EXSS 276 Cardiovascular Questions And Answers With Verified Solutions Graded A+

Anemia (RBC Deficiency) - Can be due to - - decreased Erythropoiesis (building of RBC) - increased destruction of RBCs - increased destruction of hemoglobin - more common in females than males Can result in - - decreased capacity to carry gases - decreased acid buffering capacity People with anemia can take iron supplements but It will take a period of time before a difference in energy is felt- months AP (action potential) in Heart Muscle Fibers - - rapid depolarization due to Na+ inflow when voltage gated fast Na+ channels open - plateau due to Ca2+ inflow when voltage gates slow Ca2+ channels open and some K+ channels close - depolarization due to K+ outflow when voltage gated K+ channels open - refractor per dis longer than contraction itself - no summation can occur - alternation between relaxation and contraction aids in blood flow - ANS signals and hormones modify HR and contractility, but they do not establish the fundamental rhythm Atrioventricular Valves Closed - AV valves close preventing back flow of blood into atria - occurs when ventricles contract, pushing valve cusps closed - chord tendinae are taut, papillary muscles contracted Atrioventricular Valves Open - AV valves open nd allow blood to flow from atria into ventricles when ventricular pressure is lower than atrial pressure- occurs when ventricles are relaxed, chord tendinae are slack and papillary muscles are relaxed; once there is blood in the ventricle we want to close the valve so that blood cannot go back Autoregulation - - blood vessels in tissues regulate blood flow by changing their diameter - ability of the vessels in some tissues of our body to regulate blood flow through them by changes in their diameter - very important in skeletal muscle and heart - posture changes Blood Clotting - a blood clot consists of a network of insoluble protein fibers called fibrin in which the formed elements are trapped Blood Doping - Injecting previously stored RBC's before an athletic event - more cells available to deliver oxygen to tissues Dangerous - increased blood viscosity - forces heart to work harder Banned by Olympic committee Blood exchange at capillaries - Filtration = greater fluid out of capillary Reabsorption = greater fluid moving into capillary Blood exchange at capillaries: Key Points - Blood hydrostatic pressure - pressure generated by pumping action of the heart Blood colloid osmotic pressure - force generating absorption of fluid caused by suspension of proteins - proportional to plasma proteins (attracts fluid to blood)Blood Flow - right atrium, tricuspid valve, right ventricle, pulmonary valve, left atrium, mitral (bicuspid) valve, left ventricle, aortic calve, out aorta Blood Groups and Blood Types - Type A - has A antigen, makes antibodies against B because It doesn't know B Type B - has B antigen, makes antibodies against A because It doesn't know A Type AB - has both A and B antigens, knows And B antigens so makes no antibodies Type O - has neither A or B antigens so It makes both A and B antibodies - RBC surfaces are marked by genetically determined glycoproteins and glycolipids - name the blood type based on what antigen is on the surface of the RBC Blood Plasma - 55% - Over 90% water 7% plasma proteins - created in liver; made in liver, found in plasma - confined to bloodstream 1. albumin 54% - maintain blood osmotic pressure 2. globulins (immunoglobulins) 38% - antibodies bind to foreign substances called antigens - form antigen-antibody complexes 3. Fibrinogen 7% - involved in clotting - strings of proteins 2% other substances ** - electrolytes, nutrients, hormones, gases, waste products Blood Pressure - pressure extended by blood on walls of a vessel - caused by contraction of ventricles- highest in aorta = 120mm Hg during systole/80 during diastole pressure falls steadily in systemic circulation with distance from left ventricle -35 mm Hg entering capillaries -0mm Hg entering the right atrium Blood Vessel Length - Total blood vessel length - the longer the vessel, the greater the resistance to flow - greater resistance to flow = greater BP - 200 miles of blood vessels for every pound of fat --obesity causes high BP