1.
Cholecystokinin (CCK) is a peptide hormone released from cells in the small intestine. It binds to receptors on:
Correct Answer
D. Ascinar cells in the pancreas
Explanation
Cholecystokinin (CCK) is a peptide hormone that is released from cells in the small intestine. It acts by binding to receptors on certain cells in the body. In this case, the correct answer is "ascinar cells in the pancreas." Ascinar cells are responsible for producing and releasing digestive enzymes in the pancreas. When CCK binds to receptors on these cells, it stimulates the release of digestive enzymes into the small intestine, aiding in the digestion and absorption of nutrients.
2.
In the mucosa of the stomach, the _____ cell is enriched for carbonic anhydrase and contains receptors for _____ .
Correct Answer
D. Parietal cell, gastrin
Explanation
The correct answer is parietal cell, gastrin. Parietal cells in the stomach mucosa are known for their high concentration of carbonic anhydrase, an enzyme that helps in the production of gastric acid. Parietal cells also contain receptors for gastrin, a hormone that stimulates the secretion of gastric acid. This interaction between gastrin and parietal cells plays a crucial role in the regulation of gastric acid secretion in the stomach.
3.
In the stomach, the region that is enriched for elastin and permits its expansion is the:
Correct Answer
B. Submucosa
Explanation
The correct answer is submucosa. The submucosa is a layer of connective tissue in the stomach that is rich in elastin. Elastin is a protein that allows tissues to stretch and recoil, so the presence of elastin in the submucosa allows the stomach to expand and accommodate food during digestion. The other options, such as the mucosa, muscular layer, serosa, and mesothelium, do not specifically contain high concentrations of elastin and do not play a significant role in stomach expansion.
4.
Which of the following is (are) enzymes that act in the bulk fluid in the lumen of the intestine?
Correct Answer
E. A and b are correct
Explanation
Pancreatic amylase and trypsin are enzymes that act in the bulk fluid in the lumen of the intestine. Pancreatic amylase is responsible for breaking down starch into smaller sugar molecules, while trypsin helps in the digestion of proteins by breaking them down into smaller peptides. Carboxy peptidase and maltase, on the other hand, act on the surface of the intestinal cells, not in the bulk fluid. Therefore, the correct answer is that both pancreatic amylase and trypsin act in the bulk fluid in the lumen of the intestine.
5.
In the salivary glands of the mouth, Na+ channels are found predominately on the basilar membrane. The Na+/K+ ATPases are located on the _____ surface of the secretory epithelial cells. The _____ cells lack aquaporins.
Correct Answer
A. Apical, duct
Explanation
In the salivary glands, Na+ channels are primarily found on the basilar membrane, which suggests that they are involved in the movement of sodium ions from the basolateral side to the apical side of the secretory epithelial cells. The Na+/K+ ATPases, on the other hand, are responsible for maintaining the concentration gradient of sodium and potassium ions across the cell membrane. Since they work in opposition to the Na+ channels, it is logical to assume that they are located on the apical surface of the secretory epithelial cells. The aquaporins, which are responsible for water transport, are not present in the mentioned cells. Therefore, the correct answer is "apical, duct."
6.
Glycogen is a polymer of:
Correct Answer
C. Glucose
Explanation
Glycogen is a polymer of glucose. Glycogen is a storage form of glucose in animals and humans. It is formed by the bonding of multiple glucose molecules together in a branched structure. This allows for efficient storage and release of glucose when needed for energy. Amino acids are the building blocks of proteins, cellulose is a carbohydrate found in plant cell walls, sucrose is a disaccharide composed of glucose and fructose, and starch is a polymer of glucose found in plants. Therefore, glucose is the correct answer as it is the specific monomer that makes up glycogen.
7.
When our mouth "waters" at the sight or smell of food. The source of this is effect is the:
Correct Answer
A. Parasympathetic activation of salivary glands
Explanation
The correct answer is parasympathetic activation of salivary glands. When our mouth "waters" at the sight or smell of food, it is due to the parasympathetic nervous system activating the salivary glands. The parasympathetic nervous system is responsible for rest and digest activities, including increasing saliva production in preparation for eating. This activation stimulates the release of saliva, which helps to moisten the food and begin the process of digestion.
