,Homeostasis refers to maintaining a relatively stable internal environment. The "internal
environment" is:
a) the blood cells
b) body parts beneath the skin
c) the cytoplasm of all the cells in the body
d) plasma, interstitial fluid, and transcellular fluid
e) intracellular fluid
Answer: plasma, interstitial fluid, and transcellular fluid
These fluids surround and bathe the body’s cells and are the primary medium through which
nutrients, gases, and wastes are exchanged.
Which of the following is an example of positive feedback?
a) Consuming caffeine increases urine output, causing dehydration
b) The arrival of platelets at a wound causes the release of clotting factors which cause more
platelets to arrive at the wound
c) When a person stands up, blood pressure decreases because of blood pooling in the feet and
legs, causing the heart to beat faster and blood vessels to constrict
d) both a) and b) are correct
e) both b) and c) are correct
Answer: The arrival of platelets at a wound causes the release of clotting factors which
cause more platelets to arrive at the wound
This process amplifies the initial response until the clot is formed, which is characteristic of
positive feedback.
,Following an increase in body temperature, which of the following responses will NOT
occur?
a) an increase in skin blood flow
b) an increase in skin temperature
c) an increase in non-shivering thermogenesis
d) an increase in sweat production
e) an increase in evaporation of the skin
Answer: an increase in non-shivering thermogenesis
Non-shivering thermogenesis generates heat and is reduced when the body is attempting to cool
down.
When pyrogens are present, vasodilation is used by the body to create a fever.
a) True
b) False
Answer: True
Pyrogens raise the hypothalamic set point, leading to physiological responses that increase body
temperature.
Mice from a certain lab strain remain healthy as long as you feed them regularly and do
not let them exercise. If they fast or exercise, their blood glucose drops dangerously. Which
hypothesis best explains their problem?
a) The mice have insulin-dependent diabetes
b) the mice lack insulin receptors on their cells
c) the mice lack glucagon receptors on their cells
d) The mice can't synthesize glycogen from glucose
Answer: The mice lack glucagon receptors on their cells
Without glucagon signaling, the mice cannot raise blood glucose during fasting or exercise.
, Liver cells produce glycogen in response to:
a) glucagon
b) insulin
Answer: insulin
Insulin promotes glucose uptake and storage as glycogen following meals.
One of insulin's mechanisms of action is to:
a) activate Na⁺/K⁺ pump
b) increase the activity of SGLT
c) increase the facilitated diffusion of glucose into certain cells in the body
d) increase the number of sodium-linked glucose transporters in the cell membrane
e) more than one of the above is correct
Answer: increase the facilitated diffusion of glucose into certain cells in the body
Insulin promotes the insertion of glucose transporters into cell membranes, allowing glucose to enter
insulin-sensitive cells more efficiently.
NADH is produced from each reaction described except one. Identify the EXCEPTION.
a) during "aerobic" glycolysis
b) during the electron transport chain
c) in the Krebs cycle
d) during the conversion of pyruvate to acetyl CoA
e) more than one answer applies
Answer: during the electron transport chain
In the electron transport chain, NADH is oxidized to NAD⁺ rather than being produced.
Under low oxygen conditions, ____________ must unload its electrons to allow glycolysis to
continue its production of ATP:
a) FADH₂
b) lactic acid
c) NAD⁺
environment" is:
a) the blood cells
b) body parts beneath the skin
c) the cytoplasm of all the cells in the body
d) plasma, interstitial fluid, and transcellular fluid
e) intracellular fluid
Answer: plasma, interstitial fluid, and transcellular fluid
These fluids surround and bathe the body’s cells and are the primary medium through which
nutrients, gases, and wastes are exchanged.
Which of the following is an example of positive feedback?
a) Consuming caffeine increases urine output, causing dehydration
b) The arrival of platelets at a wound causes the release of clotting factors which cause more
platelets to arrive at the wound
c) When a person stands up, blood pressure decreases because of blood pooling in the feet and
legs, causing the heart to beat faster and blood vessels to constrict
d) both a) and b) are correct
e) both b) and c) are correct
Answer: The arrival of platelets at a wound causes the release of clotting factors which
cause more platelets to arrive at the wound
This process amplifies the initial response until the clot is formed, which is characteristic of
positive feedback.
,Following an increase in body temperature, which of the following responses will NOT
occur?
a) an increase in skin blood flow
b) an increase in skin temperature
c) an increase in non-shivering thermogenesis
d) an increase in sweat production
e) an increase in evaporation of the skin
Answer: an increase in non-shivering thermogenesis
Non-shivering thermogenesis generates heat and is reduced when the body is attempting to cool
down.
When pyrogens are present, vasodilation is used by the body to create a fever.
a) True
b) False
Answer: True
Pyrogens raise the hypothalamic set point, leading to physiological responses that increase body
temperature.
Mice from a certain lab strain remain healthy as long as you feed them regularly and do
not let them exercise. If they fast or exercise, their blood glucose drops dangerously. Which
hypothesis best explains their problem?
a) The mice have insulin-dependent diabetes
b) the mice lack insulin receptors on their cells
c) the mice lack glucagon receptors on their cells
d) The mice can't synthesize glycogen from glucose
Answer: The mice lack glucagon receptors on their cells
Without glucagon signaling, the mice cannot raise blood glucose during fasting or exercise.
, Liver cells produce glycogen in response to:
a) glucagon
b) insulin
Answer: insulin
Insulin promotes glucose uptake and storage as glycogen following meals.
One of insulin's mechanisms of action is to:
a) activate Na⁺/K⁺ pump
b) increase the activity of SGLT
c) increase the facilitated diffusion of glucose into certain cells in the body
d) increase the number of sodium-linked glucose transporters in the cell membrane
e) more than one of the above is correct
Answer: increase the facilitated diffusion of glucose into certain cells in the body
Insulin promotes the insertion of glucose transporters into cell membranes, allowing glucose to enter
insulin-sensitive cells more efficiently.
NADH is produced from each reaction described except one. Identify the EXCEPTION.
a) during "aerobic" glycolysis
b) during the electron transport chain
c) in the Krebs cycle
d) during the conversion of pyruvate to acetyl CoA
e) more than one answer applies
Answer: during the electron transport chain
In the electron transport chain, NADH is oxidized to NAD⁺ rather than being produced.
Under low oxygen conditions, ____________ must unload its electrons to allow glycolysis to
continue its production of ATP:
a) FADH₂
b) lactic acid
c) NAD⁺
