Q&A Hero

Q: Venous valves play a role in counteracting the gravitational effects of upright posture by helping minimize the backflow of blood and by temporarily supporting portions of the column of blood when the skeletal muscles are relaxed. a. True b. False

Q: Reflex venous vasoconstriction can completely compensate for gravitational effects without skeletal muscle activity. a. True b. False

Q: Veins have a large radius, so they offer little resistance to flow. a. True b. False

Q: Elephantiasis is caused by a bacterial infection. a. True b. False

Q: An increased concentration of plasma proteins is a cause of edema. a. True b. False

Q: Transport of absorbed fat is a function of the lymphatic system. a. True b. False

Q: On average, the hydrostatic pressure is 37 mm Hg at the arteriolar end of a tissue capillary. a. True b. False

Q: Discontinuous capillaries form large channels known as sinusoids that are 100 times wider than traditional capillaries. a. True b. False

Q: Vasopressin is primarily involved in maintaining water balance by regulating the amount of water the kidneys retain for the body during urine formation. a. True b. False

Q: Arterioles have no significant parasympathetic innervation, with the exception of the abundant parasympathetic vasodilator supply to the arterioles of the genitalia. a. True b. False

Q: When shear stress increases, endothelial cells release nitric oxide, which diffuses to the underlying smooth muscle and promotes vasodilation. a. True b. False

Q: Decreased blood flow in response to enhanced tissue activity is called active hyperemia. a. True b. False

Q: When a tissue's blood supply is blocked, carbon dioxide levels decrease in the deprived tissue. a. True b. False

Q: The systolic pressure is the peak pressure exerted in the arteries when blood is pumped into them during ventricular systole. a. True b. False

Q: At resting heart rate, about 80% of the cardiac cycle is spent in systole and 20% in diastole. a. True b. False

Q: During systole, no blood enters the arteries, while blood continues to leave, driven by elastic recoil. a. True b. False

Q: Although ventricular pressure falls to 0 mm Hg during diastole, arterial pressure does not fall to 0 mm Hg because the next cardiac contraction refills the arteries before all the blood drains off. a. True b. False

Q: Arteries carry blood from the organs towards the heart. a. True b. False

Q: Viscosity refers to the friction developed between the molecules of a fluid as they slide over each other during flow of the fluid. a. True b. False

Q: Large percentages of the cardiac output are distributed to the kidneys in order to eliminate metabolic wastes and adjust water and electrolyte composition. a. True b. False

Q: What harmful compound does the pancreas release when it does not get enough blood due to circulatory shock? a. vasopressin b. acetylcholine c. protease d. myocardial toxic factor e. insulin

Q: Following severe loss of blood, how long does it take for red blood cells to be replaced? a. a few hours b. at least 1 day c. at least 1 week d. at least 1 month e. about 45 days

Q: The most important baroreceptors involved in the moment-to-moment regulation of blood pressure are located in the: a. medulla and glossopharyngeal nerve b. internal carotid and vagus nerve c. carotid sinus and aortic arch d. glossopharyngeal nerve and vagus nerve e. medulla and carotid sinus

Q: Circulatory shock from extensive loss of blood volume is known as: a. cardiogenic shock b. vasogenic shock c. neurogenic shock d. extensive shock e. hypovolemic shock

Q: Hypertension is defined as blood pressure above: a. 120/70 mm Hg b. 130/75 mm Hg c. 140/90 mm Hg d. 150/95 mm Hg e. 160/100 mm Hg

Q: Where are the chemoreceptors located that are sensitive to low oxygen or high acid levels in the blood? a. medulla in the brain stem b. right atrium c. carotid and aortic arteries d. apex of the heart e. vena cava

Q: Mean arterial pressure within the circulatory system is constantly monitored by: a. heart sensors b. baroreceptors c. endothelial cells d. pressure sinuses e. ganglions

Q: Which hormone controls water balance in the bloodstream? a. vasopressin b. renin c. angiotensin d. aldosterone e. dopamine