8.
The cells that release glucose in response to low blood glucose are the:
Correct Answer
E. Hepatocytes
Explanation
Hepatocytes are liver cells that release glucose in response to low blood glucose levels. When blood glucose levels drop, the liver breaks down glycogen into glucose and releases it into the bloodstream to maintain normal blood glucose levels. This process is known as glycogenolysis. Therefore, hepatocytes play a crucial role in regulating blood glucose levels and ensuring that the body has a constant supply of energy.
9.
Which of the following is (are) G-protein coupled receptors that affect acid secretion in the stomach?
Correct Answer
E. All except d are correct
Explanation
The correct answer is "all except d are correct." This means that all of the options listed (gastrin receptor, acetylcholine receptor, and H2 histamine receptor) are G-protein coupled receptors that affect acid secretion in the stomach, except for the K+/H+ ATP-dependent exchanger.
10.
The role of lipase is to:
Correct Answer
A. Digest lipids into a molecule of monoglyceride and two molecules of fatty acid
Explanation
Lipase is an enzyme that plays a crucial role in the digestion of lipids. It breaks down lipids into smaller molecules, specifically a molecule of monoglyceride and two molecules of fatty acid. This process is essential for the body to absorb and utilize the nutrients present in lipids. Therefore, the correct answer is "digest lipids into a molecule of monoglyceride and two molecules of fatty acid."
11.
Bile salts and bile acids are generated from cholesterol and glycine or taurine in the:
Correct Answer
E. Hepatocytes in the liver
Explanation
Bile salts and bile acids are generated from cholesterol and glycine or taurine in the hepatocytes of the liver. The liver plays a crucial role in the synthesis and secretion of bile, which is essential for the digestion and absorption of dietary fats. Hepatocytes are responsible for synthesizing bile salts and bile acids from cholesterol, and these compounds are then transported to the gall bladder for storage and later release into the small intestine.
12.
For lipids to enter adipocytes from chylomicrons, the enzyme lipoprotein lipase in endothelial cells:
Correct Answer
C. Converts triglycerides in the chylomicrons into fatty acids and monoglycerides
Explanation
The enzyme lipoprotein lipase in endothelial cells converts triglycerides in chylomicrons into fatty acids and monoglycerides. This process allows the lipids to be taken up by adipocytes for storage or energy production.
13.
If you observe the smooth muscle of the gall bladder contract, the hormone that produced this response is likely:
Correct Answer
D. Cholecystokinin (CCK)
Explanation
Cholecystokinin (CCK) is a hormone that is released by the small intestine in response to the presence of fatty acids and amino acids. It stimulates the contraction of the smooth muscle in the gall bladder, causing it to contract and release bile into the small intestine. This helps in the digestion and absorption of fats. Secretin, gastrin, histamine, and glucagon do not have a direct effect on the contraction of the gall bladder, making cholecystokinin the most likely hormone responsible for this response.
14.
In the process of digestion _____ enter the subclavian vein from the lymphatic system.
Correct Answer
D. Chylomicrons
Explanation
Chylomicrons are large lipoprotein particles that are formed in the small intestine during the digestion of dietary fats. They are responsible for transporting dietary fats, including triglycerides, from the small intestine to the bloodstream. Chylomicrons are then taken up by the lymphatic system and eventually enter the subclavian vein, where they are transported to various tissues and organs throughout the body. Therefore, chylomicrons enter the subclavian vein from the lymphatic system during the process of digestion.
15.
Hexose sugars that diffuse across the basilar membrane of intestinal epithelial cells first enter the:
Correct Answer
C. Hepatic portal vein
Explanation
Hexose sugars that diffuse across the basilar membrane of intestinal epithelial cells first enter the hepatic portal vein. The hepatic portal vein is responsible for transporting blood from the intestines to the liver. This allows the liver to process and metabolize the nutrients absorbed from the intestines before they are distributed to the rest of the body. By entering the hepatic portal vein, the hexose sugars can be efficiently processed by the liver before being released into the general circulation.
