exam two (ch.16) Flashcards
Both unconscious reflexes and conscious (voluntary)
movements may be
motivated
Maintains the internal environment within a narrow physiological
range
homeostasis
Regulation of homeostasis
* Regulates a number of
behaviors:
* Hunger
* Thirst
* Body temperature
* Sleep/circadian rhythms
* Sex
* Parenting and attachment
hypothalamus
the hypothalamus has three repsonses to changes in homeostasis; what are they?
humoral, somatic motor, visceromotor
the humoral response is (by cerebellum)
release or inhibtion of pituiatry hormones
the visceromotor response is (by cerebellum)
adjustment of autonomic system
the somatic motor repsonse is (by cerebellum)
induction of somatic motor behavioral response
the ___ state is characterized by full intestines and anabolism (energy balance of long term regulation of feeding behavior)
prandial
the ___ state is characterized by empty intestines and catabolism (energy balance of long term regulation of feeding behavior)
postabsorptive
brain monitors body fat (adipose) and acts to defend against disturbances to this energy store
lipostatic hypothesis
protein released by fat cells
(adipocytes); regulates
body mass
leptin
when leptin are ____ Increases appetite; Incites adaptive responses
to fight starvation
low
__ leptin levels decreases appetite; increases energy expenditure
high
bilateral lesions of the
ventromedial hypothalamus
* Rats ate like crazy
* Suggested that working VMH reduces
feeding
which caused?
obesity
bilateral lesions of lateral
hypothalamus
* Rats wouldn’t eat
* Suggested that LH stimulates feeding
this caused
anorexia
three hypothalamic nuclei important for control of feeding
paraventricular, lateral and arcuate
leptin binds to receptors on neurons in ___ nucleus
arcuate
activation of the arcuate neurons stimulates release of
alpha MSH and CART
AlphaMSH and CART ____ appetite
diminish (released in times of high leptin)
_____ neurons project to brain regions that orchestrate coordinated humoral, visceromotor, and somatic
responses
arcuate
with alphaMSH and CART release the humoral respose is stimulation of
ACTH and thyrotropin (ant. pituitary; via paraventricular nucleus)
with alphaMSH and CART release the visceromotor response is
activation of sympathetic nervous system (raises metabolic rate and body temp.)
with alphaMSH and CART release the somatic motor response is
inhibition of feeding behavior via lateral hypothalamus
low leptin activates arcuate neurons which release
NPY and AgRP (opposite alphaMSH and CART)
NPY and AgRP (orexigenic prptides) ____ appetite
increase
the visceromotor response to NPY and AgRP is to
activate parasympathetic
the somatic response to NPY and AgRP is to
stimulate feeding behavior (LH stimulation)
alphaMSH (agonist) and AgRP (antagonist) produce opposite effects at the ____ receptor in lateral hypothalamus
MC4
when arcuate neurons NPY and AgRP project to lat. hypothalamus the neurons of hypothalamus release
melanin concentrating hormone and orexin (start and prolong meal) increase appetite
what are the three phases of short term regulation of feeding
cephalic, gastric, substrate
sight and smell of food activates parasympathetic (what phase?)
cephalic
stomach responds to chewing, swallowing and filling (what phase?)
gastric
absorbance of nutrients from the intestine (what phase?)
substrate
during cephalic state (hunger) ____ is released (empty stomach)
ghrelin (activates NPY and AgRP neurons)
substrate phase releases ___ in response to certain foods and _____
CCK; insulin
released during all phases of eating regulation; highest level during substrate phase
insulin
what type of thirst is triggered by decrease in blood volume
volumetric (hypovolemic) thirst
what type of thirst is triggered by increased concentration of substrates
osmotic thirst
decrease in blood volume (hypovolemia) results in release of ____ from post. pituitary
vasopressin
kindeys or mechanoreceptors in the walls of major blood vessels can release
vasopressin
_____; increased conc. of dissolved substances in blood also results in release of vasopressin
hypertonicity
high salt in sensed by ____ neurons which stimulate vasopressin and lat. hypothalamus
OVLT
neurons for temp. homeostasis are in
ant. hypothalamus
temp. neurons stimulate neurons in the ___ ___ area of hypothalamus for humoral and visceromotor response
medial preoptic
temp. neurons stimulate neurons in the ___ ___ area for somatic motor response
lateral hypothalamus
drop in blood temperature humoral response
TSH (from ant. pit.) then thyronxin (from thyroid) and increase in cell metabolism
drop in blood temperature visceromotor and somatic response
goosebumps, blood vessel constriction; shivering
changes in seratonin in response to eating; preabsorptive period
low seratonin
changes in seratonin in response to eating: anticipation
rise
changes in seratonin in response to eating; during meals
futher rise
drugs that increase seratonin levels; reduce
appetite
anorexia and bulimis are both abnormalities in brain; often accompanied by depression and is caused by issues with what NT
seratonin
what are effective sites for self stimulation
trajectory of dopaminergic axons in the ventral tegmental area (medial forebrain bundle)
drugs that block dopamine receptors ____ self-stimulation of projection
reduce
amount of ______
released somehow determines how rewarding (or relevant) an event is
dopamine
Highly addictive drugs such as nicotine and cocaine increase the level of dopamine in the ___ ___
nucleus accumbens
dopamine depleted animals “like” food but do not ____ food; dopamine signals drive the wanting (schultz)
seek
