting host cells and hijacking their machinery. - The viral genetic material is replicated, and new virus particles are assembled. - This process often damages or destroys the host cell. Mode of action - Invasion of susceptible cell - Asymptomatic latent viral infection - Acute cell necrosis and degeneration - Cell hyperplasia and proliferation - Slowly progressive cell injury - Neoplasia - Formation of inclusion bodies Types of Viruses 1. DNA Viruses - Examples: Herpes, Adenovirus 2. RNA Viruses - Examples: Influenza, HIV 3. Retroviruses - Examples: HIV, HTLV 4. Coronaviruses - Examples: SARS-CoV-1,-2 COVID-19 Fungi - Growth factors - Treatment - Other fungi - Molds Types of Fungal Infections Superficial Fungal Infections - Skin and nails are commonly affected. - Examples include athlete’s foot and ringworm. Mucous Membrane Infections (Candida) - It affects mucous membranes in the mouth, throat, and genital areas. - They are commonly known as thrush or yeast infections. Systemic Fungal Infections - Infect internal organs and can be life-threatening. - Examples include histoplasmosis, coccidioidomycosis, blastomycosis, and cryptococcosis. Types of Fungal Infections Parasite and Its Host - Animal parasites - Not capable of a free-living existence - Have a complex life cycle - Live within the intestinal tract and discharge eggs in feces - Transmission favored by poor sanitation, high temperature, humidity - Common in tropical climates; less frequent in cold or temperate climates Guinea Worm Protozoal Infections - Malaria - Amebic dysentery - Genital tract trichomonad - Giardiasis - Toxoplasmosis Malaria Metazoal Infections The three most important roundworms that parasitize - human beings: - Ascaris - Pinworm - Trichinella - Tapeworms - Flukes - Arthropod Infections - Crab louse Communicable Diseases Note: this is the only required reading from Chapter 10 Communicable disease: Disease transmitted from - person to person - Endemic - Epidemic Methods of Transmission Communicable disease perpetuates with continuous transmission - Direct transmission - Indirect transmission through an intermediary mechanism - Insects - Food-Borne Infection Methods of Control - Immunization - Identification, isolation, and treatment of infected persons - Control of means of indirect transmission - Requirements for effective control Immunization Identification, isolation, and treatment Lesson 4 The Cardiovascular System Summary 1. Objectives 2. Anatomy - Valves - Blood supply - Cardiac Cycle 3. Heart Disease - Congenital - Primary - Valvular - Infective - Ischemia - Infarction Objectives - Understand heart anatomy, physiology, and common diseases. - Identify causes and effects of congenital and valvular heart diseases. - Explain the pathogenesis of myocardial disease and ischemia. - Recognize clinical signs of coronary heart disease. Cardiac Structure and Function Function: Muscular pump; propels blood through lungs and tissues Location: Mediastinum, 5 inches from 2nd rib to 5th intercostal space, resting on the diaphragm, anterior to the vertebral column, posterior to the sternum - Two-thirds of the heart lies left of the midsternal line - The apex points downward toward the left hip Heart Location Anatomy Valves Heart Location Coronary blood vessels Circulation Fetal Circulation Conduction Congenital Heart Disease Causes: - Viruses - Genetic factors - Substance use disorder - Undetermined causes Specific Defects: Fetal bypass channels fail to close: - Patent ductus arteriosus - Patent foramen ovale Septal defects (atrial, ventricular, or combined) Obstructive flow abnormalities (stenosis) Abnormal formation of heart components Congenital Heart Defects: PFO and PDA Congenital Heart Disease Primary Myocardial Disease Two types: Myocarditis: Inflammation Cause: Viruses, parasites, fungi, or hypersensitivity Cardiomyopathy: Enlargement Dilated cardiomyopathy: Enlargement of heart and dilatation of chambers Hypertrophic cardiomyopathy: Hereditary, muscle fibers in disarray Valvular Heart Disease - Rheumatic fever and rheumatic heart disease - Nonrheumatic aortic stenosis - Mitral valve prolapse Rheumatic Heart Disease - Commonly encountered in children - Complication of group A beta-hemolytic streptococcal infection Nonrheumatic Aortic Stenosis - Occurs in 2% of population - The aortic valve has two cusps rather than three Mitral Valve Prolapse - Common, but only a few patients develop problems - One or both leaflets enlarge, stretch, and prolapse into - LA during ventricular systole Infective Endocarditis - Affects abnormal or damaged mitral and aortic valves Subacute Endocarditis: - Low-virulence organisms - Complicates valvular heart disease - Mild infection symptoms Acute Endocarditis: - Highly pathogenic organisms - Severe infection symptoms - Can affect normal valves Cardiac arrhythmias - Disturbances in heart rate or rhythm Atrial fibrillation (AF) - Atria quiver versus normal contraction Ventricular fibrillation (VF) - Ventricles unable to contract normally Myocardial Ischemia What could happen? - Sudden blockage of a coronary artery from a thrombus or atheromatous debris (next slide) - Hemorrhage into an atheromatous plaque - Arterial spasm - Vigorous physical activities - Arrhythmia The heart could stop! Cardiac arrest: - Asystole Myocardial Ischemia Arteriosclerosis of coronary arteries - Narrowing of arteries - Platelet accumulation → thrombus - Insufficient blood supply to cardiac muscle cells - Severe myocardial ischemia occurs Myocardial Ischemia Conditions - Coronary heart disease - Due to decreased blood supply to heart muscle - Clinical manifestations are variable - Asymptomatic or angina Angina Myocardial Infarction - Necrosis of heart muscle from severe ischemia - Insufficient blood flow through one of the coronary arteries - Transmural infarct - Subendocardial infarct Myocardial Infarction: Location - Often involves muscles of the left ventricle and septum - Thicker walls require a rich blood supply Myocardial Infarction: Diagnosis Myocardial Infarction: Complications - Arrhythmias from irritability of ischemic heart muscle - Heart failure from ventricle damage - Intracardial thrombi: forms on ventricular wall → breaks off → travels to major organs - Pericarditis: Infarct extends to epicardial surface → inflammation - Cardiac rupture: Blood leaks into the pericardial sac from the perforation in the necrotic muscle - Papillary muscle dysfunction: Infarcted papillary muscle unable to control mitral valve - Ventricular aneurysm: Outward bulging of healing infarct; reduces left ventricular function and cardiac output Aspirin and Heart Disease COVID-19 and Myocardial Infarction New concerns - The COVID-19 pandemic has raised concerns about its impact on cardiovascular health. Connection - The potential link between COVID-19/ increased risk of MI Risk Factors - COVID-19 can lead to a pro-inflammatory state and hypercoagulability, which may increase MI risk. Clinical Implications - Increased vigilance for MI symptoms in COVID-19 patients and following infection. - Timely diagnosis and treatment are essential to reduce morbidity and mortality. What do I know now... - COVID-19 and MI are interconnected Heart Failure Lesson 6 The Respiratory System Summary 1. Objectives 2. Anatomy 3. Dysfunction - Pneumothorax - Pneumonia - SARS - Tuberculosis - Bronchitis - COPD - Emphysema - A-1 AD - Asthma - ARDS - Pulmonary Fibrosis - Lung Cancer 4. Next Class Objectives - Understand the basic anatomy of the lungs and the blood vessels - Explain the basic anatomic and physiologic principles of ventilation and gas exchange. - Describe pneumothorax, atelectasis, bronchitis, COPD, and pneumonia. - Explain the causes and effects of pulmonary fibrosis. - Describe the special problems associated with asbestosis. - List the major types of lung carcinoma. Anatomy Lung Anatomy Gas Exchange Two functions of respiration - Ventilation - Gas exchange Atmospheric pressure at sea level is 760 mm Hg Partial pressure: Part of total atmospheric pressure exerted by a gas The partial pressure of oxygen (PO2) PO2= 0.20×760 mm Hg =152 mm Hg Gas Exchange - Gases diffuse among blood, tissues, and pulmonary alveoli due to differences in their partial pressures Requirements for efficient gas exchange - Large capillary surface area - Unimpeded diffusion - Normal pulmonary blood flow - Normal pulmonary alveoli Dysfunction Pneumothorax Escape of air into pleural space due to lung injury or disease Manifestations - Chest pain - Shortness of breath - Reduced breath sounds on the affected side - Diagnostic: Lung collapse and air in the pleural cavity Atelectasis Collapse of lung Obstructive atelectasis - Mucus secretions, tumor, foreign object - Obstructed bronchus - Reduced volume - Mediastinal structures shift - Diaphragm elevation Pneumonia - Inflammation of the lung - Etiology: Most important, it serves as a guide for treatment - Location: What part of the lung is impacted? - Predisposing factors? - Post-op pneumonia - Aspiration pneumonia2 - Obstructive pneumonia Pneumocystis Pneumonia Cause: Pneumocystis carinii, a protozoan parasite of low pathogenicity - Affects mainly immunocompromised persons - Organisms attack and injure the alveolar lining - Cough, dyspnea, pulmonary consolidation - Diagnosis made by lung biopsy, bronchoscopy, or from bronchial secretions Introduction to SARS-CoV-1 - Official Name: Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-1) - First Identified: November 2002 in Guangdong, China - Family: Coronaviridae - Genome: Single-stranded RNA - Transmission: Human-to-human transmission primarily through respiratory droplets - Disease: Causes SARS Impact of SARS-CoV-1 - Outbreak: The 2002-2003 SARS outbreak - Global Spread: Spread to more than 24 countries across North America, South America, Europe, and Asia - Health Impact: Over 8,000 confirmed cases and 774 deaths globally - Symptoms: Fever, cough, difficulty breathing, pneumonia - Containment: Effective public health measures led to containment by July 2003 Key Message Rapid response and global cooperation were key in controlling the SARS-CoV-1 outbreak. SARS-CoV-2 Official Name: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) First Identified: December 2019 in Wuhan, China Family: Coronaviridae Genome: Single-stranded RNA Transmission: Primarily through respiratory droplets Disease: Causes Coronavirus Disease 2019 (COVID-19) Impact of SARS-CoV-2 - Global Pandemic: Declared a pandemic by the World Health Organization in March 2020 - Health Impact: Millions of confirmed cases and deaths worldwide - Symptoms: Range from mild (fever, cough) to severe (pneumonia, organ failure) - Vaccination: Development and global distribution of vaccines - Social Changes: Adoption of new norms like social distancing, remote work, and increased focus on hygiene Key Message Managing SARS-CoV-2 is crucial for global health. Tuberculosis - Infection from acid-fast bacterium,Mycobacterium tuberculosis - Organisms resistant to destruction - Transmission: Airborne droplets - Granuloma: Giant cell with central necrosis, indicates development of cell-mediated immunity - Multinucleated giant cells: Bacteria plus fused monocytes and periphery of lymphocytes and plasma cells - Organisms lodge within pulmonary alveoli - Granulomas are formed - Spreads into kidneys, bones, uterus, fallopian tubes, others - If infection is arrested, granulomas heal with scarring - Infection may be asymptomatic, detected only by chest X-ray and/or Mantoux test - Secondary focus of infection may progress, even if pulmonary infection has healed - Diagnosis - Skin test (Mantoux test) - Chest X-ray - Sputum culture Reactive Tuberculosis Reactivated tuberculosis: Active tuberculosis