Human Body And Disorders Exams Prep Test
Are you familiar with the human body and disorders? Here is a quiz to enhance your knowledge. This quiz entails recognizing what protein catabolism is, what is not a function of the kidneys, the renal cortex, what fluid immediately precedes urine, the state of a healthy kidney, and what stimulates the constriction of the glomerular inlet and outlet. The human body is a mystery; let this quiz clear your mind.
- 1.
This byproduct of protein catabolism constitutes approximately one-half of all nitrogenous waste.
- A.
Urea
- B.
Creatinine
- C.
Ammonia
- D.
Uric acid
- E.
Azotemia
Correct Answer
A. UreaExplanation
Urea is the correct answer because it is a byproduct of protein catabolism and makes up about half of all nitrogenous waste. Urea is formed in the liver when proteins are broken down and is then excreted by the kidneys in urine. Creatinine is also a waste product of muscle metabolism, but it is not as abundant as urea. Ammonia is a toxic waste product that is converted to urea in the liver. Uric acid is a waste product of purine metabolism and is excreted in urine. Azotemia is a condition characterized by high levels of nitrogenous waste in the blood.Rate this question:
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- 2.
Which is not a function of the kidneys?
- A.
They regulate osmolarity of the body fluids
- B.
They fight osteoporosis by synthesizing vitamin D.
- C.
They help control blood pressure.
- D.
They release waste into the bloodstream.
- E.
They indirectly increase oxyhemoglobin.
Correct Answer
D. They release waste into the bloodstream.Explanation
The kidneys do not release waste into the bloodstream. Instead, they filter waste products from the bloodstream and excrete them in the form of urine. This is one of the main functions of the kidneys, along with regulating osmolarity of body fluids, synthesizing vitamin D, helping control blood pressure, and indirectly increasing oxyhemoglobin levels.Rate this question:
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- 3.
A patient enters a hospital after a motorcycle accident. He complains of mid-back pain. X-rays reveal both rib and pelvic fractures. His emergency room examination includes urinalysis. Which of the following findings from the urinalysis would most likely suggest trauma to the kidneys from the accident, but not to the urinary bladder?
- A.
Pyuria
- B.
Hematuria
- C.
Albuminuria
- D.
Uremia
- E.
Phenylketonuria
Correct Answer
C. AlbuminuriaExplanation
Albuminuria is the presence of albumin in the urine, which is a protein normally found in the blood. In the context of trauma to the kidneys, albuminuria suggests damage to the glomerular filtration barrier, allowing the protein to leak into the urine. This finding is specific to kidney injury and not commonly associated with trauma to the urinary bladder. Pyuria refers to the presence of pus in the urine and can be seen in both kidney and bladder trauma. Hematuria, the presence of blood in the urine, can also be seen in both kidney and bladder trauma. Uremia refers to the buildup of waste products in the blood due to kidney dysfunction and is not specific to trauma. Phenylketonuria is a genetic disorder and not related to trauma.Rate this question:
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- 4.
Which of these correctly traces blood flow from the renal artery into the renal cortex?
- A.
Arcuate a. → interlobar a. → afferent arteriole → interlobular a.
- B.
Interlobar a. → interlobular a. → segmental a. → arcuate a.
- C.
Segmental a. → interlobar a. → arcuate a. → interlobular a.
- D.
Afferent arteriole → interlobular a. → arcuate a. → interlobar a.
- E.
Segmental a. → arcuate a. → interlobar a. → interlobular a
Correct Answer
C. Segmental a. → interlobar a. → arcuate a. → interlobular a.Explanation
The correct answer traces the blood flow from the renal artery into the renal cortex in the following order: segmental artery, interlobar artery, arcuate artery, and interlobular artery. This is the correct sequence of blood vessels that carry oxygenated blood to the renal cortex, allowing for the filtration of waste products and reabsorption of water and nutrients in the kidneys.Rate this question:
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- 5.
Which of these correctly traces blood flow from the renal cortex to the renal vein?
- A.
Interlobular v. → interlobar v. → segmental v. → renal v.
- B.
Arcuate v. → interlobar v. → segmental v. → renal v.
- C.
Interlobar v. → interlobular v. → arcuate v. → renal v.
- D.
Segmental v. → arcuate v. → interlobar v. → renal v.
- E.
Interlobular v. → arcuate v. → interlobar v. → renal v.
Correct Answer
E. Interlobular v. → arcuate v. → interlobar v. → renal v.Explanation
The correct answer traces the blood flow correctly from the renal cortex to the renal vein. It starts with the interlobular veins, which drain blood from the renal cortex. The blood then flows into the arcuate veins, which are located at the boundary between the renal cortex and medulla. From there, it goes into the interlobar veins, which travel through the renal columns. Finally, the blood enters the renal vein, which carries it out of the kidney.Rate this question:
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- 6.
