Internal Environment And Homeostasis Trivia Quiz
Are you aware of Internal environment and homeostasis? If you have learned about the process, there are a lot of things that take place when it comes to the human body and its adaptation to changes. Do you feel like you know enough to help you pass this test? Well take up the quiz below and get to find out for sure.
- 1.
Which of the following fluids constitutes a portion of the internal environment:
- A.
Interstitial fluid
- B.
Plasma
- C.
Both
- D.
Neither
Correct Answer
C. BothExplanation
Both interstitial fluid and plasma constitute a portion of the internal environment. Interstitial fluid is the fluid that surrounds and bathes the cells, while plasma is the fluid component of blood. Both of these fluids play important roles in maintaining the internal environment of the body by transporting nutrients, oxygen, and waste products between cells and organs.Rate this question:
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- 2.
Homeostasis refers to the:
- A.
Ability of humans to stand on two feet
- B.
Capability to control the external surroundings of the organism
- C.
Nearly constant conditions that are maintained in the internal environment of multicellular organisms
Correct Answer
C. Nearly constant conditions that are maintained in the internal environment of multicellular organismsExplanation
Homeostasis refers to the nearly constant conditions that are maintained in the internal environment of multicellular organisms. This includes the regulation of body temperature, pH levels, blood sugar levels, and other physiological processes to ensure optimal functioning of the organism. Homeostasis is essential for the survival and proper functioning of cells, tissues, and organs within the body.Rate this question:
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- 3.
Select the response demonstrating homeostasis
- A.
Blood sugar drops during starvation
- B.
Body temperature rises during fever
- C.
The acidity of the extracellular fluid remains the same as diet changes
- D.
An individual slips into irreversible shock
Correct Answer
C. The acidity of the extracellular fluid remains the same as diet changesExplanation
The correct answer is "the acidity of the extracellular fluid remains the same as diet changes." This response demonstrates homeostasis because it shows that the body is able to maintain a stable pH level in the extracellular fluid despite changes in the diet. Homeostasis is the body's ability to regulate and maintain a stable internal environment, and in this case, it is maintaining the acid-base balance within a narrow range.Rate this question:
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- 4.
Interstitial fluid is:
- A.
Larger in volume than the plasma volume
- B.
One of the extracellular fluids in the body
- C.
Part of the internal environment
- D.
The region found between cells
- E.
All of the above
Correct Answer
E. All of the aboveExplanation
The interstitial fluid is a component of the extracellular fluid in the body and is larger in volume than the plasma volume. It is found between cells and is considered part of the internal environment. Therefore, all of the given statements are correct.Rate this question:
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- 5.
Plasma osmolarity:
- A.
Has a range of 290 to 310 mOsmoles
- B.
Is critical for maintaining fluid compartmentalization
- C.
Is important for proper cell function
- D.
Is equal to extracellular fluid osmolarity
- E.
All of the above
Correct Answer
E. All of the aboveExplanation
The plasma osmolarity has a range of 290 to 310 mOsmoles, which means that it falls within this specific range. It is critical for maintaining fluid compartmentalization, as it helps to regulate the movement of fluids between different compartments in the body. Additionally, plasma osmolarity is important for proper cell function, as it affects the balance of water and solutes within cells. Lastly, plasma osmolarity is equal to extracellular fluid osmolarity, meaning that they have the same concentration of solutes. Therefore, all of the statements mentioned above are correct.Rate this question:
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- 6.
If a decrease in blood pressure were the stimulus for a negative feedback control system, the response produced by the effector cells of the control system would:
- A.
Decrease blood pressure
- B.
Increase blood pressure
- C.
No change blood pressure
Correct Answer
B. Increase blood pressureExplanation
If a decrease in blood pressure were the stimulus for a negative feedback control system, the response produced by the effector cells of the control system would be to increase blood pressure. In a negative feedback system, the response works to oppose the original stimulus and restore the system to its normal state. Therefore, when blood pressure decreases, the effector cells would work to increase it back to the normal level.Rate this question:
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- 7.
A decrease in the hematocrit of a patient from 55% to 40% could occur if there was a (n):
- A.
Increase in erythrocyte production
- B.
Decrease in blood plasma volume
- C.
Insufficient vitamin B12
- D.
Both a and b are correct
- E.
None of the above are correct
Correct Answer
C. Insufficient vitamin B12Explanation
A decrease in hematocrit refers to a decrease in the percentage of red blood cells in the blood. This can occur due to various reasons, such as a decrease in erythrocyte production or a decrease in blood plasma volume. However, in this case, the correct answer is insufficient vitamin B12. Vitamin B12 is essential for the production of healthy red blood cells, and a deficiency in this vitamin can lead to a decrease in hematocrit levels.Rate this question:
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- 8.
