ENH 220 Unit 1 Notes PDF

ENH 220 - UNIT 1 NOTES Readings: ch 2 & 5 CELLS & TISSUES, & INFLAMMATION & REPAIR What is pathophysiology? - pathos = suffering/disease - physis = origin - logos = study of - study of abnormalities in the body CELL...

ENH 220 - UNIT 1 NOTES Readings: ch 2 & 5 CELLS & TISSUES, & INFLAMMATION & REPAIR What is pathophysiology? - pathos = suffering/disease - physis = origin - logos = study of - study of abnormalities in the body CELLS STRUCTURE - organelle - cell - tissue - organ - organ system - organism Somatic cells - Neuron - Red blood cell - Osteocycle - Skeletal muscle cells ORGANELLES - Nucleus - the control center of the cell - contains genetic material (DNA) - directs cell activities - nucleolus's primary function is to produce ribosomes and transfer them - Lysosomes - Contains enzymes for intracellular digestion. - Breaks down waste materials and cellular debris. - Participates in autophagy (self-digestion) and apoptosis - can clean waste or kill the cell - it engulfs waste and tries to take it out - self-digestion - Mitochondria - Powerhouse of the cell - Generates energy (ATP) through cellular respiration - Has their own DNA to control these processes - Endoplasmic reticulum - Network of membranes throughout the cell. - Rough ER has ribosomes, involved in protein synthesis. - Smooth ER is involved in lipid metabolism. - Golgi apparatus - Modifies, sorts, and packages proteins and lipids. - Consists of flattened sacs (cisternae). - Plays a key role in intracellular transport. - Centrioles - Involved in cell division (mitosis and meiosis). - Organize microtubules during spindle formation. - Present in animal cells and some protists. - Has some sensory parts like in the eyes - Cytoskeleton - Network of protein filaments and tubules. - Provides structural support and shape to the cell. - Involved in cell movement and intracellular transport. - The 3 types of filaments are - 1. Microtubules: are the smallest - 2. intermediate filaments - 3. Actin filaments - Lipid bilayer - Phospholipid bilayer - Integral protein - Extracellular fluid - Integral protein - Pore - Channel - Polar head (hydrophilic) - Fatty acid tail (hydrophobic) - Cellular transport - Active transport - movement against the concentration gradient using ATP - - more like a key to a door to let things in - Passive transport - movement along the concentration gradient without ATP - simple diffusion - facilitated diffusion: more selective  - Osmosis - hypertonic - isotonic solution - hypotonic solution - Endo- & Exocytosis - Exocytosis: active transport out - Endocytosis: goes in - Pino- & phagocytosis - Phagocytosis: bigger molecules: a little more energy-intensive - Pinocytosis: smaller molecules: lower energy expenditure - Cellular Changes - Hyperplasia - increase in cell number - controlled division - control process: ex. breast inflation in pregnancy to produce milk - Hypertrophy - increase in cell size - due to workload or hormones - can build up muscle in the heart which is bad, cardio output - can be good too - Metaplasia - reversible cell type change - due to chronic irritation like smoking in the lungs - Dysplasia - abnormal cell development - can further along cancer - Necrosis & Apoptosis - Nec : uncontrolled - Apop : programmed death, minimal impact - eventually things don't work as they used too - Note: cell aging - dysfunction of the cells, a consequence of downstream effect the body uses to combat dying cells DYSFUNCTIONS - Mitochondria - symptoms: sudden vision loss, usually in young adults - genetic mutations in mtDNA are responsible  - impaired ATP production in retinal cells leads to cell death - treatment options are limited, and no cure exists - Endoplasmic Reticulum (ER) - 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 - disrupts iron and water transport - patients often get pneumonia - Lysosome - 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 - it is rare and likely fatal, destroys nerves in heart and brain function, otherwise manageable disease TISSUES MAJOR CLASSES - Nervous tissues - Epithelial tissues - Muscle tissues - Connective tissue TISSUE TYPES - Epithelium - Forms a protective barrier - Lines body surfaces and cavities - in the digestive tract, uterus, bladder - Squamous: allows materials to pass through tissue by diffusion, and secrets fluids, in the lungs and lining in the heart - Cuboidal: located in the kidneys - Columnar: absorbs and secrets, enzyme regulation - 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) - Dense connective tissue - Adipose tissue - Areolar tissue - Compact bone - the matrix of the blood is a