Hypothalamus

Question 1

3 zones of hypothalamus

Answer 1

periventricular, medial, lateral

Question 2

lateral zone nuclei

Answer 2

lateral preoptic nucleus, lateral hypothalamic area, tuberomammillary nucleus

Question 3

lateral preoptic nucleus

Answer 3

anterior portion, “telencephalic”

Question 4

lateral hypothalamic area

Answer 4

feeding center (induces eating when stimulated), contains melanin-concentrating hormone, orexins

Question 5

tuberomammillary (lateral tuberal) nucleus

Answer 5

release histamine as a neurotransmitter to forebrain (wakefulness, attention/arousal). inhibited during sleep

Question 6

medial zone

Answer 6

preoptic, anterior (supraoptic), middle (tuberal), posterior (mammillary)

Question 7

preoptic region

Answer 7

anterior. contains medial preoptic nucleus that regulates gonadotropin secretion. also contains interstitial nuclei, of one is sexually dimorphic

Question 8

anterior (supraoptic) region

Answer 8

contains 4 nuclei: suprachiasmatic nucleus, anterior hypothalamic nucleus, paraventricular nucleus, supraoptic nucleus

Question 9

suprachiasmatic nucleus

Answer 9

dorsal to optic chiasm, gets direct input from retina. circadian rhythm.

Question 10

anterior hypothalamic nucleus

Answer 10

between suprachiasmatic and paraventricular nuclei. temperature regulation/heat dissipation. lesion = hyperthermia. also parasympathetic drive of ANS

Question 11

paraventricular nucleus

Answer 11

arginine vasopressin, oxytocin, CRH. excitation to sympathetic preganglionic neurons

Question 12

supraoptic nucleus

Answer 12

AVP, oxytocin. project to neurohypophysis, released into circulation.

Question 13

middle (tuberal) region

Answer 13

dorsomedial nucleus, ventromedial nucleus, arculate nucleus

Question 14

dorsomedial nucleus

Answer 14

BP regulation. stimulation = aggression

Question 15

ventromedial nucleus

Answer 15

inhibits urge to eat. relays ingestion-related signals to brainstem. lesion = hyperphagia

Question 16

arcuate nucleus

Answer 16

projections to median eminence and portal vessels, controls release/non-release of adenophypophyseal hormones. feeding behaviors.

Question 17

posterior (mammillary) region

Answer 17

posterior nucleus, mammillary nucleus

Question 18

posterior nucleus

Answer 18

thermoregulation. lesion = inability to regulate (poikilothermia)

Question 19

mammillary nucleus

Answer 19

part of limbic system. input from hippocampus via fornix. project to anterior nucleus of thalamus via MTT. damage = memory disturbances. also get sensory input

Question 20

periventricular zone

Answer 20

contains periventricular nucleus. line walls of third ventricle. sort of part of medial zone nuclei.

Question 21

fornix tract

Answer 21

hippocampus to mammillary bodies

Question 22

mammillothalamic tract

Answer 22

from mammillary bodies to anterior nucleus of thalamus (part of Papez)

Question 23

stria terminalis

Answer 23

amygdala connected to medial zone of hypothalamus

Question 24

medial forebrain bundle

Answer 24

50 pathways. throughout entire lateral hypothalamic zone, from septal nuclei to brainstem

Question 25

supraopticohypophyseal tract

Answer 25

from supraoptic and paraventricular nuclei to neurophypophysis (posterior pit). magnocellular axons, synth of AVP/oxytocin

Question 26

tuberoinfundibular tract

Answer 26

from arcuate nucleus to hypophyseal portal system at median eminence. take neuropeptides made in hypothalamus to posterior pituitary, which then act on anterior pituitary cells

Question 27

hypothalamospinal tract

Answer 27

descending axons regulate spinal cord preganglionic neurons from both ANS division. primarily from paraventricular nucleus. lesion = Horners

Question 28

major regulatory functions of hypothalamus

Answer 28

body temperature, emergency responses to stress, feeding and energy metabolism, BP and electrolyte composition, reproductive functions

Question 29

thermoregulation

Answer 29

anterior = warmth sensation, heat dissipation; posterior = cold sensitive, heat conservation

Question 30

stress responsiveness

Answer 30

fight or flight. increases sympathetic, decreases parasympathetics. interconnections from many regions including amygdala and hippocampus

Question 31

feeding and energy metabolism.

Answer 31

central role from arcuate nucleus. output integrated at NTS

Question 32

agouti-related peptide and neuropeptide Y

Answer 32

signal increased feeding, decrease in metabolism

Question 33

MSH (POMC) and CART

Answer 33

activation = decreased feeding, increased metabolism

Question 34

ghrelin

Answer 34

stimulates feeding/food intake

Question 35

PPY

Answer 35

inhibits feeding

Question 36

leptin

Answer 36

released by fat cells, signals decrease in feeding (insulin is similar)

Question 37

CCK

Answer 37

satiety

Question 38

orexin and MCH

Answer 38

increase feeding

Question 39

CRH re: stress and central oxytocin secretion

Answer 39

inhibit feeding

Question 40

craniopharyngioma

Answer 40

congenital tumor in kids, grows up toward optic chiasm (pressure –> bitemporal hemianopia), hypothalamic syndrome (adiposity, diabetes, temp regulation issues, sleepiness)

Question 41

memory disturbances

Answer 41

posterior hypothalamic lesions involving mammillary comples: inability to form new memories, eg korsakoff syndrome (thiamine deficiency, chronic EtOH)

Question 42

klein-levin syndrome

Answer 42

adolescent males, hypothalamic lesion. compulsive eating, hypersomnolence, hypersexuality (may be from decrease in dopaminergic tone during symptomatic phase)