Which of the following will stimulate the production of erythrocytes by the bone marrow:
- A.
Increased arterial oxygen partial pressure
- B.
Increased circulating concentrations of glucocorticoids
- C.
Increased circulating erythropoietin
- D.
All of the above
Correct Answer
C. Increased circulating erythropoietinExplanation
Increased circulating erythropoietin stimulates the production of erythrocytes by the bone marrow. Erythropoietin is a hormone produced by the kidneys in response to low oxygen levels in the blood. It acts on the bone marrow to increase the production and maturation of red blood cells, which carry oxygen throughout the body. Therefore, when circulating erythropoietin levels are increased, it signals the bone marrow to produce more erythrocytes, leading to an increase in red blood cell production.Rate this question:
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- 9.
Blood flowing from the lungs to the heart in the pulmonary veins enters the:
- A.
Left atrium
- B.
Left ventricle
- C.
Right atrium
- D.
Right ventricle
Correct Answer
A. Left atriumExplanation
The pulmonary veins carry oxygenated blood from the lungs back to the heart. This oxygenated blood enters the left atrium of the heart. From the left atrium, the blood will then pass through the mitral valve into the left ventricle before being pumped out to the rest of the body. Therefore, the correct answer is left atrium.Rate this question:
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- 10.
A decrease in the value of which of the following will increase resistance to blood flow:
- A.
Blood vessel length
- B.
Blood vessel radius
- C.
Blood vessel viscosity
Correct Answer
B. Blood vessel radiusExplanation
A decrease in blood vessel radius will increase resistance to blood flow. This is because the radius of a blood vessel directly affects its cross-sectional area. As the radius decreases, the cross-sectional area also decreases, resulting in a smaller space for blood to flow through. This leads to an increase in the velocity of blood flow and an increase in resistance. Conversely, an increase in blood vessel radius would result in a larger cross-sectional area, allowing for easier blood flow and decreased resistance.Rate this question:
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- 11.
Cardiac action potentials are transmitted from the pacemaker region throughout the rest of the heart by:
- A.
Gap junctions between adjacent cardiac muscle cells
- B.
Nerves from the pacemaker region that synapse on individual cardiac muscle cells
- C.
Paracrine agent released from cardiac muscle cells
- D.
Synapses between adjacent cardiac muscle cells
Correct Answer
A. Gap junctions between adjacent cardiac muscle cellsExplanation
Cardiac action potentials are transmitted from the pacemaker region throughout the rest of the heart by gap junctions between adjacent cardiac muscle cells. Gap junctions are specialized protein channels that allow for direct electrical communication between cells, allowing the action potential to spread rapidly and efficiently. These gap junctions ensure that the depolarization wave is transmitted smoothly and synchronously, allowing for coordinated contraction of the entire heart. Nerves from the pacemaker region do not directly synapse on individual cardiac muscle cells, paracrine agents are not involved in transmitting action potentials, and synapses between adjacent cardiac muscle cells are not present in the heart.Rate this question:
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- 12.
The ion principally responsible for the resting membrane potential is:
- A.
Calcium
- B.
Chloride
- C.
Potassium
- D.
Sodium
Correct Answer
C. PotassiumExplanation
Potassium is the ion principally responsible for the resting membrane potential. This is because there is a higher concentration of potassium ions inside the cell compared to outside. This concentration gradient creates an electrochemical gradient, where potassium ions tend to move out of the cell. However, the cell membrane is selectively permeable to potassium ions, allowing only a small fraction of them to leave. This results in a negative charge inside the cell, leading to the resting membrane potential.Rate this question:
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- 13.
The plateau phase of the cardiac action potential is the result of an increased membrane permeability to:
- A.
Calcium ions
- B.
Chloride ions
- C.
Potassium ions
- D.
Sodium ions
Correct Answer
A. Calcium ionsExplanation
During the plateau phase of the cardiac action potential, there is a sustained depolarization of the cell membrane. This is primarily due to the increased membrane permeability to calcium ions. Calcium ions enter the cell through voltage-gated calcium channels, which prolongs the depolarization phase and allows for the contraction of cardiac muscle. The influx of calcium ions also triggers the release of additional calcium ions from the sarcoplasmic reticulum, leading to further muscle contraction. Therefore, the increased permeability to calcium ions is responsible for the plateau phase and the subsequent contraction of the heart.Rate this question:
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- 14.
