Eating behavior - Biological explanations of eating

Question 1

what are the biological explanations for eating behavior?

Answer 1

neural and hormonal

Question 2

what is leptin?

Answer 2

hormone produce by adipose/fat cells

Question 3

what are fat cells named?

Answer 3

adipose cells

Question 4

does leptin stimulate hunger or satiety?

Answer 4

satiety

Question 5

explain the cycle of leptin in hunger cycle

Answer 5

1) leptin = hormone produced by adipose
2) levels of leptin in the blood increases with fat cells
3) this increase is detected by the VMH
4) if levels increase to a certain point the individual feels full and stops eating

Question 6

what is Ghrelin?

Answer 6

hormone secreted by the stomach

Question 7

explain the role of Ghrelin in the hunger cycle

Answer 7

1) Ghrelin is secreted by the stomach
2) marks how long since we have eaten
3) amount produced is proportional to how empty the stomach is
4) ghrelin levels are detected by the part of the hypothalamus called arcuate nucleus
5) when ghrelin reaches a certain point the arcuate nucleus send signals to LH
6) the LH secretes neuropeptide
7) this stimulates hunger

Question 8

what transmitter stimulates hunger?

Answer 8

neuropeptide

Question 9

what part of the brain detects rise in ghrelin levels?

Answer 9

a part of the hypothalamus called arcuate nucleus

Question 10

evaluate hormonal explanation of eating cycle

Answer 10

+ research support - wren
+ research support - licinio
+ PA - give leptin to people who are leptin deficient
- reductionist
-deterministic

Question 11

what was wrens research?

Answer 11

injected ghrelin intravenously (in the veins) and found that there was a short term increases in food eaten

Question 12

what was licinios research

Answer 12

people with a disorder that meant they had less leptin (makes u eat)
gave them leptin
weight loss of 40%
food intake decreases by 49%

Question 13

what is homeostasis?

Answer 13

keeping of constant internal environment at a stable level
such as blood glucose and temperature

Question 14

hypothalamus role in homeostasis

Answer 14

monitors and controls the internal environment specifically, the glucose-sensing neurons within the hypothalamus detects fluctuations in blood glucose levels
it influences the secretion of insulin and anti-insulin hormones which effect blood-glucose levels

Question 15

what brain structures provide homeostasis?

Answer 15

lateral hypothalamus
ventromedial hypothalamus

Question 16

role of VMH in homeostasis of hunger

Answer 16

detects a rise in blood glucose levels and inhibits feeling of satiety to stop a person eating

Question 17

role of LH in homeostasis of hunger

Answer 17

detects a drop in blood glucose levels and triggers feeling of hunger so people eat

Question 18

explain the neural homeostasis cycle to trigger eating

Answer 18

optimum blood glucose levels
drop in BG
LH detects change
feel hungry
glucose levels rise

Question 19

role of VMH in homeostasis of satiety

Answer 19

optimum levels of blood glucose
rise in BG
VMH detects rise
satiety
stop eating
fall in blood glucose

Question 20

evaluate neural explanations for eating

Answer 20

+ Hetherington and Ranson
- cross specie validity
- over simplified ignore social factors

Question 21

WHAT IS THE DUAL CENTRE MODEL OF EATING?

Answer 21

suggests that two structures of the hypothalamus provide homeostatic control

Question 21

WHAT IS THE DUAL CENTRE MODEL OF EATING?

Answer 21

suggests that two structures of the hypothalamus provide homeostatic control

Question 22

what is he hypothalamus

Answer 22

a pea sized brain structure that plays significant roles in the endocrine and nervous system

Question 23

what was Hetherington and Ransons research?

Answer 23

lesioned VMH in rats and found they became hyperphagic until they were severely obese this is because VMH didn’t detect rise in blood glucose and didn’t trigger satiety