16.
Type II diabetes results from the lack of _____ where as Type I diabetes results from a lack of _____ .
Correct Answer
B. Functional insulin receptors, functional pancreatic beta cells
Explanation
Type II diabetes results from the lack of functional insulin receptors, while Type I diabetes results from a lack of functional pancreatic beta cells. In Type II diabetes, the body's cells become resistant to insulin, leading to high blood sugar levels. This is often associated with lifestyle factors such as obesity and physical inactivity. In Type I diabetes, the immune system mistakenly attacks and destroys the pancreatic beta cells, which are responsible for producing insulin. This results in a complete deficiency of insulin, requiring individuals to take insulin injections to regulate their blood sugar levels.
17.
Individuals who can most effectively gain nutrition from milk can absorb _____ digested from _____ .
Correct Answer
B. Glucose, lactose
Explanation
Glucose is the correct answer because it is the main source of energy for the body and can be easily absorbed. Lactose is also the correct answer because it is the primary sugar found in milk and needs to be broken down into glucose and galactose before it can be absorbed. Therefore, individuals who can effectively gain nutrition from milk can absorb glucose that is digested from lactose.
18.
After a large meal of bread and spaghetti you would expect _____ cells in the endocrine pancreas to be secreting ____ .
Correct Answer
C. Beta cells, insulin
Explanation
After consuming a meal high in carbohydrates like bread and spaghetti, the body's blood sugar levels increase. In response to this, the beta cells in the endocrine pancreas secrete insulin. Insulin helps to lower blood sugar levels by allowing cells to take in glucose from the bloodstream for energy or storage. Therefore, the correct answer is beta cells, insulin.
19.
Which of the following is NOT a brush border enzyme?
Correct Answer
D. Amylase
Explanation
Amylase is not a brush border enzyme. Brush border enzymes are enzymes that are found on the surface of the microvilli in the small intestine and are responsible for the final breakdown of carbohydrates, proteins, and fats. Sucrase, maltase, carboxypeptidase, and lactase are all examples of brush border enzymes involved in the digestion of carbohydrates and proteins. Amylase, on the other hand, is an enzyme produced by the salivary glands and pancreas that begins the digestion of carbohydrates in the mouth and continues in the small intestine.
20.
Amino acids in the small intestine move from the lumen of the small intestine into the epithelial cells by:
Correct Answer
D. Cotransport with Na+
Explanation
Amino acids in the small intestine move from the lumen of the small intestine into the epithelial cells by cotransport with Na+. This means that they are transported together with sodium ions across the cell membrane. This process is facilitated by a protein transporter that couples the movement of sodium ions with the movement of amino acids. This mechanism allows for efficient absorption of amino acids from the small intestine into the bloodstream.
21.
Elastic recoil of the lungs:
Correct Answer
E. All of the above are correct
Explanation
The elastic recoil of the lungs refers to their ability to return to their original shape after being stretched during inhalation. This recoil, if not opposed, would cause the lungs to collapse. However, when combined with the elastic recoil properties of the chest wall, it creates a subatmospheric intrapleural pressure. This pressure difference between the intrapleural space and the lungs forces air to leave the lungs during expiration. Therefore, both statements a and b are correct. Additionally, since all the statements are correct, the answer is "all of the above".
22.
An infant born with immature type II alveolar cells:
Correct Answer
A. Will have abnormally low lung compliance
Explanation
An infant born with immature type II alveolar cells will have abnormally low lung compliance. Lung compliance refers to the ability of the lungs to expand and contract. Immature type II alveolar cells produce surfactant, a substance that reduces surface tension in the alveoli and helps them to expand during inhalation. Without sufficient surfactant production, the alveoli may not be able to expand properly, resulting in decreased lung compliance. This can lead to difficulties in breathing and impaired gas exchange.
23.