If the SA node of the heart were destroyed, the atria and the ventricles would no longer contact
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
If the SA node of the heart were destroyed, the atria and ventricles would still be able to contract, although not in a coordinated manner. This is because the SA node, also known as the natural pacemaker of the heart, initiates electrical impulses that regulate the heart's rhythm. However, if the SA node is destroyed, other cells in the heart, such as the AV node or Purkinje fibers, can take over the pacemaking function, albeit at a slower rate. This would result in a slower and less coordinated contraction of the atria and ventricles, but they would still be able to contract.Rate this question:
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- 15.
Which of the following is responsible for the change in resting membrane potential in the ischemic zone of the heart?
- A.
The permeability of ions is altered
- B.
The Na+ / K+ ATPase pumps have limited action
- C.
The gap junctions no longer facilitate conduction
Correct Answer
B. The Na+ / K+ ATPase pumps have limited actionExplanation
In the ischemic zone of the heart, the change in resting membrane potential is due to the limited action of the Na+/K+ ATPase pumps. These pumps are responsible for maintaining the concentration gradients of sodium and potassium ions across the cell membrane. In ischemia, there is reduced oxygen supply to the heart muscle, leading to a decrease in ATP production. As a result, the activity of the Na+/K+ ATPase pumps is compromised, leading to an imbalance in ion concentrations and a change in resting membrane potential.Rate this question:
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- 16.
The T wave of the electrocardiogram corresponds with which phase of cardiac activity?
- A.
Contraction of the atria
- B.
Contraction of the ventricles
- C.
Relaxation of the atria
- D.
Relaxation of ventricles
Correct Answer
D. Relaxation of ventriclesExplanation
The T wave of the electrocardiogram corresponds with the relaxation of the ventricles. This is because the T wave represents the repolarization of the ventricles, which occurs during the relaxation phase of the cardiac cycle. During this phase, the ventricles are filling with blood and preparing for the next contraction. The T wave is an important marker on the ECG that helps in diagnosing various cardiac abnormalities.Rate this question:
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- 17.
The heart is innervated by the:
- A.
Autonomic nervous system
- B.
Central nervous system
- C.
Peripheral nervous system
- D.
Both A and C are correct
- E.
All of the above
Correct Answer
D. Both A and C are correctExplanation
The heart is innervated by both the autonomic nervous system and the peripheral nervous system. The autonomic nervous system controls the involuntary functions of the heart, such as heart rate and blood pressure, while the peripheral nervous system controls the voluntary functions, such as the sensation of pain in the heart. Therefore, both options A and C are correct.Rate this question:
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- 18.
Atropine is a drug that blocks the action of acetylcholine at muscarinic receptors. How will the administration of atropine affect heart rate?
- A.
Heart rate will increase
- B.
Heart rate will decrease
- C.
Heart rate will not change
Correct Answer
A. Heart rate will increaseExplanation
Atropine is a drug that blocks the action of acetylcholine at muscarinic receptors. Acetylcholine normally slows down the heart rate by binding to muscarinic receptors in the heart. By blocking the action of acetylcholine, atropine prevents this slowing effect and allows other factors that increase heart rate to dominate. Therefore, the administration of atropine will increase heart rate.Rate this question:
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- 19.
A patient presents with a hematocrit of 68%. What additional piece of evidence from the choices below would be of the greatest help in differentiating a diagnosis for this patient?
- A.
Blood pressure
- B.
Heart rate
- C.
Hemoglobin levels
- D.
Leukocyte count
Correct Answer
C. Hemoglobin levelsExplanation
Hematocrit is a measure of the volume percentage of red blood cells in the blood. A hematocrit of 68% indicates an abnormally high concentration of red blood cells, which could be indicative of conditions such as polycythemia or dehydration. Hemoglobin levels, which represent the amount of oxygen-carrying protein in the red blood cells, would provide additional information to confirm or rule out these conditions. Therefore, checking the hemoglobin levels would be the most helpful piece of evidence in differentiating a diagnosis for this patient.Rate this question:
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- 20.
With a hematocrit of 68%, what is the best differential diagnosis?
- A.
Increased red blood cell formation or increased erythropoietin
- B.
Increased red blood cell formation or decreased red blood cell destruction
- C.
Increased red blood cell numbers or reduced blood plasma volume
- D.
Decreased red blood cell numbers or increased blood plasma volume
Correct Answer
C. Increased red blood cell numbers or reduced blood plasma volumeExplanation
The correct answer is increased red blood cell numbers or reduced blood plasma volume. A hematocrit of 68% indicates a high concentration of red blood cells in the blood. This can be caused by either an increase in red blood cell production or a decrease in blood plasma volume. Both of these conditions can lead to an elevated hematocrit level.Rate this question:
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- 21.