tissue, a connective tissue at the cellular level TYPES OF CONNECTIVE TISSUE FIBERS - Collagen fibers - Connect and support tissues - Dont stretch well - Elastic fibers - Responsible for distensibility of arteries - Makes arteries stretchy but not too much - Reticular fibers - Form supporting framework of organs - Are thin and delicate, gives the spleen its structure as an organ but flexibility MUSCLES TISSUES - Contracts and generate force - Enables movement of body parts - Cardiac muscle: - run parallel, look like tubes, are smooth, have no control, cover walls of the heart muscle, can get damaged and become hypertrophic - Skeletal muscle: - parallel, no space tightly packed, voluntary movements, muli-nucleated to break down muscle at the gym to rebuild - Smooth muscle:  - is not parallel, but spindle-shaped, one nucleus, moves things through the digestive tract NERVOUS TISSUE - Nerve - Transmits electrical signals - Coordinates and controls body functions - Components: Neurons and supporting cells (glia) - Examples: - Ependymal cell - Microglia - Schwann cell - Oligodendrocyte - Astrocyte - Satellite cell - Tissue Disorders - Ehlers-Danlos Syndrome - hyper flexibility, can stretch skin far, easy to dislocate joints, a genetic disorder that affects collagen, in a vascular case can be life-threatening - Osteoarthritis - common joint disease, bone starts to break down, bone on bone hurts, often genetic, can happen as aging occurs INFLAMMATION PROCESS - is a complex response to tissue injury or infection - is local and systemic - increases capillary permeability - plays a crucial role in immune response and tissue repair ACUTE INFLAMMATION - Earliest phase of the inflammatory response. - Occurs immediately after injury and lasts for 24 to 48 hours. - Acute inflammation has both a vascular component (blood vessel-related) and a cellular component, which relies on cells that circulate in the blood - PMNs look for debris and go to work, the body's response depends on the damage  RESOLUTION - Regression of an inflammatory process without significant tissue destruction and with the return of the tissues to normal. - PMNs will be stopped and digestive themselves EFFECTS LOCAL EFFECT OF INFLAMMATION - Capillary Dilatation - Increased Blood Flow and Redness - Increased Capillary Permeability - Swelling - Attraction of Leukocytes - Leukocytes Migration - Adhesion to Endothelium SYSTEM EFFECTS OF INFLAMMATION - Fever - Leukocytes - Immune Activation - Cytokine Release - Tissue Repair - Changes in skin tone and colour CELLULAR REACTION & 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 & CELL-DERIVED MEDIATORS - Chemical Agents Instenifying 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. - Specialized cells that are widely distributed throughout the connective tissues of the body but often found proximate to blood vessels. Their cytoplasm is filled with preformed granules containing histamine and other chemicals. MEDIATORS FROM BLOOD PLASMA - Bradykinin - It’s a mediator released during inflammation - It contributes to vasodilation & increased vascular permeability - Chemical mediators of inflammation derived from components in the blood plasma. - Complement System - Consists of proteins that interact in a regular sequence - Activated by antigen-antibody reactions, it generates various mediators LYSOSOMAL ENZYMES & HARMFUL EFFECTS - Lysosomal Enzymes - Neutrophils & monocytes contain lysosomal enzymes - These enzymes can digest protein material and contribute to tissue injury - Tissue injury results from both the injurious agent & the inflammatory reaction itself INITIATION - Recognition of Harmful Stimuli - Pattern recognition receptors (PRRs) recognize both pathogen-associated molecular patterns (PAMPs) & damage-associated molecular patterns (DAMPs) - Activation of immune Cells - Macrophages, dendritic cells, and mast cells release cytokines & chemokines AMPLIFICATION - Recruitment of Immune Cells - Neutrophils, monocytes, and lymphocytes migrate to the site of inflammation - Release of Mediators  - Pro-inflammatory cytokines (IL-1, TNF-alpha), prostaglandins, and leukotrienes amplify the immune response REPAIR RESOLUTION - Removal of Harmful Agents - Phagocytosis of pathogens & cellular debris by macrophages - Anti-inflammatory Signals - Anti-inflammatory cytokines (IL-10, TGF-beta) dampen the immune response DYSFUNCTION CHRONIC INFLAMMATION - Prolonged Inflammatory Response - Persistent stimuli (persistent infection, autoimmune reactions) lead to sustained inflammation - Tissue Damage & Fibrosis - Chronic inflammation can result in tissue damage, scarring, and fibrosis