All of the following are composed of cuboidal epithelium with the exception of
- A.
The thin segment of the nephron loop.
- B.
The thick segment of the nephron loop.
- C.
The collecting duct.
- D.
The distal convoluted tubule.
- E.
The distal convoluted tubule.
Correct Answer
A. The thin segment of the nepHron loop.Explanation
The thin segment of the nephron loop is composed of simple squamous epithelium, not cuboidal epithelium like the other structures mentioned.Rate this question:
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- 7.
In the nephron, the fluid that immediately precedes urine is known as
- A.
Plasma.
- B.
Glomerular filtrate.
- C.
Tubular fluid.
- D.
Renal filtrate.
- E.
Medullary filtrate.
Correct Answer
C. Tubular fluid.Explanation
The correct answer is tubular fluid. In the nephron, the fluid that immediately precedes urine is known as tubular fluid. This fluid is formed by the filtration of blood in the glomerulus and then modified through reabsorption and secretion as it passes through the renal tubules. Eventually, the tubular fluid will be further concentrated and transformed into urine as it moves through the collecting ducts and into the renal pelvis.Rate this question:
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- 8.
Glucose and amino acids are reabsorbed from the glomerular filtrate by
- A.
The renal corpuscle.
- B.
The proximal convoluted tubule.
- C.
The distal convoluted tubule.
- D.
The collecting duct.
- E.
The glomerular capillaries.
Correct Answer
B. The proximal convoluted tubule.Explanation
Glucose and amino acids are reabsorbed from the glomerular filtrate by the proximal convoluted tubule. This is because the proximal convoluted tubule is the first segment of the renal tubule and it plays a major role in reabsorbing valuable substances from the filtrate back into the bloodstream. It has a large surface area and is lined with specialized cells that actively transport glucose and amino acids from the tubule lumen into the surrounding capillaries. This reabsorption process helps to maintain the body's glucose and amino acid levels and prevent their loss in the urine.Rate this question:
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- 9.
In a healthy kidney, very little ___ is filtered by the glomerulus.
- A.
Amino acids
- B.
Electrolytes
- C.
Glucose
- D.
Vitamins
- E.
Protein
Correct Answer
E. ProteinExplanation
In a healthy kidney, the glomerulus acts as a filtration unit and is responsible for filtering waste products and excess substances from the blood. Protein is a large molecule that is not normally filtered by the glomerulus, as it is essential for various bodily functions and is usually reabsorbed by the kidney. Therefore, very little protein is filtered by the glomerulus in a healthy kidney.Rate this question:
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- 10.
Which of the following would reduce the glomerular filtration rate?
- A.
Vasoconstriction of the efferent arteriole
- B.
A drop in oncotic pressure
- C.
Vasodilation of the afferent arteriole
- D.
Vasoconstriction of the afferent arteriole
- E.
An increase in osmotic pressure in the glomerular capsule
Correct Answer
D. Vasoconstriction of the afferent arterioleExplanation
Vasoconstriction of the afferent arteriole would reduce the glomerular filtration rate. The afferent arteriole supplies blood to the glomerulus, where filtration occurs. When the afferent arteriole constricts, it reduces the amount of blood flow into the glomerulus, thereby decreasing the glomerular filtration rate. This constriction decreases the pressure within the glomerulus, leading to a decrease in the filtration of waste products and excess fluids from the blood.Rate this question:
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- 11.
In response to a drop in overall blood pressure, ___ stimulates constriction of the glomerular inlet and even greater constriction of the outlet.
- A.
Azotemia
- B.
Sodium chloride
- C.
Parathyroid hormone
- D.
Aldosterone
- E.
Angiotensin II
Correct Answer
E. Angiotensin IIExplanation
In response to a drop in overall blood pressure, angiotensin II stimulates constriction of the glomerular inlet and even greater constriction of the outlet. Angiotensin II is a hormone that is released by the kidneys in response to low blood pressure. It acts on the blood vessels to constrict them, which helps to increase blood pressure. In the case of the glomerular inlet and outlet, angiotensin II constricts them even more to regulate the flow of blood and maintain proper filtration in the kidneys.Rate this question:
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- 12.
Assuming all other values are normal, calculate the net filtration pressure in a patient with a drop in capsular hydrostatic pressure to 8 mmHg.
- A.
10 mm Hg out
- B.
20 mm Hg out
- C.
30 mm Hg out
- D.
40 mm Hg out
- E.
