Ingestive Behaviour and Metabolism Flashcards

This set of vocabulary flashcards covers the physiological and neural mechanisms of ingestive behavior, metabolism regulation, and factors contributing to obesity based on the lecture notes.

Adipose tissue

Body energy stores containing $85\%$ fat.

Metabolism

The chemical reactions occurring within the body.

Respiration

The breakdown of glucose making energy available to the organism.

Cephalic Phase

The preparatory phase of metabolism set off by the sight or expectation of food.

Absorptive Phase

The phase meeting the body’s immediate energy requirements where insulin is high, glucagon is low, and excess glucose is stored as fat.

Fasting Phase

The phase where energy is withdrawn from stores, insulin is low, glucagon is high, and fat is converted to fatty acids.

Ghrelin

A peptide hormone released by the stomach that increases eating, stimulates thoughts about food, and increases before each meal.

Leptin

A hormone produced by fat in adipose tissue that signals the brain to stop eating; found to be deficient in "Ob mice".

Vagus nerve

The nerve that records the stretch of the stomach to signal a feeling of fullness.

Cholecystokinin (CCK)

A hormone released by the entry of food into the duodenum that suppresses feeding.

Peptide YY (PYY)

A hormone released by the stomach after a meal in proportion to calories consumed that inhibits the size of meals.

Arcuate nucleus

An aggregation of neurons in the mediobasal hypothalamus that responds to Ghrelin and Leptin to control hunger and satiation.

Neuropeptide Y (NPY)

A peptide secreted by the arcuate nucleus in response to Ghrelin that leads to ravenous hunger when infused into the hypothalamus.

Lateral Hypothalamus

Often called the "Feeding Centre"; electrical stimulation here elicits eating while lesions cause a lack of eating.

Melanin-concentrating hormone (MCH)

A hormone produced by neurons in the lateral hypothalamus that stimulates hunger and decreases metabolic rate.

Orexin

A hormone produced in the lateral hypothalamus that stimulates hunger and decreases metabolic rate to preserve energy stores.

Anorexigens

Appetite-suppressing chemicals, such as CART and $\alpha-MSH$, that inhibit MCH and orexin neurons.

Fructose

A sugar found in high fructose corn syrup that, unlike glucose, does not stimulate insulin or leptin production.

NEAT

Stands for "nonexercise activity thermogenesis"; refers to involuntary activity such as fidgeting that affects energy expenditure.

Uncoupling Protein (UCP)

A protein found in muscles where increasing levels are associated with an increased metabolic rate, resulting in less glucose stored as fat.