Atherosclerosis and Skin Infections Quiz

Inflammatory Response

• Inflammation is a crucial component of the innate immune system, triggered by injury to vascularized tissues.
• The process is rapid and non-specific, aimed at containing damage, eliminating pathogens, and initiating healing.
• Key features include activation (within seconds of injury), vascular changes (increased blood flow causing redness and heat, increased capillary permeability causing swelling and pain), cellular events (recruitment and phagocytosis of leukocytes), and cytokine signaling (regulation of immune response).
• Acute inflammation is characterized by redness, swelling, heat, pain, and loss of function.
• Processes include vasodilation, increased vascular permeability, and leukocyte recruitment.
• Chronic inflammation results from unresolved acute inflammation or persistent triggers (infections, autoimmune diseases).
• It's characterized by infiltration of lymphocytes and macrophages, forming fibrosis and scar tissue.
• Granulomatous chronic inflammation involves macrophages and eosinophils forming granulomas to isolate foreign bodies or infected areas.

Cells Involved in Inflammation

• Mast cells: Located near epithelial surfaces and blood vessels, release histamine upon activation, increasing vascular permeability.
• Also release cytokines (TNF-α, IL-4, IL-5, IL-6, IL-13) to further amplify the inflammatory response.
• Macrophages: Resident in tissues or recruited from the blood, engulf pathogens and cellular debris.
• Release pro-inflammatory cytokines (TNF-α, IL-1, IL-6) that promote leukocyte recruitment and induce systemic effects like fever.
• Present antigens to T helper cells for adaptive immune response.

Hypersensitivity Reactions

• Hypersensitivity reactions are exaggerated or misdirected immune responses to an antigen.
• Type I: IgE-mediated hypersensitivity reactions are mediated by IgE antibodies and occur within minutes to hours.
• Common examples include allergic rhinitis, asthma, and anaphylaxis.
• Pathophysiology includes: sensitization, IgE binding, re-exposure and degranulation, release of mediators, and clinical manifestations.

Innate Immune System

• The innate system is the body's first line of defense against injury and infection providing immediate, non-specific response.
• Components include physical barriers (skin, mucous membranes), biochemical barriers (antimicrobial peptides), human microbiome (beneficial microorganisms), and immune cells.

Adaptive Immune System

• The adaptive immune system provides a more specific and long-lasting response to pathogens.
• T lymphocytes (T cells) mature in thymus and differentiate into T helper cells (orchestrate the immune response), T cytotoxic cells (kill infected cells), and regulatory T cells (suppress immune response).
• B lymphocytes (B cells) mature in bone marrow and differentiate into plasma cells (produce antibodies) and memory B cells (provide long-term immunity).

Other Inflammatory Disorders

• Contact dermatitis: Skin reaction to allergens like poison ivy, related to delayed hypersensitivity.
• Tuberculin skin test: Positive reaction indicates previous TB exposure, linked to delayed hypersensitivity.
• Graft rejection: T cells recognize foreign antigens on transplanted tissues leading to attack.

Cachexia

• Cachexia is a complex metabolic disorder characterized by muscle wasting and atrophy.
• This is often accompanied by a loss of white adipose tissue and leads to weakness and fatigue.
• Key factor is energy imbalance (energy input not meeting needs).
• Inflammation plays a role in the development and progression of cachexia.

Contributing Factors to Infection

• Communicability: The ability of a microorganism to spread from one person to another.
• Immunogenicity: The ability of a microorganism to induce an immune response.
• Infectivity: The ability of a microorganism to invade and multiply within the host.
• Mechanism of action: How the microorganism causes damage to tissues.
• Pathogenicity: The ability of a microorganism to cause disease.
• Portal of entry: Route through which the microorganism enters the body.
• Toxigenicity: The ability to produce toxins.
• Virulence: The organism's capacity to cause severe disease.

Infection Concepts

• ID50: Estimated number of organisms/viral particles needed to infect 50% of a population.
• Endogenous microorganisms: Microorganisms already present in the body as part of the normal microbiome.

Skin Infections

• Possible causative agents: S. Aureus, streptococci, and group A Streptococcus.
• Infection types: Impetigo, folliculitis, and cellulitis.
• Viral skin infections: HSV types 1 and 2, varicella-zoster virus, and HPV.
• Fungal infections (Dermatophytes): trichophyton, microsporum.

Skin Cancer

• Most likely cause of skin cancers is chronic exposure to UV radiation.
• Subtypes of skin cancer: basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma.