The volume of blood pumped by each ventricle during one cardiac cycle is:
- A.
Cardiac output
- B.
End diastolic volume
- C.
End systolic volume
- D.
Stroke volume
Correct Answer
D. Stroke volumeExplanation
Stroke volume refers to the volume of blood pumped by each ventricle during one cardiac cycle. It is the difference between the end diastolic volume (the volume of blood in the ventricle at the end of diastole) and the end systolic volume (the volume of blood in the ventricle at the end of systole). Therefore, stroke volume represents the amount of blood ejected from the ventricle with each heartbeat.Rate this question:
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- 22.
During mid-diastole:
- A.
All valves are closed
- B.
Aortic and pulmonary valves are open
- C.
Ventricular pressure is greater than atrial pressure
- D.
All of the above
- E.
None of the above
Correct Answer
E. None of the aboveExplanation
During mid-diastole, the ventricles are relaxed and filling with blood. At this stage, the atrioventricular valves (mitral and tricuspid) are open, allowing blood to flow from the atria into the ventricles. The semilunar valves (aortic and pulmonary) are closed to prevent backflow of blood into the ventricles. Ventricular pressure is lower than atrial pressure during mid-diastole, as the ventricles are in a relaxed state and not actively contracting. Therefore, the correct answer is "none of the above."Rate this question:
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- 23.
During isovolumetric ventricular contraction:
- A.
All valves into and out of the heart are closed
- B.
Blood is being ejected from the ventricles
- C.
Blood is flowing from the atria to the ventricles
- D.
All of the above
Correct Answer
A. All valves into and out of the heart are closedExplanation
During isovolumetric ventricular contraction, all valves into and out of the heart are closed. This means that the atrioventricular (AV) valves, which separate the atria from the ventricles, are closed to prevent blood from flowing back into the atria. Additionally, the semilunar valves, which separate the ventricles from the major arteries (aorta and pulmonary artery), are also closed to prevent blood from flowing back into the ventricles. As a result, no blood is being ejected from the ventricles and no blood is flowing from the atria to the ventricles. Therefore, the correct answer is that all valves into and out of the heart are closed.Rate this question:
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- 24.
Question 24if an individual has an aortic stenosis, then:
- A.
Blood will pass into the left ventricle from the aorta during diastole
- B.
Blood will not pass into the right ventricle from the right atrium
- C.
The ejection of blood into the left ventricle will be enhanced
- D.
The ejection of blood through the valve during systole will be restricted
Correct Answer
D. The ejection of blood through the valve during systole will be restrictedExplanation
If an individual has aortic stenosis, the ejection of blood through the valve during systole will be restricted. Aortic stenosis is a condition where the aortic valve, which allows blood to flow from the heart's left ventricle to the aorta, becomes narrowed. This narrowing obstructs the flow of blood, making it difficult for the heart to pump blood out to the body. As a result, the ejection of blood through the valve during systole, the contraction phase of the heart, will be restricted.Rate this question:
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- 25.
Question 25Insufficiency of the left AV valve will produce a murmur heard during:
- A.
Systole
- B.
Diastole
Correct Answer
A. SystoleExplanation
Insufficiency of the left AV valve, also known as mitral valve regurgitation, occurs when the valve does not close properly during systole (contraction of the ventricles). This allows blood to flow back into the left atrium, causing a characteristic murmur that can be heard during systole. During diastole (relaxation of the ventricles), the valve should be closed, so a murmur would not be heard during this phase.Rate this question:
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- 26.
Question 26With an increase in left atrial pressure, you would expect to find:
- A.
Pulmonary congestion
- B.
Peripheral edema
- C.
Increased right ventricular pressure
- D.
Both A and C
- E.
Both B and C
Correct Answer
D. Both A and CExplanation
An increase in left atrial pressure can lead to pulmonary congestion, as the increased pressure causes fluid to accumulate in the lungs. This can result in symptoms such as shortness of breath and coughing. Additionally, the increased left atrial pressure can cause an increase in right ventricular pressure, as the two chambers are connected. This can lead to right ventricular hypertrophy and eventually heart failure. Therefore, both options A and C are expected findings with an increase in left atrial pressure.Rate this question:
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- 27.
Question 27Which of the following will NOT increase stroke volume?
- A.
Increased end-diastolic volume
- B.
Increased contractility
- C.
Increased end-systolic volume
- D.
Increased stretch of the cardiac muscle fibers during ventricular filling
- E.