The respiratory disease that results from excessive constriction of the smooth muscle that lines the airways is:
Correct Answer
A. Asthma
Explanation
Asthma is the correct answer because it is a respiratory disease that is characterized by excessive constriction of the smooth muscle lining the airways. This constriction leads to difficulty in breathing, wheezing, and coughing. Emphysema, chronic bronchitis, and chronic obstructive pulmonary disease (COPD) are all respiratory conditions, but they do not specifically involve excessive constriction of the smooth muscle in the airways like asthma does. Therefore, the correct answer is asthma.
24.
The conducting airways have a volume of about 150ml which is not capable of exchanging gases with the blood. This is referred to as:
Correct Answer
B. Anatomical dead space
Explanation
The conducting airways in the respiratory system, such as the trachea and bronchi, do not participate in gas exchange with the blood. This is because they do not have alveoli, which are the tiny air sacs where gas exchange occurs. The volume of these conducting airways is approximately 150ml, and this space is referred to as the anatomical dead space. Therefore, the correct answer is anatomical dead space.
25.
The vital capacity is the sum of:
Correct Answer
A. Tidal volume + inspiratory reserve volume + expiratory reserve volume
Explanation
The vital capacity is the maximum amount of air that can be exhaled after a maximum inhalation. It is calculated by summing up the tidal volume (the amount of air inhaled or exhaled during normal breathing), the inspiratory reserve volume (the additional amount of air that can be inhaled after a normal inhalation), and the expiratory reserve volume (the additional amount of air that can be exhaled after a normal exhalation). Therefore, the correct answer is tidal volume + inspiratory reserve volume + expiratory reserve volume.
26.
Which of the following statements regarding the transport of O2 in blood is true?
Correct Answer
C. Most of the O2 carried by blood is bound to iron
27.
Which of the following is the "most important (effective)" mode of transport of carbon dioxide in the blood?
Correct Answer
A. As bicarbonate
Explanation
Bicarbonate is the most important mode of transport of carbon dioxide in the blood because it accounts for the majority of carbon dioxide transport. Carbon dioxide combines with water in the red blood cells to form carbonic acid, which then dissociates into bicarbonate ions and hydrogen ions. The bicarbonate ions are then transported out of the red blood cells into the plasma, where they are carried to the lungs to be eliminated. This process allows for efficient transport of carbon dioxide from the tissues to the lungs for exhalation.
28.
Central chemoreceptors which participate in the regulation of ventilation respond most directly to:
Correct Answer
C. H+
Explanation
Central chemoreceptors are responsible for regulating ventilation, specifically by monitoring the levels of carbon dioxide (PCO2) and hydrogen ions (H+) in the blood. These chemoreceptors are sensitive to changes in the acidity of the blood, which is primarily determined by the concentration of H+. When the levels of H+ increase, indicating higher acidity, the central chemoreceptors signal the respiratory system to increase ventilation in order to eliminate excess carbon dioxide and restore normal blood pH levels. Therefore, H+ is the correct answer as it directly affects the central chemoreceptors and their regulation of ventilation.
29.
Which of the following will cause the partial pressure of oxygen in the alveoli (pressureO2) to increase?
Correct Answer
D. All of the above would increase the pressureO2 in the alveoli
Explanation
An increase in the pressureO2 in the surrounding air would cause the partial pressure of oxygen in the alveoli to increase because the alveoli exchange gases with the surrounding air. A decrease in the rate of oxygen consumption by the cells of the body would also cause the pressureO2 in the alveoli to increase because less oxygen is being taken up by the cells, allowing more oxygen to remain in the alveoli. Additionally, an increase in the rate and depth of ventilation would increase the pressureO2 in the alveoli because it would enhance the exchange of gases, increasing the amount of oxygen entering the alveoli. Therefore, all of the above factors would contribute to an increase in the pressureO2 in the alveoli.
30.
The major automatic (involuntary) regulatory centers for respiration, especially the inspiratory centers, are located in the _____ region of the brain.
Correct Answer
D. Medulla
Explanation
The medulla is the correct answer because it is the region of the brain that contains the major automatic regulatory centers for respiration, including the inspiratory centers. The medulla is responsible for controlling the basic rhythm and pattern of breathing, ensuring that the body receives enough oxygen and removes carbon dioxide. The other options, such as the spinal cord, cerebral cortex, and diencephalon, are not directly involved in the regulation of respiration.
