Midterm review 2

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Questions and Answers

Which bacterial toxins are primarily responsible for blister formation in bullous forms?

Staphylococcus (correct)

Clostridium

Corynebacterium

Streptococcus

What type of rash is associated with chickenpox?

Vesicular rash without itching

Itchy, blistering rash (correct)

Nodular rash

Maculopapular rash

What is the primary transmission method for measles virus?

Direct contact

Vector-borne transmission

Fomites

Respiratory droplets (correct)

What causes shingles to occur in a previously infected individual?

Reactivation of VZV from nerve ganglia Signup and view all the answers

Which fungal infection is characterized by lesions that feed on keratin?

Tinea infections Signup and view all the answers

Which factor is NOT a recognized risk factor for fungal skin infections?

Direct sunlight exposure Signup and view all the answers

Which virus is primarily associated with cold sores?

Herpes simplex virus type 1 (HSV-1) Signup and view all the answers

What is the primary role of Th2 cells in asthma?

Secretion of IL-4, IL-5, IL-8, and IL-13 Signup and view all the answers

Which symptom is NOT typically associated with bronchoconstriction in asthma?

Increased capillary permeability Signup and view all the answers

What structural change occurs as a result of untreated chronic inflammation in asthma?

Goblet cell hyperplasia Signup and view all the answers

Which type of antibody is primarily involved in the allergic response in asthma?

IgE Signup and view all the answers

What typically happens to arterial CO2 levels during an asthma attack when ventilation is impaired?

They remain normal or low. Signup and view all the answers

What is the primary function of diastole in the cardiac cycle?

Filling the heart's chambers with blood Signup and view all the answers

Which statement best describes the concept of preload?

The volume and pressure in the ventricle at the end of diastole Signup and view all the answers

What is the effect of increased afterload on the heart during systole?

Increases the resistance against which the heart must contract Signup and view all the answers

Which condition is primarily associated with atherosclerosis?

Formation of lipid-laden macrophages in artery walls Signup and view all the answers

What is a major consequence of damaged endothelial cells in atherosclerosis?

Increased inflammation and attraction of immune cells Signup and view all the answers

Which risk factor for atherosclerosis is primarily related to lifestyle choices?

Physical inactivity Signup and view all the answers

According to the Frank-Starling Law, what happens when myocardial fibers are stretched?

Force of ventricular contraction increases Signup and view all the answers

Which of the following factors is NOT considered a risk factor for atherosclerosis?

Healthy diet Signup and view all the answers

How does diabetes contribute to atherosclerosis?

By damaging blood vessels due to high sugar levels Signup and view all the answers

What is the primary role of the renin-angiotensin-aldosterone system (RAAS) in response to reduced blood flow to the kidneys?

To stimulate renal sodium and water retention, increasing preload Signup and view all the answers

Which condition is a common cause of right-sided heart failure?

Left-sided heart failure Signup and view all the answers

How does pulmonary hypertension affect the right ventricle?

It increases the resistance the right ventricle must overcome Signup and view all the answers

Which factor does NOT contribute to the development of pulmonary hypertension?

Increased circulating blood volume Signup and view all the answers

What triggers the sympathetic nervous system (SNS) when there is a drop in blood pressure?

Activation of baroreceptors Signup and view all the answers

Which statement accurately describes a complication of left-sided heart failure?

It leads to decreased systemic blood flow and renal perfusion. Signup and view all the answers

Which of the following results from the interaction of RAAS and sympathetic nervous system activity during heart failure?

Increased preload and afterload due to fluid retention Signup and view all the answers

What is a common consequence of hypoxic pulmonary vasoconstriction?

Increased resistance leading to pulmonary hypertension Signup and view all the answers

What creates increased afterload on the left ventricle during heart failure?

Aortic valve disease and systemic hypertension Signup and view all the answers

Which of the following conditions does NOT typically lead to right-sided heart failure?

Mitral valve prolapse Signup and view all the answers

What physiological response is triggered by hypercapnia?

