Ch 9 Definitions: Homeostasis, Motivation, and Reward Flashcards
homeostasis
a physiological state of equilibrium or balance
set point
a value that is defended by regulatory systems, such as core temperature or a particular body weight
motivation
the process of activating and directing behavior
endotherm
an animal that can use internal methods, such as perspiration or shivering, to maintain body temperature
ectotherm
an animal that relies on methods, such as moving into the sun or shade, for maintaining body temperature
fever
a carefully controlled increase in the body’s thermal set point that is often helpful in ridding the body of disease-causing organisms
hyperthermia
a life-threatening condition in which core body temperature increases beyond normal limits in an uncontrolled manner
serotonin syndrome
a life-threatening condition characterized by hyperthermia and muscular rigidity caused by excess serotonin activity due to use of therapeutic or recreational drugs
hypothermia
a potentially fatal core body temperature below 31C/87.8F
preoptic area (POA)
a part of the hypothalamus involved in a number of regulatory functions,
including temperature control
solute
a chemical dissolved in solution
solution
a fluid containing solutes
electrolyte
a substance that has broken up into ions in solution
interstitial fluid
a type of extracellular fluid surrounding the body’s cells
isotonic
having same concentration of solutes as a reference solution
osmosis
the movement of water to equalize concentration on two sides of a membrane
hypotonic
having a relatively lower concentration of solutes than a reference solution
hypertonic
having a relatively higher concentration of solutes than a reference solution
kidney
one of a pair of structures located in the lower back responsible for maintaining fluid balance and for producing urine
osmotic thirst
thirst produced by cellular dehydration
hypovolemic thirst
thirst that results from a decrease in the volume of the extracellular fluid
diabetes mellitus
a disease characterized by insulin deficiency, resulting in hunger, excess sugar in blood and urine, and extreme thirst
osmoreceptor
a receptor that detects cellular dehydration
organum vasculosum of the lamina terminalis (OVLT)
an area located around the third ventricle in the brain that detects cellular dehydration
baroreceptor
a receptor in the heart and kidneys that measures blood pressure
antidiuretic hormone (ADH)
a hormone that promotes retention of fluid by signaling the kidneys to reduce urine production and by stimulating the release of renin
aka vasopressin