Chapter 13 Flashcards & Key Terms

adipose tissue
Tissue made up of fat cells.
agouti-related peptide (AgRP)
A peptide that is a naturally occurring antagonist to α-melanocyte-stimulating hormone at melanocortin receptors.
aldosterone
A mineralocorticoid hormone, secreted by the adrenal cortex, that promotes conservation of sodium by the kidneys.
angiotensin II
A substance that is produced in the blood by the action of renin and that may play a role in the control of thirst.
anorexia nervosa
A syndrome in which individuals severely deprive themselves of food.
aphagia
Refusal to eat.
aquaporins
Channels spanning the cell membrane that are specialized for conducting water molecules into or out of the cell.
arcuate nucleus
An arc-shaped hypothalamic nucleus implicated in appetite control.
atrial natriuretic peptide (ANP)
A hormone, secreted by the heart, that normally reduces blood pressure, inhibits drinking, and promotes the excretion of water and salt at the kidneys.
bariatric
Having to do with obesity.
baroreceptor
A pressure receptor in the heart or a major artery that detects a fall in blood pressure.
basal metabolism
The consumption of energy to fuel processes such as heat production, maintenance of membrane potentials, and all the other basic life-sustaining functions of the body.
binge eating
The paroxysmal intake of large quantities of food, often of poor nutritional value and high calories.
brown fat
Also called brown adipose tissue. A specialized type of fat tissue that generates heat through intense metabolism.
bulimia
Also called bulimia nervosa. A syndrome in which individuals periodically gorge themselves, usually with “junk food,” and then either vomit or take laxatives to avoid weight gain.
cholecystokinin (CCK)
A peptide hormone that is released by the gut after ingestion of food high in protein and/or fat.
circumventricular organ
An organ that lies in the wall of a cerebral ventricle and monitors the composition of the cerebrospinal fluid.
cocaine- and amphetamine-regulated transcript (CART)
A peptide produced in the brain when an animal is injected with either cocaine or amphetamine. It is also associated with the appetite control circuitry of the hypothalamus.
dehydration
Excessive loss of water.
diabetes insipidus
Excessive urination, caused by the failure of vasopressin to induce the kidneys to conserve water.
diabetes mellitus
Excessive glucose in the urine, caused by the failure of insulin to induce glucose absorption by the body.
digestion
The process by which food is broken down to provide energy and nutrients.
ectotherm
An animal whose body temperature is regulated by, and whose heat comes mainly from, the environment. Examples include snakes and bees.
endocannabinoid
An endogenous ligand of cannabinoid receptors; thus, an analog of marijuana that is produced by the brain.
endotherm
An animal whose body temperature is regulated chiefly by internal metabolic processes. Examples include mammals and birds.
extracellular compartment
The fluid space of the body that exists outside the cells.
ghrelin
A peptide hormone emanating from the gut.
glucagon
A hormone, released by alpha cells in the islets of Langerhans, that increases blood glucose
glucodetector
A cell that detects and informs the nervous system about levels of circulating glucose.
gluconeogenesis
The metabolism of body fats and proteins to create glucose.
glucose transporter
A molecule that spans the external membrane of a cell and transports glucose molecules from outside the cell to inside for use.
glucose
An important sugar molecule used by the body and brain for energy.
glycogen
A complex carbohydrate made by the combining of glucose molecules for a short-term store of energy.
glycogenesis
The physiological process by which glycogen is produced.
glycogenolysis
The conversion of glycogen back into glucose, triggered when blood concentrations of glucose drop too low.
homeostasis
The tendency for the internal environment to remain constant.
homeostatic
Referring to the active process of maintaining a particular physiological parameter relatively constant.
hunger
The internal state of an animal seeking food.
hyperphagia
Excessive eating.
hypertonic
Referring to a solution with a higher concentration of salt than that found in interstitial fluid and blood plasma (more than about 0.9% salt).