Increased ventilation Signup and view all the answers

Which condition can result in a pH of less than or equal to 7.25?

Acute respiratory failure Signup and view all the answers

In respiratory acidosis, what is the primary issue occurring in the body?

Inadequate removal of carbon dioxide Signup and view all the answers

What is the most common cause of a high V/Q ratio?

Pulmonary embolism Signup and view all the answers

Which of the following describes emphysema?

Permanent enlargement of gas-exchange airways Signup and view all the answers

What is the effect of low pulmonary arterial CO2 on arterioles?

Relaxes pulmonary arterioles Signup and view all the answers

Which cells are predominantly involved in the airway inflammation caused by chronic obstructive pulmonary disease?

Th1 cells, macrophages, and neutrophils Signup and view all the answers

What occurs during metabolic alkalosis?

Loss of acid or excess of bicarbonate Signup and view all the answers

How does chronic inflammation affect small airways in the lungs?

Causes structural changes and narrowing of airways Signup and view all the answers

What is the primary consequence of neutrophil and macrophage activity in emphysema?

Destruction of alveolar walls and decreased surface area Signup and view all the answers

What is the primary role of T helper (Th) cells in the adaptive immune response?

Orchestrate the immune response by releasing cytokines Signup and view all the answers

Which type of hypersensitivity reaction is characterized by the involvement of IgE antibodies and occurs within minutes?

Type I hypersensitivity Signup and view all the answers

In which major mechanism can Type II hypersensitivity reactions lead to cell destruction?

Complement-mediated lysis Signup and view all the answers

How do memory B cells function in the adaptive immune system?

They provide long-term immunity by remembering past pathogens. Signup and view all the answers

What is the outcome of antigen-presenting cells interacting with T cells in the adaptive immune response?

They trigger the adaptive immune response. Signup and view all the answers

Which statement best describes Type IV hypersensitivity reactions?

They involve a delayed immune response primarily mediated by T cells. Signup and view all the answers

What is the primary effect of cytokines produced during the adaptive immune response?

Enhance the effectiveness of the innate immune system Signup and view all the answers

What is a significant consequence of post-obstructive diuresis following urinary tract obstruction?

Potential for dehydration if unmanaged Signup and view all the answers

Which condition is most likely associated with overflow incontinence?

Prostate enlargement Signup and view all the answers

Which anatomical issues can lead to lower urinary tract obstruction?

Prostate enlargement Signup and view all the answers

What causes urinary tract infections primarily?

Retrograde movement of bacteria from the gut Signup and view all the answers

Neurogenic bladder is primarily a dysfunction due to damage in which area?

Nerve pathways controlling bladder function Signup and view all the answers

What characterizes the energy imbalance in patients with cachexia?

Decreased energy input and increased energy output Signup and view all the answers

Which mechanism allows HIV to remain inactive within a host cell?

Incorporates its DNA into the host genome Signup and view all the answers

Which of the following is a result of acute or chronic inflammation in cachexia?

Elevated levels of pro-inflammatory cytokines Signup and view all the answers

How does HIV primarily destroy the immune system over time?

By killing CD4+ T helper cells Signup and view all the answers

Which of the following substances is involved in enhancing energy imbalance in cachexia?

TNF-α Signup and view all the answers

What is the primary role of reverse transcriptase in HIV infection?

To convert viral RNA into DNA Signup and view all the answers

What happens to CD4+ T cell counts after the initial HIV infection peak?

They improve temporarily but eventually decline Signup and view all the answers

How is HIV primarily transmitted from one individual to another?

Through blood, fluids, and sexual contact Signup and view all the answers

Which outcome signifies the progression from HIV to AIDS?

A drastic reduction in CD4+ T helper cells Signup and view all the answers

What is the primary cause of the rapid skin cell turnover observed in psoriasis?

Immune system dysregulation. Signup and view all the answers

Which characteristics are commonly associated with basal cell carcinoma (BCC)?

Pearly or waxy bumps. Signup and view all the answers

Which factor is the most significant risk factor for developing skin cancer?

