Pathophysiology Exam Review

Flashcards covering key vocabulary from lecture notes on Innate and Adaptive Immunity, Disorders of Immune Response (including HIV/AIDS), and Disorders of Blood Flow Part I.

Immune System Functions

To protect the body from pathogens, identify and destroy abnormal cells (like cancer cells), and remove dead or damaged cells and tissues.

Innate Immune Response

The body's immediate, non-specific defense mechanism against pathogens, present from birth and providing rapid, broad protection before acquired immunity develops.

Adaptive Immune Response

A specific and memory-based defense mechanism that targets particular pathogens, developing after exposure and improving with subsequent encounters.

Antibody Production

A process initiated by B cell activation upon encountering specific antigens, leading to their differentiation into plasma cells that secrete antibodies and memory B cells.

CD8+ T Cell Activation

A process where cytotoxic T cells are activated by antigen-presenting cells (APCs) displaying specific antigens on MHC class I molecules, leading to their differentiation into effector cytotoxic T lymphocytes and memory T cells.

Cell-Mediated Immunity

Immune response directly involving T lymphocytes to defend against intracellular pathogens and cancer cells, rather than by antibodies.

Humoral Immunity

Immune response mediated by antibodies produced by B lymphocytes, effective against extracellular pathogens and their toxins.

Pattern Recognition Receptors (PRRs)

Receptors primarily on innate immune cells that detect molecular patterns associated with pathogens (PAMPs) or host damage (DAMPs) to initiate immune responses.

Pathogen-Associated Molecular Patterns (PAMPs)

Conserved molecular structures found on microbes but not on host cells, recognized by PRRs of the innate immune system.

Active Immune Response

Immunity developed by the body's own immune system in response to exposure to an antigen (e.g., infection or vaccination), leading to long-lasting protection and memory.

Passive Immune Response

Temporary immunity acquired by the transfer of antibodies from an immune individual to a non-immune individual (e.g., maternal antibodies to fetus, antitoxins), without the recipient's immune system being activated.

Opsonization

The process by which pathogens are coated with opsonins (e.g., antibodies, complement proteins), making them more susceptible to phagocytosis by immune cells. It aids immune function by enhancing the efficiency of pathogen clearance.

Primary Immune Response

The initial immune reaction to an antigen, characterized by a lag phase, a slower rise in antibody levels, and often a lower antibody titer compared to subsequent exposures.

Secondary Immune Response

A rapid and robust immune reaction triggered by subsequent exposure to the same antigen, due to the presence of memory B and T cells, resulting in a quicker, stronger, and more sustained antibody response.

Complement System

A cascade of plasma proteins that, when activated, enhances immune responses by directly lysing pathogens, opsonizing them for phagocytosis, and promoting inflammation.

Hypersensitivity Reactions

Exaggerated or inappropriate immune responses that cause tissue damage, typically classified into four types (I, II, III, IV).

Anaphylaxis

A severe, potentially life-threatening systemic hypersensitivity (Type I) reaction characterized by widespread vasodilation, bronchoconstriction, and systemic shock, often treated with epinephrine.

Immunodeficiency

A state in which the immune system's ability to fight infectious diseases and cancer is compromised or absent, presenting clinically as recurrent, severe, or unusual infections.

Primary Immune Deficiency

Immunodeficiency caused by genetic or developmental defects in immune cell development or function, often present from birth.

Secondary Immune Deficiency

Immunodeficiency acquired later in life due to external factors such as malnutrition, infection (e.g., HIV), immunosuppressive drugs, radiation, or cancer.

Autoimmune Disease

A condition in which the body's immune system mistakenly attacks its own healthy tissues, leading to chronic inflammation and tissue damage, often due to a breakdown in self-tolerance.

Alloimmunity

An immune response directed against antigens from another individual of the same species, such as in solid organ transplant rejection or transfusion reactions.

Solid Organ Transplant Rejection

An immune response by the recipient's immune system against the transplanted organ, which is recognized as foreign, leading to damage and potential failure of the graft.

Graft Versus Host Disease (GVHD)

A complication following allogeneic stem cell or bone marrow transplantation, where immunocompetent T cells in the transplanted graft recognize the recipient's tissues as foreign and attack them.

HIV Transmission

Primarily occurs through contact with infected body fluids, including blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk, often via unprotected sexual contact, sharing needles, or from mother to child during birth or breastfeeding.

HIV Replication

A process involving enzymes like reverse transcriptase (to convert RNA to DNA), integrase (to insert viral DNA into host genome), and protease (to cleave viral polyproteins into functional proteins), ultimately producing new viral particles that infect CD4+ T cells.

