Ch. 9: Internal Regulation

Anorexia nervosa

Disorder characterized by refusal to eat enough to remain healthy

Arcuate nucleus

Hypothalamic area with sets of neurons for hunger and satiety

Bulimia nervosa

A condition in which people alternate between binges of overeating and periods of strict dieting

Cholecystokinin (CCK)

A peptide hormone and neurotransmitter that acts as a powerful satiety signal in biological psychology

Duodenum

Part of the small intestine adjoining the stomach; first digestive site that absorbs nutrients

Ghrelin

Chemical released by the stomach during a period of food deprivation; also released as a neurotransmitter in the brain, where it stimulates eating

Glucagon

Pancreatic hormone that stimulates the liver to convert stored glycogen to glucose

Insulin

Pancreatic hormone that enables glucose to enter the cells

Lactase

Intestinal enzyme that metabolizes lactose

Lactose

Sugar in milk

Lateral hypothalamus

Area of the hypothalamus that controls insulin secretion, alters taste responsiveness, and facilitates feeding in other ways

Leptin

Hormone released by fat cells in proportion to their volume

Melanocortins

A family of peptide hormones and neurotransmitters that act as critical regulators of energy balance, appetite suppression, and skin pigementation in biological psychology

Sham-feeding

Procedure in which everything that an animal swallows leaks out a tube connected to the esophagus or stomach

Type 1 diabetes

Impaired glucose absorption caused by low levels of insulin secretion

Type 2 diabetes

A chronic metabolic disorder that biological psychology examines as a profound driver of neurological, cognitive, and behavioral dysfunction

Vagus nerve

Tenth cranial nerve, which has branches to and from stomach and several other organs

Ventromedial hypothalamus (VMH)

Region of the hypothalamus in which damage leads to faster stomach emptying and increase secretion of insulin

Allostasis

The adaptive way in which the body changes its set points depending on the situation

Basal metabolism

Energy used to maintain a constant body temperature while at resst

Ectothermic

Controlling temperature by relying on external sources of heat or cooling

Endothermic

Controlling temperature by the body’s phsiological mechanisms

Homeostasis

Tendency to maintain a variable, such as temperature, within a fixed range

Negative feedback

Homeostasis processes that reduce discrepancies from the set point

Preoptic area/anterior hypothalamus POA/AH

A brain region involved in regulating body temperature, sleep, and s*xual behavior

Set point

A value that the body works to maintain

Aldosterone

Adrenal hormone that causes the body to retain salt

Angiotensin II

Hormone that constricts the blood vessles, compensating for the drop in blood pressure; triggers thirst

Antidiueretic hormone (ADH)

Hormone that enables the kidneys to reabsorb water from urine; also known as vasopressin

Hypovolemic thirst

Thirst caused by a loss of fluids and salts from the body

Lateral preoptic area

Part of hypothalamus that controls drinking

Osmotic pressure

Tendency of water to flow across a semipermeable membrane from the area of low solute concentration to the area of high solute concentration

Osmotic thirst

Thirst triggered by certain neurons that detect the loss of their own water

OVLT

A brain structure that detects changes in blood fluid balance and helps regulate thirst

Paraventricular nucleus (PVN)

Part of the hypothalamus in which activity tends to limit meal size and damage leads to excessively large meals

Sodium-specific hunger

Increased preference for salty tastes

Subfornical organ (SFO)

Brain structure adjoining the third ventricle of the brain, where its cells monitor osmotic pressure and sodium concentration

Supraoptic nucleus

Part of the hypothalamus that controls the release rate of vasopressin

Vasopressin

A hormone that helps the body retain water and regulate blood pressure