Excessive sun exposure. Signup and view all the answers

What does the ABCDE rule help identify in relation to skin conditions?

Characteristics of melanoma. Signup and view all the answers

What role do Th1 and Th17 cells play in the pathology of psoriasis?

They induce accelerated skin cell turnover. Signup and view all the answers

How does squamous cell carcinoma (SCC) typically present itself?

Flat lesions with scaly surfaces. Signup and view all the answers

What is the nature of the antigenic trigger in psoriasis?

It remains unknown. Signup and view all the answers

Which skin condition is characterized by thickened plaques due to rapid cell turnover?

Psoriasis. Signup and view all the answers

What type of skin lesion is typically associated with melanoma?

Dark spots that evolve over time. Signup and view all the answers

Which of the following cytokines is associated with the inflammation in psoriasis?

IL-17. Signup and view all the answers

What characterizes unstable angina in comparison to myocardial infarction?

The thrombus disperses within 20 minutes. Signup and view all the answers

What distinguishes NSTEMI from STEMI in terms of ECG findings?

ST segment depression. Signup and view all the answers

Which condition is primarily associated with coronary artery spasm?

Prinzmetal/Variant Angina. Signup and view all the answers

Which symptom is commonly associated with acute coronary syndromes?

Chest pain radiating to the arms. Signup and view all the answers

What is the primary risk factor for acute coronary syndromes?

Hypertension. Signup and view all the answers

How long does a stable thrombus typically occlude a vessel during a myocardial infarction?

More than 2 hours. Signup and view all the answers

Which of the following symptoms is NOT typically associated with acute coronary syndromes?

Severe headaches. Signup and view all the answers

What type of myocardial infarction typically involves damage to the myocardium beneath the endocardium?

Subendocardial MI. Signup and view all the answers

Which treatment is effective for relieving Prinzmetal/Variant Angina?

Calcium channel blockers. Signup and view all the answers

What occurs during a myocardial infarction with complete blockage of a coronary artery?

Sustained ischemia and myocyte necrosis. Signup and view all the answers

Study Notes

Inflammatory Response

Inflammation is a crucial part of the innate immune system, triggered by tissue injury.
It's a rapid, non-specific process that contains damage, eliminates pathogens, and initiates healing.
Key features include activation (seconds after injury), vascular changes (increased blood flow and capillary permeability causing redness, heat, swelling, and pain), cellular events (leukocyte recruitment and phagocytosis), and cytokine release (regulating the immune response).

Characteristics of Acute Inflammation

Redness, swelling, heat, pain, and loss of function are characteristic.
Inflammation is a protective response to injury and microbial invasion, neutralizing microorganisms, and promoting tissue repair.
It resolves within days of initial injury or microbial invasion.
Involves cells of the innate immune system, specifically cytokines and chemokines.
Cytokines signal immune cells and chemokines attract them to the injury site.
Chronic inflammation can lead to tissue destruction and attempts at repair.
This can result in fibrosis (scarring) and the infiltration of lymphocytes and macrophages.
Granulomatous inflammation is a specific type; this is characterized by macrophages and eosinophils walling off foreign bodies or infected areas to form granulomas.

Cells Involved in Inflammation

Mast Cells release histamine and other inflammatory molecules immediately upon activation to cause vasodilation and increased vascular permeability
Macrophages, present in tissues and recruited from the bloodstream, engulf pathogens, cellular debris, and release pro-inflammatory cytokines and present antigens.
Neutrophils, the most abundant leukocytes, rapidly recruited to the site of infection to destroy pathogens and release enzymes, ROS.
Dendritic cells bridge the innate and adaptive immune system by capturing antigens, migrating to lymph nodes displaying them to T cells to trigger an adaptive immune response.
Eosinophils primarily involved in fighting parasites and regulate vascular mediators of other cells impacting allergic reactions and can cause tissue damage.

Innate and Adaptive Immune Systems

The innate immune system is the body's first line of defense against infection and injury. It provides immediate, nonspecific responses.
The adaptive immune system provides a more specific, long-lasting response to pathogens through lymphocytes (T cells and B cells).

