1 Which of these is not a function of the circulatory system?A) removing wastes B) transporting blood C) conducting neuron impulses D) delivering oxygen 2 What are the three major types of blood vessels?A) arteries, valves, arterioles B) arteries, veins, capillaries C) veins, arterioles, capillaries D) capillaries, arterioles, valves 3 Which part of the vessels shown here prevents blood from flowing backwards? (24.0K)
A) smooth muscle B) endothelium C) connective tissue D) valve 4 The heart pumps ____ blood to the lungs.A) deoxygenated B) oxygenated C) oxygen-rich D) depressurized 5 Which of these three vessels carries blood back to the heart? (21.0K)
A) artery; largest cross section B) vein, medium sized cross section C) capillary; smallest cross section D) none of these 6 Where does oxygenated blood flow to first in this circulatory loop? (13.0K)
A) to the pulmonary artery leading to the lungs B) to the right ventricle from the lungs C) to the left atrium from the lungs D) to the vein leading away from the body 7 How does atherosclerosis cause health problems?A) clogged arteries decrease blood pressure B) clogged arteries put stress on heart C) clogged veins decrease blood pressure D) clogged veins increase blood volume 8 Which structure sends the initial signal for the heart to contract? (18.0K)
A) SA node B) AV node C) excitable fibers D) atrium 9 Why is the endothelial layer of arteries thicker than that of other blood vessels?A) Arteries must be rigid and inflexible. B) Arteries carry blood back to the heart. C) Artery blood exerts less pressure than blood in veins. D) Blood pumped from the heart exerts a high pressure. 10 What crucial cell function is oxygen necessary for?A) DNA sequencing B) external respiration C) osmosis D) cellular respiration 11 Individual air sacs in lung bronchioles are called ____.A) tracheas B) alveoli C) capillaries D) cilia 12 What activity would prevent venous blood clots in bedridden hospital patients?A) putting ice on legs B) keeping legs and feet perfectly still C) moving feet up and down in bed D) keeping legs uncovered 13 The ____ maintain homeostasis by removing wastes and excess water.A) dendrites B) lungs C) urethras D) kidneys 14 What process allows lost water, glucose, and minerals to reenter the capillaries around the renal tubule?A) acid-base balance B) reabsorption C) homeostasis D) respiration 15 What important structure consists of the parts shown here? (49.0K)
A) renal artery B) renal cortex C) nephron D) renal pelvis