1.
Angiotensin 1 is formed from the plasma protein ______ by the action of the enzyme ______
Correct Answer
A. Angiotensinogen, rennin
Explanation
Angiotensin 1 is formed from the plasma protein angiotensinogen by the action of the enzyme renin.
2.
Sympathatic nervous system stimulation will lead to
Correct Answer
B. Stimulation to adrenal medulla causing release of epinepHrine and norepinepHrine
Explanation
Sympathetic nervous system stimulation activates the adrenal medulla, which releases epinephrine and norepinephrine. These hormones increase heart rate, contractility, and venous return. Therefore, the correct answer is that sympathetic nervous system stimulation leads to stimulation of the adrenal medulla, causing the release of epinephrine and norepinephrine.
3.
The main site for delay in conductivity for heart conduction system is
Correct Answer
C. AV node
Explanation
The AV node is the main site for delay in conductivity for the heart conduction system. This node is located between the atria and the ventricles and acts as a gatekeeper, slowing down the electrical signals coming from the atria before they reach the ventricles. This delay allows for proper coordination and synchronization of the atria and ventricles, ensuring efficient pumping of blood. Without this delay, the ventricles would contract too soon, leading to inefficient blood flow.
4.
Which of the following pairs is incorrect
Correct Answer
A. PR interval: repolarization of the atrium
Explanation
The given pair "PR interval: repolarization of the atrium" is incorrect because the PR interval represents the time it takes for the electrical impulse to travel from the atria to the ventricles and includes both atrial depolarization and the delay at the atrioventricular node. Repolarization of the atrium is represented by the T wave.
5.
Which of the following vessels has the largest effect on total peripheral resistance
Correct Answer
B. Arterioles
Explanation
Arterioles have the largest effect on total peripheral resistance. Arterioles are small blood vessels that regulate blood flow to the capillaries. They have smooth muscle in their walls, allowing them to constrict or dilate and control the amount of blood flowing through them. By constricting, arterioles increase resistance to blood flow, leading to higher total peripheral resistance. This helps regulate blood pressure and control blood distribution to different organs and tissues. Veins, large arteries, and capillaries have less influence on total peripheral resistance compared to arterioles.
6.
During exercise all of the following occur except
Correct Answer
C. Vasoconstriction of coronary arteries
Explanation
During exercise, the body requires increased blood flow to the working muscles. This is achieved through vasodilation of peripheral arteries, allowing more blood to flow through them. Additionally, the heart rate increases to pump more blood to the muscles. The cardiac output, which is the amount of blood pumped by the heart per minute, also increases during exercise. However, vasoconstriction of coronary arteries does not occur during exercise. The coronary arteries supply blood to the heart muscle itself, and constriction of these arteries would limit the blood flow and oxygen supply to the heart, which is not desirable during exercise when the heart needs more oxygen.
7.
Which of the following is not a mechanism to promote venous return and reduce blood pooling
Correct Answer
A. Parasympathatic stimulation
Explanation
Parasympathetic stimulation is not a mechanism to promote venous return and reduce blood pooling. Parasympathetic stimulation primarily slows down the heart rate and promotes rest and digestion, rather than increasing blood flow or constricting veins. Veins constriction, increase in blood volume, and sympathetic stimulation are all mechanisms that help promote venous return and reduce blood pooling.
8.
Right ventricular afterload is determined by
Correct Answer
C. Palmunary vascular resistance
Explanation
Right ventricular afterload is determined by pulmonary vascular resistance. Afterload refers to the resistance that the heart must overcome to pump blood out into the circulation. In the case of the right ventricle, it pumps blood into the pulmonary circulation. The resistance in the pulmonary blood vessels, known as pulmonary vascular resistance, determines the afterload for the right ventricle. If the pulmonary vascular resistance is high, the right ventricle has to work harder to pump blood into the lungs, leading to increased strain on the heart. Therefore, pulmonary vascular resistance is a crucial factor in determining right ventricular afterload.
9.
Which of the following hormones is regulated directly by hypothalmus
Correct Answer
A. Prolactin
Explanation
Prolactin is directly regulated by the hypothalamus. The hypothalamus produces and releases dopamine, which inhibits the release of prolactin from the pituitary gland. When dopamine levels decrease, the inhibition is lifted, leading to an increase in prolactin secretion. This regulation is important for the control of lactation in females and plays a role in reproductive function and behavior in both males and females.
10.
One of the following is equivelant to G-protein coupled receptors
Correct Answer
C. Muscarinic receptors
Explanation
Muscarinic receptors are a type of G-protein coupled receptor (GPCR). GPCRs are a large family of cell surface receptors that are involved in signal transduction. They are activated by a ligand, such as a neurotransmitter or hormone, which then triggers a series of intracellular signaling events through the G-protein. Muscarinic receptors specifically respond to acetylcholine and are found in various tissues, including the central and peripheral nervous systems. Therefore, muscarinic receptors are equivalent to G-protein coupled receptors.