Hypersensitivity Reactions

Three major types: Allergy (environmental antigens), Autoimmunity (self antigens), and Alloimmunity (tissues from another individual).
Four major mechanisms, type I, type II, type III, and type IV.
Type I (IgE-mediated) reactions occur rapidly to allergen exposure causing vasodilation, increased vascular permeability, bronchoconstriction, mucus secretion, tissue damage.
Type II (tissue-specific) reactions involve antigen-directed antibodies causing cell destruction or dysfunction by complement-mediated lysis.
Type III (immune complex-mediated) characterized by the formation of antigen-antibody complexes that deposit in tissues triggering complement activation and neutrophil-mediated damage.
Type IV (cell-mediated) reactions are mediated by T cells rather than antibodies, and delayed, occurring 24 to 72 hours after antigen exposure.

Antibody-dependent cellular cytotoxicity (ADCC)

Antibodies bind to target cells; activating immune response cells (e.g., natural killer cells, macrophages, neutrophils).

Immune Complex-Mediated Hypersensitivity

Immune complexes are aggregates of antigen and antibody.
These complexes circulate and deposit in tissues, leading to complement activation and neutrophil damage.

Cell-Mediated Hypersensitivity

Immune response driven by T cells.
It is characterized by delayed reactions (24-72 hours).
Macrophage activation and tissue damage are common characteristics.

Cachexia

Cachexia is a complex metabolic disorder marked by muscle wasting and atrophy, sometimes with a loss of white adipose tissue.
Often accompanied by weakness, fatigue, and energy imbalance.

HIV/AIDS

HIV is a retrovirus that primarily infects and destroys CD4+ T helper cells of the adaptive immune system. It also infects and damages macrophages, dendritic cells, NK cells, and cytotoxic T cells.

Infection Concepts

Communicability, Immunogenicity, Infectivity, Mechanism of action, Pathogenicity, Portal of entry, Toxigenicity, and Virulence are key factors influencing the ability of microorganisms to cause infection.
ID50 (infectious dose for 50% of the population) is the estimated number of organisms required to cause infectious disease in 50% of the population.

Epidermis

Keratinocytes (the predominant cells) produce keratin, providing strength and resilience to the skin.
Melanocytes produces melanin, which protects the skin from UV damage.
The epidermal layers (stratum corneum, stratum granulosum, stratum spinosum, stratum basale) differentiate and flatten as keratinocytes move upwards in the process of keratinization to eventually be shed.

Bacterial Skin Infections

Staphylococcus aureus and streptococci are common causes of folliculitis and cellulitis (infection of the dermis and subcutaneous tissue)

Viral Skin Infections

Herpes simplex virus (HSV-1 and 2), varicella-zoster virus (VZV), human papillomavirus (HPV), measles, are examples of viral skin infections.

Fungal Skin Infections

Dermatophytes (e.g., Trichophyton, Microsporum) cause superficial skin infections on keratinous structures, such as tinea capitis.
Mycoses are fungal infections characterized by different locations.
Candida albicans is a yeast-like fungus causing candidiasis affecting skin and mucous membranes.

Skin Cancer

Various types of skin cancer exist, including Basal cell carcinoma, Squamous cell carcinoma, and Melanoma, each with different risk factors, characteristics, and prognoses.

Psoriasis

Inflammation-driven skin disorder causing thickened, flaky, and red plaques, predominantly on the scalp, elbows, or knees.
It's a long-term chronic inflammatory condition.
Exact cause is unknown, but genetic factors, environmental triggers, immune system dysregulation, and other factors are involved.

Atherosclerosis

Atherosclerosis is a condition characterized by plaque buildup in artery walls, which can lead to vascular damage throughout the body.
Risk factors include smoking, hypertension, diabetes, high cholesterol, obesity, and family history of heart disease.
Progression involves inflammation, macrophage recruitment, LDL oxidation, fatty streak formation, plaque rupture, and thrombus formation.

