Chapter 13 Flashcards

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 induces the kidneys to conserve sodium ions.
angiotensin II
A substance that is produced in the blood by the action of renin and plays a role in the control of thirst.
anorexia nervosa
A syndrome in which individuals severely deprive themselves of food.
anorexigenic neurons
Neurons of the hypothalamic appetite system that inhibit feeding behavior.
aphagia
Refusal to eat; often related to damage to the lateral hypothalamus. Compare hyperphagia.
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. See Figure 13.23.
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.
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. See Figure 13.12.
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.
diabetes mellitus
Excessive glucose in the urine, caused by the failure of insulin to induce glucose absorption by the body. Two types of diabetes mellitus are known: Type I (juvenile-onset) and Type II (adult-onset).
diffusion
The spontaneous spread of molecules of one substance among molecules of another substance until a uniform concentration is achieved. See Figure 3.2.
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. Compare endotherm.
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. Compare ectotherm.
enterotype
Each individual’s personal composition of gut flora.
epigenetic transmission
The passage of epigenetic modifications of a gene from one generation to another.
extracellular compartment
The fluid space of the body that exists outside the cells. See Figure 13.10. Compare intracellular compartment.
fecal transplantation
A medical procedure in which gut flora, via fecal matter, are transferred from a donor to a host.
ghrelin
A peptide hormone emanating from the gut. See Figure 13.23. Compare obestatin.
glucagon
A hormone, released by alpha cells in the islets of Langerhans, that increases blood glucose. See Table 5.2. Compare insulin.
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
An important sugar molecule used by the body and brain for energy.
glucose transporter
A molecule that spans the external membrane of a cell and transports glucose molecules from outside the cell to inside for use.
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.
homeostatic
Referring to the process of maintaining a particular physiological parameter relatively constant.
hunger
The internal state of an animal seeking food. Compare satiety.
hyperphagia
Excessive eating. Compare aphagia.
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). Compare hypotonic and isotonic.
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).Compare hypertonic and isotonic.
hypovolemic thirst
A desire to ingest fluids that is stimulated by a reduced volume of extracellular fluid. Compare osmotic thirst.
insulin
A hormone, released by beta cells in the islets of Langerhans, that lowers blood glucose. See Table 5.2. Compare glucagon.
intracellular compartment
The fluid space of the body that is contained within cells. See Figure 13.10. Compare extracellular compartment.
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). Compare hypertonic and hypotonic.
ketones
A metabolic fuel source liberated by the breakdown of body fats and proteins.
lateral hypothalamus (LH)
A hypothalamic region involved in the control of appetite and other functions. See Figure 13.20.
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 melanocortinreceptor.
melanocortins
One category of endogenous opioid peptides.
motivation
A drive state that prompts homeostatic behaviors.
negative feedback
The property by which some of the output of a system feeds back to reduce the effect of input signals. Compare positive feedback.
neuropeptide Y (NPY)
A peptide neurotransmitter that may carry some of the signals for feeding.
normal flora
Also called gut flora. The large population of microorganisms that normally inhabit the digestive tract.
NPY/AgRP neurons
Neurons involved in the hypothalamic appetite control system, so named because they produce both neuropeptide Y and agouti-related peptide. Compare POMC/CART neurons.
nucleus of the solitary tract (NST)
A complicated brainstem nucleus that receives visceral and taste information via several cranial nerves. See Figure 13.23.
nutrient
A chemical that is needed for growth, maintenance, and repair of the body but is not used as a source of energy.
obligatory losses
Unavoidable loss of a regulated variable, such as energy, water, or temperature, as a consequence of life processes.
orexigenic neurons
Neurons of the hypothalamic appetite system that promote feeding behavior.
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. See Figures 13.10, 13.15
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 a solute.
osmotic thirst
A desire to ingest fluids that is stimulated by high concentration of solute (like salt) in the extracellular compartment. Compare hypovolemic thirst.
paraventricular nucleus (PVN)
A nucleus of the hypothalamus implicated in the release of oxytocin and vasopressin, and in the control of feeding and other behaviors. See Figures 5.11, 13.23.
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. Compare NPY/AgRP neurons.
pro-opiomelanocortin (POMC)
A pro-hormone that can be cleaved to produce the melanocortins, which also participate in feeding control. See Figure 13.23.
PYY3-36
A peptide hormone, secreted by the intestines, that probably acts on hypothalamic appetite control mechanisms to suppress appetite.
satiety
A feeling of fulfillment or satisfaction. Compare hunger.
set point
The point of reference in a feedback system. An example is the setting of a thermostat.
set zone
The range of a variable that a feedback system tries to maintain.
subfornical organ
One of the circumventricular organs. See Figure 13.12.
thermoregulation
The active process of closely regulating body temperature around a set value.
trophic factor
A substance that promotes cell growth and survival. See also neurotrophic factor.
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. See Figures 2.9, 13.23.
vasopressin
See arginine vasopressin.
ventromedial hypothalamus (VMH)
A hypothalamic region involved in eating and sexual behaviors. See Figures 12.6, 13.20.
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