Increased venous return
Correct Answer
C. Increased end-systolic volumeExplanation
Increased end-systolic volume refers to the amount of blood remaining in the ventricle after contraction. Increasing this volume would not increase stroke volume because it represents the blood that is not being ejected from the heart during each contraction. Therefore, increasing end-systolic volume would actually decrease stroke volume.Rate this question:
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- 28.
Question 28Starling's law of the heart refers to the increase in the force of cardiac contraction produced by increased:
- A.
Cardiac muscle fiber length
- B.
Circulating epinephrine
- C.
SA node activation
- D.
Sympathetic stimulation
Correct Answer
A. Cardiac muscle fiber lengthExplanation
Starling's law of the heart states that the force of cardiac contraction increases with an increase in the length of the cardiac muscle fibers. This means that when the muscle fibers stretch, they generate a stronger contraction, allowing the heart to pump more blood with each beat. This mechanism helps the heart to adapt to changes in venous return and maintain an adequate cardiac output.Rate this question:
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- 29.
Question 29Release of calcium into the cytosol of cardiac muscle cells:
- A.
Decreases binding to troponin
- B.
Diminishes actin-myosin cross bridge binding
- C.
Is in response to acetylcholine activity in the heart
- D.
Leads to more force development in the heart
Correct Answer
D. Leads to more force development in the heartExplanation
The release of calcium into the cytosol of cardiac muscle cells leads to more force development in the heart. Calcium is a key regulator of cardiac muscle contraction. When calcium is released into the cytosol, it binds to troponin, which causes a conformational change in the troponin-tropomyosin complex. This change exposes the myosin-binding sites on actin, allowing actin and myosin to form cross-bridges and initiate muscle contraction. Therefore, an increase in calcium release results in increased force development in the heart.Rate this question:
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- 30.
Question 30Arterial pressure does not fall to zero in the arteries during diastole because:
- A.
Blood continues to flow through the heart even when its not beating
- B.
Contraction of the smooth muscle in the atrial walls maintains arterial pressure
- C.
Skeletal muscle contraction compress the arteries, maintaining arterial pressure
- D.
The elastic fibers in the walls of the arteries that were stretched during systole maintain the arterial pressure as they relax during diastole
Correct Answer
D. The elastic fibers in the walls of the arteries that were stretched during systole maintain the arterial pressure as they relax during diastoleExplanation
During systole, the contraction of the heart pushes blood into the arteries, causing them to stretch and expand. This stretching is due to the presence of elastic fibers in the arterial walls. These elastic fibers store potential energy during systole and then release it during diastole, helping to maintain the pressure in the arteries even when the heart is not actively pumping. This prevents the arterial pressure from falling to zero during diastole.Rate this question:
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- 31.
Question 31 MAP is:
- A.
Closer to diastolic pressure than systolic pressure
- B.
Closer to systolic pressure than to diastolic pressure
- C.
The average of the two pressures
Correct Answer
A. Closer to diastolic pressure than systolic pressureExplanation
MAP stands for mean arterial pressure, which represents the average pressure in the arteries during one cardiac cycle. It is calculated by adding one-third of the difference between systolic and diastolic pressure to the diastolic pressure. Since MAP takes into account both systolic and diastolic pressure, but gives more weight to diastolic pressure, it is closer to diastolic pressure than systolic pressure.Rate this question:
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- 32.
Question 32 Sympathetic fibers stimulate vascular smooth muscle to produce:
- A.
Vasoconstriction, decreased resistance
- B.
Vasoconstriction, increased resistance
- C.
Vasodilation, decreased resistance
- D.
Vasodilation, increased resistance
Correct Answer
B. Vasoconstriction, increased resistanceExplanation
Sympathetic fibers stimulate vascular smooth muscle to produce vasoconstriction, which refers to the narrowing of blood vessels. This narrowing increases resistance, meaning that it becomes more difficult for blood to flow through the vessels. This response is part of the body's fight or flight response and helps redirect blood flow to areas that need it most during times of stress or danger.Rate this question:
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- 33.
Question 33You are experiencing mild anxiety and stress at this point in the quiz and epinephrine is being released in low amount from the adrenal gland medulla. What is the physiological consequence of the stress?
- A.
B1 and B2 receptor activation elicits an increase in heart rate and vasodilation
- B.
B1 and B2 receptor activation elicits an increase in heart rate and vasoconstriction
- C.
B1 and muscarinic receptor activation elicits increased heart rate and vasodilation
- D.
