Ch.6 Bio Psych Flashcards
Absorptive Phase
The period of a few hours following a meal during which the body relies on the nutrients arriving from the digestive system.
Agouti-Related Protein (Agrp)
A transmitter released by NPY/AgRP neurons in the arcuate nucleus of the hypothalamus when nutrients diminish, which stimulates feeding.
Amino Acids
The building blocks of peptides, which in turn make up proteins. In digestion, the result of the breakdown of proteins.
Angiotensin II
A hormone that signals lowered blood volume and, thus, volemic thirst to the brain.
Anorexia Nervosa
An eating disorder in which the person restricts food intake to maintain weight at a level so low that it is threatening to health.
Arcuate Nucleus
A structure in the hypothalamus that monitors the body’s nutrient condition and regulates eating behavior.
Area Postrema
A brain area unprotected by the blood-brain barrier; blood-borne toxins entering here induce vomiting.
Arousal Theory
The hypothesis that people behave in ways that keep them at their preferred level of arousal.
Basal Metabolism
The amount of energy required to fuel the brain and other organs and to maintain body temperature.
Binge Eating Disorder
A disorder characterized by frequent consumption of excessive amounts of food during a short interval of time and a feeling of loss of control over what and how much is eaten.
Body Mass Index (BMI)
The person’s weight in kilograms divided by the squared height in meters; an indication of the person’s deviation from the ideal weight for the person’s height.
Bulimia Nervosa
An eating disorder involving bingeing on food, followed by purging by vomiting or using laxatives.
Cholecystokinin (CCK)
A peptide hormone released as food passes into the duodenum. CCK acts as a signal to the brain that reduces meal size
Diabetes
An insulin disorder in which the person produces too little insulin (type 1), resulting in overeating with little weight gain, or the person’s brain is insensitive to insulin (type 2), resulting in overeating with weight gain.
Diabetes Gene
A gene on chromosome 4 that produces diabetes and obesity; mice with the gene are insensitive to leptin.
Drive
An aroused condition resulting from a departure from homeostasis, which impels the individual to take appropriate action, such as eating.
Drive Theory
Hypothesis based on the assumption that an unmet need will result in behavior that will satisfy that need in order to maintain a condition of homeostasis.
Duodenum
The first section of the small intestine, where most digestion occurs.
Epigenetic
Referring to inheritable characteristics resulting from modifications in gene expression.
Fasting Phase
The period following the absorptive phase, when the glucose level in the blood drops and the body must rely on its energy stores.
Fatty Acids
Breakdown product of fat, which supplies the muscles and organs of the body (except for the brain).
Ghrelin
A hormone released by the stomach during fasting; initiates eating.
Glucagon
A hormone released by the pancreas that stimulates the liver to transform stored glycogen back into glucose during the fasting phase.
Glucose
One of the sugars; the body’s main source of energy, reserved for the nervous system during the fasting phase; a major signal for hunger and satiation.
Glycerol
A breakdown product of fats, which is converted to glucose for the brain during the fasting period.
Glycogen
The form in which glucose is stored in the liver and muscles during the absorptive phase; converted back to glucose for the brain during the fasting phase.
Homeostasis
A body system seeks and maintains this condition of balance or equilibrium and has mechanisms to minimize changes to the system.
Hypovolemic Thirst
A fluid deficit that occurs when the blood volume drops due to a loss of extracellular water.
Incentive Theory
A theory that recognizes that people are motivated by external stimuli (incentives), not just internal needs.
Instinct
A complex behavior that is automatic and unlearned and occurs in all the members of a species.
Insulin
A hormone secreted by the pancreas that enables entry of glucose into cells (not including the nervous system) during the absorptive phase and facilitates storage of excess nutrients.
Lateral Hypothalamus
A nucleus of the hypothalamus with roles in feeding and metabolism, aggression, and waking arousal.
Learned Taste Aversion
Learned avoidance of a food (based on its taste) eaten prior to becoming ill.
Learned Taste Preference
Preference for a food containing a needed nutrient (identified by the food’s taste), learned, presumably, because the nutrient makes the individual feel better.
Leptin
A hormone secreted by fat cells, which is proportional to the percentage of body fat and which signals fat level to the brain.
Median Preoptic Nucleus
A nucleus of the hypothalamus that initiates drinking in response to osmotic and volumetric deficits.
Motivation
factors that initiate, sustain, and direct behavior.
Neuropeptide Y (NPY)
A transmitter released by NPY/AgRP neurons in the arcuate nucleus of the hypothalamus when nutrient levels diminish; it is a powerful stimulant for eating and conserves energy.
Nucleus of the Solitary Tract (NST)
A part of the medulla that monitors several signals involved in the regulation of eating.
Obesity Gene
A gene on chromosome 6 that causes obesity; in mice, it results in an inability to produce leptin.
Orexin
A neuropeptide released by lateral hypothalamic neurons that increases feeding and arousal; also known as hypocretin.
Organum Vasculosum Lamina Terminalis (OVLT)
A structure bordering the third ventricle that monitors fluid content in the cells and contributes to the control of osmotic thirst.
Osmotic Thirst
Thirst that occurs when the fluid content is low inside the body’s cells.
Paraventricular Nucleus (PVN)
A structure in the hypothalamus that monitors several signals involved in the regulation of eating, including input from the NST; it helps regulate metabolic processes.
Peptide YY3-36 (PYY)
An appetite-suppressing peptide hormone released in the intestines in response to food.
Preoptic Area
A structure in the hypothalamus that contains warmth-sensitive cells and cold-sensitive cells and participates in the control of body temperature. See medial preoptic area regarding regulation of sexual behavior.
Satiety
Satisfaction of appetite.
Sensory-Specific Satiety
Decreased attractiveness of a food as the person or animal eats more of it.
Set Point
A value in a control system that is the system’s point of equilibrium or homeostasis; departures from this value initiate actions to restore the set-point condition.
Subfornical Organ (SFO)
One of the structures bordering the third ventricle that increases drinking when stimulated by angiotensin II.