50 mm Hg out
Correct Answer
B. 20 mm Hg outExplanation
A drop in capsular hydrostatic pressure to 8 mmHg would decrease the net filtration pressure. The net filtration pressure is calculated by subtracting the sum of the opposing forces (capsular hydrostatic pressure and blood colloid osmotic pressure) from the glomerular hydrostatic pressure. Since the question states that all other values are normal and does not provide any information about the other pressures, we can assume they remain constant. Therefore, the net filtration pressure would be 20 mmHg out, as it is the only value that is lower than the initial glomerular hydrostatic pressure of 30 mmHg.Rate this question:
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- 13.
Because of the great deal of active transport that occurs here, the _________ of all the nephrons collectively account for about 6% of one's daily resting ATP and caloric consumption.
- A.
Proximal convoluted tubules
- B.
Distal convoluted tubules
- C.
Loops of Henle
- D.
Glomerul
- E.
Collecting ducts
Correct Answer
A. Proximal convoluted tubulesExplanation
The proximal convoluted tubules are responsible for a significant amount of active transport, which requires ATP and consumes calories. This active transport is necessary for reabsorbing important substances such as glucose, amino acids, and ions back into the bloodstream. Due to the high energy demand of active transport in the proximal convoluted tubules, it accounts for about 6% of one's daily resting ATP and caloric consumption.Rate this question:
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- 14.
Proximal convoluted tubules are responsible for reabsorbing all of the following except
- A.
Potassium.
- B.
Sodium chloride.
- C.
Hydrogen ions.
- D.
Urea.
- E.
Water.
Correct Answer
C. Hydrogen ions.Explanation
The proximal convoluted tubules in the kidneys are responsible for reabsorbing various substances from the filtrate back into the bloodstream. These substances include sodium chloride, potassium, urea, and water. However, hydrogen ions are not reabsorbed by the proximal convoluted tubules. Instead, they are secreted into the tubules to help regulate the body's pH levels.Rate this question:
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- 15.
Total saturation of protein transporters for a given solute in the renal tubules would result in
- A.
Reabsorption of all the solute.
- B.
A renal clearance of zero.
- C.
Appearance of that solute in the urine.
- D.
Absence of that solute from the urine.
- E.
A net filtration pressure of 1.0.
Correct Answer
C. Appearance of that solute in the urine.Explanation
When the protein transporters in the renal tubules are fully saturated with a given solute, it means that they are unable to reabsorb any more of that solute back into the bloodstream. This leads to the solute being unable to be reabsorbed and therefore appearing in the urine. So, the correct answer is the appearance of that solute in the urine.Rate this question:
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- 16.
Which of the following is a direct result of antidiuretic hormone?
- A.
Decreased urine volume
- B.
Decreased urine molarity
- C.
Increased urine volume
- D.
Increased urine salinity
- E.
Increased urine acidity
Correct Answer
A. Decreased urine volumeExplanation
Antidiuretic hormone (ADH) is released by the pituitary gland and its main function is to regulate water balance in the body. When ADH is released, it acts on the kidneys to increase water reabsorption, leading to decreased urine volume. Therefore, the correct answer is decreased urine volume.Rate this question:
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- 17.
Aldosterone acts on
- A.
The proximal convoluted tubule.
- B.
The medullary portion of the collecting duct.
- C.
The descending limb of the nephron loop.
- D.
The distal convoluted tubule.
- E.
The glomerulus.
Correct Answer
D. The distal convoluted tubule.Explanation
Aldosterone acts on the distal convoluted tubule. The distal convoluted tubule is the part of the nephron where reabsorption of sodium ions and water occurs. Aldosterone increases the reabsorption of sodium ions and the secretion of potassium ions in the distal convoluted tubule, which helps regulate blood pressure and electrolyte balance. This hormone is produced by the adrenal glands and is released in response to low blood pressure or low sodium levels in the blood.Rate this question:
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- 18.
Atrial natriuretic peptide reduces blood volume and pressure by all of the following means except
- A.
Increasing glomerular filtration rate.
- B.
Inhibiting renin and aldosterone secretion.
- C.
Inhibiting the action of ADH on the kidney.
- D.
Inhibiting NaCl reabsorption by the collecting duct.
- E.
Preventing sodium loss in the urine.
Correct Answer
E. Preventing sodium loss in the urine.Explanation
Atrial natriuretic peptide (ANP) is a hormone released by the heart in response to increased blood volume and pressure. It acts to reduce blood volume and pressure by various mechanisms. ANP inhibits renin and aldosterone secretion, which leads to decreased reabsorption of sodium and water in the kidneys. It also inhibits the action of antidiuretic hormone (ADH) on the kidney, which reduces water reabsorption. ANP inhibits NaCl reabsorption by the collecting duct, further promoting water and sodium excretion. However, preventing sodium loss in the urine would not contribute to reducing blood volume and pressure, therefore it is the exception in this case.Rate this question:
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- 19.
Hypocalcemia stimulates
- A.
A decrease in aldosterone production.
- B.