in adults from reactivation of an old infection; the healed focus of tuberculosis flares up with lowered immune resistance Miliary tuberculosis: Multiple foci (small, white nodules, 1-2 mm in diameter) of disseminated tuberculosis, resembling millet seeds Drug-resistant TB Resistant strains of organisms emerge with failure to complete treatment or premature cessation of treatment - Multidrug-resistant tuberculosis (MDR TB) - Extensively drug-resistant tuberculosis (XDR TB) Bronchitis - Inflammation of the tracheobronchial mucosa - Acute bronchitis - Chronic bronchitis - Bronchiectasis - Diagnosis made by bronchogram via chest x-ray COPD - Chronic obstructive pulmonary disease (COPD) - Destruction of the fine alveolar structure of lungs with the formation of large cystic spaces Three main anatomic derangements in COPD - Inflammation and narrowing of terminal bronchioles - Dilatation and coalescence of pulmonary air spaces - Loss of lung elasticity Chronic irritation: Smoking and inhalation of injurious agents Pathogenesis - Inflammatory swelling of mucosa - Narrows bronchioles; increased resistance to expiration - Leukocytes accumulate in bronchioles and alveoli - Coughing and increased intrabronchial pressure - Retention of secretions predisposes to pulmonary infection - Lungs damaged by emphysema cannot be restored to normal Emphysema - Chronic lung condition - Part of Chronic Obstructive Pulmonary Disease (COPD) - This leads to shortness of breath Causes and Risk Factors: - Long-term exposure to irritants (e.g., tobacco smoke) - Genetic factors (e.g., Alpha-1 antitrypsin deficiency) - Age and history of smoking Alpha-1 antitrypsin deficiency - Low antitrypsin level correlates with lung disease because it protects the lungs from proteolytic enzymes - Released from leukocytes in lung - Deficiency permits enzymes to damage lung tissue - Severe antitrypsin deficiency - Digestion of connective tissues of alveolar septa, terminal air passages - Develops progressive pulmonary emphysema - Moderate antitrypsin deficiency - Does not develop into severe emphysema at an early age - Susceptible to lung damage from smoking, atmospheric pollution, and respiratory infections Asthma - Spasmodic contraction of smooth wall muscles of bronchi and bronchioles - Dyspnea and wheezing on expiration - Greater impact on expiration than on inspiration - Attacks are precipitated by allergens: Inhalation of dust, pollens, animal dander, other allergens ARDS - Acute respiratory distress syndrome (ARDS) - Severe injury - Systemic infection - Aspiration of acid gastric contents - Inhalation of irritant or toxic gases - Damage caused by SARS - Damaged alveolar capillaries leak fluid and protein - Impaired surfactant production from damaged alveolar lining cells - Formation of intra-alveolar hyaline membrane Pulmonary Fibrosis - Fibrous thickening of alveolar septa from irritant gases, organic and inorganic particles - Makes lungs rigid, restricting normal respiratory excursions - Diffusion of gases hampered due to increased alveolar thickness - Causes progressive respiratory disability similar to emphysema - Collagen diseases - Pneumoconiosis Lung cancer - Usually smoking-related neoplasm - Common malignant tumor in both men and women - Arises from mucosa of bronchi and bronchioles - bronchogenic carcinoma Classification - Squamous cell carcinoma - Adenocarcinoma - Large cell carcinoma - Small cell carcinoma Lesson 7 The Urinary and Gastrointestinal Tracts Summary 1. Urinary Tract - Anatomy - Dysfunction - Nephrosclerosis - Injury - Tumors - Stones - ESRD - UTI 2. GI Tract - Anatomy - Dysfunction - H. pylori - Colitis - Obstructions - Hernias - Hemorrhoids - Tumors 3. Next Class Objectives - Describe the normal structures of the kidneys and their functions with special emphasis on the nephron - Describe chronic kidney disease and its most common causes. - Explain the pathogenesis of glomerulonephritis, nephrosis, and nephrosclerosis. Describe the clinical manifestations of each of these disorders. - Describe the clinical manifestations and complications of urinary tract infections. - Differentiate the major forms of cystic disease of the kidney and their prognoses. - Name the more common kinds of tumors affecting the urinary tract. - Describe the causes, symptoms, and treatment of renal failure. Urinary Tract Kidney location Kidney interior Kidney blood flow Glomerulus Kidneys: waste out Kidneys: nutrients in Urinary bladder: biological female Urinary bladder: biological male Normal urine output Congenital Abnormalities - Renal agenesis - Failure of one or both kidneys to develop - Bilateral → rare - Unilateral → common Hypertensive Nephrosclerosis - Complication of severe hypertension - Common cause of chronic renal disease - Reduced glomerular filtration - Kidneys shrink - May progress to ESRD Diabetic Nephropathy - Complication of long-standing diabetes - Manifestations - Progressive impairment of renal function - Protein loss may lead to nephrotic syndrome Nephropathies: Glomerulonephritis - Inflammation of the glomeruli caused by antigen-antibody reaction within the glomeruli - Immune-complex glomerulonephritis Nephrotic Syndrome - Marked loss of protein in the urine - Failure of the filtration barrier in the glomerulus - Protein is lost in urine - Protein level in the blood falls - Causes edema due to low plasma osmotic pressure Clinical manifestations - Marked leg edema - Ascites Prognosis - In children: Minimal change of disease, complete recovery - In adults: Manifestation of progressive renal disease Acute Renal Tubular Injury Pathogenesis - Impaired renal blood flow - Tubular necrosis is caused by toxic drugs or chemicals Clinical manifestation - Acute renal failure: Oliguria, anuria - Tubular function gradually recovers - Treated by dialysis until function returns Tubulointerstitial Nephritis - Both tubules and surrounding interstitium were affected - Often an allergic reaction to a drug Renal Cysts Solitary cysts are common; and not associated with impairment of renal function Multiple cysts are uncommon; they may be associated with impaired renal function - Congenital polycystic kidney disease - Autosomal (adult) dominant polycystic kidney disease Renal Tumors - Cortical tumors: arise from the epithelium of renal tubules - Adenomas: usually small and asymptomatic - Carcinomas more common Nephroblastoma (Wilms Tumor) Vesicoureteral Reflux Renal Calculi - Stones may form anywhere in the urinary tract Chronic Renal Disease - A renal function fails as the number of functioning nephrons declines to 30% of normal - Remaining nephrons ”work harder” at higher blood pressure and are injured - Abnormal renal function for > 3 months is chronic renal disease - Chronic renal disease may progress to end-stage renal disease (ESRD) - ESRD requires treatment such as dialysis or renal transplant to sustain life End-Stage Renal Disease (Uremia) - Retention of excessive by-products of protein metabolism in the blood - Fluid, electrolyte, and acid-base regulation fail - Metabolic acidosis occurs - Lack of erythropoietin leads to anemia - Level of urea in blood (blood urea nitrogen BUN) correlates with clinical condition - Measurement of severity of renal failure Renal Failure - Renal failure is the inability of kidneys to regulate and excrete - Uremia is the end stage of many kidney diseases. Associated with: - Retention of urea in the blood - Metabolic acidosis - Ketoacidosis derived from fat metabolism Urinary Tract Infections/ Cystitis - Very common; may be acute or chronic - Gram-negative bacteria cause most infections Cystitis - Affects only the bladder - More common in women than men; urethra in females is shorter; in young, sexually active women, sexual intercourse promotes the transfer of bacteria from the urethra to the bladder - Common in older men because an enlarged prostate interferes with complete bladder emptying GI Tract Gastrointestinal Tract - Name and describe common lesions of the esophagus. - Describe the common types of gastritis and their clinical manifestations. - Explain the pathogenesis of peptic ulcer. - Differentiate between appendicitis and Meckel diverticulitis in terms of pathogenesis, clinical manifestations, and treatment. - Describe the common types of chronic and acute enteritis and their clinical manifestations. - Describe the pathogenesis of diverticulitis, and explain the role of diet in the development of lesions. GI Tract Esophagus abnormalities Two major disturbances of cardiac sphincter - Cardiospasm (achalasia) - Incompetent cardiac sphincter Obsruction - Carcinoma: Can arise anywhere in esophagus - Stricture: From scar tissue due to necrosis and inflammation from corrosive chemicals, such as lye - Mucosal tears - Caused by retching and vomiting - Linear tears in the mucosa or lining of esophagus - Leads to bloody vomit Acute Gastritis - Inflammation of the gastric lining - Self-limited inflammation of short duration - May be associated with mucosal ulceration or bleeding - Associated with lifestyle and some medications Helicobacter pylori Gastritis - Small, curved, gram-negative organisms that colonize the surface of gastric mucosa - Grow within a layer of mucus covering epithelial cells Peptic Ulcer Pathogenesis - Digestion of mucosa due to increased acid secretions or digestive enzymes (gastric acid and pepsin) - Common sites: Distal stomach or proximal duodenum - Complications: Hemorrhage, perforation, peritonitis, obstruction from scarring Enteritis Acute enteritis - Intestinal infections; common; of short duration - Nausea, vomiting, abdominal discomfort, loose stools Chronic enteritis - Less common, more difficult to treat - Regional enteritis or Crohn’s disease Meckel’s Diverticulum - Outpouching at distal ileum, 12 to 18 inches proximal to cecum - From the persistence of a remnant of the vitelline duct, a narrow tubular channel connecting the small intestine with the yolk sac embryologically Colitis What is Colitis? - Inflammation of the inner - lining of the colon - Symptoms include: abdominal pain, diarrhea, and rectal bleeding Types of Colitis - Ulcerative Colitis - Crohn’s Disease - Infectious Colitis - Ischemic Colitis Diagnosis - Diagnosis through colonoscopy, CT scans, and blood tests Irritable Bowel Syndrome - Also known as spastic colitis or mucous coliti - Episodes of crampy abdominal discomfort, loud gurgling bowel sounds, and disturbed bowel function without structural or biochemical abnormalities - Excessive mucus secreted by colonic mucosal glands Appendicitis The most common inflammatory lesion of the bowel - Generalized abdominal pain localizing in the right lower quadrant; rebound tenderness Intestinal Obstructions - Conditions blocking normal passage of intestinal contents - High intestinal obstruction Severe, crampy abdominal pain from vigorous peristalsis Intestinal Obstructions Low intestinal obstruction - Symptoms less acute - Mild, crampy abdominal pain Common causes of intestinal obstruction - Adhesion - Hernia - Tumor - Volvulus - Intussusception Hernia types intussusception Diverticulosis - Diverticulosis: Outpouchings or diverticula of colonic mucosa through weak areas in the muscular wall of the large intestine - Acquired, usually asymptomatic, seen in older people - Common site: Sigmoid colon - Diverticulitis: Inflammation incited by bits of fecal material trapped within outpouchings - Complications: Inflammation, perforation, bleeding, scarring, abscess Hemorrhoids Varicose veins of hemorrhoidal venous plexus that drains rectum and anus Internal hemorrhoids - Veins of the lower rectum - May erode and bleed, become thrombosed, or prolapse External hemorrhoids - Veins of anal canal and perianal skin - May