B1 and B2 receptor activation elicits a decrease in heart rate and vasodilation
Correct Answer
D. B1 and B2 receptor activation elicits a decrease in heart rate and vasodilationExplanation
The correct answer is B1 and B2 receptor activation elicits a decrease in heart rate and vasodilation. When epinephrine is released in low amounts from the adrenal gland medulla during mild anxiety and stress, it activates both B1 and B2 receptors. Activation of these receptors leads to a decrease in heart rate (B1 receptor activation) and vasodilation (B2 receptor activation). This physiological response helps to counteract the effects of stress and anxiety, promoting a state of relaxation and reducing the impact of the stress on the body.Rate this question:
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- 34.
Question 34Venous return to the right atrium is increased by:
- A.
Increasing depth of respiration
- B.
Vigorous walking
- C.
An increase in ventricular contraction strength
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
Increasing depth of respiration, vigorous walking, and an increase in ventricular contraction strength all contribute to an increase in venous return to the right atrium. When the depth of respiration increases, it enhances the negative intrathoracic pressure, which helps in pulling the blood towards the heart. Vigorous walking increases the venous return by promoting the contraction of skeletal muscles, which squeeze the veins and propel the blood towards the heart. An increase in ventricular contraction strength results in a more forceful ejection of blood from the ventricles, leading to an increased venous return. Therefore, all of these factors contribute to an increased venous return to the right atrium.Rate this question:
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- 35.
Question 35The principle force that causes movement of the fluid from the tissues into the capillaries at rest is:
- A.
The hydrostatic pressure of the interstitial fluid
- B.
The hydrostatic pressure of the blood in the arteries
- C.
The osmotic pressure created by the plasma proteins
- D.
The osmotic pressure created by the interstitial proteins
- E.
None of the above
Correct Answer
C. The osmotic pressure created by the plasma proteinsExplanation
The correct answer is the osmotic pressure created by the plasma proteins. Osmotic pressure is the force that causes fluid to move across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. In this case, the plasma proteins create an osmotic gradient that draws fluid from the tissues into the capillaries. The hydrostatic pressure of the interstitial fluid and the hydrostatic pressure of the blood in the arteries may play a role in fluid movement, but they are not the primary forces at rest.Rate this question:
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- 36.
Question 36The net filtration of fluid from the arterial end of the capillaries to the interstitial fluid:
- A.
Normally exceeds the flow of the fluid into capillaries from the interstitial fluid
- B.
Provides most of the nutrients and oxygen delivered to a tissue
- C.
Is described by diffusion
- D.
Is described by bulk flow
- E.
Both A and D
Correct Answer
E. Both A and DExplanation
The correct answer is both A and D. The net filtration of fluid from the arterial end of the capillaries to the interstitial fluid normally exceeds the flow of the fluid into capillaries from the interstitial fluid. This is due to the process of bulk flow, which is the movement of fluid and solutes across a membrane driven by pressure differences. Bulk flow is responsible for the movement of nutrients, oxygen, and waste products between the capillaries and the surrounding tissues. Therefore, both options A and D are correct.Rate this question:
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- 37.
Question 37As a consequence of starvation or protein-deficient diet, the protein concentration:
- A.
Increases and water accumulates in the tissue spaces
- B.
Decreases and water accumulates in the tissue spaces
- C.
Increases and water accumulates in the tissue cells
- D.
Decreases and water accumulates in the tissue cells
Correct Answer
B. Decreases and water accumulates in the tissue spacesExplanation
Starvation or a protein-deficient diet can lead to a decrease in protein concentration in the body. This is because the body starts to break down its own proteins for energy when there is not enough protein intake from the diet. As a result, water accumulates in the tissue spaces as the decrease in protein concentration disrupts the balance of fluid in the body.Rate this question:
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- 38.
Question 38Rapid adjustments in systemic blood pressure are controlled by:
- A.
Autoregulation of arteriolar resistance
- B.
Baroreceptor reflexes
- C.
Chemoreceptor reflexes
- D.
Kidney regulation of blood volume
Correct Answer
B. Baroreceptor reflexesExplanation
Baroreceptor reflexes are responsible for rapid adjustments in systemic blood pressure. Baroreceptors are specialized nerve endings located in the walls of certain blood vessels, particularly in the carotid sinus and aortic arch. They detect changes in blood pressure and send signals to the brain to initiate appropriate responses to maintain blood pressure within a normal range. When blood pressure increases, the baroreceptors inhibit sympathetic activity and stimulate parasympathetic activity, causing vasodilation and decreased heart rate. Conversely, when blood pressure decreases, the baroreceptors stimulate sympathetic activity and inhibit parasympathetic activity, leading to vasoconstriction and increased heart rate. This reflex mechanism helps maintain blood pressure homeostasis.Rate this question:
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- 39.
Question 39 Each is a response to decreased systemic blood pressure from hemorrhage EXCEPT:
- A.
Arteriole dilation
- B.
