Exam 3 Flashcards
Aneurysm
A weak point in an artery or heart wall.
Forms a bulging sac that pulsates with each heartbeat.
May rupture at any time.
Causes: congenital weakness of vessels, or trauma, or bacterial infection.
Most common causes: atherosclerosis and hypertension.
Most common sites: abdominal aorta, renal arteries, Circle of Willis.
Dissecting Aneurysm
Blood accumulates between the tunics of the artery and separates them, usually because of degeneration of tunica media.
Varicose Veins
Blood pools. Veins stretched. Cusps of venous valves are pulled apart. Backflow of blood. Veins swell more. Vessel walls grow weak. Varicose veins, with twisted pathways and irregular dilations. Causes: hereditary weakness, obesity, pregnancy.
Hemmorrhoids
Varicose veins of the anal canal.
Hypertension
Chronic high BP, greater than 140/90.
“Silent-killer”.
Causes/Risk Factors: obesity, sedentary behavior, diet, nicotine, heredity, race, sex.
Damages heart by increasing afterload.
Hypotension
Chronic low BP, less than 90/60.
Causes: blood loss, dehydration, anemia.
Edema
Accumulation of excess fluid in a tissue.
Occurs when fluid filters into a tissue faster than it is absorbed.
Three main causes: increased capillary filtration, reduced capillary absorption, obstructed lymphatic drainage.
Circulatory Shock
Any state in which cardiac output is insufficient to meet metabolic needs.
Cardiogenic Shock
Inadequate pumping of the heart (usually a result of MI).
Low Venous Return (LVR) Shock
Cardiac output is low because too little blood is returning to the heart.
Hypovolemic shock, obstructed venous return shock, and venous pooling (vascular) shock.
Hypovolemic Shock
Type of LVR shock. Most common.
Causes: loss of blood volume due to trauma, burns, dehydration.
Obstructed Venous Return Shock
Type of LVR shock.
Causes: an object, like a tumor or aneurysm, that compresses a vein and impedes flow.
Venous Pooling (Vascular) Shock
Type of LVR shock.
Normal total blood volume, but too much accumulates in the lower body.
Causes: long periods of standing or sitting; widespread vasodilation.
Neurogenic Shock
A form of venous pooling shock.
Results from sudden loss of vasomotor tone that allows the vessels to dilate.
Causes: vary, from emotional shock to brainstem injury.
Septic Shock
Bacterial toxins trigger vasodilation and increased capillary permeability.
Anaphylactic Shock
Severe immune reaction to an antigen.
Causes a histamine release, generalized vasodilation and increased capillary permeability.
Responses to Shock
Compensated Shock: several homeostatic mechanisms bring about spontaneous recovery (e.g., fainting and gravity restoring blood flow to the brain).
Decompensated Shock: compensated shock mechanisms fail, so life-threatening positive feedback loops occur.
Hypercapnia
High CO2 levels.
CO2 levels increase in the brain, pH decreases, triggers vasodilation, and perfusion improves.
Hypocapnia
Low CO2 levels.
Raises pH, stimulates vasoconstriction, reduces perfusion, giving CO2 a chance to rise to a normal level.
Transient Ischemic Attack (TIA)
Brief episodes of cerebral ischemia; mini-strokes.
Causes: spasms of diseased cerebral arteries.
Cerebral Vascular Accident (CVA)
Sudden death of brain tissue caused by ischemia.
Causes: atherosclerosis, thrombosis, ruptured aneurysm..
Metastasis
Phenomenon in which cancerous cells break free from the original, primary tumor, travel to other sites in the body and establish new tumors.
Metastasizing cancer cells can easily enter lymphatic vessels because of the high permeability of lymphatic capillaries.
Cancerous lymph nodes are usually swollen, firm, and usually painless.
Cardinal Signs of Inflammation
Heat
Redness
Swelling
Pain
Reye Syndrome
Serious disorder in children younger than 15 following an acute viral infection (e.g., chickenpox or influenza).
Characterized by swelling of brain neurons, fatty infiltration of liver and other viscera.
Neurons die from swelling and cause nausea, vomiting, disorientation, seizures, coma.
Can be triggered by aspirin used to control fever.
Autoimmune Diseases
Failure of self-tolerance.
Produce antibodies that attack the body’s own tissues.
Severe Combined Immunodeficiency Disease (SCID)
Hereditary lack of B and T cells.
Highly vulnerable to opportunistic infection and must live in protective enclosures.
Acquired Immunodeficiency Syndrome (AIDS)
Caused by infection with HIV.
HIV invades helper T cells, macrophages, and dendritic cells.
Destroys helper T cells which are involved in all immune responses: nonspecific, humoral, and cellular.
Helper T cell count below 200, and opportunistic infection present.
AIDS: Symptoms
Early symptoms are flu-like.
Progress into severe weight loss, fatigue, lymphadenitis.
Helper T cell count below 200, and opportunistic infection present.
AIDS: Treatments
AZT: inhibits reverse transcriptase.
Protease Inhibitors: inhibit enzymes that HIV needs for replication.
Arrhythmia
Any abnormal cardiac rhythm.
Ventricular Fibrillation
Serious arrhythmia caused by signals reaching different regions at different times.
Atrial Fibrillation
Between heartbeats, the atria exhibit weak, chaotic, high frequency depolarizations instead of normal P waves.
Heart Block
Failure of any part of the conduction system to conduct signals.
Usually a result of disease and degeneration of conduction system fibers.
Premature Ventricular Contractions (PVCs)
Result of ventricular ectopic focus firing and setting off an extra beat before normal SA node signal arrives.
May result from stimulants, stress, or lack of sleep.
Ectopic Focus
Another part of the heart fires before the SA node.
Caused by hypoxia, electrolyte imbalance, caffeine, nicotine, and other drugs.
Congestive Heart Failure
Results from the failure of either ventricle to eject blood effectively.
Usually due to a heart weakened by MI, chronic hypertension, valvular insufficiency, or congenital defects in heart structure.
Cardiomyopathy
Any disease of the myocardium not resulting from coronary artery disease, valvular disfunction, or other cardiovascular disorders.
Can cause dilation and failure of the heart, thinning of heart wall, or thickening of the interventricular septum.
Coronary Artery Disease
A constriction of the coronary arteries usually resulting from atherosclerosis (an accumulation of lipid deposits that degrade the arterial wall and obstruct the lumen).
Most dangerous consequence is MI.
Risk factors: heredity, aging, being male, obesity, smoking, lack of exercise, stress, diet.
Pericarditis
Inflammation of the pericardium.
Membranes become roughened and produce a painful friction rub with each heartbeat.
Myocardial Infarction
Heart attack.
Interruption of blood supply to the heart from a blood clot or fatty deposit (atheroma) that can cause death of cardiac cells.
IgA
Prevents pathogen adherence to epithelia and penetrating underlying tissues.
Provides passive immunity to newborns.
IgD
B cell activation by antigens.
IgE
Stimulates release of histamine and other mediators of inflammation and allergy.
IgG
Crosses placenta to fetus.
Secreted in secondary immune response.
Complement fixation.
IgM
Secreted in primary immune response.
Agglutination and complement fixation.
