Studied by 5 peopledef 3 motivated beh
food
thirst
temperature
def 2 types of beh
Unconscious reflexes
voluntary movements
def motivation
the need or desire to do something
def 4 theories for motivation
evolutionary perspective
drive-reduction theory
optimal arousal
Maslow’s hierarchy of needs
analogy for motivation
ionic driving force - motivation depends on many factors
what 2 things vary with the driving force needed to perform the behavior
probability, direction
def Homeostasis
Maintains internal environment within a narrow physiological range
which part of the brain regulates homeostasis
hypothalamus
def 3 components of neuronal response
Humoral response
Visceromotor response
Somatic motor response
def humoral response
stimulating/inhibiting release of pituitary hormones
def visceromotor response
a reflex response to noxious stimulation of a visceral organ (the soft internal organs of the body)
def somatic motor response
voluntary muscle movement.
def 2 energy balance states
Prandial state—anabolism
Postabsorptive state—catabolism
funct: anabolism v catabolism
storing energy v using (breaking down) energy
Loading and Emptying the Body’s Energy Reserves
anabolism v catabolism
what hormone regulates body mass by decreasing what and increasing what
Leptin: Decreases appetite, Increases energy expenditure
what incites adaptive responses to fight starvation
leptin
what do experiments with parabiosis show (Lipostatic hypothesis)
our body has a set point of weight, we can adjust it with food, but usually regression to mean
what disorder arises from lateral hypothalamic syndrome
anorexia
what disorder arises from ventromedial hypothalamic syndrome
obesity
what part of the hypothalamus controls feeding
Arcuate nucleus of hypothalamus
def 3 phases of regulation of Feeding
cephalic
gastric
substrate
def cephalic
hunger
what happens to Ghrelin during _____ phase
cephalic, it is released when the stomach is empty
what does ghrelin do once it is released in the cephalic phase
Activates NPY/AgRP-containing neurons in arcuate nucleus
Removal of ghrelin-secreting cells of stomach thought to cause…
loss of appetite
def gastric
feeling full
Gastric distension signals brain via during _____ phase
gastric, vagus nerve
Gastric distension works synergistically with ____ release
CCK
what peaks during eating a meal
insulin levels
insulin is released from β cells of the… and is important for…
pancreas, anabolism
both insulin and serotonin levels are highest during what phase
substrate phase
serotonin levels rise in… spike during… and are low during the… in what period of eating
Rise in anticipation of food
Spike during meal
Low during the postabsorptive period
what NT is correlated with drive to eat
dopamine
effective sites for self-stimulation: dopaminergic axons in the ventral tegmental area projecting to the forebrain
drugs that block dopamine receptors: reduce self-stimulation
Stimulation of the dopamine axons: Produces craving for food without increasing the hedonic impact
eating: liking v wanting
hedonic v drive reduction
how do we identify brain sites of reinforcement
electrical self-stimulation experiments
Former belief of Role of Dopamine in Motivation
dopamine projection served hedonic (liking) reward
New understanding of Role of Dopamine in Motivation
Dopamine-depleted animals “like” food but do not “want” food.
Lack motivation to seek food but enjoy it when available
Disorders in which NT regulation results in anorexia nervosa or bulimia nervosa
serotonin
what is the automatic beh response when body is cold
mobilize: Body shivers, blood shunted away from the body surface, urine production inhibited, body fat reserves—mobilized
def Hypovolemia
pathway that decreases blood volume
what leads to volumetric drinking
hypovolemia
def hypertonicity
pathway that increased concentration of dissolved
substances in blood (solutes)
what leads to osmotic drinking
hypertonicity
what hormone acts on the kidneys and increases water retention and inhibits urine production
vasopressin
vasopressin causes an inc or dec in drinking motivation
inc
when the temperature falls, what hormone is released
TSH
TSH is released by…
anterior pituitary
TSH stimulates release of…
thyroxin (from thyroid gland)
TSH leads to an inc in…
cellular metabolism
Food - Fat: location, blood leptin levels, aMSH/CART neurons, NYP/AgRP neurons, TSH/ACTH, sympathetic, parasympathetic, eat
hypothalamus arcuate nucleus, +, +, -, +, +, -, -
Drink - thirsty: humoral, visceromotor, somatic motor
inc vasopressin, inc sympathetic, drink
Temp - Cold: location, humoral, visceromotor, somatic motor
medial preoptic area, inc TSH, inc sympathetic (constricted blood vessels in the skin), shivering/seeking warmth
Note
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