Chapter12 Flashcards
Digestion
Gastrointestinal process of breaking down food and absorbing its constituents into the body through the lining of the gastrointestinal tract.
Lipids
Fats.
Amino Acids
The breakdown products of proteins.
Glucose
A simple sugar that is the breakdown product of complex carbohydrates.
Cephalic phase
Preparatory phase. Often begins with the sight, smell, or thought of food and ends when the food starts to be absorbed into the blood stream.
Absorptive phase
Period during which energy absorbed into the bloodstream from a meal is meeting the body’s immediate energy needs.
Fasting phase
Period during which all of the unstirred energy from the pervious mean has been used and the body is withdrawing energy from it’s reserves to meet it’s immediate energy needs. It ends with the beginning of the next cephalic phase.
Insulin
A pancreatic hormone that facilitates the energy of glucose into cells. It promotes the use of glucose as the primary source of energy by the body, it promotes the conversion of the blood borne fuels to forms that can be stored, and it promotes the storage of glycogen in liver and muscle, fat in adipose tissue, and protein in muscle.
Glucagon
a pancreatic hormone that promotes the release of free fatty acids from adipose tissue, their conversion to ketones, and the use of both as sources of energy.
Gluconeogenesis
The process by which protein is converted to glucose.
Free fatty acids
The main source of the body’s energy during fasting phase; released from adipose tissue in response to high levels of glucagon.
Ketones
Breakdown products of free fatty acids that are used by muscles as a source of energy during the fasting phase.
Set point
The value of a physiological parameter that is maintained constantly by physiological or behavioral mechanisms.
Set-point assumption
The assumption that hunger is typically triggered by the decline of the body’s reserves below their set point.
Negative feedback systems
Systems in which feedback from changes in one direction elicit compensatory effects in the opposite direction.
Homeostasis
The stability of an organism’s constant internal environment.
Glucostatic theory
The theory that eating is controlled by deviations from a hypothetical blood glucose set point.
Lipostatic theory
The theory that eating is controlled by deviations from the hypothetical body-fat set point.
Positive-insintive theory
The idea that behaviors are motivated by their anticipated pleasurable effects.
Positive-insintive value
The anticipated pleasure associated with a particular action.
Satiety
The motivational state that terminates a mean when there is food remaining.
Nutritive Density
Calories per unit volume of a food.
Sham eating
The experimental protocol in which an animal chews and swallows food, which immediately exits the body through a tube implanted in its esophagus.
Appetizer effect
The increase in hunger that is produced by the consumption of small amounts of palatable food.
Cafeteria diet
A diet offered to experimental animals that is composed of a wide variety of palatable foods.
Sensory-specific satiety
The fact that the consumption of a particular food produces increased satiety for foods of the same taste than for other foods.
Ventromedial hypothalamus (VMH)
The area of the hypothalamus thought to contain a satiety center.
Lateral hypothalamus (LH)
The area of the hypothalamus once thought to be the feeding center.
Hyperphagia
Excessive eating.
Dynamic phase
The first phase of the VMH syndrome, characterized by grossly excessive eating and rapid weight gain.
Static phase
The second phase of the VMH syndrome, during which the grossly obese animal maintains a stable level of obesity.
Aphagia
Complete cessation of eating.
Adipsia
Complete cessation of drinking.
Lipogenesis
The production of body fat.
Lipolysis
The breakdown of body fat.
Paraventricular nuclei
Hypothalamic nuclei that play a role in eating and synthesize hormones released by the posterior pituitary.
Duodenum
The upper portion of the intestine through which most of the glucose and amino acids are absorbed into the bloodstream.
Cholecystokinin (CCK)
A peptide that is released by the gastrointestinal tract and is thought to function as a satiety signal.
Prader-Willi syndrome
A neurodevelopment disorder that is characterized by insatiable appetite and exceptionally slow metabolism.
Diet-induced thermogenesis
The homeostasis-defending increases in body temperature that are associated with increases in body fat.
Basal metabolic rate
The rate at which an individual utilizes energy to maintain bodily processes.
Settling point
The point at which various factors that influence the level of some regulated function (such as body weight) achieve an equilibrium.
Leaky-barrel model
A settling-point model of body-fat regulation.
NEAT
Non exercise activity thermogenesis, which is generated by activities such as fidgeting and the maintenance of posture and muscle tone.
Leptin
A protein normally synthesized in fat cells; it is thought to act as a negative feedback fat signal, reducing consumption.
Ob/ob mice
Mice that are homozygous for the mutant ob gene; their body fat produces no leptin, and they become very obese.
Subcutaneous fat
Body fat that is stored under the skin and is positively correlated with leptin levels.
Visceral fat
Body fat that is stored in the organs of the body and is positively correlated with insulin levels.
Arcuate nucleus
A nucleus of the hypothalamus that contains high concentrations of both leptin receptors and insulin receptors.
Neuropeptide Y
A neuropeptide that is released both in the gut and by neurons, particularly those in the arcuate nucleus; its release is associated with hunger.
Melanocortins
A class of neuropeptides that includes α-melancyte-stimulating hormone, which surpasses eating.
Melanocortin system
Neurons in the arcuate nucleus that regulate α-melancyte-stimulating hormone and in so doing play a role in satiety.
Gastric bypass
A surgical procedure for treating extreme obesity in which the intestine is cut and connected to the upper portion of the stomach, which is isolated from the rest of the stomach by a row of staples.
Adjustable gastric band procedure
A surgical procedure for treating extreme obesity in which an adjustable band is implanted around the stomach to reduce the flow of food.
Anorexia nervosa
An eating disorder that is characterized by a pathological fear of obesity and that results in health-threatening weight loss.
Bulimia nervosa
An eating disorder that is characterized by recurring cycles of fasting, bingeing, and purging without dangerous weight loss.
