food intake

Question 1

several neuronal centers of the ____ act as feeding/hunger and satiety centers (e.g. the ____ , ____ , ____ , and ____ nuclei of the hypothalamus)

Answer 1

hypothalamus

paraventricular, dorsomedial, arcuate, and ventromedial

Question 2

leptin

Answer 2

hormones symthesized from adipose tissue cells and released in proportion to the amount of fat in the adipose tissue

Question 3

functions of leptin

• *

Answer 3

causes an increase in metabolic rate

acts on the hypothalamus to reduce food intake, partly by inhibiting the release of neuropeptide Y, a hypothalamic transmitter that stimulates appetite

Question 4

leptin is probably important in the long-term matching of:

(its disappearance from the blood during times of starvation results in a decrease in the basal metabolic rate, thereby prolonging life)

Answer 4

caloric intake to energy expenditure, as its effect on metabolic rate is its primary function

Question 5

other satiety signals act on the hypothalamus and other brain regions to provide short-term regulation of meal length and meal frequency, partly by making one cease feeling hungry; these include:

Answer 5

insulin (which increases during food absorption)

gut hormones such as CCK

activation of stretch receptors in the stomach and duodenum, which trigger neural signals in the vagus Nn to the brain

Question 6

ghrelin

Answer 6

hormone released by the stomach in response to low calorie diets or fasting

Question 7

functions of ghrelin

Answer 7

increases hunger by stimulating the relase of neuropeptide Y and other neuropeptides in the feeding centers

more important in short-term than in long-term regulation of food intake

Question 8

a decreased blood glucose concentration causes hunger, which has led to the

some studies have shown similar effects for blood concentration of amino acides and lipid breakdown products

Answer 8

glucostatic theory of hunger and feeding regulation

Question 9

the hypothalamic melanocortin system plays a powerful role in regulating the energy stores of the body:

• ____ neurons of the ____ nucleus
  
  • produce ____-stimulating hormone and other molecules
  • when activated ____ food intake and ____ energy expenditure
• other arcuate nucleus neurons
  
  • produce ____ ____ and ____ protein
  • when activated ____ food intake and ____ energy expenditure

Answer 9

• pro-opiomelanocortin (POMC) arcuate
  
  • alpha-melanocyte
  • decreases increases
• • neuropeptide Y and agouti-related protein (AGRP)
    
    • increases decreases

Question 10

within the hypothalamus, there is interaction between the ____ regulating system and the ____ regulating system

Answer 10

food-intake temperature

e.g. an animal exposed to cold tends to increase feeding and one exposed to heat tends to decrease it)