G150/ PHA1500 MODULE 1
Negative and Positive
feedback Review Exam
Q&A
2024
,1. A patient with diabetes mellitus has a high blood glucose level. Which
of the following is an example of negative feedback that occurs in
response to this condition?
a) The pancreas secretes more insulin to lower the blood glucose level.
b) The liver converts more glucose into glycogen for storage.
c) The kidneys excrete more glucose in the urine.
d) The cells take up more glucose from the blood.
Answer: a) The pancreas secretes more insulin to lower the blood glucose
level. Rationale: Negative feedback is a mechanism that restores a
deviation from a set point to normal. In this case, the high blood glucose
level is the deviation and the normal range is the set point. The pancreas
secretes insulin, a hormone that lowers the blood glucose level by
stimulating the cells to take up glucose from the blood and the liver to
convert glucose into glycogen. This is an example of negative feedback
because the action of insulin reduces the deviation from the set point.
2. A patient with hypothyroidism has a low metabolic rate and feels cold
most of the time. Which of the following is an example of positive
feedback that occurs in response to this condition?
a) The hypothalamus releases more thyrotropin-releasing hormone (TRH)
to stimulate the pituitary gland.
b) The pituitary gland releases more thyroid-stimulating hormone (TSH)
to stimulate the thyroid gland.
c) The thyroid gland releases more thyroid hormones (T3 and T4) to
increase the metabolic rate.
d) The body shivers to generate heat and maintain the body temperature.
Answer: d) The body shivers to generate heat and maintain the body
temperature. Rationale: Positive feedback is a mechanism that amplifies a
deviation from a set point rather than restoring it to normal. In this case,
the low metabolic rate and low body temperature are the deviations and
the normal range is the set point. The body shivers, which is a muscular
activity that generates heat and increases the metabolic rate. This is an
example of positive feedback because the action of shivering increases the
deviation from the set point.
3. A patient with hypertension has a high blood pressure. Which of the
following is an example of negative feedback that occurs in response to
, this condition?
a) The heart beats faster and stronger to pump more blood.
b) The blood vessels constrict to increase the resistance to blood flow.
c) The kidneys retain more water and sodium to increase the blood
volume.
d) The baroreceptors in the carotid arteries and aorta sense the high blood
pressure and send signals to the brainstem.
Answer: d) The baroreceptors in the carotid arteries and aorta sense the
high blood pressure and send signals to the brainstem. Rationale: Negative
feedback is a mechanism that restores a deviation from a set point to
normal. In this case, the high blood pressure is
the deviation and the normal range is the set point. The baroreceptors are
sensory receptors that detect changes in blood pressure and send signals to
the brainstem, which regulates the cardiovascular system. This is an
example of negative feedback because
the action of baroreceptors initiates a response that reduces
the deviation from
the set point.
4. A patient with severe bleeding has a low blood volume and low blood
pressure. Which of
the following is an example of positive feedback that occurs in response to
this condition?
a) The heart beats slower and weaker to conserve blood.
b) The blood vessels dilate to decrease
the resistance to blood flow.
c) The kidneys excrete more water and sodium to decrease
the blood volume.
d) The platelets adhere to
the damaged blood vessel wall and release chemicals that attract more
platelets.
Answer: d) The platelets adhere to
the damaged blood vessel wall and release chemicals that attract more
platelets. Rationale: Positive feedback is a mechanism that amplifies a
deviation from a set point rather than restoring it to normal. In this case,
the low blood volume and low blood pressure are
the deviations and
the normal range is
Negative and Positive
feedback Review Exam
Q&A
2024
,1. A patient with diabetes mellitus has a high blood glucose level. Which
of the following is an example of negative feedback that occurs in
response to this condition?
a) The pancreas secretes more insulin to lower the blood glucose level.
b) The liver converts more glucose into glycogen for storage.
c) The kidneys excrete more glucose in the urine.
d) The cells take up more glucose from the blood.
Answer: a) The pancreas secretes more insulin to lower the blood glucose
level. Rationale: Negative feedback is a mechanism that restores a
deviation from a set point to normal. In this case, the high blood glucose
level is the deviation and the normal range is the set point. The pancreas
secretes insulin, a hormone that lowers the blood glucose level by
stimulating the cells to take up glucose from the blood and the liver to
convert glucose into glycogen. This is an example of negative feedback
because the action of insulin reduces the deviation from the set point.
2. A patient with hypothyroidism has a low metabolic rate and feels cold
most of the time. Which of the following is an example of positive
feedback that occurs in response to this condition?
a) The hypothalamus releases more thyrotropin-releasing hormone (TRH)
to stimulate the pituitary gland.
b) The pituitary gland releases more thyroid-stimulating hormone (TSH)
to stimulate the thyroid gland.
c) The thyroid gland releases more thyroid hormones (T3 and T4) to
increase the metabolic rate.
d) The body shivers to generate heat and maintain the body temperature.
Answer: d) The body shivers to generate heat and maintain the body
temperature. Rationale: Positive feedback is a mechanism that amplifies a
deviation from a set point rather than restoring it to normal. In this case,
the low metabolic rate and low body temperature are the deviations and
the normal range is the set point. The body shivers, which is a muscular
activity that generates heat and increases the metabolic rate. This is an
example of positive feedback because the action of shivering increases the
deviation from the set point.
3. A patient with hypertension has a high blood pressure. Which of the
following is an example of negative feedback that occurs in response to
, this condition?
a) The heart beats faster and stronger to pump more blood.
b) The blood vessels constrict to increase the resistance to blood flow.
c) The kidneys retain more water and sodium to increase the blood
volume.
d) The baroreceptors in the carotid arteries and aorta sense the high blood
pressure and send signals to the brainstem.
Answer: d) The baroreceptors in the carotid arteries and aorta sense the
high blood pressure and send signals to the brainstem. Rationale: Negative
feedback is a mechanism that restores a deviation from a set point to
normal. In this case, the high blood pressure is
the deviation and the normal range is the set point. The baroreceptors are
sensory receptors that detect changes in blood pressure and send signals to
the brainstem, which regulates the cardiovascular system. This is an
example of negative feedback because
the action of baroreceptors initiates a response that reduces
the deviation from
the set point.
4. A patient with severe bleeding has a low blood volume and low blood
pressure. Which of
the following is an example of positive feedback that occurs in response to
this condition?
a) The heart beats slower and weaker to conserve blood.
b) The blood vessels dilate to decrease
the resistance to blood flow.
c) The kidneys excrete more water and sodium to decrease
the blood volume.
d) The platelets adhere to
the damaged blood vessel wall and release chemicals that attract more
platelets.
Answer: d) The platelets adhere to
the damaged blood vessel wall and release chemicals that attract more
platelets. Rationale: Positive feedback is a mechanism that amplifies a
deviation from a set point rather than restoring it to normal. In this case,
the low blood volume and low blood pressure are
the deviations and
the normal range is
