Topic 2: Motivation Flashcards
Which neurons in the arcuate nucleus of the hypothalamus respond to an increase in blood leptin levels? Choose the correct option.
Select one:
A. NPY/AgRP neurons
B. αMSH/CART neurons
C. Adipocytes
D. TSH/ACTH neurons
B. αMSH/CART neurons
Warm- and cold-sensitive neurons are located in what part of the brain? Choose the correct option.
Select one:
A. OVLT
B. Anterior hypothalamus
C. Ventromedial hypothalamus
D. Motor cortex
B. Anterior hypothalamus
Which of the following describes ghrelin? Choose the correct option.
Select one:
A. A peptide highly concentrated in the intestines that is released into the bloodstream when the intestines are empty
B. A peptide released by the magnocellular cells of the hypothalamus when the stomach is full
C. A peptide released by the magnocellular cells of the hypothalamus when the stomach is empty
D. A peptide highly concentrated in the stomach that is released into the bloodstream when the stomach is empty
D. A peptide highly concentrated in the stomach that is released into the bloodstream when the stomach is empty
Which of the following represents the humoral response to a drop in leptin levels? Choose the correct option.
Select one:
A. Decreased secretion of TSH and ACTH from the pituitary gland
B. Increased secretion of TSH and ACTH from the pituitary gland
C. Activate the parasympathetic division of the ANS.
D. Activate the sympathetic division of the ANS.
A. Decreased secretion of TSH and ACTH from the pituitary gland
Neurons in the lateral hypothalamus that receive a direct projection from leptin-sensitive cells in the arcuate nucleus contain which of the following peptide neurotransmitters? Choose the correct option.
Select one:
A. NPY and AgRP
B. αMSH and CART
C. MCH and orexin
D. NPY and CART
C. MCH and orexin
Orexin is to _____ as MCH is to _____.
a. Appetite suppression; feelings of satiety
b. Appetite suppression; feelings of hunger
c. Meal initiation; feelings of satiety
d. Meal initiation; prolonged consumption
d. Meal initiation; prolonged consumption
Behaviour includes:
a. unconscious reflexes and voluntary movement
b. humoral responses, visceromotor responses and somatic motor responses
c. homeostasis
d. maintaining an energy balance
a. Unconscious reflexes and voluntary movement
Which of the following is NOT true regarding ob/ob mice:
a. They contain two copies of the ob gene
b. They can’t code for leptin
c. Their obesity can be greatly moderated through parabiosis
d. They cannot regulate their body mass by bloodborne leptin
a. They contain two copies of the ob gene
They lack the ob gene
During the ______, anabolism occurs and energy is stored as glycogen and triglycerides.
a. Postabsorptive state
b. Prandial state
c. Cephalic phase
d. Gastric phase
b. Prandial state
Leptin depletion (select all that apply):
a. Decreases appetite
b. Incites adaptive responses to fight starvation
c. Suppresses energy expenditure and reproductive behaviour
d. Increases energy expenditure
leptin depletion
b. Incites adaptive responses to fight starvation
c. Suppresses energy expenditure and reproductive behaviour
Lesions to the lateral hypothalamus cause lateral
hypothalamic syndrome. This entails:
a. Obesity
b. Anorexia
c. The upregulation of food seeking behaviour coupled with the downregulation of hedonics
d. Sham rage
b. Anorexia
Food seeking behaviour is stopped
The lateral hypothalamus is the Hunger centre
Elevations/increases in leptin are detected by:
a. The lateral hypothalamus
b. aMSH and CART neurons in the arcuate nucleus
c. NYP and AgRP neurons in the arcuate nucleus
d. The paraventricular nucleus
b. aMSH and CART neurons in the arcuate nucleus
Define the postabsorptive state.
Postabsorptive state—catabolism: breaking down complex macromolecules
for energy
State the humoral, visceromotor and somatic responses to elevated levels of leptin.
Humoral: ACTH and thyrotropin release from the anterior pituitary. These increase metabolic rate.
