BIOPSYCH Ch. 12 (Eating)

The value of a physiological parameter that is maintained constantly by physiological or behavioural mechanisms - the body's energy resources are often assumed to be maintained at a constant optimal level by compensatory changes in hunger - a set-point model does a poor job of describing human feeding behavior

To supply the body with the molecular building blocks and energy it needs to survive and function

The gastrointestinal process of breaking down food and absorbing its constituents into the body

1. lipids (fats), 2. amino acids (the breakdown product of protein), and 3. glucose (a simple sugar that is the breakdown product of complex carbohydrates, that is, complex starches and sugars)

The body uses energy continuously but consumes energy intermittently - therefore, it must store energy for use in the intervals between meals

1. fats, 2. glycogen, and 3. proteins

Fats and relatively little are stored as glycogen and proteins - thus, changes in body weights of adult humans are largely a consequence of changes in the amount of their stored body fat

Glycogen is readily converted to glucose and glucose is the body's main directly utilizable source of energy, so one might expect that glycogen would be the preferred mode BUT 1. one gram of fat can store twice as much energy as one gram of glycogen and 2. glycogen attracts and holds substantial quantities of water, fat does not

The chemical changes by which energy is made available for an organisms use - 3 phases: 1. cephalic phase, 2. absorptive phase, and 3. fasting phase

Preparatory phase, which is initiated by the sight, smell, or expectation of food

Nutrients from a meal meeting the body's immediate energy requirements, with the excess being stored

Energy being withdrawn from stores to meet the body's immediate needs

By 2 pancreatic hormones: insulin and glucagon

The pancreas releases a great deal of insulin into the bloodstream and very little glucagon - the insulin does 3 things: 1. it promotes the use of glucose as the primary source of energy in the body, 2. it promotes the the conversion of bloodborne fuels to forms that can be stored: glucose as glycogen and dat, amino acids to proteins, and 3. it promotes the storage of glycogen in liver and muscle, fat in adipose tissue, and proteins in muscle -> CEPHALIC STAGE: LOWERS BLOODBORNE FUELS (PRIMARILY GLUCOSE) IN ANTICIPATION OF THE IMPENDING INFLUX AND THEN IN ABSORPTIVE STAGE: MINIMIZE THE INCREASING LEVELS OF BLOODBORNE FUELS BY UTILIZING AND STORING THEM

High blood levels of glucagon and low levels of insulin -