hypotonic
Referring to a solution with a lower concentration of salt than that found in interstitial fluid and blood plasma (less than about 0.9% salt).
hypovolemic thirst
A desire to ingest fluids that is stimulated by a reduced volume of extracellular fluid.
insulin
A hormone, released by beta cells in the islets of Langerhans, that lowers blood glucose.
intracellular compartment
The fluid space of the body that is contained within cells.
isotonic
Referring to a solution with a concentration of salt that is the same as that found in interstitial fluid and blood plasma (about 0.9% salt).
ketones
A metabolic fuel source liberated by the breakdown of body fats and proteins.
kilocalorie (kcal)
A measure of energy commonly applied to food; formally defined as the quantity of heat required to raise the temperature of 1 kg of water by 1°C.
lateral hypothalamus (LH)
A hypothalamic region involved in the control of appetite and other functions.
leptin
A peptide hormone released by fat cells.
lipids
Large molecules (commonly called fats) consisting of fatty acids and glycerol that are insoluble in water.
melanocortin type-4 receptors (MC4Rs)
A specific subtype of melanocortin receptor.
melanocortins
One category of endogenous opioid peptides.
α-melanocyte stimulating hormone (α-MSH)
A peptide that binds the melanocortin receptor.
metabolism
The breakdown of complex molecules into smaller molecules.
negative feedback
The property by which some of the output of a system feeds back to reduce the effect of input signals.
neuropeptide Y (NPY)
A peptide neurotransmitter that may carry some of the signals for feeding.
NPY/AgRP neurons
Neurons involved in the hypothalamic appetite control system, so named because they produce both neuropeptide Y and agouti-related peptide.
nucleus of the solitary tract (NST)
A complicated brainstem nucleus that receives visceral and taste information via several cranial nerves.
nutrient
A chemical that is needed for growth, maintenance, and repair of the body but is not used as a source of energy.
orexins
Also called hypocretins. Neuropeptides produced in the hypothalamus that are involved in switching between sleep states, in narcolepsy, and in the control of appetite.
osmolality
The number of solute particles per unit volume of solvent.
osmosensory neuron
A specialized neuron that measures the movement of water into and out of the intracellular compartment.
osmosis
The passive movement of molecules from one place to another.
osmotic pressure
The tendency of a solvent to move through a membrane in order to equalize the concentration of solute.
osmotic thirst
A desire to ingest fluids that is stimulated by loss of water from the extracellular compartment.
paraventricular nucleus (PVN)
A nucleus of the hypothalamus.
POMC/CART neurons
Neurons involved in the hypothalamic appetite control system, so named because they produce both pro-opiomelanocortin and cocaine- and amphetamine-related transcript.
pro-opiomelanocortin (POMC)
A pro-hormone that can be cleaved to produce the melanocortins, which also participate in feeding control.
PYY3–36
A peptide hormone, secreted by the intestines, that probably acts on hypothalamic appetite control mechanisms to suppress appetite.
redundancy
The property of having a particular process, usually an important one, monitored and regulated by more than one mechanism.
satiety
A feeling of fulfillment or satisfaction.
set point
The point of reference in a feed-back system. An example is the setting of a thermostat.
set zone
The range of a variable that a feedback system tries to maintain.
shivering
Rapid involuntary muscle contractions that generate heat in hypothermic animals.
solute
A solid compound that is dissolved in a liquid.
solvent
The liquid (often water) in which a compound is dissolved.
spinal animal
An animal whose spinal cord has been surgically disconnected from the brain to enable the study of behaviors that do not require brain control.
subfornical organ
One of the circumventricular organs.
trophic factor
A substance that promotes cell growth and survival.
vagus nerve
Cranial nerve X, which provides extensive innervation of the viscera (organs). The vagus both regulates visceral activity and transmits signals from the viscera to the brain.
ventromedial hypothalamus (VMH)
A hypothalamic region involved in eating and sexual behaviors.
Go