The Cardiovascular and Lymphatic Systems 12 The Cardiovascular and Lymphatic Systems 1

1. ____ bring oxygenated, nutrient-rich blood to skeletal muscles, while ____ drain waste-ridden blood away from them. Venules; veins Arteries; veins Veins; arteries Veins; arterioles B. Arteries; veins

1. ____ bring oxygenated, nutrient-rich blood to skeletal muscles, while ____ drain waste-ridden blood away from them. Answer: b. Arteries; veins Explanation: Arteries carry nutrient-rich, oxygenated blood toward organs. After gas exchange in the organs, veins carry deoxygenated, waste-ridden blood away from the organs.

2. Which is the smallest blood vessel? Arteriole Artery Capillary Vein C. Capillary

2. Which is the smallest blood vessel? Answer: c. Capillary Explanation: Capillaries are microscopic blood vessels that connect arterioles and venules. Their walls are only one cell layer thick.

3. The slits between capillary endothelial cells allow ____ to pass through. white blood cells nutrient-rich fluid dissolved hormones All of the above D. All of the above

3. The slits between capillary endothelial cells allow ____ to pass through. Answer: d. All of the above Explanation: Nutrients and hormones travel in the blood dissolved in plasma. Water and white blood cells leave the bloodstream in the capillaries, and one way they traverse the capillary wall is through the slits.

4. Blood flow through a capillary bed is regulated by precapillary sphincters in response to ____. the metabolic needs of the tissue stimulus from the parasympathetic nervous system elevated blood pressure the P wave of the ECG A. the metabolic needs of the tissue

4. Blood flow through a capillary bed is regulated by precapillary sphincters in response to ____. Answer: a. the metabolic needs of the tissue Explanation: Precapillary sphincters are bands of smooth muscle tissue surrounding capillaries. The sphincters open and close in response to the metabolic needs of the local tissues.

5. One of the main forces pushing blood through veins back toward the heart is ____. blood pressure osmotic pressure skeletal muscle contractions heart contractions C. skeletal muscle contractions

5. One of the main forces pushing blood through veins back toward the heart is ____. Answer: c. skeletal muscle contractions Explanation: Heart contractions cause blood pressure, which has dissipated greatly by the time blood enters the veins. Osmotic pressure draws fluid into a solution by osmosis. Skeletal muscle contractions squeeze blood through the veins.

6. The thick fibrous sac that encloses the heart is called the ____. pericardium endocardium endothelium septum A. pericardium

6. The thick fibrous sac that encloses the heart is called the ____. Answer: a. pericardium Explanation: The pericardium anchors the heart in the center of the chest without compromising movements of the heart during contraction and relaxation.

7. The valves between the atria and ventricles are called ____ valves, while the valves that guard exits from the heart are called ____ valves. semilunar; atrioventricular atrioventricular; semilunar bicuspid; tricuspid atrial; ventricular B. atrioventricular; semilunar

7. The valves between the atria and ventricles are called ____ valves, while the valves that guard exits from the heart are called ____ valves. Answer: b. atrioventricular; semilunar Explanation: The bicuspid and tricuspid valves are atrioventricular valves. The pulmonary and aortic valves are semilunar valves.

8. Heart sounds result from ____. closing of the heart valves contraction of the ventricles expansion and elastic recoil of arteries flow of blood as it enters the heart A. closing of the heart valves

8. Heart sounds result from ____. Answer: a. closing of the heart valves Explanation: The characteristic sounds of the heart are associated with the closing of the valves. The first sound is produced when the AV valves shut, and the second heart sound results from the closure of the semilunar valves.

9. Which of the following contains blood with the highest oxygen content? Capillaries in the tissues Pulmonary artery Pulmonary vein Superior vena cava C. Pulmonary vein

9. Which of the following contains blood with the highest oxygen content? Answer: c. Pulmonary vein Explanation: The pulmonary vein carries blood from the lungs to the heart. Blood receives oxygen in the lungs and will contain more oxygen there than at any other time.