Q: What is the mechanism called that pushes blood from the lower veins to the chest veins due to a pressure difference? a. chest flow b. chest gradient c. chest pump d. respiratory pump e. respiratory gradient

Q: On average, how far apart are the one-way valves in large veins? a. 1 mm intervals b. 5-8 mm intervals c. 1 cm intervals d. 2-4 cm intervals e. 8 cm intervals

Q: What does a closed venous valve prevent? a. escape of blood from the vessel b. muscle contraction c. hypertension d. backflow of lymph e. backflow of blood

Q: By the time the blood enters the venous system, blood pressure averages only: a. 10 mm Hg b. 17 mm Hg c. 27 mm Hg d. 30 mm Hg e. 50 mm Hg

Q: Under resting conditions, what percent of the body's total blood volume is within the venous system? a. 60% b. 54% c. 48% d. 40% e. 33%

Q: What happens to blood flow as it approaches the heart? a. speeds up b. slows down c. pools d. becomes thicker e. becomes thinner

Q: Where does the extra fluid filtered out of the capillaries go? a. blood b. urine c. lymphatic system d. spleen e. spinal canal

Q: When pressure inside the capillary exceeds pressure on the outside, fluid is pushed out through the pores in a process known as: a. passive diffusion b. ultrafiltration c. active osmosis d. phagocytosis e. infusion

Q: What are precapillary sphincters made of? a. connective tissue b. elastin fibers c. collagen fibers d. endothelial cells e. a ring ofsmooth muscle cells

Q: The large holes within the leaky capillaries of the kidneys and intestines are known as: a. micro pores b. macro pores c. Fick's funnels d. fenestrations e. capillary beds

Q: At any point in time, what percentage of the body's total blood volume is within capillaries? a. 0.5% b. 2% c. 5% d. 10% e. 15%

Q: How many capillaries are within a human body? a. between 100 to 250 million b. 750 million c. between 1 to 2.5 billion d. 5 billion e. between 10 to 40 billion

Q: How thick are capillary walls? a. 1 micrometer b. 10 micrometers c. 100 micrometers d. 1 millimeter e. 10 millimeters

Q: With the exception of the brain, how are materials exchanged across capillary walls elsewhere in the body? a. by carrier-mediated transport systems b. by active protein carriers c. by capillary shuttles d. mainly by diffusion e. mainly by membrane binding

Q: What part of the body doesn"t have α1 receptors within its arterioles? a. the brain b. the kidneys c. the small intestine d. the skin e. the heart

Q: Local arteriolar myogenic and chemical mechanisms that keep tissue blood flow fairly constant (despite rather wide deviations in mean arterial driving pressure) is termed: a. hemo-control b. autoregulation c. hemo-stimulation d. pararegulation e. sympathetic balance

Q: What is the most potent vasoconstricting paracrine yet identified? a. cyclic GMP b. acetylcholine c. nitric oxide d. dopamine e. endothelin

Q: What compound brings about local arteriolar vasodilation by causing relaxation of arteriolar smooth muscle in the vicinity? a. sodium chloride b. acetylcholine c. nitric oxide d. dopamine e. endothelin

Q: What vasoactive chemicals do arteriolar endothelial cells release? a. paracrines b. histamines c. adrenal hormones d. neurotransmitters e. acetylcholine

Q: Vasodilation is associated with: a. increased sympathetic nervous system stimulation b. increased carbon dioxide and nitric oxide levels c. increased oxygen levels and myogenic activity d. decreased nitric oxide levels and increased histamine release e. decreased carbon dioxide and myogenic activity

Q: Vasoconstriction is associated with: a. decreased sympathetic nervous system stimulation b. increased oxygen levels and myogenic activity c. increased carbon dioxide and nitric oxide levels d. decreased oxygen levels and myogenic activity e. decreased endothelin and nitric oxide levels