become thrombosed, causing discomfort Tumors of the Colon Benign: pedunculated polyps - Frequent - Tip may erode, causing bleeding - Removed by colonoscopy Carcinoma: Cecum and the right half of colon - Does not obstruct because the caliber is large and bowel contents are relatively soft Left half of the colon - Causes obstruction and symptoms of lower intestinal obstruction Lesson 8 The Liver, Biliary System, and Pancreas Summary 1. Anatomy - Liver - Pancreas 2. Liver Dysfunction - Hepatitis - Complications - Cirrhosis - Cholelithiasis 3. Pancreas - Pancreatitis - Diabetes - Tumors 4. Next Class Learning Objectives For the liver, biliary system and pancreas: - Describe the normal structure, and explain the functions as they relate to the major diseases. - List the major causes of injury, and describe their effects on function. - Understand types of infections and afflictions in terms of their pathogenesis. - Explain the adverse effects of excess alcohol intake on structure and function. Anatomy Liver The Pancreas Liver Dysfunction Causes of Liver Injury 1. Viral Hepatitis: - Viral hepatitis is a group of infectious diseases caused by hepatitis viruses, including A, B, C, D, and E. 2. Fatty Liver Disease: - Fatty liver disease, also known as non-alcoholic fatty liver disease (NAFLD), is characterized by the accumulation of fat in liver cells. 3. Alcohol Use Disorder Liver Disease: - Excessive alcohol consumption can harm the liver, leading to liver disease. 4. Cirrhosis: - Cirrhosis is the advanced scarring of the liver tissue caused by long-term liver damage and inflammation. Hepatitis - Hepatitis viruses are a significant cause of liver-related diseases worldwide, with different types labeled A, B, C, D, and E. - Understanding the specifics of each hepatitis virus is crucial for preventing transmission and managing infections effectively. Hepatitis A Hepatitis B - Incubation Period: Variable, usually 6 weeks to 6 months. - Transmission: Through contact with infected blood, bodily fluids, or from mother to child during childbirth. Hepatitis C - Incubation Period: Usually 2 weeks to 6 months. - Transmission: Primarily through contact with infected blood. Hepatitis D Hepatitis E Hepatic Encephalopathy Deterioration of brain function is characterized by impaired consciousness, confusion, disorientation, and eventually coma. Fatty Liver Fat accumulates in the liver secondary to injury. Alcohol Use Disorder Liver Disease - Refers to a group of structural and functional changes in the liver resulting from excessive alcohol consumption. - Severity depends on the amount and duration of alcohol consumption. Manifestations of Cirrhosis - Bypass routes connect systemic-portal venous systems. - Anastomoses develop between branches of the portal and system veins - Risk of fatal hemorrhage from esophageal varices. Reye Syndrome - Pathogenesis involves the combined effect of viral illness and the use of acetylsalicylic acid (aspirin). Jaundice Biliary Cirrhosis Primary biliary cirrhosis is an autoimmune disease that attacks small intrahepatic bile ducts. Cholelithiasis Cholelithiasis is the formation of stones in the gallbladder. Cholecystitis Cholecystitis is inflammation of the gallbladder, often associated with chronic infection and gallstones. Liver Tumors - Hepatocellular carcinoma is the most common liver cancer. - Common in developed countries. Pancreas Acute Pancreatitis (Pathogenesis) - Acute pancreatitis involves the activation of pancreatic enzymes that auto-digest the pancreas. - This condition can be initiated by factors such as gallstones, alcohol abuse, medications, or viral infections.  - The hallmark symptom is sudden and severe abdominal pain, often radiating to the back. - In severe cases, complications like pancreatic necrosis, pseudocysts, and systemic inflammatory response can occur. Prediabetes - Prediabetes is characterized by blood glucose levels that are higher than normal but not yet high enough for a diabetes diagnosis. - It often precedes Type 2 diabetes and indicates impaired glucose metabolism. - Without intervention, many individuals with prediabetes progress to Type 2 diabetes. - Lifestyle modifications can significantly reduce the risk of progression to diabetes. Prediabetes (Pharmacologic Treatment) - In some cases, medications like metformin may be used to manage blood glucose levels. - These medications help improve insulin sensitivity and delay the onset of Type 2 diabetes. - The primary focus remains on lifestyle changes such as diet, weight management, and physical activity. Type 1 Diabetes - Type 1 diabetes is primarily an autoimmune condition - This results in little to no insulin production - Genetic predisposition and possibly environmental triggers. - Early detection and ongoing management crucial - Insulin therapy - Blood glucose monitoring - Dietary management and physical activity - Continuous education, psychological support, and - regular healthcare Type 2 Diabetes The pathophysiology involves a combination of insulin resistance and inadequate insulin secretion. Pregnancy-Associated Diabetes - During pregnancy, hormonal changes can lead to insulin resistance, resulting in gestational diabetes. - It’s important to manage blood glucose levels during pregnancy to avoid complications. Treatment of Diabetes  - Diet plays a crucial role in managing both Type 1 and Type 2 diabetes. - A balanced diet helps to maintain blood glucose levels within a normal range. - In Type 2 diabetes, diet and exercise can significantly improve insulin sensitivity. Treatment of Diabetes - Medication, including insulin and oral hypoglycemic agents, is often required in diabetes management. - Type 1 diabetes always requires insulin therapy, while - Type 2 may be managed with oral medications. - The choice of medication depends on the type of diabetes, blood sugar levels, and