Acute Coronary Syndromes

Result from sudden blockage of a coronary artery, typically from thrombus formation over ruptured atherosclerotic plaques.
Types include unstable angina and myocardial infarction (MI).

Hypertension

Persistently high blood pressure (140/90 mmHg or higher)
Is the silent killer, characterized by a sustained increase in blood pressure
Risk factors include age, family history, race, obesity, inactivity, unhealthy diet, and stress.
It involves various mechanisms, including changes in the SNS, RAAS, hormones, and increased vascular volume to various pathophysiology factors

Deep Vein Thrombosis (DVT)

A blood clot in a deep vein, usually in the leg.
Associated with venous stasis, endothelial damage, and hypercoagulability.
Risk factors include immobility, previous DVT, surgery (especially orthopedic), and pregnancy.
Three factors promote DVT: venous stasis, venous endothelial damage, and hypercoagulable states.

Heart Failure

Left-sided heart failure involves the left ventricle's inability to pump effectively.
Right-sided heart failure is a weakened right side of the heart.
Common causes include coronary artery disease, hypertension, mitral valve disease, and renal failure to name a few.
Several factors can lead to the pathophysiology of heart failure.

Pulmonary Hypertension

Elevated pulmonary artery pressure, often due to lung disease (e.g., COPD, cystic fibrosis), pulmonary embolism, or inflammation.
Risk factors include hypoxia, inflammation, and other factors.

Asthma

Characterized by shortness of breath, wheezing, and coughing, primarily triggered by hyper-responsiveness of the airways, inflammation, and remodeling of the airways.
Factors include allergens, environmental triggers, and genetic predisposition.

Inflammatory Bowel Disease (IBD)

Crohn's disease: Inflammation can affect any part of the gastrointestinal tract.
Ulcerative colitis: Inflammation primarily affects the colon.
Exact cause is unknown, but factors include genetics, immune response, environmental factors, and microbiota involvement
Some examples of IBD types include Crohn's disease, or ulcerative colitis

Irritable Bowel Syndrome (IBS)

Affects the gastrointestinal tract resulting in frequent abdominal pain, altered bowel habits, or other symptoms (primarily abdominal discomfort)
Characterized by recurrent abdominal pain with altered bowel habits.
Visceral hypersensitivity and abnormal gut motility are implicated mechanisms.

Peptic Ulcer Disease

Sores in the lining of the stomach or duodenum.
Caused by Helicobacter pylori infection, NSAID use, or other factors damaging the protective mucus layer and increasing acid exposure.
Symptomatic with burning abdominal pain to name a few.

Diarrhea and Constipation

Osmotic and secretory diarrhea are types of diarrhea distinguished by the underlying mechanisms.
Osmotic diarrhea results from non-absorbable substance drawing water into the lumen.
Secretory diarrhea is caused by exceeding mucosal secretions of chloride.
Constipation is characterized by infrequent bowel movements and difficulty with stool evacuation that can be caused by many factors.

Hepatitis

Hepatitis A, B, and C are viral infections affecting the liver, which can lead to inflammation, organ damage, and potentially chronic conditions.

Urinary Tract Obstructions

Kidney stones or other obstructions in the urinary tract result in reduced or impaired urine flow.
Types of obstructions may be based on location (upper or lower), or etiologies, or various risk factors.

Glomerulonephritis

Inflammation of the glomeruli, the filtering units of the kidneys.
Acute type is often triggered by bacterial infections (e.g., streptococci).
Chronic types are often associated with systemic conditions (e.g., lupus, diabetes).

Acute Kidney Injury (AKI)

A sudden decline in kidney function caused by reduced blood flow, direct kidney damage, or obstruction of urine outflow.
Several causes may affect this condition.

Tumors

Many types of tumors exist, each with a unique pathophysiology impacting the body in many different ways.

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Description

Test your knowledge on bacterial toxins, viral infections like chickenpox and measles, and the immune response in asthma. This quiz covers various aspects of skin infections, respiratory issues, and the cardiac cycle. Perfect for medical students and healthcare professionals!