11.
Which of the following best describes oxytocin action
Correct Answer
B. Enhance milk release
Explanation
Oxytocin is a hormone that is responsible for stimulating contractions of the uterus during childbirth and also plays a role in milk release during breastfeeding. It acts on the smooth muscles of the breast, causing them to contract and release milk. Therefore, the best description of oxytocin's action is to enhance milk release.
12.
Which of the following enzymes will reduce the amount of cyclic AMP inside the cell
Correct Answer
B. pHospHodiesterase
Explanation
Phosphodiesterase is the correct answer because it is an enzyme that breaks down cyclic AMP into non-cyclic AMP, effectively reducing the amount of cyclic AMP inside the cell. Protein kinase A, adenylate cyclase, and phospholipase C do not directly reduce the amount of cyclic AMP.
13.
Hormone released from posterior pituitary gland will be synthesized in
Correct Answer
C. Hypothalmus
Explanation
The hormone released from the posterior pituitary gland is synthesized in the hypothalamus. The hypothalamus is a region of the brain that controls the release of hormones from the pituitary gland. It produces hormones that are then transported to the posterior pituitary gland, where they are stored and released into the bloodstream when needed. This process allows for the regulation of various bodily functions, such as water balance, blood pressure, and childbirth.
14.
Which of the following is not a type of signaling molecule
Correct Answer
B. Adenylate cyclase
Explanation
Adenylate cyclase is not a type of signaling molecule. It is an enzyme that converts ATP to cyclic AMP (cAMP), which is a second messenger molecule involved in intracellular signaling. Ca+2 and DAG are also signaling molecules, while cAMP is a type of signaling molecule. Therefore, the correct answer is Adenylate cyclase.
15.
Which of the following signaling molecule binds to a receptor situated in the cytosol rather than the outer membrane of the cell
Correct Answer
A. Progesterone
Explanation
Progesterone is the correct answer because it is a steroid hormone that can easily diffuse across the plasma membrane of the cell. Once inside the cell, progesterone binds to its receptor, which is located in the cytosol. This hormone-receptor complex then translocates to the nucleus, where it can regulate gene expression and cellular processes. In contrast, growth hormone, epinephrine, and ACTH all bind to receptors located on the outer membrane of the cell and initiate signaling cascades through membrane-bound receptors.
16.
Which of the following process involves combining a message with one signaling molecule with that of another to either enhance or inhibit a cellular effect
Correct Answer
A. Signal Integration
Explanation
Signal integration involves combining a message with one signaling molecule with that of another to either enhance or inhibit a cellular effect. This process allows for the coordination and regulation of multiple signals to generate a specific cellular response. It involves the integration of different signaling pathways to achieve a more complex and precise cellular response. Cross-talk refers to the communication between different signaling pathways, while signal transduction is the process by which a signal is transmitted from the cell surface to the nucleus. Signal combination is not a recognized term in the context of cellular signaling.
17.
Which of the following is not a part of the dead space
Correct Answer
A. Alveoli
Explanation
The dead space refers to the areas in the respiratory system where no gas exchange occurs. The alveoli, on the other hand, are the tiny air sacs in the lungs where gas exchange takes place. Therefore, the alveoli are not a part of the dead space.
18.
Which of the following keeps the lungs inflated
Correct Answer
B. Surfactant
Explanation
Surfactant is a substance produced by the cells in the alveoli of the lungs. It helps to reduce the surface tension of the alveoli, preventing them from collapsing and keeping the lungs inflated. Without surfactant, the alveoli would stick together and make it difficult for the lungs to expand and contract properly during breathing. Therefore, surfactant plays a crucial role in maintaining lung function and preventing respiratory issues.
19.
The volume of gas in the lungs is at the end of maximal inspration is referred to as the
Correct Answer
B. Total lung capacity
Explanation
Total lung capacity refers to the maximum volume of gas that can be held in the lungs after a maximal inspiration. It is the sum of all the lung volumes, including tidal volume (the volume of air inhaled and exhaled during normal breathing), inspiratory reserve volume (the additional volume of air that can be inhaled after a normal inspiration), and expiratory reserve volume (the additional volume of air that can be exhaled after a normal expiration). Therefore, total lung capacity represents the maximum amount of air that the lungs can hold.
20.
CO2 in the blood is mainly transported in the form of
Correct Answer
A. Bicarbonate
Explanation
CO2 in the blood is mainly transported in the form of bicarbonate. When CO2 enters the red blood cells, it combines with water to form carbonic acid, which then dissociates into bicarbonate and hydrogen ions. Bicarbonate is then transported out of the red blood cells into the plasma, where it can be carried to the lungs for elimination. This bicarbonate transport mechanism is the primary way in which CO2 is transported in the blood, accounting for the majority of CO2 transport.
21.