other individual health factors. Monitoring Control of Diabetes - Regular monitoring of blood glucose - Methods include self-monitoring of blood glucose and HbA1c (”A1c”) tests. - Continuous glucose monitoring systems offer real-time insights into glucose levels. Continuous Monitoring of Blood Glucose - Continuous glucose monitoring (CGM) systems provide real-time, dynamic glucose information. - They are particularly useful in patients with Type 1 diabetes and sometimes Type 2 diabetes Complications of Diabetes - Diabetes complications include microvascular and macrovascular complications - Poor glycemic control increases risk of other complications Hyperglycemia - Hyperglycemia is a condition characterized by high levels of glucose in the blood. - Prolonged hyperglycemia can lead to serious health complications like diabetic ketoacidosis and hyperosmolar hyperglycemic state. Hyperosmolar Hyperglycemic Nonketotic Coma Hypoglycemia in Diabetes - Hypoglycemia refers to abnormally low blood sugar levels - Symptoms range from mild discomfort to severe complications - Certain medications and alcohol consumption can also increase the risk - Continuous monitoring and proper insulin dosing Hypoglycemia in Diabetes - Insulin shock, a severe form of hypoglycemia - Immediate treatment with fast-acting carbohydrates is essential. Tumors of the Pancreas  - Pancreatic carcinoma often arises in the head of the pancreas, leading to obstructive jaundice. Tumors of the Pancreas (Islet Cell Tumors) - Islet cell tumors, also known as pancreatic neuroendocrine tumors, arise from the hormone-producing cells of the pancreas. - These tumors can be benign or malignant and often lead to an overproduction of insulin, causing hypoglycemia. Lesson 10 The Nervous System Summary 1. Anatomy 2. Dysfunction - Congenital - Vascular injury - Infections - Viruses - Alheimer’s - MS - Parkinson’s - Huntington’s - Neurodegenerative - Tumors 3. Next Class Learning Objectives - Describe the normal structure and basic functions of the brain, meninges, and cerebrospinal fluid. - Define muscle tone and voluntary motor activity, and relate these concepts to the two forms of muscle paralysis. - Explain the pathogenesis and clinical manifestations of closure defects of the central nervous system. Namethe techniques used for prenatal diagnosis. - Describe the pathogenesis and manifestations of hydrocephalus, and relate them to treatment measures. Anatomy Dysfunction Muscle Paralysis Flaccid paralysis: - Weak muscles due to motor neuron loss (e.g., polio or ALS). Destruction of motor neurons: - Vital for brain-to-muscle signals. - Diseases like ALS lead to weakness and paralysis. Interruption of reflex arc: - Maintains muscle tone; disruption causes flaccidity. Prenatal Detection Elevated alpha-fetoprotein: - Indicates neural tube defects or fetal issues. Ultrasound at 16 weeks: - Visualizes fetal development and detects problems. Hydrocephalus Congenital hydrocephalus: - Caused by CSF flow obstruction in developing brain (genetics or infections). Acquired Hydrocephalus Acquired hydrocephalus: - Develops due to factors like tumors or adhesions blocking CSF flow. No head enlargement in adults: - Cranial structures fused by adulthood. Cerebral Injury Torn brain blood vessels: - Traumatic brain injuries cause vessel tearing, leading to hemorrhages. Epidural hemorrhage: - Bleeding between skull and dura mater after head injury. Subdural hemorrhage: - Bleeding beneath dura mater but outside the brain. Cerebral Injury (Contd.) Subarachnoid hemorrhage: - Bleeding between arachnoid membrane and pia mater (ruptured aneurysms). Concern about CTE: - Neurodegenerative condition from repeated head trauma, seen in contact sports. Stroke: Cerebrovascular Accident Stroke (Cerebrovascular Accident): - Brain tissue injury due to disrupted blood supply. Types of stroke: - Ischemic (blocked vessels) and hemorrhagic (bleeding). Stroke: Cerebrovascular Accident Predisposing factors: - Risk factors: hypertension, smoking, diabetes, high cholesterol. - Thrombus after heart attack. - Thrombus on diseased heart valves. Stroke: Cerebrovascular Accident Diagnosis: - Imaging like cerebral angiography. Carotid endarterectomy: - Surgery to remove carotid artery plaque. Other Neurologic Dysfunction Transient ischemic attack (TIA): - Brief neurologic episodes, often from carotid plaque embolization. Cerebral aneurysm: - Weak or bulging blood vessel wall; rupture can cause hemorrhagic stroke. Multi-infarct vascular dementia: - Dementia from multiple small strokes. TIA Brief neurologic episodes: - Temporary blood supply reductions to the brain. From carotid plaque embolization: - Small particles break from plaque deposits and block brain vessels. Stroke Cerebral Aneurysm Congenital aneurysms: - Present from birth, related to circle of Willis abnormalities. Congenital wall weakness: - Weak arterial walls allow aneurysm development. Weakness develops in adulthood: Multi-Infarct Vascular Dementia Cumulative brain damage from small strokes: - Progressive brain damage from multiple small strokes. Second most common cause of dementia: - After Alzheimer’s, often linked to hypertension. Treated by addressing underlying cause: - Managing conditions like hypertension can slow progression. Infections of the Nervous System Three types: Bacterial, fungal, and viral infections of the nervous system. Meningitis Infection affecting meninges: - Primarily targets protective brain membranes. Encephalitis Infection of brain tissue: - Directly affects brain tissue, causing inflammation and symptoms. Meningoencephalitis Affects both meninges and brain tissue: - Severe infection involving both meninges and brain. Meningitis from Bacteria and Fungi Meningococcus (Neisseria meningiditis), Pneumococcus (Streptococcus pneumoniae), etc. - Bacteria causing bacterial meningitis, can be