Viral Load (in HIV)

A measure of the number of HIV RNA copies in the blood, indicating the level of viral replication; it is inversely related to CD4 count and correlates with the progression to AIDS and clinical presentation.

CD4 Count (in HIV)

A measure of the number of helper T cells (CD4+ T cells) in the blood, which are targets of HIV. A declining CD4 count indicates immune system damage and increases susceptibility to opportunistic infections, signaling progression to AIDS.

Self-Tolerance of Adaptive Immune Cells

A critical process by which the immune system learns to distinguish between self-antigens and foreign antigens, preventing the destruction of the body's own tissues, primarily achieved through central and peripheral tolerance mechanisms.

Deep Vein Thrombosis (DVT)

The formation of a blood clot (thrombus) in a deep vein, typically in the legs or pelvis, which can lead to pain, swelling, and potentially pulmonary embolism if the clot dislodges.

Triad of Virchow

Three primary factors contributing to the formation of thrombi: venous stasis (slow blood flow), endothelial injury (damage to blood vessel lining), and hypercoagulability (increased tendency for blood to clot).

Varicose Veins

Abnormally swollen, twisted veins, most often in the legs, caused by incompetent valves that allow blood to pool, leading to increased venous pressure and distention.

Venous Insufficiency

A condition in which the veins have trouble sending blood from the legs back to the heart, often due to damaged valves, leading to blood pooling, swelling, skin changes, and sometimes ulcers.

Peripheral Artery Disease (PAD)

A circulatory condition in which narrowed arteries reduce blood flow to the limbs, most commonly the legs, leading to symptoms like intermittent claudication, numbness, and coldness in the affected limb.

Raynaud Disease

A primary vasospastic disorder causing episodic constriction of small arteries, typically in the fingers and toes, in response to cold or stress, with no underlying disease process.

Raynaud Phenomenon

A secondary form of vasospasm similar to Raynaud Disease, but associated with an underlying medical condition, medication, or injury.

Thromboangiitis Obliterans (Buerger's Disease)

A rare inflammatory disease, strongly associated with smoking, that causes small and medium-sized arteries and veins to become inflamed and occluded, typically affecting the hands and feet and potentially leading to tissue loss.

Atherosclerosis

A chronic inflammatory disease characterized by the thickening and hardening of arterial walls due to the formation of atherosclerotic plaques, leading to reduced blood flow and increased risk of cardiovascular events.

Fatty Streak

The earliest recognizable lesion in atherosclerosis, composed of foam cells (lipid-laden macrophages) that accumulate beneath the endothelium, often appearing as yellow streaks on arterial walls.

Fibrous Atheromatous Plaque

An advanced atherosclerotic lesion characterized by the accumulation of lipids, smooth muscle cells, collagen, and elastic fibers, forming a distinct plaque that protrudes into the arterial lumen and can cause significant narrowing.

Complicated Lesion (Atherosclerosis)

An advanced atherosclerotic plaque that has undergone calcification, rupture, hemorrhage, or superimposed thrombosis, posing a high risk for acute cardiovascular events like myocardial infarction or stroke.

Atheromas

Deposits of fatty material, cholesterol, macrophages, and other cellular debris that form plaques within the inner lining of arteries, leading to atherosclerosis.

Dyslipidemia

An abnormal concentration of lipids (e.g., cholesterol, triglycerides, lipoproteins) in the blood, including elevated total cholesterol, LDL cholesterol, or triglycerides, or low HDL cholesterol, increasing the risk for atherosclerosis.

Primary Hyperlipidemia

High lipid levels in the blood caused by genetic defects in lipid metabolism, independent of other medical conditions or lifestyle factors.

Secondary Hyperlipidemia

High lipid levels in the blood resulting from other medical conditions (e.g., diabetes, hypothyroidism, kidney disease) or lifestyle factors (e.g., diet, obesity, medications).

LDL (Low-Density Lipoprotein)

Often called 'bad cholesterol,' LDL transports cholesterol from the liver to cells; high levels contribute to plaque formation in arteries.

HDL (High-Density Lipoprotein)

Often called 'good cholesterol,' HDL helps remove excess cholesterol from cells and transport it back to the liver for excretion, thus protecting against atherosclerosis.

Aortic Aneurysms

Localized, abnormal dilations of the aorta, caused by weakening of the arterial wall, which can rupture and lead to life-threatening hemorrhage.

Dissection of the Aorta

A life-threatening condition where a tear in the inner layer of the aorta allows blood to surge between the layers of the arterial wall, separating them and creating a false lumen, which can compromise blood flow to organs.