East Los Angeles College » Physiology » Physiology 001 - Introduction to Human Physiology » Summer 2021

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Question #1

Which of the following most accurately describes the renal transport of Na+?

A. Most of the Na+ transport occurs in the distal convoluted tubule and collecting ducts.

B. Primary active transport of Na+ allows for secondary active transport of glucose and H+ in the proximal tubule.

C. Na+ is actively secreted into the nephron lumen by cells in the cortical collecting ducts.

D. Na+ is actively transported in all segments of the tubule.

E. Na+ is actively transported across the luminal membrane of proximal tubule cells in exchange for K+, by Na+/K+ ATPase pumps.

Question #2

Which is TRUE regarding renal tubular reabsorption?

A. Reabsorption of Na+ only occurs from nephron regions that come after the descending limb of the loop of Henle.

B. Urea reabsorption cannot occur at any point along the nephron.

C. Reabsorption of glucose saturates at a maximum transport rate.

D. Reabsorption of Na+ from the proximal tubule occurs as a result of water reabsorption.

E. Toxic substances are removed from the body by reabsorption from peritubular capillaries into the proximal tubule.

Question #3

Carbonic anhydrase catalyzes a reaction that combines which of the following?

A. H2O and O2

B. H+ and HCO3-

C. H2O and CO

D. CO2 and O2

E. H2O and CO2

Question #4

What is the primary regulator of the magnitude of alveolar ventilation under normal circumstances?

A. The H+ concentration in the arterial blood, which is monitored by central chemoreceptors

B. The H+ concentration in the brain extracellular fluid, which is monitored by central chemoreceptors

C. The PO2 of the arterial blood, which is monitored by central chemoreceptors

D. Stretch receptors in the lung

E. The PO2 of the arterial blood, which is monitored by peripheral chemoreceptors

Question #5

You (a healthy individual) are swimming underwater when you can no longer resist the urge to breathe. This overwhelming urge is probably due to

A. the decrease in O2 available to the cells of the body.

B. the autorhymthic cells in your diaphragm contracting.

C. the increase in plasma H+.

D. the increase in pH has made your blood dangerously alkaline.

Question #6

In which region of the nephron does the fractional reabsorption of water vary the most in response to variation in the state of hydration?

A. The loop of Henle

B. The proximal convoluted tubule

C. The collecting duct

D. The glomerulus

E. The distal convoluted tubule

Question #7

How does the renal countercurrent multiplier mechanism allow the creation of a concentrated urine?

A. By pumping NaCl and urea into the ascending limb of the loop of Henle, it raises the solute load, which turns into a concentrated urine once water is extracted from the collecting duct.

B. When anti-diuretic hormone is present, it stimulates the pumping of NaCl from the medullary interstitial fluid and water follows, concentrating the urine.

C. It transports NaCl from the medullary interstitial fluid into the collecting duct, which directly increases the osmolarity of the urine.

D. It transports urea from the medullary interstitial fluid into the collecting duct, which directly increases the osmolarity of the urine.

E. By concentrating NaCl in the renal medullary interstitial fluid, it allows water to be reabsorbed from the collecting ducts when vasopressin is present.

Question #8

The amount of a substance that is excreted in the urine is equal to the amount that is ________ plus the amount that is ________ minus the amount that is ________.

A. reabsorbed; secreted; filtered

B. filtered; secreted; reabsorbed

C. reabsorbed; filtered; secreted

D. filtered; reabsorbed; secreted

E. secreted; reabsorbed; filtered

Question #9

Which of the following drugs, administered as an aerosol spray, would be most likely to help a patient during an asthmatic attack?

A. A muscarinic agonist

B. Histamine

C. Pulmonary surfactant

D. A β2-adrenergic agonist

E. A β2-adrenergic antagonist

Question #10

Which one of the following substances is LEAST dependent on the kidney for regulation of its plasma concentration?

A. Water

B. Na+

C. HPO42-

D. Glucose

E. K+

Question #11

Constriction of the ________ decreases hydrostatic pressure in ________.

A. efferent arterioles; proximal convoluted tubules

B. renal vein; peritubular capillaries

C. afferent arterioles; glomerular capillaries

D. efferent arterioles; glomerular capillaries

E. efferent arterioles; Bowman's capsule

Question #12

Which of these is demonstrated by the oxygen-hemoglobin dissociation curve?

A. As PO2 increases, the saturation of hemoglobin with oxygen increases linearly.

B. The greater the PO2 of the blood, the greater the dissociation of O2 from hemoglobin.

C. At normal resting systemic arterial PO2, hemoglobin is almost 100% saturated with oxygen.

D. At normal resting systemic venous PO2, only about 75% of the hemoglobin is in the form of deoxyhemoglobin.

E. More additional oxygen binds to hemoglobin when going from a PO2 of 60 to 100 mmHg, than is added when going from a PO2 of 40 to 60 mmHg.