31.
Functions of the respiratory system include:
Correct Answer
E. All of the above are correct
Explanation
The respiratory system performs various functions, including the regulation of blood pH, protection against microbes, and the production of sounds used for speaking. These functions are essential for maintaining the body's overall health and functioning. By regulating blood pH, the respiratory system helps to maintain the body's acid-base balance. It also plays a role in protecting against microbes by trapping and removing harmful particles from the air we breathe. Additionally, the respiratory system is responsible for producing sounds that are used for speaking. Therefore, all of the above options are correct functions of the respiratory system.
32.
_____ , released from the juxtaglomerular cells, affects _____ .
Correct Answer
A. Renin, blood pressure
Explanation
Renin is an enzyme released from the juxtaglomerular cells. It plays a crucial role in regulating blood pressure. Renin acts on angiotensinogen, a plasma protein produced by the liver, and converts it into angiotensin I. Angiotensin I is then converted to angiotensin II by angiotensin-converting enzyme (ACE). Angiotensin II is a potent vasoconstrictor, causing the blood vessels to constrict and increasing blood pressure. It also stimulates the release of aldosterone from the adrenal glands, which promotes sodium (Na+) resorption in the kidneys, leading to increased blood volume and further elevation of blood pressure. Therefore, the correct answer is renin, blood pressure.
33.
Glucose and amino acids are resorbed almost entirely in the:
Correct Answer
E. Proximal convoluted tubule
Explanation
The proximal convoluted tubule is responsible for the reabsorption of glucose and amino acids in the kidney. This is where the majority of these substances are reabsorbed back into the bloodstream from the filtrate. The vasa recta is a network of blood vessels that surrounds the tubules and helps maintain the concentration gradient in the renal medulla. The distal convoluted tubule and glomerulus are involved in further processing and filtration of the urine, but not in the reabsorption of glucose and amino acids. Therefore, the correct answer is the proximal convoluted tubule.
34.
Blood in the paratubular capillaries where they first contact the proximal convoluted tubule contains a high concentration of _____ to produce a(n) _____ pressure gradient allowing water to return to the capillary.
Correct Answer
D. Albumin, osmotic
35.
Cells of the macula densa recognize changes in _____ and contribute to the control of the _____ .
Correct Answer
B. NaCl concentration, glomerular filtration rate
Explanation
The cells of the macula densa in the kidneys are responsible for detecting changes in the concentration of sodium chloride (NaCl). These cells play a crucial role in regulating the glomerular filtration rate (GFR), which is the rate at which blood is filtered by the kidneys. When the macula densa cells sense a decrease in NaCl concentration, they signal for the dilation of the afferent arteriole, which increases the GFR. Conversely, an increase in NaCl concentration leads to constriction of the afferent arteriole and a decrease in GFR. Therefore, the correct answer is NaCl concentration, glomerular filtration rate.
36.
The region of the kidney where the glomeruli and Bowman's capsules are located is the:
Correct Answer
D. Renal cortex
Explanation
The renal cortex is the correct answer because it is the outer region of the kidney where the glomeruli and Bowman's capsules are located. The glomeruli and Bowman's capsules are part of the renal corpuscle, which is responsible for the initial filtration of blood in the kidney. The renal pyramid, renal calyx, renal medulla, and afferent arteriole are not the specific regions where the glomeruli and Bowman's capsules are located.
37.
If the adrenal cortex overproduces aldosterone, as happens in Cushing's disease:
Correct Answer
E. All of the above are correct
Explanation
In Cushing's disease, the adrenal cortex overproduces aldosterone, which leads to an abnormally large number of Na+ channels being incorporated in the apical plasma membranes of epithelial cells in the distal convoluted tubule. Additionally, there is an abnormally large number of Na+/K+ ATPases incorporated in the basilar membrane of these cells. This results in an abnormally large amount of Na+ returning to the paratubular capillaries around the distal convoluted tubule, causing Na+ ion concentrations to become abnormally high and water to be retained. Therefore, all of the given statements are correct.