Exam 3 Flashcards
Homeostasis
The process by which the body achieves a stable, balanced internal environment
set points
the points where the Physiological systems functions best
set zone
range within which a physiological system can function
negative feedback
when homeostasis counteracts the deviation of a set point
Thermoregulation
proses by which the body maintains an ideal temperature
Preoptic area
POA, takes care of the physiological responces that raise body temp
shivering
heat generating heat through metabolic burn required for motions
construction of blood vessels in bods exterior
reduced blood flow makes skin and fat more effective as insulations
Lateral hypothalamus
is the part of the hypothalamus to seek heat sources
Osmotic thirst
Body filled with water- when fluid levels drop salt concentration in the fluid of the cells increase.
Caused by upswing in salt levels via salt consumption or urination
Hypovolemic thirst
Decrease in bodily fluids; blood and sweating
happens even if salt levels don’t drop
osmosensory neurons
found in the circumventricular organs
detect changes in the concentration of salt in the cerebrospinal fluid of ventricular system
circumventricular organs
when fluid is salty around the osmosensory neurons they shrink. when not salty it swells
Osmosis
difusion of solvent molecules across a permeable membrain
What is homeostasis and how does it occur?
Homeostasis is the process by which the body achieves a stable, balanced internal environment. Occures through the maintenance of optimall set point at which a given physiological system functions
Explain how homeostasis operates based on negative feedback
When there is negative feedback homeostasis counteracts it by doing the opposite in order to find the set point again.
Is thermoregulation also behavioral?
Theramorgan is partially behavioral when the temp outside the body is to cold you can take action to prevent heat loss
How does the preoptic area (POA) of the hypothalamus help to raise body temperature in response to the cold?
Through two types: Shivering, Construction of blood vessels: reduces blood flow makes skin and fat better at insolation.
How do the lateral hypothalamus and POA differ in their role for thermoregulation?
One is behavioral (seaking out heat like sun or fire)
What are the two forms of thirst that serve as motivational responses for fluid regulation?
Osmotic thirst: your body is filled with salt water when fluid levels drop, salt concentrations in the fluid between your cells increase. This kind of thirst is triggered by upswing in salt levels via urination
Hypovolemic thirst: decrease volume of bodily fluids, such as blood, triggered even if salt concentrations are not affected.
Name the three regions that comprise the circumventricular organs
Subfornical organ, OVOLT, 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 (select the choice that best completes the statement).
When the fluid around the osmosensory neurons is too salty, they —–
Shrink
When it is not salty enough, they —
swell
——-causes a generator potential that makes the osmosensory neuron more likely to fire an action potential.
shrinking
POA also triggers physiological responses by causing the release of the hormone vasopressin from the pituitary gland.
What amino acid is the chemical basis of the neurotransmitter serotonin?
Tryptophan
Which physiological responses ensure that an optimal level of glucose is available to be metabolized?
Insulin
type 1 diabeates
Type-I diabetes is Juvenile-onset and occurs when the pancreas stops making insulin
type 2
Type-II is adult-onset and occurs when cells no longer respond to insulin
Basal metabolism energy goes towards
heat production, Maintenance of Ion gradients, and Life-sustaining cellular processes
What is located in the hypothalamus that monitors the levels of various hunger and satiety relevant hormones?
Arcuate nucleus
Differentiate between POMC neurons and NPY neurons
POMC: inhibits hunger
NPY: promoted feeding
List three hunger and satiety hormones
Ghrelin: drops after eating, high levels activate NPY
Insulin: response to food, high insulin activates POMC, Low activated NPY, increases satiety
Leptin: released from fat cells. Circulating leptin reduces hunger and produces satiety. POMC activated
The body is adapted to —— not —- (select the choice that best completes the statement)
scarcity; excess
Name an example of a biological rhythm and some of the processes that fluctuate on that cycle
Circadian Rhythms
Explain how the internal clock is synced up with the external environment
Zeitgebers: Light signals something about time of day, sum up and down
Where in the brain is the circadian clock located?
Suprachiasmatic nucleus in the hypothalamus
What pathway is specifically designed to sync the circadian clock up with the time of day?
SCN gets direct input from a population of ganglion cells in the retina that carry info about phase shift in light levels.