ch.21 plzzz get a C in bio

42. When eating dessert, you notice the sweetness of sugar when ________ are stimulated.

a. chemoreceptors

8. Which of the following statements about hemoglobin is true?

c. Hemoglobin binds to oxygen and releases it near cells that are performing cellular respiration.

10. The figure shown indicates the ________ of a neuron.

cell body

9. Receptors in the eye that provide vision are called ________.

photoreceptors

19. For a human to inhale, the rib muscles and the diaphragm must

a. contract, decreasing pressure inside the lungs.

4. Blood vessels that are designed to carry blood under high pressure are called ________. Blood vessels that have thin, porous walls are called ________.

arteries;capillaries

26. The concentration of oxygen in blood plasma near an alveolus is lowered when

b. oxygen diffuses into red blood cells and binds to hemoglobin.

2. Another name for the "pacemaker" of the heart is the

b. sinoatrial (SA) node.

2. The force of blood pushing against the walls of blood vessels is called ________.

blood pressure

17. Blood flows rapidly within the arterial system but slows dramatically as it enters the capillaries. What is the benefit of having blood move slowly through the capillaries?

c. It ensures that the blood has enough time to exchange material with the surrounding cells.

38. If you were to step on a nail with your right foot, which of the following things would NOT happen?

c. Motor output from your right leg would be interpreted by your brain as sensory input.

3. One side of the heart pumps blood into the pulmonary circuit, and the other side of the heart pumps blood to the systemic circuit. How do these different functions affect the structure of the heart?

c. The left side of the heart has a thicker muscular wall than the right side.

4. Which of the following does NOT facilitate exchange of materials by diffusion?

c. the presence of the extracellular matrix within connective tissue

11. Why do humans rely on a circulatory system to distribute oxygen?

d. Diffusion is very slow over all but the shortest distances, so oxygen must be delivered to our cells to speed up the process.

7. The liquid portion of human blood cannot absorb enough oxygen to meet the body's demands. However, ________ in our red blood cells greatly increase(s) the oxygen-carrying capacity of human blood.

d. hemoglobin

10. At high altitudes, gases are less concentrated. You might gasp for air, because

d. the amount of oxygen that could diffuse into your blood will be decreased.

22. Which of the following structures has the smallest diameter?

d. the bronchioles

34. As you take this exam, which part of your brain is helping you decide which answer is correct?

d. the cerebral cortex

25. The breaking open of alveoli in people who have emphysema decreases their rate of gas exchange because

d. their lungs have less surface area available for diffusion.

18. The structure that is highlighted in this figure is the

d. trachea.

27. Which of the following is a characteristic of an organ used for gas exchange?

d. very thin tissues

6. Gases move from an area of ________ concentration to an area of ________ concentration.

higher; lower

21. Which of the following things happens during inhalation?

a. Oxygen-rich air enters the alveoli.

13. Which of the following features could be found in a vein, but NOT in an artery?

a. a one-way valve

24. In cystic fibrosis, parts of the respiratory tract can become clogged with mucus, inhibiting gas exchange. The area(s) of the respiratory tract where gases are directly exchanged is/are the

a. alveoli.

44. The branched structures on a nerve cell that receive information are called

a. dendrites.

9. People with sickle-cell disease have deformed hemoglobin molecules and often suffer muscle pains, even at low levels of exertion. These symptoms might occur because the deformed hemoglobin

a. is unable to carry the amount of oxygen required for normal muscle activities.

20. Which of the following sequences correctly describes the journey of a molecule of oxygen from the pharynx to an alveolus?

a. pharynx to trachea to bronchus to bronchiole to alveolus

36. You accidentally rest your hand on a hot stove. This sensory information will ultimately be relayed to the appropriate part of your brain by the

a. thalamus.

12. Which component of whole blood would an investigator examine to determine the concentration of dissolved carbon dioxide or hormones, such as testosterone?

a. the plasma

41. Sensory neurons that contain specialized membrane channels activated by moderate temperatures are

a. thermoreceptors.

32. Which of the following functions occurs in the urinary bladder but NOT in nephrons?

a. urine storage

14. Large blood vessels that return deoxygenated blood from the legs to the heart are

a. veins.

30. If you were to compare the filtrate that is leaving the glomerulus to urine that is exiting the body, you would find that some substances — such as hydrogen ions and toxins — are more concentrated in the urine. Which of the following statements explains this process?

b. Hydrogen ions and toxins are secreted from capillaries.

35. Which of the following statements about the peripheral nervous system (PNS) is NOT true?

b. The PNS may integrate and process information.

29. Which of the following statements accurately describes the movement of water and waste within a nephron?

b. Water and waste both filter through the glomerulus; water is later reabsorbed from capillaries.

5. Shortages of iron in our diet can cause iron deficiency anemia, a condition that reduces the amount of hemoglobin in red blood cells. Iron deficiency anemia is a potentially serious condition that is characterized primarily by

b. a reduction in the blood's capacity to transport oxygen.

46. The structures that carry signals away from the cell body of a neuron are called

b. axons.

15. The blood vessels that allow diffusion between blood and nearby body cells are

b. capillaries.

40. The sensory receptor types that provide information about body position and balance to help you coordinate your dance moves are

b. mechanoreceptors.

5. ________ is the process of expelling carbon dioxide from the lungs and taking oxygen into the lungs.

breathing

6. A newborn is diagnosed shortly after birth with a rare heart defect that prevented the valve between the left atrium and the left ventricle from fully forming. Which of the following would be an expected outcome of this defect?

c. Body cells would receive less oxygen-rich blood than normal.

23. Air that is entering the lungs has

c. a higher concentration of oxygen and a lower concentration of carbon dioxide than air in an alveolus.

31. If the glomerulus remained intact but other capillaries were not in close physical contact with nephrons, which of the following functions would NOT be lost?

c. filtration of plasma

37. As you are driving to school one morning, the driver in front of you suddenly slams on his brakes and turns right without using his turning signal. Despite the potentially irritating situation, you remain calm because your ________ helped you control your emotions.

c. limbic system

1. Blood leaving the right ventricle of the heart travels next to the

c. lungs.

39. Which of the following sensory receptor types is NOT found in humans?

c. magnetoreceptors

43. The external signals and information that are received by an organism are called

c. stimuli.

28. When blood arrives at an alveolus,

c. the concentration of carbon dioxide is higher in the blood than in the alveolus.

8. The thalamus is part of the ________ nervous system.

central

16. The pulmonary ________ carries ________ blood from the heart to the lungs.

d. artery; oxygen-poor

48. The figure shown indicates a(n)

d. axon.

47. The ________ of a neuron contain(s) all of the structures, such as a nucleus, that are common to animal cells.

d. cell body.

45. Which of the following sequences correctly describes the pathway that a signal travels in a neuron?

d. dendrite to cell body to axon

33. Which of the following processes is NOT a function of nephrons?

d. diffusion of oxygen into body cells

1. When the ________ of the heart contracts, blood is pumped into the systemic circuit.

left ventricle

3. The majority of carbon dioxide is carried in the blood component called ________.

plasma

7. Valuable solutes, such as sugar and small proteins, that enter a nephron are ________ by capillaries.

reabsorbed