Bio Study Guide Ch 21

Another name for the "pacemaker" of the heart is the: a. atrioventricular (AV) node b. sinoatrial (SA) node c. atrium d. ventricle

b

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: a. a change in the color of blood from its normal red to various shades of blue and purple b. a reduction in the blood's capacity to transport oxygen c. a delay in the time required for the blood to clot and a potential for extensive blood loss in the event of trauma d. a reduction in the concentration of white blood cells and an increased vulnerability to infection

b

The pulmonary _______ carries ________ blood from the heart to the lungs. a. vein; oxygen-rich b. artery; oxygen-rich c. vein; oxygen-poor d. artery; oxygen-poor

d

For a human to inhale, the rib muscles and the diaphragm must: a. contract, decreasing pressure inside the lungs b. relax, increasing pressure inside the lungs c. contract, increasing pressure inside the lungs d. relax, decreasing pressure inside the lungs

a

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 b. bronchi c. diaphragm d. tranchea

a

Large blood vessels that return deoxygenated blood from the legs to the heart are: a. veins b. capillaries c. arteries d. arteries and capillaries

a

Which component of whole blood would an investigator examine to determine the concentration of dissolved carbon dioxide of hormones, such as testosterone? a. the plasma b. the platelets c. the white blood cells d. the red blood cells

a

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

arteries; capillaries

The blood vessels that allow diffusion between blood and nearby blood cells are: a. veins b. capillaries c. arteries d. veins and capillaries

b

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

blood pressure

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

breathing

Blood leaving the right ventricle of the heart travels next to the: a. right atrium b. body c. lungs d. left ventricle

c

The thalamus is part of the ________ nervous system.

central

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

left ventricle

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

plasma

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

reabsorbed

Which of the following statements accurately describes the movement of water and waste within a nephron? a. water and waste both filter through the glomerulus; additional water is later secreted from capillaries b. water and waste both filter through the glomerulus; water is later reabsorbed from capillaries c. only waste filters through the glomerulus; water is secreted by capillaries along the length of the nephron d. only water filters through the glomerulus; waste is secreted by capillaries along the length of the nephron

b

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? a. secretion of toxins b. reabsorption of water and sugars c. filtration of plasma d. concentration of urine

c

The external signals and information that are received by an organism are called: a. sensory receptors b. dendrites c. stimuli d. nodes

c

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. a. carbon dioxide b. ions c. water d. hemoglobin

d

Sensory neurons that contain specialized membrane channels activated by moderate temperatures are: a. thermoreceptors b. chemoreceptors c. pain receptors d. electroreceptors

a

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 b. hypothalamus c. cerebrum d. cerebellum

a

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? a. hydrogen ions and toxins are reabsorbed by capillaries b. hydrogen ions and toxins are secreted from capillaries c. hydrogen ions and toxins are not filtered in nephrons d. hydrogen ions and toxins are stored in nephrons

b

The sensory receptor types that provide information about body position and balance to help you coordinate your dance moves are: a. chemoreceptors b. mechanoreceptors c. magnetoreceptors d. electroreceptors

b

The structures that carry signals away from the cell body of a neuron are called: a. dendrites b. axons c. nuclei d. synapses

b

Which of the following statements about the peripheral nervous system (PNS) is NOT true? a. the PNS may stimulate muscles b. the PNS may integrate and process information c. the PNS may inhibit endocrine cells d. the PNS may stimulate organs

b

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. a. cerebrum b. thalamus c. limbic system d. reticular formation

c

When blood arrives at an alveolus: a. the concentration of oxygen is lower in the alveolus than in the blood b. the concentration of carbon dioxide is higher in the alveolus than in the blood c. the concentration of carbon dioxide is higher in the blood than in the alveolus d. the concentration of carbon dioxide in the blood is equal to the concentration of oxygen in the alveolus

c

As you take this exam, which part of your brain is helping you decide which answer is correct? a. the cerebellum b. the pons b. the thalamus d. the cerebral cortex

d

Which of the following is a characteristic of an organ used for gas exchange? a. limited surface area b. waterproofing layers c. dry surfaces d. very thin tissues

d

Which of the following structures has the smallest diameter? a. the pharynx b. the trachea c. the bronchi d. the bronchioles

d

Why do humans rely on a circulatory system to distribute oxygen? a. diffusion does not occur in organisms that have more than about 300 cells b. humans do not need as much oxygen as small organisms do, so we use inefficient transport systems like the circulatory system rather than diffusion c. humans need an internal transport system in order to quickly replace oxygen that is lost because of our high surface area of skin d. diffusion is very slow over all but the shortest distances, so oxygen must be delivered to our cells to speed up the process

d

People with sickle-cell disease have deformed hemoglobin molecules and often suffer muscle pains, even at low levels of exertion. The symptoms might occur because the deformed hemoglobin: a. is unable to carry the amount of oxygen required for normal muscle activities b. cannot diffuse across the cells' membranes from the blood plasma c. causes damage to the muscle cells as it enters the muscle d. decreases the ratio of surface area to volume in a person's lungs