10. Which type of blood vessel plays the most important role in regulating blood pressure? Veins Venules Arterioles Capillaries C. Arterioles

10. Which type of blood vessel plays the most important role in regulating blood pressure? Answer: c. Arterioles Explanation: Arterioles have a thick middle layer of smooth muscle. When the arterioles constrict, blood pressure increases. Relaxation of the smooth muscle wall of arterioles lowers blood pressure.

11. An embolus that lodges in a coronary artery can cause a condition called a(n) ____. cerebrovascular accident myocardial infarction angioplasty angiogram B. myocardial infarction

11. An embolus that lodges in a coronary artery can cause a condition called a(n) ____. Answer: b. myocardial infarction Explanation: A traveling blood clot, or embolus, that lodges in a coronary artery blocks blood flow to the myocardium. This is called a myocardial infarction (“cell death”). An angiogram is an imaging test that uses x-rays to view the body’s blood vessels. Angioplasty is a treatment for Acute Myocardial Infarction. A stroke, or cerebrovascular accident (CVA), is the rapid loss of brain function(s) due to disturbance in the blood supply to the brain.

12. Which of these most correctly traces the path of blood from the heart to a kidney and back to the heart again? Left ventricle, inferior vena cava, renal vein, kidney, renal artery, aorta, right atrium Right atrium, aorta, renal artery, kidney, renal vein, superior vena cava, left atrium Left ventricle, renal artery, kidney, renal vein, superior vena cava, right atrium Left ventricle, aorta, renal artery, kidney, renal vein, inferior vena cava, right atrium D. Left ventricle, aorta, renal artery, kidney, renal vein, inferior vena cava, right atrium

12. Which of these most correctly traces the path of blood from the heart to a kidney and back to the heart again? Answer: d. Left ventricle, aorta, renal artery, kidney, renal vein, inferior vena cava, right atrium Explanation: From the left ventricle, blood flows through the aorta to the renal artery, through the kidney and out the renal vein. The renal vein empties into the inferior vena cava, which enters the heart in the right atrium.

13. What does the QRS wave of an ECG represent? Atrial systole Generation of a signal by the SA node Spread of the electrical signal over the ventricles Spread of the electrical signal through the intercalated disks of the atria C. Spread of the electrical signal over the ventricles

13. What does the QRS wave of an ECG represent? Answer: c. Spread of the electrical signal over the ventricles Explanation: The P wave of an ECG indicates the spread of the electrical signal from the SA node through the atria. The QRS wave reflects the spread of the signal throughout the ventricles.

14. True or false? The spleen and lymph nodes have similar functions; they both filter blood of old, worn-out red blood cells, platelets, and microbes. True False B. False

14. True or false? The spleen and lymph nodes have similar functions; they both filter blood of old, worn-out red blood cells, platelets, and microbes. Answer: b. False Explanation: The spleen filters blood, while lymph nodes filter lymph.

15. Which of the following is a function of the lymphatic system? Transport nutrients Defend against disease Provide a mechanism for the spread of cancer cells Transport red blood cells B. Defend against disease

15. Which of the following is a function of the lymphatic system? Answer: b. Defend against disease Explanation: The lymphatic system functions to return excess tissue fluid to the bloodstream, transport products of fat digestion from the small intestine to the bloodstream, and help defend against disease-causing organisms.

16. Which of the following help move lymph through the lymphatic vessels? Contraction of skeletal muscle Presence of one-way valves Pressure changes in the thorax All of the above D. All of the above

16. Which of the following help move lymph through the lymphatic vessels? Answer: d. All of the above Explanation: With no pump to propel it, lymph moves through lymphatic vessels driven by the same mechanisms that move blood through veins—contraction of skeletal muscle, one-way valves, and the pressure changes in the chest cavity during respiration.

17. Which of the following lymphatic organs functions in the maturation of T lymphocytes during childhood? Spleen Tonsils Thymus Peyer’s patches C. Thymus

17. Which of the following lymphatic organs functions in the maturation of T lymphocytes during childhood? Answer: c. Thymus Explanation: The thymus functions during early childhood to help T lymphocytes mature to protect us from specific disease-causing organisms.