Secretion of parathyroid hormone.
- C.
Secretion of renin.
- D.
An increase in blood urea nitrogen.
- E.
Vasoconstriction of the afferent arterioles.
Correct Answer
B. Secretion of parathyroid hormone.Explanation
Hypocalcemia refers to low levels of calcium in the blood. Parathyroid hormone (PTH) is responsible for regulating calcium levels in the body. When calcium levels are low, the parathyroid glands secrete more PTH, which stimulates the release of calcium from bones, increases calcium absorption in the intestines, and reduces calcium excretion in the kidneys. Therefore, in the case of hypocalcemia, the correct answer is the secretion of parathyroid hormone.Rate this question:
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- 20.
Which renal structure is responsible for producing hypertonic urine by reabsorbing water while allowing metabolic wastes and NaCl to pass through?
- A.
Glomerulus
- B.
Proximal convoluted tubule
- C.
Distal convoluted tubule
- D.
Collecting duct
- E.
Nephron loop
Correct Answer
D. Collecting ductExplanation
The collecting duct is responsible for producing hypertonic urine by reabsorbing water while allowing metabolic wastes and NaCl to pass through. This structure plays a crucial role in concentrating the urine by reabsorbing water back into the bloodstream and allowing the passage of solutes such as metabolic wastes and NaCl. This selective reabsorption helps in maintaining the body's water and electrolyte balance. The other structures mentioned, such as the glomerulus, proximal convoluted tubule, distal convoluted tubule, and nephron loop, also play important roles in the renal system but are not primarily responsible for producing hypertonic urine.Rate this question:
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- 21.
The urine is most likely to be hypotonic when
- A.
The body's water volume is high.
- B.
The body's pH is low.
- C.
The output of antidiuretic hormone is high.
- D.
The output of natriuretic peptides is high.
- E.
A person is lost and deprived of drinking water.
Correct Answer
A. The body's water volume is high.Explanation
When the body's water volume is high, it means there is an excess of water in the body. This leads to a decrease in the concentration of solutes in the urine, making it hypotonic. In a hypotonic urine, the concentration of solutes is lower compared to the concentration in the blood. This occurs because the excess water is not being reabsorbed by the kidneys, resulting in a larger volume of urine with a lower concentration of solutes.Rate this question:
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- 22.
The overall purpose of the countercurrent exchange system is
- A.
To supply salt and urea to the renal medulla.
- B.
To supply nutrients and oxygen to the renal cortex.
- C.
To supply nutrients and oxygen to the renal medulla.
- D.
To remove metabolic wastes from the renal cortex.
- E.
To remove metabolic wastes from the renal medulla.
Correct Answer
C. To supply nutrients and oxygen to the renal medulla.Explanation
The countercurrent exchange system is a mechanism that allows for the efficient exchange of substances, such as oxygen and nutrients, between blood vessels in close proximity. In the context of the renal system, the countercurrent exchange system plays a crucial role in maintaining the concentration gradient necessary for the reabsorption of water and solutes. By supplying nutrients and oxygen to the renal medulla, the countercurrent exchange system ensures that the medulla has the necessary resources to carry out its functions, such as concentrating urine and regulating water balance.Rate this question:
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- 23.
Which of these induces renin secretion, constricts afferent arterioles, and reduces GFR, and urine volume?
- A.
Aldosterone
- B.
Antidiuretic hormone
- C.
Parathyroid hormone
- D.
Norepinephrine
- E.
Angiotensin II
Correct Answer
D. NorepinepHrineExplanation
Norepinephrine induces renin secretion, constricts afferent arterioles, and reduces GFR (glomerular filtration rate) and urine volume. Norepinephrine is a neurotransmitter and hormone that is released by the sympathetic nervous system in response to stress or low blood pressure. It acts on the kidneys to decrease blood flow and filtration, which helps to conserve water and increase blood volume. This response is part of the body's physiological mechanism to maintain blood pressure and fluid balance.Rate this question:
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- 24.
Normal urine from a healthy person can be expected to contain all of the following except
- A.
Creatinine
- B.
Urobilin
- C.
Glucose
- D.
Ammonia
- E.
Magnesium
Correct Answer
C. GlucoseExplanation
Normal urine from a healthy person does not typically contain glucose. Glucose is usually reabsorbed by the kidneys and returned to the bloodstream. The presence of glucose in urine can indicate a condition such as diabetes or kidney disease. Therefore, it is expected that normal urine from a healthy person would not contain glucose.Rate this question:
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- 25.
Prior to chemical tests for glycosuria, clinicians checked for sweetness of the urine as a sign of
- A.
Diabetes insipidus.
- B.
Acute glomerulonephritis.
- C.
Diabetes mellitus.
- D.
Renal calculus.
- E.