a

The branched structures on a nerve cell that receive information are called: a. dendrites b. axons c. neurons d. synapses

a

When eating dessert, you notice the sweetness of sugar when ________ are stimulated. a. chemoreceptors b. photoreceptors c. thermoreceptors d. mechanoreceptors

a

Which of the following features could be found in a vein, but NOT in an artery? a. a one-way valve b. muscle c. oxygen-rich blood d. blood that is under high pressure

a

Which of the following functions occurs in the urinary bladder but NOT in nephrons? a. urine storage b. filtration c. secretion d. reabsorption

a

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 b. pharynx to bronchiole to bronchus to trachea to alveolus c. pharynx to trachea to bronchiole to bronchus to alveolus d. pharynx to bronchus to bronchiole to trachea to alveolus

a

Which of the following things happens during inhalation? a. oxygen-rich air enters the aveoli b. lung volume decreases c. pressure in the lungs remains constant d. the diaphragm relaxes

a

The concentration of oxygen in blood plasma near an alveolus is lowered when: a. nearby red blood cells release carbon dioxide b. oxygen diffuses into red blood cells and binds to hemoglobin c. carbon dioxide diffuses into the alveolus d. oxygen diffuses into the alveolus

b

A newborn is diagnosed shortly after birth with a rare hear 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? a. oxygen-poor and oxygen-rich blood would mix b. blood would flow through the body in more than one direction c. body cells would receive less oxygen-rich blood than normal d. blood flow from the left ventricle to the body would increase

c

Air that is entering the lungs has: a. a higher concentration of carbon dioxide than air in an alveolus b. a higher concentration of both carbon dioxide and oxygen than air in an alveolus c. a higher concentration of oxygen and a lower concentration of carbon dioxide than air in an alveolus d. a lower concentration of oxygen but the same concentration of carbon dioxide as air in an alveolus

c

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? a. it enables capillaries to conserve the blood's pressure gradient so that enough pressure remains to return the blood to the heart b. it provides the time needed for white blood cells to capture any bloodborne pathogens that might be present c. it ensures that the blood has enough time to exchange material with the surrounding cells d. it decreases the probability of frictional scarring on the capillary wall and the subsequent development of atherosclerosis

c

If you were to step on a nail with your right foot, which of the following things would NOT happen? a. sensory input from your right foot would be processed in your central nervous system b. motor output would travel to both of your legs; your right foot would be raised and your left leg would stiffen to prevent you from falling over c. motor output from your right leg would be interpreted by your brain as sensory input d. the thalamus would filter and sort the sensory input that is entering your brain

c

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? a. the left side of the heart has one large chamber, whereas the right side has two chambers b. the right side of the heart has 3 chambers, whereas the left side has 2 chambers b. the left side of the heart has a thicker muscular wall than the right side d. the right side of the heart has a thicker muscular wall than the left side

c

Which of the following does NOT facilitate exchange of materials by diffusion? a. cells lying within 0.03 millimeters of blood vessels b. a large surface area within alveoli c. the presence of the extracellular matrix within connective tissue d. thin, porous walls in capillaries

c

Which of the following sensory receptor types is NOT found in humans? a. chemoreceptors b. mechanoreceptors c. magnetoreceptors d. thermoreceptors

c

Which of the following statements about hemoglobin is true? a. hemoglobin is an enzyme involved in the process of cellular respiration b. hemoglobin transports oxygen from cells that are undergoing cellular respiration to red blood cells c. hemoglobin binds to oxygen and releases it near cells that are performing cellular respiration d. hemoglobin makes the blood more acidic, enabling it to absorb more oxygen

c

At high altitudes, gases are less concentrated. You might gasp for air, because: a. the surface area of your lungs will be decreased b. the amount of hemoglobin in your blood will decrease c. hemoglobin will not be able to bind to oxygen as well at a higher altitude d. the amount of oxygen that could diffuse into your blood will be decreased

d

The ________ of a neuron contain(s) all of the structures, such as a nucleus, that are common to animal cells. a. dendrites b. axons c. synapses d. cell body

d

The breaking open of alveoli in people who have emphysema decreases their rate of gas exchange because: a. there is a decrease in the distance between the air they breathe in and their blood b. there is less pressure in the lungs to force the oxygen to dissolve in their blood c. the concentration of oxygen in their lungs becomes much greater than the concentration of oxygen in their blood d. their lungs have less surface area are available for diffusion

d

Which of the following processes is NOT a function of nephrons? a. filtration of plasma b. reabsorption of water c. secretion of some toxins d. diffusion of oxygen into body cells

d

Which of the following sequences correctly describes the pathway that a signal travels in a neuron? a. cell body to axon to dendrite b. axon to dendrite to cell body c. dendrite to axon to cell body d. dendrite to cell body to oxygen

d

Gases move from an area of _______ concentration to an area of _________ concentration.

high; low

Receptors in the eye that provide vision are called __________.

photoreceptors