Question #13

Which of the following most accurately describes the actions of aldosterone?

A. Aldosterone decreases Na+ reabsorption and K+ secretion in the cortical collecting ducts.

B. Aldosterone increases Na+ reabsorption and K+ secretion in the proximal tubule.

C. Aldosterone increases Na+ reabsorption and K+ secretion in the cortical collecting ducts.

D. Aldosterone increases Na+ secretion and K+ reabsorption in the cortical collecting ducts.

E. Aldosterone increases Na+ secretion and K+ reabsorption in the proximal tubule.

Question #14

In the presence of aldosterone, which nephron region reabsorbs the greatest fraction of the filtered Na+?

A. Cortical collecting duct

B. Distal convoluted tubule

C. Proximal tubule

D. Macula densa

E. Descending limb of the loop of Henle

Question #15

Which is TRUE about the hormone vasopressin (also known as antidiuretic hormone, ADH)?

A. It triggers insertion of aquaporins into the apical membranes of collecting duct cells.

B. It promotes the excretion of more water in the urine.

C. It stimulates the excretion of K+ in the urine.

D. It is a peptide hormone released from the adrenal gland.

E. Its main function is to trigger the secretion of aldosterone.

Question #16

Under normal circumstances, which of the following would result from an increase in transpulmonary pressure?

A. Exhalation/expiration

B. Pneumothorax

C. Inhalation/inspiration

D. Emphysema

E. A collapsed lung

Question #17

A. A drug that enhances the activity of angiotensin-converting enzyme

B. A drug that decreases sympathetic stimulation of renal arterioles

C. A drug that decreases liver production of angiotensinogen

D. A drug that interferes with aldosterone synthesis

E. A drug that is an agonist of atrial natriuretic factor

Question #18

After CO2 is produced by tissues, in what form is most of that carbon transported to the lungs for removal from the body?

A. As dissolved HCO3-

B. As carbonic anhydrase

C. As H2CO3

D. As dissolved CO2

E. Bound to hemoglobin

Question #19

During a run, your gastrocnemius (calf) muscle has a temperature of 38.5° C, while your biceps brachii (upper arm) muscle has a temperature of 37.5° C. Which of the following is TRUE of the red blood cells as they pass by these muscles?

A. The hemoglobin molecules will have a higher affinity for oxygen as they pass by the biceps brachii compared to the gastrocnemius.

B. The hemoglobin molecules will have the same affinity for oxygen at both locations.

C. The hemoglobin molecules may denature as they pass by the gastrocnemius.

D. The hemoglobin molecules will have a higher affinity for oxygen as they pass by the gastrocnemius compared to the biceps brachii.

Question #20

You walk into your dorm room and find your roommate in the midst of anxiety-induced hyperventilation. You're unable to calm her down, so you call an ambulance. When she arrives at the ER, which of the following is her likely diagnosis?

A. Respiratory acidosis

B. Respiratory alkalosis

C. Increased blood PCO2

D. Metabolic alkalosis

E. Metabolic acidosis

Question #21

What is one function of the type II alveolar cells?

A. Phagocytizing bacteria and other foreign particles

B. Production of surfactant

C. Make up the majority of the epithelial wall of the alveoli

D. Lining the pleural space

E. Secretion of mucus

Question #22

What is the rate-limiting (regulated) step for stimulating the secretion of aldosterone?

A. Conversion of angiotensinogen to angiotensin I in the blood

B. Secretion of ACTH by the anterior pituitary

C. Conversion of angiotensin I to angiotensin II in the blood

D. Secretion of angiotensin II by the kidney

E. Secretion of angiotensinogen by the liver

Question #23

In the condition diabetes mellitus, why does glucose appear in the urine?

A. The filtered load of glucose becomes greater than the tubular maximum for its reabsorption.

B. The plasma concentration of glucose becomes so high that it diffuses from peritubular capillaries into the proximal tubule, down its concentration gradient.

C. Without insulin, the glomerular filtration barrier becomes extremely leaky to glucose, which is not normally filterable.

D. The rate of tubular secretion of glucose becomes greater than the sum of glucose filtration and reabsorption.

E. Without the hormone insulin, glucose cannot enter proximal tubule epithelial cells.

Question #24

Which of the following would cause a decrease in the binding affinity of hemoglobin for oxygen?

A. Decreased DPG levels in erythrocytes

B. The presence of carbon monoxide

C. Increased pH of the blood

D. Decreased concentration of H+ in the blood

E. Increased temperature of the blood

Question #25

Yolanda was born with a rare genetic disease in which the proximal tubules of her nephrons express half the number of aquaporins as is typical. What will be the result?