Pyelitis
Correct Answer
C. Diabetes mellitus.Explanation
Prior to chemical tests for glycosuria, clinicians checked for sweetness of the urine as a sign of diabetes mellitus. Diabetes mellitus is a condition characterized by high levels of glucose in the blood, which can lead to glucose spilling into the urine. This excess glucose in the urine can give it a sweet taste. Therefore, the sweetness of the urine was used as an indicator for the presence of diabetes mellitus. The other options listed are unrelated to the presence of glucose in the urine and do not cause sweetness.Rate this question:
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- 26.
A hospital patient produces 4 mL/min of urine with a urea concentration of 8 mg/mL. Venous blood draw reveals urea concentration of 0.4 mg/mL. What is the percentage of cleared urea from glomerular filtrate?
- A.
40%
- B.
56
- C.
64%
- D.
72%
- E.
80%
Correct Answer
C. 64%Explanation
The percentage of cleared urea from glomerular filtrate can be calculated using the formula: (urine concentration - blood concentration) / urine concentration * 100. In this case, the urine concentration is 8 mg/mL and the blood concentration is 0.4 mg/mL. Plugging these values into the formula, we get (8 - 0.4) / 8 * 100 = 7.6 / 8 * 100 = 0.95 * 100 = 95%. Therefore, the correct answer is 95%.Rate this question:
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- 27.
Which two substances are most useful for determining a patient's glomerular filtration rate?
- A.
Insulin and glucose
- B.
Inulin and creatinine
- C.
Sodium and water
- D.
Albumin and inulin
- E.
Insulin and urea
Correct Answer
B. Inulin and creatinineExplanation
Inulin and creatinine are the most useful substances for determining a patient's glomerular filtration rate. Inulin is a plant polysaccharide that is freely filtered by the glomerulus and is not reabsorbed or secreted by the renal tubules. Therefore, its clearance provides an accurate measure of the glomerular filtration rate. Creatinine is a waste product of muscle metabolism that is also freely filtered by the glomerulus and minimally reabsorbed by the renal tubules. Its clearance is commonly used as an estimate of the glomerular filtration rate in clinical practice.Rate this question:
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- 28.
Creatinine has a renal clearance of 140 mL/min due to the fact that
- A.
It is absorbed by the loop of Henle.
- B.
It is secreted by the glomerulus.
- C.
It is absorbed by the renal tubules.
- D.
It is secreted by the renal tubules.
- E.
It is produced in the pulmonary tissue.
Correct Answer
D. It is secreted by the renal tubules.Explanation
Creatinine is a waste product produced by muscles and filtered by the glomerulus in the kidneys. However, a small amount of creatinine is also actively secreted by the renal tubules into the urine. This secretion process helps to eliminate creatinine from the body more efficiently. Therefore, the correct answer is that creatinine is secreted by the renal tubules.Rate this question:
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- 29.
Which of the following is not found in the ureter?
- A.
Adventitia
- B.
Two layers of smooth muscle
- C.
Three layers of smooth muscle
- D.
Transitional epithelium
- E.
Skeletal muscle
Correct Answer
E. Skeletal muscleExplanation
The ureter is a tube that carries urine from the kidneys to the bladder. It is composed of three layers of smooth muscle, known as the muscularis layer, which helps propel urine through the ureter. The adventitia is the outermost layer of the ureter, providing support and protection. Transitional epithelium is the innermost layer of the ureter, which allows for stretching and expansion. Skeletal muscle is not found in the ureter, as it is not needed for the function of transporting urine.Rate this question:
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- 30.
The buccal phase of swallowing is under _____________ control and the pharyngo-esophageal phase is ______________.
- A.
Central nervous system; also controlled by the central nervous system
- B.
Central nervous system; controlled by autonomic reflexes
- C.
Autonomic nervous system; controlled by autonomic reflexes
- D.
Voluntary; also voluntary
- E.
Involuntary; also involuntary
Correct Answer
B. Central nervous system; controlled by autonomic reflexesExplanation
The buccal phase of swallowing, which involves the initial voluntary movement of food into the mouth, is under central nervous system control. On the other hand, the pharyngo-esophageal phase, which involves the involuntary movement of food through the pharynx and esophagus, is controlled by autonomic reflexes.Rate this question:
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- 31.
Pepsinogen is produced by ____________ and is activated by ___________.
- A.
Chief cells; carbonic anhydrase (CAH) secreted by parietal cells
- B.
Chief cells; hydrochloric acid (HCl) secreted by parietal cells
- C.
Parietal cells; hydrochloric acid (HCl) secreted by chief cells
- D.
Parietal cells; carbonic anhydrase (CAH) secreted by chief cells
- E.