Decreased parasympathetic discharge to the heart
- C.
Increased heart rate
- D.
There are no exceptions listed
Correct Answer
A. Arteriole dilationExplanation
This question is asking which response is not a result of decreased systemic blood pressure from hemorrhage. The correct answer is arteriole dilation. When there is decreased blood pressure due to hemorrhage, the body typically responds by increasing heart rate and decreasing parasympathetic discharge to the heart in order to maintain blood flow. Arteriole dilation, on the other hand, would actually help to increase blood flow and therefore would not be a response to decreased blood pressure.Rate this question:
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- 40.
Question 40 Following a hemorrhage, blood volume is partially restored by movement of fluid from the interstitial fluid compartment to the blood because:
- A.
Arteriole vasoconstriction decreases capillary blood pressure
- B.
Increased levels of circulating ADH increases the reabsorption of water
- C.
Of an increase in the return of lymph to the venous blood
- D.
Plasma protein concentration decreases
Correct Answer
A. Arteriole vasoconstriction decreases capillary blood pressureExplanation
Arteriole vasoconstriction decreases capillary blood pressure, which in turn increases the movement of fluid from the interstitial fluid compartment to the blood. When arterioles constrict, the diameter of the blood vessels decreases, leading to a decrease in blood pressure. This decrease in pressure allows fluid to move from the interstitial fluid compartment into the blood, helping to restore blood volume after a hemorrhage.Rate this question:
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- 41.
Question 41 Which substance is present in a lower concentration in the glomerular filtrate than in the blood plasma?
- A.
Glucose
- B.
Potassium
- C.
Protein
- D.
Sodium
- E.
Urea
Correct Answer
C. ProteinExplanation
Protein is present in a lower concentration in the glomerular filtrate than in the blood plasma. This is because the glomerular filtration barrier in the kidneys prevents larger molecules, such as proteins, from passing through into the filtrate. Glucose, potassium, sodium, and urea are all small enough to pass through the filtration barrier and are present in higher concentrations in the glomerular filtrate compared to the blood plasma.Rate this question:
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- 42.
Question 42If more of a substance appears in the urine than was filtered at the glomerulus, which of the following must have occurred:
- A.
Tubular reabsorption
- B.
Tubular secretion
Correct Answer
B. Tubular secretionExplanation
If more of a substance appears in the urine than was filtered at the glomerulus, it suggests that the substance was added to the urine after the filtration process. This indicates that the substance must have undergone tubular secretion, where it is actively transported from the blood into the renal tubules. Tubular reabsorption, on the other hand, involves the movement of substances from the renal tubules back into the blood. Therefore, tubular secretion is the most likely explanation for the increased presence of the substance in the urine.Rate this question:
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- 43.
Question 43 Afferent arteriolar vasoconstriction __ blood flow into the glomerulus, which causes the glomerular capillary blood pressure to ____, leading to a(n) ____ in the net filtration pressure and a resultant ___ in the GFR
- A.
Increases, increase, increase, increase
- B.
Decreases, decrease, decrease, decrease
- C.
Increases, increase, decrease, decrease
- D.
Decreases, decrease, increase, increase
Correct Answer
B. Decreases, decrease, decrease, decreaseExplanation
Afferent arteriolar vasoconstriction decreases blood flow into the glomerulus, which causes the glomerular capillary blood pressure to decrease, leading to a decrease in the net filtration pressure and a resultant decrease in the GFR.Rate this question:
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- 44.
Question 44The reabsorption of water from the renal tubules:
- A.
Occurs by the active transport of water across the plasma membranes of the renal epithelial cells
- B.
Occurs only in the distal tubule and collecting ducts
- C.
Requires a solute gradient
- D.
Requires the presence of ADH
Correct Answer
C. Requires a solute gradientExplanation
The correct answer is "requires a solute gradient". Reabsorption of water from the renal tubules occurs by the movement of water through osmosis. This movement is driven by the presence of a solute gradient, meaning that there is a higher concentration of solutes in the interstitial fluid surrounding the tubules compared to the tubular fluid. This creates an osmotic gradient that causes water to move out of the tubules and into the interstitial fluid, leading to water reabsorption.Rate this question:
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- 45.
Question 45Most (about 65%) of the salt and water filtered at the glomerulus is reabsorbed from which portion of the renal tubules in a normally hydrated individual:
- A.
Collecting ducts
- B.
Distal tubule
- C.
Loop of Henle
- D.