Chronic Inflammatory Skin Disorders

• Psoriasis is a chronic inflammatory skin disorder.
• Characteristics include scaly, thick, silvery elevated, well-demarcated plaques.
• Affected sites are often scalp, elbows, or knees.
• Increased skin cell turnover time.
• Inflammatory response involves Th1 and Th17 cells.

Inflammatory Disorders of the Skin

• Dermatitis (including atopic dermatitis)
• Allergic contact dermatitis
• Urticaria (hives)

Cardiovascular Conditions

• Atherosclerosis: Buildup of lipid-laden macrophages in artery walls, causing plaque formation.
• This can lead to coronary artery disease, peripheral artery disease, and cerebrovascular disease.
• Hypertension: Persistently high blood pressure (≥140/90 mmHg) that can damage blood vessels.
• Risk factors: Age, family history, race, obesity, unhealthy diet, physical inactivity, smoking, stress, and chronic diseases.
• Acute coronary syndromes (including unstable angina and myocardial infarction), involve sudden blockage of a coronary artery, and involve thrombus formation over a ruptured atherosclerotic plaque.

Vascular Conditions

• Venous stasis, endothelial damage, and hypercoagulable states contribute to venous thrombosis.
• These factors promote the development of clots within the veins, most commonly in the lower extremities.

Respiratory Conditions

• Hypercapnia: Excess CO2 in the blood
• Hypoxemia: Low O2 in the blood.
• Acute respiratory failure: A sudden decline in the ability of the lungs to provide adequate oxygenation and/or removal of carbon dioxide from the blood.
• Chronic obstructive pulmonary disease (COPD): Characterized by inflammation, airflow limitation, and alveolar destruction.

Infectious Diseases- Other than Skin

• Infectious diseases- other than skin: TB or tuberculosis
• Most likely causative agents: TB bacteria or Mycobacterium tuberculosis.
• Transmission: Respiratory droplets.

Inflammatory Bowel Disease (IBD)

• Crohn's Disease: Inflammation in any part of the GI tract; often in the ileum and proximal colon;
• Inflammation is discontinuous(skip lesions) and affects the entire wall of the GI tract.
• Ulcerative Colitis: Inflammation limited to the mucosal lining of the large intestine, typically starting in the rectum and progressing proximally; no skip lesions.
• Risk factors: Genetics, altered intestinal microbiome, smoking, NSAIDs, high carbohydrate diet, and certain medications.

Gastroesophageal Reflux Disease (GERD)

• GERD is the reflux of chyme from the stomach into the esophagus.
• Risk factors: Sliding hiatal hernia, obesity, smoking, alcohol use, increased abdominal pressure, certain medications (e.g., anticholinergics, nitrates, calcium channel blockers).

Peptic Ulcer Disease

• Ulcers in the stomach (gastric ulcers) or duodenum (duodenal ulcers).
• Most likely caused by Helicobacter pylori infection or NSAID use.
• Symptoms: Burning pain, feeling of fullness, nausea, vomiting, black/tarry stools.

Urinary Tract Obstructions

• Nephrolithiasis (Kidney stones): Formation of crystals from salts in the urine.
• Lower Urinary Tract Obstruction: Obstructions due to anatomical abnormalities (prostate enlargement, urethral stricture) or neurogenic bladder.
• Compensatory Mechanisms: The body tries to compensate by increasing kidney size/function or by increasing urine output after obstruction is relieved.
• Urinary Incontinence: Leakage of urine as a result of various conditions.

Viral Hepatitis

• Infections caused by hepatitis viruses(A,B,C,D,E or G)
• Clinical presentation includes jaundice, dark urine, and clay-colored stools; fatigue, anorexia, malaise, as well as a range of symptoms depending on cause.

Glomerulonephritis

• An inflammation of the glomeruli (filtering units in kidneys).
• Subtypes include acute, chronic, and secondary.
• Acute: Typically related to bacterial infections.
• Chronic: Progressive loss of kidney function.
• Symptoms include hematuria, proteinuria, edema, hypertension, oliguria,

Acute and Chronic Kidney Injury

• AKI: Rapid decline in kidney function.
• CKD: Progressive loss of kidney function over time.
• Risk factors: Pre-existing kidney disease, diabetes, hypertension, older age, and certain medications.

This quiz covers key concepts related to atherosclerosis and skin infections, including types, causes, and risk factors. Questions explore the roles of adipocytes, cytokines in inflammation, and common pathogens involved in conditions like cellulitis and folliculitis. Test your knowledge on these crucial health topics!