Enteroendocrine cells; carbonic anhydrase (CAH) secreted by parietal cells
Correct Answer
B. Chief cells; hydrochloric acid (HCl) secreted by parietal cellsExplanation
Pepsinogen, the inactive form of the enzyme pepsin, is produced by chief cells in the stomach. It is then activated into pepsin by hydrochloric acid (HCl) secreted by parietal cells. Therefore, the correct answer is "chief cells; hydrochloric acid (HCl) secreted by parietal cells."Rate this question:
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- 32.
Why are several digestive enzymes secreted as zymogens?
- A.
Because this saves one step in their synthesis
- B.
Because gastric cells do not have the necessary enzymes for their synthesis
- C.
So they start digesting intracellular proteins of the gastric cells more quickly
- D.
So they act only in the stomach lumen and do not digest intracellular proteins
- E.
So they can start digesting dietary proteins more quickly
Correct Answer
D. So they act only in the stomach lumen and do not digest intracellular proteinsExplanation
Several digestive enzymes are secreted as zymogens to ensure that they act only in the stomach lumen and do not digest intracellular proteins. Zymogens are inactive forms of enzymes that are converted into their active forms when needed. This prevents the enzymes from prematurely digesting intracellular proteins within the gastric cells themselves. By remaining inactive until they reach the stomach lumen, the enzymes can then start digesting dietary proteins more quickly and efficiently.Rate this question:
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- 33.
The enterogastric reflex serves to
- A.
Relax the stomach in preparation for swallowed food.
- B.
Stimulate acid and enzyme secretion when food enters the stomach.
- C.
Stimulate intestinal motility when there is food in the stomach.
- D.
Inhibit gastric motility when there is chyme in the small intestine.
- E.
Relax the ileocecal valve when chyme is on its way to the colon.
Correct Answer
D. Inhibit gastric motility when there is chyme in the small intestine.Explanation
The enterogastric reflex is a neural reflex that inhibits gastric motility when there is chyme (partially digested food) in the small intestine. This reflex helps to slow down the emptying of the stomach and allows for proper digestion and absorption of nutrients in the small intestine.Rate this question:
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- 34.
The _______________ synthesizes bile acids by metabolizing ____________________.
- A.
Duodenum; neutral fats
- B.
Ileum; bilirubin
- C.
Gallbladder; cholesterol
- D.
Pancreas; bile salts
- E.
Liver; cholesterol
Correct Answer
E. Liver; cholesterolExplanation
The liver synthesizes bile acids by metabolizing cholesterol.Rate this question:
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- 35.
Which of the following enzymes functions at the lowest pH?
- A.
Salivary amylase
- B.
Pancreatic amylase
- C.
Pepsin
- D.
Trypsin
- E.
Dipeptidase
Correct Answer
C. PepsinExplanation
Pepsin functions at the lowest pH because it is an enzyme found in the stomach, where the pH is highly acidic (around pH 1-2). Pepsin is responsible for breaking down proteins into smaller peptides, and its activity is optimal in this acidic environment. Salivary amylase and pancreatic amylase function at a slightly higher pH in the mouth and small intestine, respectively. Trypsin and dipeptidase also function at a higher pH in the small intestine. Therefore, pepsin is the enzyme that functions at the lowest pH.Rate this question:
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- 36.
Which of these is the site of contact digestion?
- A.
Gastric pits
- B.
Surface of the gastric mucosa
- C.
Intestinal crypts
- D.
Brush border of the small intestine
- E.
Cytoplasm in the cells of the small intestine
Correct Answer
D. Brush border of the small intestineExplanation
The brush border of the small intestine is the site of contact digestion. The brush border refers to the microvilli on the surface of the intestinal epithelial cells. These microvilli greatly increase the surface area available for digestion and absorption of nutrients. Enzymes located on the brush border, such as sucrase, lactase, and maltase, break down disaccharides into monosaccharides, which can then be absorbed by the cells. Therefore, the brush border plays a crucial role in the digestion of carbohydrates in the small intestine.Rate this question:
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- 37.
The small intestine has a very large absorptive surface associated with all these structures except
- A.
Circular folds (plicae circulares).
- B.
Intestinal length.
- C.
Microvilli.
- D.
Villi.
- E.
Rugae
Correct Answer
E. RugaeExplanation
The small intestine has a very large absorptive surface due to the presence of circular folds (plicae circulares), microvilli, and villi. These structures increase the surface area available for absorption of nutrients. However, rugae are not associated with the absorptive surface of the small intestine. Rugae are found in the stomach and urinary bladder, and they allow for expansion and contraction of these organs.Rate this question:
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- 38.
_____________ break(s) down _______________.
- A.
Lactase; glucose
- B.
Peptidases; proteins
- C.
Lipases; micelles
- D.
Lactose; lactase
- E.