Proximal tubule
Correct Answer
D. Proximal tubuleExplanation
In a normally hydrated individual, most of the salt and water filtered at the glomerulus is reabsorbed from the proximal tubule. This is because the proximal tubule is the first part of the renal tubules where reabsorption occurs. It is responsible for reabsorbing the majority of filtered substances, such as glucose, amino acids, and ions, back into the bloodstream. The proximal tubule has a high reabsorption capacity and plays a crucial role in maintaining the body's fluid and electrolyte balance.Rate this question:
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- 46.
Question 46ADH (vasopressin):
- A.
Decreases the active reabsorption of sodium from the collecting ducts
- B.
Decreases the membrane permeability of the epithelial cells in the collecting ducts to water
- C.
Increases the active reabsorption of sodium from the collecting ducts
- D.
Increases the membrane permeability of the epithelial cells in the collecting ducts to water
Correct Answer
D. Increases the membrane permeability of the epithelial cells in the collecting ducts to waterExplanation
Vasopressin, also known as antidiuretic hormone (ADH), increases the membrane permeability of the epithelial cells in the collecting ducts to water. This allows water to be reabsorbed from the urine back into the bloodstream, leading to a more concentrated urine and the conservation of water in the body.Rate this question:
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- 47.
Question 47 The loop of Henle is the site in the renal tubule where:
- A.
A high medullary interstitial fluid osmolarity is generated
- B.
Aldosterone acts
- C.
ADH acts
- D.
Potassium ions are secreted into the renal tubule
- E.
All of the above
Correct Answer
A. A high medullary interstitial fluid osmolarity is generatedExplanation
The loop of Henle is responsible for generating a high medullary interstitial fluid osmolarity. This is achieved through a countercurrent multiplier system, where the descending limb of the loop of Henle allows water to pass out of the tubule, concentrating the filtrate. The ascending limb of the loop actively transports sodium and chloride ions out of the tubule, creating a high concentration of solutes in the medullary interstitial fluid. This high osmolarity in the medulla plays a crucial role in the reabsorption of water in the collecting duct, allowing for the concentration of urine and the conservation of water in the body.Rate this question:
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- 48.
Question 48 The ascending limb of the loop of Henle:
- A.
Actively transports NaCl into the surrounding interstitial fluid
- B.
Is impermeable to water
- C.
Is found in the renal cortex
- D.
Drains into the proximal convoluted tubule
- E.
Both A and B
Correct Answer
E. Both A and BExplanation
The ascending limb of the loop of Henle actively transports NaCl into the surrounding interstitial fluid and is impermeable to water. This means that it plays a crucial role in the reabsorption of sodium and chloride ions from the filtrate, while preventing the reabsorption of water. This helps to create a concentration gradient in the interstitial fluid, which is important for the reabsorption of water in the collecting ducts. Therefore, the correct answer is both A and B.Rate this question:
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- 49.
Question 49A person on a high salt diet would be expected to have elevated:
- A.
Renin levels in the plasma
- B.
Aldosterone levels in the plasma
- C.
Angiotensin levels in the plasma
- D.
Potassium excretion in the urine
- E.
None of the above
Correct Answer
E. None of the aboveExplanation
A person on a high salt diet would be expected to have elevated renin levels in the plasma, as high salt intake leads to decreased renin secretion. Similarly, aldosterone levels in the plasma would also be expected to be elevated, as aldosterone is released in response to high salt intake. Angiotensin levels in the plasma would also increase, as angiotensin is formed from renin and is involved in regulating blood pressure. Potassium excretion in the urine may or may not be affected by a high salt diet, but it is not the expected outcome. Therefore, the correct answer is "none of the above".Rate this question:
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- 50.
Question 50Which of the following will increase the GFR:
- A.
Decreasing arterial blood pressure
- B.
Decreased plasma concentration of ADH
- C.
Increased plasma concentration of angiotensin II
- D.
Vasodilation of the afferent arterioles to the glomerular capillaries
Correct Answer
D. Vasodilation of the afferent arterioles to the glomerular capillariesExplanation
Vasodilation of the afferent arterioles to the glomerular capillaries will increase the GFR. The afferent arterioles are responsible for supplying blood to the glomerulus, where filtration occurs. By dilating these arterioles, more blood can flow into the glomerulus, resulting in an increased glomerular filtration rate (GFR). This allows for more efficient filtration of waste products and reabsorption of necessary substances by the kidneys. Decreasing arterial blood pressure, decreased plasma concentration of ADH, and increased plasma concentration of angiotensin II would all have the opposite effect, reducing the GFR.Rate this question:
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_.jpg "Question 33You are experiencing mild anxiety and stress at this point in the quiz and epinephrine is being released in low amount from the adrenal gland medulla. What is the physiological consequence of the stress?")
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Mar 18, 2023Quiz Edited by
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