Visceromotor: sympathetic nervous system tone increases –> rise in temperature –> increase in metabolic rate.
Somatic: Lateral hypothalamic area is inhibited, so feeding behaviour is inhibited
NYP and AgRP are orexigenic peptides which stimulate feeding behaviour. Unabbreviated, they are:
a. Neuropeptide Y and agouti-related peptide
b. Neuropeptide Y and argo-reliant peptide
c. Neuron peptide Y and aggregating reliant peptide
d. Neuropeptide Y and argown-resilient peptide
a. Neuropeptide Y and agouti-related peptide
Ventromedial hypothalamic syndrome involves obesity. From this, it is concluded that the ventromedial hypothalamus:
a. is a Satiety centre
b. releases leptin
c. Initiates humoral responses that trigger feeding behaviours
a. is a Satiety centre
Which of the following are anorectic peptides (diminish appetite)?
a. TSH and ACTH
b. NYP and AgRP
c. αMSH and CART peptides
d. MCH and LH
c. αMSH and CART peptides
αMSH and AgRp compete for the:
a. MC4 receptor on neurons in the lateral hypothalamic area
b. Receptor on neurons in the paraventricular nucleus
c. NYP neurons of the arcuate nucleus
d. magnocellular neurons of the hypothalamus
a. MC4 receptor on neurons in the lateral hypothalamic area
Describe the humoral response when leptin levels increase.
Elevated leptin is detected by aMSH and CART neurons in the arcuate nucleus. These excite the paraventricular nucleus to stimulate ACTH and thyrotropin release from the anterior pituitary, which causes an increased metabolic rate.
The humoral responses in to underweight are:
a. A decrease in sympathetic nervous system activity
b. A decrease in TSH and ACTH release
c. An increase in feeding behaviour
d. An increase in parasympathetic nervous system activity
e. A decrease in aMSH/AgRP neuron activity
f. An increase in NPY/AgRP neuron activity
b. A decrease in TSH and ACTH release
The rest occur, but are not humoral responses (e and f are arcuate nucleus responses)
List the three phases of short term regulation of feeding.
cephalic, gastric, substrate
Which of the following is NOT true regarding ghrelin?
a. It activates NPY/AgRP-containing neurons in arcuate nucleus
b. It is released when the stomach is full
c. It is released by ghrelin-secreting cells of the stomach
d. It was originally isolated as a factor that stimulates GH release
b. It is released when the stomach is full
It is released when the stomach is empty
Which of the following is NOT true regarding cholecystokinin?
a. It is abbreviated to CCK
b. It exerts its major effect on the vagus sensory axons
c. It is released in response to all foods entering the intestines
d. It is a satiety peptide that inhibits feeding behaviour
c. It is released in response to all foods entering the intestines
It is released in response to certain foods, esp. fatty ones
Which site was found to be most effective for electrical self-stimulation?
Trajectory of dopaminergic axons in the ventral
tegmental area projecting to the forebrain
Mesocorticolimbic dopamine system
Dopamine neurons
fire when reward is:
a. unexpected
b. craved
c. hedonic
d. accompanied by drugs that block dopamine receptors
a. unexpected
Drugs that elevate serotonin:
a. trigger volumetric thirst
b. suppress appetite
c. decrease food hedonics
d. increase food hedonics
b. suppress appetite
Describe the difference between volumetric and osmotic thirst.
Volumetric responds to hypovolemia (decrease
in blood volume). ADH released by hypothalamus in response to bloodborne angiotensin II (acts on subfornical organ in telencephalon) and vagus nerve feedback to nucleus of solitary tract from mechanoreceptors of heart.
Osmotic thirst: response to hypertonicity (increased
concentration of dissolved
substances/solutes in blood) sensed by the vascular organ of the lamina terminalis (OVLT), which excites the magnocellular neurosecretory cells of the hypothalamus to secrete vassopressin.
Leisons to OVLT prevent behavioural and humoral response to dehydration, but not to reduced blood volume.
