Hunger and Chemical Senses Flashcards
Hunger =
Low blood glucose levels
Glucose
- preferred source of energy
- stored in glycogen
- released by the liver to replenish BG levels
- found in muslces and liver
Glycogen
- stores to help maintain BG levels over the course of the day
- Released between meals
Feeling of satiation
the pancreas secretes insulin → promotes uptake of glucose by cells for immediate use →excess glucose stored as glycogen and as adipose
Feeling of hunger
As time from last meal increases = decrease in blood sugar → Liver converts glycogen to glucose → releasing back into blood → glycogen reserves decreases
Neural Peptide Y
- Promotes food seeking behaviour
- high levels in hypothalamus = increased appetite
Brain receives feeling of being full from
- Stomach stretch receptors via vagus nerve
- GI tract secretion of digestive hormones
- The liver - monitors glucose levels to control hunger and satiety
Cholcystokinin
Hormone responsible for satiety
Hunger vs Satiety
H: NPY High, CCK low, Insulin low, glucose low
S: NPY Low, CCK high, Insulin high, glucose high
Adipose Tissue
Secretes leptin
Leptin
high levels = low appetite
- inhibits NPY
Leptin Resistance
Beyond certain level, effect of leptin on appetite is reduced
Glycogen reserves get low
- NPY levels increase
- Leptin secreted
- indicate need for food isn’t urgent
Blood glucose levels high
- CCK release
- short term satiety response
Endogenous Opioids
Naturally occurring chemical substances that have morphine-like analgesic actions in the body
- Analgesic
- block opioid receptors
