Psych- Hunger

what is glucose responsible for?

glucose is responsible for keeping your body functional

what is the preferred energy source for the brain?

glucose

what is glycogen responsible for?

responsible for storing glucose

where is glycogen stored?

in the liver or muscles

when is glucose released?

between meals and when glucose levels are low

what is insulin responsible for?

mediating the glucose glycogen balance

what happens to your blood sugar after eating?

increase

what happens when there is an uptake of glucose by cells after eating?

some is used for immediate energy, some is stored as glycogen and the excess is stored as adipose

what happens to your blood sugar as time goes on after eating?

slow decrease in blood sugar

what does the liver convert glycogen into?

glucose

what sensation do you feel when your glycogen levels decrease?

hunger

what is NPY

it is an appitite stimulant and it increases appitite and food seeking behaviors

name some satiety signals

stomach stretch receptors via vagus nerve

gastrointestinal tract secretion of digestive hormones

liver releases glucose

what is CCK stand for

Cholecystikinin

what is CCK

is a hormone responsible for feelings of satiety that come from the small intestine. This serves as a signal to stop eating and is a short term satiety feeling.

what stores long term energy?

fat

how much more energy density does fat have comapred to carbs?

more than twice the amount

how many kcal in 1 g of fat

9 kcal

how many kcal in 1 g of carbs

4 kcal

what is adipose tissue

a fat responsible for secreting a hormone called leptin

what is leptin

responsible for storing long term energy. When lepton is level high, appitite is reduced

what can lack of leptin lead to?

obseity

what is leptin resistance?

beyond regular level, the effect of leptin on appetite has no affect

how did lepton help survival historically?

low lepton levels meant that energy was low, therefore increased foraging activity

what does leptin inhibit?

NPY

what does NPY promote?

carb intake

what are endogenous opiods?

chemical substances that contribute to rewards driven feeding behaviors

what is naloxone?

a drug that reduces intake of saccharin, sucrose and saline

what happens when there is a lack of opioid receptors?

there is a decrease in sacchrin consumption/craving

what source is glucose from

food

where is glycogen sourced from

the liver

where is insulin sourced from

pancreas

where is CCK sourced from?

small intestine

where is NPY sourced from

hypothalamus

where is leptin sourced from?

Adipose

function of glucose

primary fuel

function of glycogen

stores glucose

function of insulin

stimulates glucose metabolism and glycogen synthesis

CCK function

short term satiation

NPY function

stimulates appetite

Leptin Function

high levels inhibit NPY and low levels promote feeding

what tastes are craved most

salty and umami because they indicate safe, nutritious and rich and energy

are females or males more senestive to taste?

females, espeically sensetive to bitterness during pregnancy

function of taste receptor

detects and responds to dissolved food molecules

how many taste receptor cells are on a signle taste bud?

50-150

where are taste receptors located?

on taste buds

how much of the taste buds are located on the tongue

mostt are located on the tongue. 2/3.

where else are the tastebuds located apart from the tongue?

soft palet and throat opening

name the 5 tastes

sweet, salty, bitter, sour and umami

what does sweetness indicate

high energy

what does saltiness indicate

able to digest electrolites

what does sourness and bitterness indicate?

a warning of harm, spoiled or poisonous food

what does umami indicate?

detects amino acids, glutamate and aspertate

where do food molecules go after the taste receptors?

through the gustatory nerve into the medulla

after the medulla, where is next?

thalamus

after reaching the thalamus, where can taste sensation travel to?

either:

hypothalamus + Amygdata or Gustatery cortex then primary somosatory cortex

Guestatory cortex

used to preceive taste, it is connected to other parts of the brain to combine taste with other sensations

what happens when the pathway goes from the Gustatory cortex to the primary somosatory cortex?

taste and texture are combined

what happens when the pathway goes from Gustatory cortex to the orbital cortex?

flavour is preceived because the sensation of taste is combined with smell

what situations would the taste pathway goes to thalamus into the hypothalamus and amygdata?

hormonal feeding patterns, CKK activity and satiety behaviors

what is restronasal smell?

ability to detect flavour

where is flavour processed?

nasopharynx

what happens when we detect spice

the chemical “capsaicin” is released which activates heat and pain receptors

why does smell go straight to the cortex?

smell can alert the events in the enviornment and it essential for survival as it allows you to find food, mates and preds

what happens after molecules eneter the nasal cavity?

the molecules dissolve in mucus

what do the smell molecules do after they have been dissolved

interact with olfactory cilia

where is the olfactory cilia located?

they cover the receptors surface also called the olfactory epithelium

how many cilia does each receptor get info from?

10-20 cilia

what happens after the oderants bind to the recpetoirs?

the receptors fire action potentials and travel along axons to the oldfactory bulb

what happens after the odourants reach the olfactory bulb?

receptors axons synapse with dendrites of glomuli

what do the glomuli do?

send action potentials to higher regions of the brain

what “higher regions of the brain” does the glamaruli send action potentials towards?

the limbic system, primary olfactory cortex and the orbital lobe