Q: The extent of contraction of arteriolar smooth muscle depends on the cytosolic concentration of what element? a. iron b. phosphorus c. potassium d. magnesium e. calcium

Q: While measuring blood pressure with a sphygmomanometer, where is the stethoscope placed? a. beneath the radial artery b. above the brachial plexus c. over the ulnar d. over the brachial artery e. over the radial artery

Q: The maximum pressure exerted in the arteries is when blood is ejected into them during: a. inhalation b. exhalation c. exercise d. diastole e. systole

Q: What provides arteries with tensile strength? a. elastin fibers b. collagen fibers c. glucosamine d. smooth muscle e. valves

Q: What is the inner most layer of an artery made of? a. connective tissue b. smooth muscle c. endothelium d. elastin fibers e. collagen fibers

Q: Approximately how many arterioles are there in the average human body? a. 10,000 b. 50,000 c. 500,000 d. 5 million e. 10 billion

Q: The factors that affect flow rate through a vessel are integrated within what law? a. Poiseuille's law b. Pascal's law c. Cushing's law d. laws of thermodynamics e. law of gravity

Q: The major determinant of resistance to blood flow is the: a. percentage of red blood cells b. blood's pH level c. blood vessel's strength d. blood vessel's percentage of smooth muscle e. blood vessel's radius

Q: Flow rate of blood through a vessel is inversely proportional to: a. vascular resistance b. vascular gradient c. pressure gradient d. pressure back flow e. vessel strength

Q: What are the three blood reconditioning organs? a. large bowel, spleen, kidneys b. large bowel, spleen, skin c. stomach, kidneys, skin d. digestive organs, kidneys, skin e. digestive organs, spleen, bone marrow

Q: Why is a relatively large percentage of blood (in excess of need) sometimes directed to the skin? a. to eliminate wastes b. to eliminate heat c. to pick up nutrients d. to cleanse the blood e. to produce vitamin D

Q: Discuss the nutrient supply to the heart.

Q: Explain the ejection fraction in regards to the heart.

Q: Describe the normal sounds associated with heart valves.

Q: Describe the specialized types of cardiac muscle cells.

Q: Discuss the distinct layers within the heart.

Q: Which number in the figure represents the ST segment (ventricles are contracting and emptying)?a. 1b. 2c. 3d. 4e. 5f. 6

Q: Which number in the figure represents the PR segment (AV nodal delay)?a. 1b. 2c. 3d. 4e. 5f. 6

Q: Which number in the figure represents the T wave (ventricular repolarization)?a. 1b. 2c. 3d. 4e. 5f. 6

Q: Which number in the figure represents the P wave (atrial depolarization)?a. 1b. 2c. 3d. 4e. 5f. 6

Q: Which number in the figure represents the QRS complex (ventricular depolarization)?a. 1b. 2c. 3d. 4e. 5f. 6

Q: Further contributing to vessel narrowing, oxidized LDL inhibits release of __________ from the endothelial cells.

Q: People with elevated levels of __________, a blood-borne marker of inflammation, have a higher risk for developing coronary artery disease.

Q: Atherosclerosis is characterized by __________ forming beneath the vessel lining within arterial walls.

Q: Cardiac cells form and release more __________ when cardiac activity increases, which leads to vasodilation of the coronary vessels.

Q: The primary means by which more O2 can be made available to the heart muscle is by increasing __________ blood flow.

Q: Heart failure can be of two types: __________ HF, in which the heart has difficulty pumping blood out, or __________ HF, in which the heart has trouble filling.

Q: Specifically, as a cardiac muscle fiber is stretched as a result of greater ventricular filling, its __________ are pulled closer together side by side.

Q: Parasympathetic stimulation of the __________ contractile cells shortens the __________ phase of the action potential by reducing the slow inward current carried by Ca2+.

Q: The difference between the cardiac output at rest and the maximum volume of blood the heart can pump per minute is called the __________.

Q: The average resting HR is __________ beats per minute, established by __________ node rhythmicity.