A. Reduced reabsorption of both water and Na+ in equal proportions

B. Reduced reabsorption of water, although as much reabsorption of Na+ as is typical

C. Reduced reabsorption of all materials in the proximal tubules

D. Reduced reabsorption of water, Na+, and glucose in the proximal tubules

E. No change to reabsorption at this site

Question #26

Under what condition is lung compliance increased?

A. Prolonged shallow breathing

B. Emphysema

C. Asthma

D. Cystic fibrosis

E. Respiratory distress syndrome of the newborn

Question #27

Which of the following organs is the main site of aldosterone secretion?

A. Kidneys

B. Liver

C. Systemic and pulmonary blood vessels

D. Adrenal glands

E. The atria of the heart

Question #28

Water and NaCl reabsorbed from the loop of Henle directly reenter which blood vessels?

A. Afferent arterioles

B. Vasa recta

C. Collecting ducts

D. Efferent arterioles

E. Cortical peritubular capillaries

Question #29

After prolonged exertion in a hot climate, baroreceptors would ________ firing, leading to ________ secretion of ________ and thus ________ renal reabsorption of ________.

A. increase; increased; renin; increased; Na+

B. decrease; increased; renin; decreased; Na+

C. decrease; increased; vasopressin; increased; water

D. decrease; decreased; vasopressin; increased; water

E. increase; decreased; vasopressin; decreased; water

Question #30

Compared to the normal plasma osmolarity, the tubular fluid is ________ as it enters Bowman's space, ________ at the beginning of the loop of Henle, ________ at the tip of the loop, and ________ at the beginning of the distal convoluted tubule.

A. isosmotic; isosmotic; hyperosmotic; isosmotic

B. isosmotic; isosmotic; hypoosmotic; hyperosmotic

C. isosmotic; isosmotic; hyperosmotic; hypoosmotic

D. isosmotic; isosmotic; hypoosmotic; hypoosmotic

E. isosmotic; hyperosmotic; hyperosmotic; isosmotic

Question #31

In what segment of the nephron is the greatest fraction of filtered water reabsorbed?

A. The proximal tubule

B. The distal convoluted tubule

C. The descending limb of the loop of Henle

D. The ascending limb of the loop of Henle

E. The collecting ducts

Question #32

What region of the nephron reabsorbs about two-thirds of filtered Na+ and Cl-?

A. Distal convoluted tubule

B. Proximal convoluted tubule

C. Ascending loop of Henle

D. Glomerulus

E. Collecting duct

Question #33

Which of the following statements concerning the process of glomerular filtration is correct?

A. All of the plasma that enters the glomerular capillaries is filtered.

B. The osmotic force due to plasma proteins favors filtration.

C. The hydrostatic pressure in glomerular capillaries opposes filtration.

D. The hydrostatic pressure in Bowman's space opposes filtration.

E. The glomerular filtration rate is limited by a transport maximum.

Question #34

In which form is most of the oxygen carried in arterial blood?

A. Dissolved in the cytosol of erythrocytes

B. Dissolved in the plasma

C. Bound to hemoglobin

D. Bound to myoglobin

E. Converted to HCO3-

Question #35

During a yoga class you take a deep breath, then relax and let the breath out slowly. During that exhalation, which would NOT be true?

A. Alveolar pressure is greater than atmospheric pressure.

B. Intrapleural pressure becomes less negative.

C. The diaphragm relaxes.

D. Intrapleural pressure is greater than alveolar pressure.

F. Lung volume decreases.

Question #36

Which is normally TRUE about the intrapleural pressure?

A. It is between +5 and +10 mmHg above atmospheric pressure at functional residual capacity.

B. It is lower than alveolar pressure.

C. It alternates between being less than, and greater than, atmospheric pressure.

D. It is always the same as atmospheric pressure during a passive exhale.

E. During a passive exhale, it increases to a value above atmospheric pressure.

Question #37

Which of the following is a cause of asthma?

A. Lack of pulmonary surfactant

B. Environmental chemicals that stimulate β2-adrenergic receptors

C. Inflammation of the bronchioles

D. Elevation of intrapleural pressure to equal atmospheric pressure

E. Loss of alveoli

Question #38

You have a patient with extensive birth defects that affect the kidney anatomy. Nevertheless, she does have some kidney function. One thing you've noticed in her labs is extremely low renin secretion. Which of the following anatomical locations is likely to exhibit abnormal development?

A. The efferent arteriole

B. The glomerular capillaries

C. The proximal tubule

D. The ascending limb of the loop of Henle

E. The juxtaglomerular apparatus

Question #39

Type II alveolar cells are among the last cells to mature during fetal development. In babies born prematurely, type II alveolar cells are often not ready to perform their function. Which of the following would be TRUE of these babies?