At the end of maximum inspiration, the intra alveolar pressure is
Correct Answer
C. Same as atmospHeric pressure [0]
Explanation
At the end of maximum inspiration, the intra alveolar pressure is the same as atmospheric pressure [0]. During inspiration, the diaphragm contracts and the chest cavity expands, causing a decrease in intra-alveolar pressure. This decrease in pressure allows air to flow into the lungs. At the end of maximum inspiration, the intra-alveolar pressure returns to its baseline level, which is the same as atmospheric pressure.
22.
The pressure in pleural space
Correct Answer
B. Positive in valvular pneumothorax
Explanation
In valvular pneumothorax, the pressure in the pleural space becomes positive. Normally, the pressure in the pleural space is slightly negative compared to atmospheric pressure, which helps to keep the lungs inflated. However, in valvular pneumothorax, air enters the pleural space but cannot escape, leading to an increase in pressure. This positive pressure can compress the lungs and cause them to collapse, leading to symptoms such as difficulty breathing and chest pain.
23.
Which of the following is not part of function of kdneys
Correct Answer
A. Secrete antidiuritic hormones
Explanation
The kidneys do not secrete antidiuretic hormones. Antidiuretic hormones, such as vasopressin, are produced by the hypothalamus and released by the pituitary gland. They act on the kidneys to regulate water reabsorption and urine concentration. The main functions of the kidneys include regulating blood osmolarity, which is the balance of water and solutes in the blood, regulating blood volume by controlling the amount of water and electrolytes excreted in urine, and secreting erythropoietin and renin, which are involved in the production of red blood cells and regulation of blood pressure, respectively.
24.
The normal glomular filtration rate in adult male person is ________
Correct Answer
A. 125
Explanation
The normal glomerular filtration rate in an adult male person is 125. This rate refers to the amount of blood that is filtered by the glomeruli in the kidneys per minute. It is an important measure of kidney function and can help diagnose and monitor various kidney conditions.
25.
One of the following is correct about the kidney
Correct Answer
B. Maintaining blood osmolarity
Explanation
The kidney plays a crucial role in maintaining blood osmolarity, which refers to the balance of solute concentration in the blood. It does so by regulating the amount of water and electrolytes excreted in urine. By adjusting the reabsorption and excretion of these substances, the kidney helps to keep the blood osmolarity within a narrow range, ensuring that the body's cells can function properly. This is important for maintaining proper hydration, electrolyte balance, and overall homeostasis in the body.
26.
Most of the sodium in filtrate will be reabsorbed in
Correct Answer
A. Proximal tubule
Explanation
The proximal tubule is responsible for the reabsorption of the majority of sodium in the filtrate. This is because the proximal tubule is the first segment of the renal tubule and is highly specialized for reabsorption. It has a brush border of microvilli that increases its surface area, allowing for efficient reabsorption of sodium and other solutes. Additionally, the proximal tubule actively transports sodium out of the tubular fluid and into the surrounding peritubular capillaries, maintaining sodium balance in the body.
27.
Which of the following will increase GFR:
Correct Answer
C. Efferent arteriole constriction
Explanation
Efferent arteriole constriction will increase GFR. The glomerular filtration rate (GFR) is the rate at which fluid is filtered through the glomerulus in the kidney. Constriction of the efferent arteriole, the blood vessel that carries blood away from the glomerulus, will increase the resistance to blood flow and cause an increase in the pressure within the glomerulus. This increased pressure will result in an increased filtration rate, leading to a higher GFR. Afferent arteriole constriction, on the other hand, would decrease GFR, while efferent arteriole dilation and none of the above options would not have a direct effect on GFR.
28.
All of the following will be filtrated in Glomelurus except
Correct Answer
D. Plasma Protein
Explanation
Glomelurus is a part of the renal filtration system in the kidneys. It is responsible for filtering waste products, excess water, and certain substances from the blood to form urine. Glucose, amino acids, and sodium ions are small molecules that can easily pass through the filtration membrane of Glomelurus and be filtered out. However, plasma proteins are larger molecules that are not normally filtered by Glomelurus. Therefore, plasma proteins would not be filtrated in Glomelurus.
29.
Suppose that we have 500mg of glucose in blood, calculate the amount of filtered glucose
Correct Answer
D. 100mg
Explanation
The question asks for the amount of filtered glucose, which implies that some of the glucose is being removed from the blood. Since the question does not provide any information about the filtration rate or any other relevant factors, it is not possible to accurately calculate the amount of filtered glucose. Therefore, the answer is not available.
30.
The percentage of urea reabsorbed back is
Correct Answer
C. 50%
Explanation
The correct answer is 50%. This means that 50% of the urea is reabsorbed back into the body. Urea is a waste product that is produced in the liver and excreted through the kidneys. However, a certain amount of urea is reabsorbed by the renal tubules back into the bloodstream. In this case, 50% of the urea is reabsorbed, while the remaining 50% is excreted in the urine.