Hunger

Question 1

homeostasis

Answer 1

maintenance of the body’s internal enviro within a narrow physiological range (there’s an optimal level to maintain)

Question 2

how does homeostasis occur

Answer 2

negative feedback -change detected & negative feedback elicits compensatory mechanisms

Question 3

main brain area involved in homeostasis

Answer 3

hypothalamus (Ramsay & woods, 2014)

Question 4

satiety

Answer 4

feeling full

Question 5

3 main digestive foods & broken down into what

Answer 5

carbs - glucose
fats - lipids
proteins - amino acids

Question 6

energy metabolism

Answer 6

Cephalic phase: prep phase (stimulated by seeing etc food)
Absorptive phase: when nutrients are taken from the food & excess is stored
Fasting phase:energy is withdrawn from stores to meet the body’s needs

Question 7

Cephalic phase & absorptive phase

Answer 7

Glucagon is LOW
Insulin is HIGH
- promotes conversion of excess glucose into glycogen & fats
- promotes use of blood glucose as a source of energy

Question 8

fasting phase

Answer 8

Glucagon is HIGH
Insulin is LOW
- promotes use of stored energy (glucose isn’t main source of energy anymore)

Question 9

insulin

Answer 9

1)promotes use of glucose as main source of energy in the body
2)promotes conversion of nutrients into forms which can be stored
3)promotes storage of glycogen in body
~~ helps glucose to get into cells so when insulin is LOW glucose cant be main energy store - use reserves
(saves glucose for brain - doesnt need insulin)

Question 10

what causes hunger?

Answer 10

stomach contractions

chemicals

Question 11

glucostatic theory of hunger

Answer 11

glucose levels determine set-point (thought to account for meal initiation) - hunger is caused by low levels of glucose

Question 12

neuropeptides

Answer 12

any of a group of compounds which act as neurotransmitters and are short-chain polypeptides. Feedback to the brain

Question 13

Cholecystokinin (CKK)

Answer 13

type of neuropeptide
SUPRESSESS EATING
Released in the small intestine 
Monitors food intake & inhibits eating 
Learned flavour aversion

Question 14

Gherlin

Answer 14

Type of neuropeptide
Released when we are hungry
Produced by stomach cells

Question 15

Dual centre set point model

Answer 15

Ventromedial Hypothalamus: Satiety centre (inhibits LH)
Lateral hypothalamus: Hunger centre (inhibits VMH)
BUT IT WAS WRONG

Question 16

Ventromedial lesions - evidence against dual model

Answer 16

Eventually after lesioning, eating will stablise
2 phases: dynamic (gross eating) & static period (stabilisation & return to new weight regardless)
AND
animals with VMH seem less bothered about food i.e. wont work for it

Question 17

Role of hypothalamus

Answer 17

Energy metabolism (energy flow)

Question 18

Reinterpretation of the effects of VMH & LH lesions: Insulin

Answer 18

• Bilteral VMH lesions: increase in BLOOD INSULIN LEVELS
• this increases lipogenesis & decreases lipolysis
• calories are being stored & converted into fat at a v HIGH RATE
• need more calories for immediate energy stores

Question 19

lipogenesis

Answer 19

production of body fat

Question 20

lipolysis

Answer 20

break down of body fat into energy forms

Question 21

Reinterpretation of the effects of VMH & LH lesions: structure of vmh

Answer 21

may actually be the bundle of fibres under the VMH being lesioned in the process

Question 22

Reinterpretation of the effects of VMH & LH lesions: LH

Answer 22

cessation of eating can be reversed eventually

force feeding & then should come back

Question 23

neuropeptide Y

Answer 23

• most prevalent neurop in the brain
• gut hunger peptide
• arcuate nucleus & DMH

Question 24

neuropeptide Y & arcuate nucleus

Answer 24

Many receptors to Ghrelin
Stimulates production of NPY
Thus, increases hunger

Question 25

neuropeptide Y & DMH (dorsomedial hypothalamus)

Answer 25

High number of CCK receptors
Reduces production of NYP
Thus, reduces appetite

Question 26

Leptin

Answer 26

Produced by expression of Ob gene only in FAT CELLS
This hormone promotes fat production
Leptin acts as a negative feedback signal (like insulin)

Question 27

other factors influencing hunger

Answer 27

1) anticipation
2) positive incentive
3) sensory specific satiety