Nucleases; nucleotides
Correct Answer
B. Peptidases; proteinsExplanation
Peptidases are enzymes that break down proteins into smaller peptides or amino acids. Therefore, the correct answer is "Peptidases; proteins" because peptidases break down proteins.Rate this question:
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- 39.
The sodium-glucose transport protein (SGLP)
- A.
Is a uniport carrier.
- B.
Is an antiport carrier.
- C.
Uses solvent drag to transport glucose and sodium.
- D.
Transports glucose and sodium from the intestinal lumen into the epithelial cells.
- E.
Transports glucose from the intestinal lumen into the epithelial cells, and sodium in the opposite direction.
Correct Answer
D. Transports glucose and sodium from the intestinal lumen into the epithelial cells.Explanation
The correct answer is "transports glucose and sodium from the intestinal lumen into the epithelial cells." This is because the sodium-glucose transport protein (SGLP) is responsible for facilitating the movement of both glucose and sodium ions from the intestinal lumen into the epithelial cells. This transport protein plays a crucial role in the absorption of glucose from the intestines into the bloodstream.Rate this question:
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- 40.
Amino acids and monosaccharides are absorbed in the ____________, and fatty acids are absorbed in the _______________.
- A.
Small intestine; large intestine
- B.
Small intestine; liver
- C.
Stomach; small intestine
- D.
Stomach; large intestine
- E.
Small intestine; small intestine too
Correct Answer
E. Small intestine; small intestine tooExplanation
Amino acids and monosaccharides are primarily absorbed in the small intestine. However, it is worth noting that a small amount of absorption of these molecules can also occur in the small intestine itself. This is because the small intestine has a large surface area due to the presence of villi and microvilli, which increases the absorption capacity. On the other hand, fatty acids are primarily absorbed in the small intestine as well, through a process called emulsification and subsequent formation of micelles. The large intestine mainly absorbs water and electrolytes, rather than nutrients like amino acids, monosaccharides, or fatty acids.Rate this question:
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- 41.
Bacterial flora carry out all of the following except
- A.
Digest most of the proteins we get in the diet.
- B.
Synthesize vitamin K.
- C.
Produce some of the gases found in flatus.
- D.
Digest cellulose.
- E.
Form part of the feces.
Correct Answer
A. Digest most of the proteins we get in the diet.Explanation
Bacterial flora play a crucial role in our digestive system, aiding in the breakdown and absorption of nutrients. They help in the digestion of cellulose, which is a complex carbohydrate found in plant cell walls. They also synthesize vitamin K, which is essential for blood clotting. Additionally, they produce some of the gases found in flatus and form part of the feces. However, the digestion of proteins primarily occurs in the stomach and small intestine through the action of enzymes produced by the human body, rather than by bacterial flora.Rate this question:
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- 42.
These nutrients are all absorbed without being digested except
- A.
Water.
- B.
Vitamins.
- C.
Proteins.
- D.
Minerals.
- E.
Cholesterol.
Correct Answer
C. Proteins.Explanation
Proteins are the only nutrients that require digestion before they can be absorbed by the body. Digestion breaks down proteins into amino acids, which can then be absorbed into the bloodstream. In contrast, water, vitamins, minerals, and cholesterol do not require digestion and can be directly absorbed by the body.Rate this question:
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- 43.
Each of the following lists some of the tissue layers of the digestive tract. Which one has them in correct order from lumen to external surface?
- A.
Lamina propria, muscularis mucosae, submucosa, muscularis externa, serosa
- B.
Serosa, lamina propria, submucosa, muscularis mucosae, muscularis externa
- C.
Mucosa, submucosa, muscularis mucosae, muscularis externa, lamina propria
- D.
Mucosa, muscularis mucosae, submucosa, muscularis externa, lamina propria
- E.
Mucosa, submucosa, muscularis externa, lamina propria, serosa
Correct Answer
A. Lamina propria, muscularis mucosae, submucosa, muscularis externa, serosaExplanation
The correct answer is lamina propria, muscularis mucosae, submucosa, muscularis externa, serosa. This is the correct order of the tissue layers from the lumen (innermost) to the external surface (outermost) of the digestive tract. The lamina propria is a layer of connective tissue that lies just beneath the epithelial lining of the mucosa. The muscularis mucosae is a thin layer of smooth muscle that helps to move and mix the contents of the digestive tract. The submucosa is a layer of connective tissue that contains blood vessels, nerves, and glands. The muscularis externa is a layer of smooth muscle that helps to propel food through the digestive tract. The serosa is the outermost layer of the digestive tract, which provides protection and support.Rate this question:
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- 44.
Chemical digestion breaks down ____________ into _____________.
- A.
Proteins; nucleotides
- B.
Amino acids; proteins
- C.
Polysaccharides; amino acids
- D.
Nucleic acids; nucleotides
- E.
