BIOL 252 Heart Physiology and Blood Vessels Detailed Exam 2026 Questions and Reliable Answers | Legit and Effective Solution !!!

BIO 252 BIO 252 BIOL 252 Heart Physiology and Blood Vessels Detailed Exam 2026 Questions and Reliable Answers | Legit and Effective Solution !!! Are veins red or blue? - -both the colors indicate oxygen level Give an example of a "blue artery": - -arteries are output, and blue means it's low in oxygen, so the pulmonary arteries (to the lungs to get oxygenated) How many valves are in the heart? - - 4 right and left AV valves (right: tricuspid; left: bicuspid or mitral) right (pulmonary valve) and left (aortic valve) semilunar valves AV valves prevent blood flow from: - -ventricle back into atria where it came from What causes the AV valves to close? - -ventricular contraction What causes the aortic or semilunar valves to close? - -when the heart goes into diastole, the high pressure in the aorta or pulmonary trunk pushes back on these valves and causes them to close S1 corresponds to _______. - -TURBULENCE that ocurs when the AV valves close S2 corresponds to ________. - -TURBULENCE that occurs when the aortic or pulmonary semilunar valves close Both semilunar valves have ______ cusps. - -three Where does S1 occur in the cardiac cycle? - -atrial diastole ventricular systole Where does S2 occur in the cardiac cycle? - -atrial and ventricular diastole preload - -pressure of the filled ventricles that stretches the myocardium Frank Starling law: - -the greater the EDV, the greater the SV (because more stretching more optimally aligns actin and myosin in the heart for stronger contraction--unlike overstretching in skeletal muscle) BIO 252 BIO 252 What sources of pressure contribute to the preload? - -venous pressure bringing blood back to the heart (first passive filling from atrium) then active filling of ventricles and increased pressure from atrium When we speak of the length-tension relationship, we're talking about ________ length. - -sarcomere _______ might increase preload. Why? - -exercise skeletal muscles move blood by building venous pressure--this increases preload (more blood trying to force its way into your heart) Besides increasing BP by way of exercise, how else can you increase preload? - -have a lot of sodium in your diet drink a bunch of water (ELEVATE BLOOD VOLUME)--this means that if you elevate blood pressure, no matter how you accomplish it, it will lead to greater stroke volume If you eat a lot of salt but don't drink a lot of water, would it still increase preload? - -yes, because water will be drawn from your tissues Do preload and afterload and their effects on SV depend on the nervous system? - -no! They are intrinsic properties to the heart afterload - -the blood pressure in the aorta and pulmonary trunk that resists ejection of the ventricles what happens when aortic pressure is low? - -ventricle contracts and pushes blood into the aorta What conditions must be met for blood to leave ventricle? - -must have higher pressure than aorta Afterload affects how easily the ______ can eject blood. - -ventricles Afterload is a measure of pressure on the other side of the ______ valves. - -semilunar Preload is determined by ______ pressure. - -venous Afterload is determined by _______ pressure. - -arterial How can you increase the amount of blood leaving the ventricle? - -vasodilation- reduces blood pressure How can you decrease the amount of blood leaving the ventricle? - -vasoconstriction- makes afterload greater and resists blood flow BIO 252 BIO 252 Why doesn't aortic pressure increase during isovolumetric contraction of the ventricles? - -because at this point, the pressure in the ventricle isn't greater than the aortic pressure so the volume of the ventricle isn't changing--no blood is pushed out yet Increased afterload diminishes... - -period of ventricular ejection A higher aortic pressure ______ the amount of blood ejected from the ______ ventricle. - -decreases left The afterload shifts things so that if you increase it, the isovolumetric phase is.... - longer (takes longer to surpass the pressure in the aorta) What are the consequences of a longer isovolumetric phase on ventricular ejection period and stroke volume? - -if we have a longer isovolumetric phase, then we have a shorter period of ventricular ejection, and therefore a reduced stroke volume If you wanted to maximize stroke volume, what should you do to preload and afterload? - -preload--raise it afterload--reduce it How does the heart respond to exercise in the short term? (in regards to heart rate, stroke volume, and cardiac output) - -heart rate increases and stroke volume increases, which means our cardiac output increases Why does the heart respond to exercise? What is its goal? - -to deliver more oxygen to the tissues of the body What are the steps in getting the heart rate elevated during exercise? - - 1. proprioceptors (stretch receptors that sense movement) inform the brain to anticipate oxygen need--this occurs even before oxygen and CO2 levels change 2. chemoreceptors detect low pH 3. muscles squeeze veins to elevate venous pressure--increasing preload of heart- increased SV--increased cardiac output--increased blood pressure Low pH means ______ CO2 levels - -elevated Proprioceptors and chemoreceptors feed into the ________ of the brain and _______ heart rate. - -cardiac centers increase (to benefit