life-threatening. Viral Infections CNS Various viruses: - Measles, mumps, herpes simplex virus, intestinal and respiratory viruses, cytomegalovirus, poliomyelitis virus, and arborviruses can infect the CNS. Manifestations: - Range from mild to severe, including fever, headache, altered consciousness, and seizures. Viral Infections CNS Arboviruses: - Transmitted by mosquitoes and ticks, causing meningitis and encephalitis. Infect birds, animals, humans; transmitted by mosquitoes: - Often infect multiple hosts, including humans, via mosquitoes. Includes Zika virus: - Notable for causing birth defects in pregnant women. Rabies Invariably fatal without treatment: - Almost always fatal once symptoms appear, requires immediate treatment. Poliomyelitis Eradicated by vaccination in developed world: - Largely eradicated in developed regions through vaccination. Postpolio syndrome: Muscular atrophy: - Some survivors may experience gradual muscle weakening (postpolio syndrome). Creutzfeldt-Jakob Disease Caused by abnormal proteins (prions): - Rare, fatal neurodegenerative disorder linked to abnormal proteins (prions), often from gene mutations. Normal form: PrPc, Abnormal form: PrPSc: - Normal form (PrPc) vs. abnormal form (PrPSc) of prion proteins. Mad Cow Disease Prion disease affecting cows: - Mad cow disease (bovine spongiform encephalopathy) primarily affects cattle. Transmission via contaminated feed: - Cattle become infected through contaminated feed, often including sheep tissues. Eating infected beef causes vCJD in humans: - Variant Creutzfeldt-Jakob disease (vCJD) can result from consuming contaminated beef. Other Nervous System Diseases - Alzheimer’s disease - Multiple sclerosis (MS) - Parkinson’s disease - Huntington’s disease Alzheimer’s Disease Characteristics: - Progressive mental deterioration, memory loss, and emotional disturbances. Features: - Neurofibrillary tangles, neurotic plaques, and biochemical abnormalities, including reduced acetylcholine levels. Treatment: - No cure, but some drugs may temporarily improve cerebral function by increasing acetylcholine levels. Multiple Sclerosis (MS) Probably an autoimmune disease: - Autoimmune disease with genetic predisposition, leading to immune system attacking myelin sheath of nerve fibers. Features: - Demyelination, glial scarring, and varied neurological symptoms based on plaque location. Possible viral trigger: - Some cases linked to viral infections in genetically predisposed individuals. Diagnosis: - Diagnosis involves techniques like magnetic resonance imaging (MRI) to detect CNS demyelinated plaques. Parkinson’s Disease Mostly unknown etiology: - Cause mostly unknown, possibly linked to genetics or viral infections. Manifestations: - Loss of substantia nigra neurons leading to motor symptoms like tremors and reduced dopamine levels inCNS. Treatment: - Relief with L-dopa medication; research explores embryonic stem cells for potential treatment. Huntington’s Disease Progressive autosomal dominant disease: - Autosomal dominant hereditary disorder caused by HTT gene mutation. Genetic mutation: - Mutation leads to excessive CAG triplet repeats (polyglutamine expansion) in the gene. Clinical manifestations: - Cognitive decline, psychiatric symptoms, and abnormal jerky movements (chorea). No cure: - Currently no cure; symptomatic treatment for psychiatric and movement symptoms. Neurodegenerative Diseases Spinocerebellar Degenerative Disease: - Affects both upper and lower motor neurons, leading to progressive weakness, paralysis, and respiratory problems. - No specific treatment; management focuses on symptom control and support. Amyotrophic Lateral Sclerosis (ALS) - Affects both upper and lower motor neurons, resulting in flaccid paralysis, muscle wasting, and respiratory problems. - No known cure; treatment focuses on managing symptoms and improving quality of life. Peripheral Nerve Disorders Includes nerve injuries, entrapment neuropathy, polyneuritis, Guillain-Barré syndrome, and nerve tumors. Various causes and treatments depending on thespecific condition. Peripheral Nerve Injury Associated with deep lacerations, fractures, or crushing injuries. - Carpal tunnel syndrome is a common example of nerve entrapment neuropathy in the hand. Tumors of Peripheral Nerves - Often solitary tumors originating from Schwann cells. - Neurofibromatosis can lead to multiple nerve tumors. - Clinical features include skin nodules, thickened patches, and hyperpigmentation. Brain Tumors - Primary and metastatic brain tumors. - Primary tumors include gliomas, astrocytomas, glioblastoma multiforme, oligodendroglioma, lymphoma, and meningioma. Spinal Cord Tumors - Similar tumor types as in the brain. - Spinal vertebrae tumors can compress or invade the spinal cord. - Conditions like bone metastasis and multiple myeloma can involve the spinal cord. Lesson 11 The Ocular and Auditory Systems Summary 1. Ocular System - Overview of the Eye - Glaucoma - Cataracts - Diabetic Retinopathy - Uveitis - Additional Ocular Diseases - Occupational Hazards 2. Auditory System - Overview of the Ear - Hearing Los - Otitis Media - Meniere’s Disease - Occupational Hazards Ocular System Overview of the Eye Cornea: Refracts light Sclera: Structural support Choroid: Nutrient supply to retina Lens: Focus adjustment Retina: Contains photoreceptors Optic Nerve: Transmits signals to brain Anatomy of the Human Eye Eye Fluids Retina Structure Photoreceptor Layer: Rods Cones Bipolar Cells: Signal transmission Ganglion Cells: Optic nerve transmission Macula: High-acuity vision Fovea: Highest concentration of cones Arterial Supply Venous Drainage Innervation Glaucoma Overview Definition: Optic nerve damage, elevated intracocular pressure (IOP) Types: - Open-angle - Angle-closure Glaucoma Pathophysiology Glaucoma Glaucoma Diagnosis & Treatment Diagnosis: - Tonometry - Ophthalmoscopy - Perimetry Treatment: - Medications - Laser therapy - Surgery Cataracts Overview Definition: Lens clouding, decreased vision Types: - Age-related - Congenital - Secondary - Traumatic Cataracts Pathophysiology Cataracts Diagnosis & Treatment Diagnosis: - Slit-lamp examination - Retinal examination - Visual acuity testing Treatment: - Surgical removal (Phacoemulsification) - Intraocular lens (IOL) implantation - Laser surgery Diabetic Retinopathy Overview Definition: Retinal blood vessel damage from diabetes Types: - Non-Proliferative (NPDR) - Proliferative (PDR) Diabetic Retinopathy Pathophysiology Diabetic Retinopathy Symptoms & Risk Factors Symptoms: - Gradual vision loss - Floaters, flashes (PDR) - Sudden vision loss (hemorrhage) Risk Factors: - Duration of diabetes - Poor glycemic control - Hypertension, hyperlipidemia - Smoking Diabetic Retinopathy Diagnosis & Treatment Diagnosis: - Fundoscopy - Fluorescein angiography - OCT Treatment: - NPDR: Glycemic control, laser photocoagulation - PDR: Panretinal photocoagulation, anti-VEGF, vitrectomy ` Uveitis Overview Definition: Inflammation of uveal tract Types: - Anterior - Intermediate - Posterior - Panuveitis Uveitis Causes & Pathophysiology Uveitis Symptoms & Diagnosis Symptoms: - Eye redness, pain - Photophobia, blurred vision - Floaters Diagnosis: - Slit-lamp examination - Fundoscopy - OCT, fluorescein angiography - Lab tests for underlying causes Uveitis Treatment Corticosteroids: Topical, systemic Immunosuppressants: Refractory cases Antimicrobials: If infection is cause Surgery: For complications Additional Ocular Diseases Optic Neuritis: - Inflammation of optic nerve - Symptoms: Pain with eye movement, vision loss Conjunctivitis: - Inflammation of conjunctiva - Types: Allergic, bacterial, viral - Symptoms: Redness, itching, discharge Keratitis : - Inflammation of cornea - Causes: Infections, trauma - Symptoms: Pain, redness, blurred vision Ocular Occupational Hazards UV Radiation: - Sources: Welding, arc lamps, sun - Effects: Photokeratitis, cataracts, retinal damage Chemical Exposure: - Common: Solvents, acids, alkalis - Effects: Corneal burns, conjunctivitis, retinopathy Ocular Occupational Hazards (Cont.) Physical Injuries: - Causes: Debris, machinery accidents - Effects: Corneal abrasions, traumatic cataracts Prolonged Screen Time: - Condition: Computer Vision Syndrome - Effects: Eye strain, dry eyes, blurred vision Radiation Exposure: - Sources: Lasers, radiology equipment - Effects: Retinal burns, optic nerve damage Prevention of Ocular Occupational Hazards Personal Protective Equipment (PPE): - Safety goggles, face shields, UV-blocking eyewear Engineering Controls: - Ventilation systems, shielding hazardous substances Administrative Controls: - Safety training, protocols, regular eye exams Workplace Ergonomics: - Adjustable workstations, regular breaks Emergency Procedures: - Eyewash stations, exposure protocols Auditory System Overview of the Ear Detailed Hearing Mechanism Auditory Arteries Hearing Loss Types Hearing Loss Symptoms & Diagnosis Symptoms: - Difficulty hearing faint sounds - Trouble understanding speech - Ear fullness, tinnitus Diagnosis: - Audiometry - Tympanometry - Otoacoustic Emissions (OAE) - Auditory Brainstem Response (ABR) Hearing Loss Treatment Sensorineural: - Hearing aids, cochlear implants - Assistive listening devices Conductive: - Earwax removal, treating infections - Surgery for structural issues Mixed: - Combination of sensorineural and conductive treatments Otitis Media Overview Definition: Middle ear inflammation Types: - Acute Otitis Media (AOM) - Chronic Otitis Media (COM) - Otitis Media with Effusion (OME) Otitis Media Pathophysiology Otitis Media Symptoms & Diagnosis Symptoms: - Ear pain (AOM) - Hearing loss - Fever (AOM) - Fluid drainage (COM) Diagnosis: - Otoscopy - Tympanometry - Audiometry Otitis Media Treatment AOM: - Antibiotics (if bacterial) - Pain management - Observation for mild cases COM: - Surgical intervention (tympanoplasty) - Chronic antibiotics if needed OME: - Often resolves spontaneously - Tympanostomy tubes if persistent Meniere’s Disease Overview Definition: Inner ear disorder causing vertigo, tinnitus, hearing loss Etiology: - Endolymphatic hydrops - Genetic, autoimmune, viral factors Meniere’s Disease Pathophysiology Meniere’s Disease Symptoms & Diagnosis Symptoms: - Vertigo episode - Persistent tinnitus - Progressive hearing loss - Aural fullness Diagnosis: - Clinical evaluation - Audiometry - Vestibular testing (ENG, VNG) - MRI to exclude other conditions Meniere’s Disease Treatment Dietary Modifications: - Low-sodium diet Medications: - Diuretics - Anti-vertigo meds - Corticosteroids Therapies: - Vestibular rehabilitation Surgical Interventions: - Endolymphatic sac decompression - Vestibular nerve section Lifestyle Modifications: - Stress management - Avoid triggers (caffeine, alcohol) Auditory Occupational Hazards Noise Exposure: - Sources: Construction, factories, music - Effects: NIHL, tinnitus Ototoxic Chemicals: - Common: Aminoglycosides, solvents - Effects: Cochlear damage, vestibular dysfunction Auditory Occupational Hazards (Cont.) Vibration Exposure: - Sources: Heavy machinery, power tools - Effects: White finger, inner ear damage Acoustic Trauma: - Causes: Explosions, gunshots - Effects: Acute cochlear damage, immediate hearing loss Prolonged Headphone Use: - High volumes, extended periods - Effects: Gradual hearing loss, tinnitus Extreme Temperatures: - Effects: Ear pressure changes, auditory structure damage Prevention of Auditory Occupational Hazards Hearing Protection: - Earplugs, earmuffs - Noise-canceling devices Noise Control Engineering: - Sound barriers - Quiet machinery Regular Hearing Assessments: - Audiometric testing - Early intervention Workplace Policies: - Limit exposure time - Designated quiet zones Education and Training