PBSI 235- Exam 3 questions well
answered passed
What is homeostasis? - correct answer ✔✔process by which the body achieves a stable,
balanced internal environment.
How does homeostasis occur? - correct answer ✔✔occurs through the maintenance of optimal
set points at which a given physiological system functions best
Explain how homeostasis operates based on negative feedback. - correct answer ✔✔Whatever
is happening in a physiological system to cause it to deviate from the set point, homeostasis
counteracts it by doing the opposite in order to find the set point again.
Is thermoregulation also behavioral? - correct answer ✔✔Yes - when the temperature outside
the body is too cold, you can take action prevent heat loss
How does the pre-optic area (POA) of the hypothalamus help to raise body temperature in
response to the cold? - correct answer ✔✔Shivering/ Constriction of blood vessels in the body's
exterior
How do the lateral hypothalamus and POA differ in their role for thermoregulation? - correct
answer ✔✔In contrast to the POA, the lateral hypothalamus is crucial for the behavioral
regulation of temperature
What are the two forms of thirst that serve as motivational responses for fluid regulation? -
correct answer ✔✔Osmotic thirst/ Hypovolemic thirst
, What are the three regions that comprise the circumventricular organs - correct answer ✔✔-
Subfomical organ
- Organum vasculosum of the lamina terminalis (OVLT)
- Area postrema
The circumventricular organs contain osmosensory neurons that detect changes in the
concentration of salt in the cerebrospinal fluid (CSF) of the ventricular system When the fluid
around the osmosensory neurons is too salty, they ______. When it is not salty enough, they
_____. - correct answer ✔✔shrink; swell
________ causes a generator potential that makes the osmosensory neuron more likely to fire
an action potential. - correct answer ✔✔Shrinking
POA also triggers physiological responses by causing the release of the hormone ____ from the
____ gland. - correct answer ✔✔Vasopressin; pituitary
What amino acid is the chemical basis of the neurotransmitter serotonin? - correct answer
✔✔Tryptophan
Which physiological responses ensure that an optimal level of glucose is available to be
metabolized? - correct answer ✔✔When glucose levels in the blood rise, the hormone insulin
allows glucose to enter muscles and liver cells for use or to be converted into glycogen for short-
term storage
What happens when glucose levels fall? - correct answer ✔✔glycogen is converted back into
glucose by the hormone glucagon
What happens when the body has more glucose than needed in short term? - correct answer
✔✔Goes into long-term storage in adipose tissue (fat). Decreases in glycogen cause the body to
convert fats back into glucose
answered passed
What is homeostasis? - correct answer ✔✔process by which the body achieves a stable,
balanced internal environment.
How does homeostasis occur? - correct answer ✔✔occurs through the maintenance of optimal
set points at which a given physiological system functions best
Explain how homeostasis operates based on negative feedback. - correct answer ✔✔Whatever
is happening in a physiological system to cause it to deviate from the set point, homeostasis
counteracts it by doing the opposite in order to find the set point again.
Is thermoregulation also behavioral? - correct answer ✔✔Yes - when the temperature outside
the body is too cold, you can take action prevent heat loss
How does the pre-optic area (POA) of the hypothalamus help to raise body temperature in
response to the cold? - correct answer ✔✔Shivering/ Constriction of blood vessels in the body's
exterior
How do the lateral hypothalamus and POA differ in their role for thermoregulation? - correct
answer ✔✔In contrast to the POA, the lateral hypothalamus is crucial for the behavioral
regulation of temperature
What are the two forms of thirst that serve as motivational responses for fluid regulation? -
correct answer ✔✔Osmotic thirst/ Hypovolemic thirst
, What are the three regions that comprise the circumventricular organs - correct answer ✔✔-
Subfomical organ
- Organum vasculosum of the lamina terminalis (OVLT)
- Area postrema
The circumventricular organs contain osmosensory neurons that detect changes in the
concentration of salt in the cerebrospinal fluid (CSF) of the ventricular system When the fluid
around the osmosensory neurons is too salty, they ______. When it is not salty enough, they
_____. - correct answer ✔✔shrink; swell
________ causes a generator potential that makes the osmosensory neuron more likely to fire
an action potential. - correct answer ✔✔Shrinking
POA also triggers physiological responses by causing the release of the hormone ____ from the
____ gland. - correct answer ✔✔Vasopressin; pituitary
What amino acid is the chemical basis of the neurotransmitter serotonin? - correct answer
✔✔Tryptophan
Which physiological responses ensure that an optimal level of glucose is available to be
metabolized? - correct answer ✔✔When glucose levels in the blood rise, the hormone insulin
allows glucose to enter muscles and liver cells for use or to be converted into glycogen for short-
term storage
What happens when glucose levels fall? - correct answer ✔✔glycogen is converted back into
glucose by the hormone glucagon
What happens when the body has more glucose than needed in short term? - correct answer
✔✔Goes into long-term storage in adipose tissue (fat). Decreases in glycogen cause the body to
convert fats back into glucose