A. They would be at risk of autoimmune diseases with lung complications.

B. They would be at risk of alveolar collapse due to too much surface tension in the alveoli.

C. They would be at risk of bacterial infections in the lungs.

D. They would be more likely to have coughing fits.

E. None of these would occur.

Question #40

When blood Ca2+ levels fall below normal, in what ways do the kidneys help restore them toward normal?

A. By decreasing 1,25-dihydroxyvitamin D3 formation, increasing tubular phosphate reabsorption, and increasing tubular Ca2+ reabsorption

B. Increasing 1,25-dihydroxyvitamin D3 formation and increasing secretion of parathyroid hormone

C. By increasing 1,25-dihydroxyvitamin D3 formation, decreasing tubular phosphate reabsorption, and increasing tubular Ca2+ reabsorption

D. By increasing renal secretion of parathyroid hormone and increasing bone resorption

E. By increasing 1,25-dihydroxyvitamin D3 formation, increasing tubular phosphate reabsorption, and increasing tubular Ca2+ reabsorption

Question #41

Which of these correctly describes the chloride shift?

A. In the tissues, chloride exits red blood cells in exchange for carbonic acid.

B. In the tissues, chloride enters red blood cells in exchange for bicarbonate ions.

C. In the lungs, chloride enters red blood cells in exchange for bicarbonate ions.

D. In the tissues, chloride enters red blood cells in exchange for CO2.

E. In the lungs, chloride enters red blood cells in exchange for CO2.

Question #42

You are an EMT and arrive at the scene of an opioid overdose. The overdose victim is breathing extremely slowly and shallowly. When you arrive at the ER, you report that the medical team should watch out for signs of

A. respiratory alkalosis.

B. respiratory acidosis.

C. metabolic acidosis.

D. metabolic alkalosis.

Question #43

Which of the following statements about renal control of blood acid-base balance is TRUE?

A. When hypoventilation occurs at the lungs, the kidneys compensate by reducing glutamine metabolism.

B. Excretion in the urine of hydrogen bound to phosphate buffers decreases plasma bicarbonate concentration.

C. H+ that binds to filtered bicarbonate in the tubular fluid is excreted in the urine.

D. The kidneys compensate for a metabolic alkalosis by increasing CO2 production.

E. Increased metabolism of glutamine by renal tubular cells increases the plasma bicarbonate concentration.

Question #44

If a patient with pulmonary disease began to hypoventilate, how would plasma levels of [H+], HCO3-, and PCO2 be changed, compared to normal?

A. Increased [H+], increased PCO2, and decreased [HCO3-]

B. Increased [H+], decreased PCO2, and decreased [HCO3-]

C. Increased [H+], increased PCO2, and increased [HCO3-]

D. Decreased [H+], increased PCO2, and decreased [HCO3-]

E. Decreased [H+], decreased PCO2, and decreased [HCO3-]

Question #45

Which of the following statements regarding hypoxia is correct?

A. Carbon monoxide poisoning is an example of hypoxic hypoxia.

B. Exposure to high altitude is a form of hypoxic hypoxia.

C. Cyanide poisoning is an example of hypoxic hypoxia.

D. Carbon monoxide poisoning is an example of ischemic hypoxia.

E. "Anemic hypoxia" refers to the condition of lower than normal arterial PO2.

Question #46

All of the following substances are present in proximal tubular fluid in the kidney, but which one is NOT normally present in urine?

A. K+

B. H+

C. HPO42-

D. Glucose

E. Ca2+

Question #47

You embark on a hiking trip on Mt. Kilimanjaro (altitude = 19,000 ft; Atmospheric air pressure = 379 mmHg). As you ascend, what happens to the PO2 in the alveoli?

A. No change from sea level, as long as we breathe in the same volume of air.

B. Alveolar PO2 decreases.

C. Alveolar PO2 increases.

Question #48

Which of the following is least likely to be filtered into Bowman's capsule in a normal, healthy person?

A. Bicarbonate ion

B. Urea

C. Plasma protein

D. Glucose

E. Sodium

Question #49

Which of the following is TRUE about how water is handled by the nephron?

A. Water is actively reabsorbed from the proximal tubule, and Na+ follows down its diffusion gradient.

B. The permeability of the ascending limb of the loop of Henle is modified by vasopressin.

C. Vasopressin inserts pumps in the collecting duct membrane that move water against its concentration gradient.

D. Water is actively secreted into the descending loop of Henle.

E. Water is filtered out of glomerular capillaries by bulk flow.

Question #50

Which of the following is TRUE during the initial stage of an asthma attack?

A. ΔP is increased.

B. R is decreased.

C. ΔP is decreased.

D. R is increased.

E. None of these, flow rate is unchanged during an asthma attack.

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Physiology 001 - Introduction to Human Physiology » Summer 2021 » Exam 4 Chapter 13 and 14

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