Task 6 Flashcards
what is homeostasis?
active process of maintaining a particular psychological parameter relatively constant
what happens if you alter homeostasis?
it might effect motivation
what are obligatory losses?
things that require us to conserve heat, water and food constantly because we involuntarily loss energy water or temperature as a consequence of life processes
what is an ingestive behavior?
eating or drinking
what is a system variable?
a variable that is controlled by a regulatory mechanism like temperature in heating system
what is a set point?
the optimal value of the system variable in a regulatory mechanism
what is a detector?
in a regulatory proccess the mechanism that signals when the system variable deviates from its set point
what is a correctional mechanism?
in a regulatory process the mechanism that is capable of changing the value of the system variable
what is negative feedback?
a process whereby the effect produced by an action serves to diminish or terminate that action; a characteristic of regulatory systems
what is the satiety mechanism?
a brain mechanism that causses cessation of hunger or thirst produced by adeaquate ansd availabe supplies of nutrients or water
where is most of the water in our bodies contained?
inside and outside our cells
what is the intracellular compartment?
is the fluid that exists within the cells
what is the extracellular compartment?
fluid that exists outside the cells
what does the extracelluklar compartment acts like?
as a buffer and as an indicator of conditons in the intracellular compartment (constantly controls if we need water)
what is the interstitial fluid?
the fluid between the cells
what is the blood plasma?
the protein rich fluid that carries red and white blood cells
what is the aquaporins?
channels in the cell membranes that are specialized for the conduction of water molecules into or out of the cell
how lany molecules of water can a single aquaporin conduct?
3 billlion
what is the intravascular fluid?
the fluid found within the blood vessels
what is hypovolemia?
reduction in the volume of the intravascular fluid
what are movements of water described by?
two forces diffusion and osmosis
what is diffusion?
molecules of a substance like salt ( a solute) dissolved in a quantity of another substance, such as a glass of water (solvent) will passively spread through the water because of the random movements of the molecules until they are more or less uniformly distributed throughout the glass
what is osmosis?
movement of water molecules that occurs when a semipermeable membrane separates solutions ontaining different concentrations of solute and the solute cannot spread evenly across both sides (membrane blocks the passage of salt)
what is osmotic pressure?
physical froce that pushes or pulls water across the membrane
what is osmolality ?
number of solute particles per unit volume of solvent
what are the three types of solution?
hypertonic
isotonic
hypotonic
hypertonic?
high concentration of solute that is the same as the solvent
isiotonic?
concentration of solute that is the same as solvents
hypotonic
low concentration of solute that is the same as solvents
what happens if volume is low?
hypovolemic thirst
what happens if solute concentration is high?
osmotic thirst
who gets first infromed when you have hypovolemic thirst?
carduac baroreceptors and kidney baroreceptors
who gets infromation of hypovolemic thirst after cardiac baroreceptors and kidney baroreceptors?
brainstem and the subfornical organ
how do kidney baroreceptors pass information of hypovolemic thirst to the subfornical organ?
through the release of angiotesin ii
where does te information of hypovolemic thirst go to after the brainstem and the subfornical organ?
to the preoptic area
where does the information of a hypovolemic thirst goes once it is in the preoptic area?
to the hypothalamic thirst network and the supraoptic and paraventricular nucleus
what happen if the information of hypovolemic thirst gets to the preoptic area?
you drink
what happens if the information of a hypovolemic thirst gets to the supraoptic and paraventricular nucleus?
water conservation
where does infromation goif you have osmotic thirst?
the OVLT osmosensory neurons
where does infor mation of an osmotic thirst go after the osmosensory neurons ?
to the preoptic area and you know the rest
what is osmotic thirst?
high extracellular concentration of solute triggered by tincreased saltiness of the extracellular fluid like by ingesting lots of salty foods. water will be pulled out through osmosis
what are osmosensory neurons?
specialized neurons that measure the movements of water into and out of the cells
where are osmosensory neurons usually found?
in several regions of the hypothalamus including the preoptic area, anterior hypothalamus, supraoptic nucleus, and the organum vasculosum of the lamina terminalis
what is an osmoreceptor?
neuron that detects changes in the solute concentration of the interstitial fluid that surrounds it
what is a median preoptic nucleus?
a small nucleus situated around the decussation of the anterior commisure
whered oes the preoptic nucleus play a part in?
in thirst stimulated by angiotensin
what is hypovolemic (volumetric thirst)?
low extracellular volume due too the loss of body fluids ( loss of water volume) thirst produced by hypovolemia caused by blood loss vomit and diarrhea
wht is hypovolemia?
low volume extracelllular fluid because normal everyday losses cause moderate decreas”s in extracellular fluid