Fatty acids; cholesterol
Correct Answer
D. Nucleic acids; nucleotidesExplanation
Chemical digestion is the process in which large molecules are broken down into smaller molecules by the action of enzymes. In this case, chemical digestion breaks down nucleic acids into nucleotides. Nucleic acids are large molecules that contain genetic information, such as DNA and RNA. Nucleotides are the building blocks of nucleic acids, consisting of a sugar, a phosphate group, and a nitrogenous base. Therefore, the correct answer is "nucleic acids; nucleotides."Rate this question:
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- 45.
The ___________ regulates digestive tract motility, secretion, and blood flow, and its neurons are found in the ____________.
- A.
Autonomic nervous system; serosa
- B.
Central nervous system; muscularis externa and muscularis mucosae
- C.
Enteric nervous system; submucosa and muscularis externa
- D.
Visceral sensory division; muscularis externa and submucosa
- E.
Visceral motor division; mucosa and submucosa
Correct Answer
C. Enteric nervous system; submucosa and muscularis externaExplanation
The enteric nervous system regulates digestive tract motility, secretion, and blood flow, and its neurons are found in the submucosa and muscularis externa.Rate this question:
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- 46.
The surface of the tongue is covered with ____________ stratified squamous epithelium, and has bumps called __________________, site of taste buds.
- A.
Keratinized; lingual papillae
- B.
Keratinized; lingual frenulum
- C.
Nonkeratinized; lingual papillae
- D.
Nonkeratinized; tonsils
- E.
Nonkeratinized; vallate papillae
Correct Answer
C. Nonkeratinized; lingual papillaeExplanation
The surface of the tongue is covered with nonkeratinized stratified squamous epithelium, which means that the cells on the surface of the tongue do not have a layer of keratin. The bumps on the tongue are called lingual papillae, which are the site of taste buds.Rate this question:
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- 47.
The ______________ gland is an extrinsic salivary gland, whereas the ______________ gland is an intrinsic salivary gland.
- A.
Lingual; labial
- B.
Submandibular; lingual
- C.
Submandibular; sublingual
- D.
Sublingual; parotid
- E.
Lingual; sublingual
Correct Answer
B. Submandibular; lingualExplanation
The submandibular gland is an extrinsic salivary gland located underneath the mandible, while the lingual gland is an intrinsic salivary gland located on the underside of the tongue.Rate this question:
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- 48.
Acid reflux into the esophagus ("heartburn") is normally prevented by
- A.
Pharyngeal constrictors.
- B.
The upper esophageal sphincter.
- C.
The lower esophageal sphincter (LES).
- D.
Esophageal glands.
- E.
Pharyngeal and buccal sphincters.
Correct Answer
C. The lower esopHageal spHincter (LES).Explanation
The lower esophageal sphincter (LES) is responsible for preventing acid reflux into the esophagus. This sphincter is located at the junction between the esophagus and the stomach, and its main function is to close off the opening between these two organs to prevent stomach acid from flowing back into the esophagus. When the LES is functioning properly, it acts as a barrier to keep stomach contents in the stomach. However, if the LES weakens or relaxes abnormally, acid can escape and cause heartburn or acid reflux.Rate this question:
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- 49.
_____________ is associated with food stretching the stomach and activating myenteric and vagovagal reflexes, which in turn stimulate gastric secretions.
- A.
The cephalic phase
- B.
The gastric phase
- C.
The intestinal phase
- D.
The gastrointestinal phase
- E.
The mesenteric phase
Correct Answer
B. The gastric pHaseExplanation
The gastric phase is associated with food stretching the stomach and activating myenteric and vagovagal reflexes, which in turn stimulate gastric secretions. During this phase, the stomach releases gastrin, which stimulates the secretion of gastric acid and enzymes. This phase is primarily triggered by the presence of food in the stomach and helps to prepare the stomach for digestion and absorption of nutrients.Rate this question:
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- 50.
The migrating motor complex
- A.
Milks the chyme toward the colon.
- B.
Allows a bolus to move down the esophagus.
- C.
Churns and mixes residue in the descending colon.
- D.
Churns and mixes a bolus with gastric juices.
- E.
Propels pancreatic juice down the pancreatic duct.
Correct Answer
A. Milks the chyme toward the colon.Explanation
The migrating motor complex refers to a series of contractions that occur in the gastrointestinal tract during fasting periods. These contractions help to propel any remaining food particles, known as chyme, from the stomach towards the colon. This process ensures that the chyme continues to move through the digestive system and prevents it from staying in one place for too long. Therefore, the correct answer is that the migrating motor complex milks the chyme toward the colon.Rate this question:
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Mar 21, 2023Quiz Edited by
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Jul 20, 2012Quiz Created by
Orangejuice1120
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