the body with its increased need for oxygen) What will respond to the high blood pressure produced by increase cardiac output during exercise? - -baroreceptors BIO 252 BIO 252 In the context of exercise how will the brain respond to HBP? - -leave it alone (in the absence of exercise, it would try to correct the high blood pressure) baroreceptors are located in: - -aorta carotid arteries How does the heart respond to exercise long-term? - -it gets bigger What implications from the heart increasing in size? - -bigger stroke volume leading to an increased cardiac output...and our body's needs won't really be that different at rest so we are able to lower our heart rate What is cardiac reserve and what happens to it when your heart gets bigger? - -Cardiac reserve refers to the difference between the rate at which the heart pumps blood and its maximum capacity for pumping blood at any given time--so you increase your cardiac reserve when you strengthen your heart. Resting cardiac output is ____L/min. - -5 liters What are the three types of vessels? - -arteries veins capillaries Arteries carry ______ pressure blood _____ from the heart. - -high; away Veins carry _____ pressure blood _____ the heart. - -low; to (and so have a different structure than arteries) Capillaries.... and have _______ pressure. - -connect arteries and veins moderate What do arteries have that veins do not? - -sensory patches (carotid artery and aorta) with baroreceptors What is the name of the organ that contains baroreceptors? - -carotid sinuses Baroreceptors detect blood pressure. If we have hypertension, what two things will result? - -lowering heart rate vasodilation to reduce blood pressure What is the name of the organ that contains chemoreceptors? - -carotid bodies aortic bodies Carotid and aortic bodies are found in arteries or veins? - -arteries BIO 252 BIO 252 What are the effect of chemoreceptors that sense low pH and high CO2 level? - -to increase heart rate sensory organs inside the body? - -carotid bodies and aortic bodies carotid sinuses term we use to describe whether blood is in capillaries or not? - -perfusion What prevents blood from entering capillaires (or allow) - -precapillary sphincters artery structure that leads to capillary bed? - -metarteriole channel that blood uses to bypass capillary network? - -thoroughfare channel Why not perfuse all capillary beds? - -we don't have enough blood to fill them all at one time, so we need to selectively fill the ones we need most at any given time (e.g. during fight or flight, we need blood to our skeletal muscles but not really our digestive system) Describe the structure of veins compared with arteries: - -veins have thinner walls and are less muscular and less elastic than arteries about what percent of your blood is in the systemic circuit at any given time? - -about 70% And about what percent of blood is in the veins? - -about 54% Why do veins have more blood than arteries? - -because they are more elastic and can expand more than arteries Four ways to move low pressure venous blood to the heart? - -1. muscular pump 2. respiratory pump 3. vasomotion 4. gravity Blood flow depends on differences in pressure, so why is it a challenge to bring blood back to the heart? - -because venous blood is so low that at times, it's difficult to have a pressure gradient at all The "Skeletal muscle pump" has ________ to allow for unidirectional movement of blood. - -one-way valves (veins are the ONLY vessel that have valves) Describe the respiratory pump: - -rhythmic contraction of diaphragm in our thorax- moves downward With every inspiration, your abdomen experiences a positive/negative pressure. (thorax?) - -abdomen experiences a positive (increased pressure) BIO 252 BIO 252 thorax experiences a negative (decreased pressure because volume is expanding) How does this aid venous return to heart? - -the negative pressure in your thorax causes it to be easier for venous blood to return to this cavity, and simultaneously, positive pressure in your abdomen pushes blood upward What is vasomotion, and how does it relate to venous return to heart? - -if hypovolemic, smooth muscle in veins contracts to increase venous pressure Is your body often utilizing vasomotion? - -no--this is pretty rare in veins How does gravity help venous return to heart? - -aids veins that are above the hear What is the typical circulatory route? - -artery to capillary to vein back to heart What is a portal system? - -artery to two capillary beds in a row to vein back to heart Where do you find portal systems? (3) - -hypothalamus and anterior pituitary liver kidney The vessel that extends between the connected capillary beds is: - -portal vein What is another route of circulation? - -arteriovenous anastomosis What is an arteriovenous anastomosis? - -a (gated with sphincter muscles) shunt that allows blood to flow directly from the artery to the vein, bypassing a capillary bed Where would you find arteriovenous anastomosis in the body? - -extremities (fingers and toes) What are two other types of anastomosis? - -arterial---artery to artery venous---vein to vein Where would you find arterial anastomosis? - -brain--so that if you have a stroke (blockage), blood can still get to certain regions uterus--during birth when the baby is pushing around, blockages can occur and these guys allow blood to keep making its way to important tissues