internal regulation i: temperature and water (3.2)

Question 1

homeostasis

Answer 1

biological processes that keep body variables within a fixed range (narrow range = set point)

Question 2

homeostasis includes… (2)

Answer 2

sensory transduction (of a variable and signaling changes from the optimal range); integrated response (to restore parameter back to optimal (negative feedback)

Question 3

integrated responses in homeostasis (3)

Answer 3

autonomic (visceromotor): fast physiological adjusting the balance of sympathetic and parasympathetic outputs of the ANS
endocrine (humoral): slow physiological releasing hormones
somatic (behavioral): motivating appropriate behaviors by the somatic motor system

Question 4

negative vs positive feedback

Answer 4

negative: brings you back to where you need to go (where you were)
positive: (not in homeostasis) going further in that direction that you are going

Question 5

regions of the hypothalamus (4)

Answer 5

mammillary, tuberal, supraoptic, preoptic

Question 6

paraventricular nucleus (PVN) vs lateral hypothalamus (LHA)

Answer 6

PVN: initiates the autonomic and endocrine responses (P cells -> ANS; M cells -> hormones)
LHA: motivates the somatic motor response (two output neurons: one uses orexin, other uses MCH)

Question 7

sympathetic vs parasympathetic nervous system (ANS)

Answer 7

sympathetic: fight or flight
parasympathetic: rest and digest

Question 8

endocrine system

Answer 8

consists of a number of organs whose primary function is to release hormones directly into the circulatory system (into the blood); all endocrine glands regulated directly or indirectly (via the pituitary) by the hypothalamus

Question 9

pituitary gland and lobes (2)

Answer 9

pituitary: a protrusion off the bottom of the hypothalamus
anterior pituitary: synthesizes and secretes hormones in response to hormones released by the hypothalamus (P cells)
posterior pituitary: develops as an extension of the hypothalamus; stores and secretes (but does not synthesize) hormones (M cells) (ADH)

Question 10

body temperature and heat

Answer 10

body temperature: a measure of an organism’s ability to generate and to eliminate heat; tightly regulated
heat: generated within the body as a byproduct of many chemical reactions (i.e. cellular respiration: the conversion of nutrients into ATP; controlled by thyroxin)

Question 11

amphibians, reptiles, and fish vs mammals/birds

Answer 11

ectothermic vs endothermic

Question 12

advantages of increased body temperature (2)

Answer 12

mobile all year long; protection from fungal infections

Question 13

physiological mechanisms if hot or cold (autonomic (2) vs endocrine (1))

Answer 13

autonomic: sweat (pant or lick) or shiver; increase or decrease blood flow to the skin (i.e. flushing when hot)
endocrine: decrease or increase metabolism

Question 14

behavioral mechanisms if hot or cold (4)

Answer 14

find a cool or hot place; become less or more active; sleek or fluff fur (less/more clothes); stand alone or together

Question 15

temperature sensors in the hypothalamus (2)

Answer 15

medial preoptic nucleus, anterior nucleus

Question 16

dorsomedial nucleus

Answer 16

shivering nucleus

Question 17

osmotic vs hypovolemic thirst

Answer 17

osmotic: caused by eating salty foods, which increases the concentration of solutes in the extracellular space; solved by drinking water (liquids)
hypovolemic: caused by losing fluid volume, such as by bleeding or vomiting; must drink and eat

Question 18

hypertonic vs hypotonic

Answer 18

hypertonic: too much stuff, not enough water (cells shrink, ADH)
hypotonic: too much water, not enough stuff (cells enlarge)

Question 19

ion influx in thirst

Answer 19

sodium

Question 20

cells that detect whether the concentration has changed in your body (2)

Answer 20

organum vasculosum (OVLT), subfornical organ (SFO)

Question 21

response in thirst (of 3 integrated responses)

Answer 21

endocrine (humoral)

Question 22

controls ADH (2)

Answer 22

paraventricular nucleus, supraoptic nucleus

Question 23

antidiuretic hormone (ADH//vasopressin)

Answer 23

released from posterior pituitary; enables kidneys to reabsorb water and this excrete a concentrated urine (conserves water in your blood)

Question 24

baroreceptors

Answer 24

control blood volume (blood pressure) on a minute-by-minute basis; found in the walls of arteries, veins, and the heart; excited by stretch and inhibited by relaxation of blood vessels (BP lowers when urge to pee increases)

Question 25

hypovolemia

Answer 25

causes suppression of baroreceptor activity, which stimulates the vasomotor center in the medulla to activate various nuclei in the hypothalamus to conserve water and to generate the desire to drink

Question 26

renin-angiotensin II-aldosterone system

Answer 26

creates a craving for sodium and sweet tastes (renin from kidney to liver, angiotensin I to lungs, angiotensin II to adrenal glands (eat something salty), aldosterone (stop craving))