Hypothalamus - Everything Flashcards Preview

Neurology > Hypothalamus - Everything > Flashcards

Flashcards in Hypothalamus - Everything Deck (66):
1

Posterior Nucleus; function & loc

Sympathetic output (fight or flight)
Thermogenesis
(posterior region)

2

Tuberomammillary nucleus; function & loc

Histamine sys - Promoting Wakefullness
(posterior region)

3

Fornix

memory consolidation
projects form hippocampus to mammillary bodies
(Posterior region of hypothalamus)

4

Mammillary body; function

memory consolidation
(posterior region)

5

Lateral Hypothalamus; function

feeding center
orexin sys - promoting wakefulness & appetite
(posterior region)

6

Posterior Nucleus lesion

Horner's syndrome (myosis=constriction, anhidrosis, ptosis)
Poikilothermia

7

Tuberomammillary Nuc lesion

hypersomnia - sleepiness

8

Mammillary body lesion

anterograde amnesia
confabulation

9

Lateral hypothalamus lesion

anorexia
narcolepsy

10

Posterior Region - consists of;

Posterior nucleus
Tuberomammillary nuc
Mammillary body
Lateral hypothalamus

11

Tuberal Region - consists of;

Lateral Hypothalamus
Ventromedial nuc
Arcuate nuc
Dorsomedial nuc

12

Ventromedial nuc; function

satiety center
contains leptin-sensitive neurons
(tuberal region)

13

Ventromedial nuc; lesion

hyperphagia & obesity

14

leptin

increase conc in ventromedial nuc -> cessation of eating

15

Dorsomedial nuc; function

feeding & body weight regulation
may serve as relay center of energy homeostasis
lesion: feeding & body wt dysfunction
(tuberal region)

16

Dorsomedial nuc; lesion

feeding & body wt dysfunction

17

Arcuate nuclesu; function

Secretion of hypophyseal hormones
Feeding behavior (orexigenic & anoretic neurons)
(tuberal region)

18

Hypophyseal hormones

Controlled by Arcuate nuc
Released into median eminence to act on the Anterior Pituitary

- Tuberoinfundibular dopamine (TIDA) - release dopamine -> inhib prolactin

- Growth Hormone-releasing neurones (GHRH) - release GHRH -> inc secretion of GH

19

Orexigenic GABA/NPY/AgRP neurons

of the Arcuate Nuc (tuberal region)
Project into Lateral Hypothalamus
Promote feeding
Ghrelin (from stomach) promotes these neurons

20

Anoretic POMC/CART neurons

of Arcuate nuc (tuberal region)
Project into Lateral hypothalamus
Inhibits feeding
Leptin (from adipocytes) promotes inhibition

21

Leptin

secreted by adipocytes; reflects body fat stores
nutrient abudance; leptin increased -> dec appitite, inc energy expenditure
nutrient insufficiency; leptin decreased -> inc appetite & energy conservation
+ for POMC/CART
- for GABA/etc

22

Ghrelin

produced by stomach
stimulates eating
+ for GABA/etc

23

zones of the median eminence

internal zone - contains axons of magnocellular neurosec neurons of supraoptic nuc and paraventricular nuc that project into post pituitary
external zone - hypothalamo-pituitary portal system, nerve endings of neuroendocrine neurons (that control hormonal sec of the ant pituitary gland)

24

Types of neurons that project to the external zone of the median eminence

dopamine
growth hormone releasing hormone
somatostatin
gonadotropin-releasing hormone
corticotropin-releasing hormon
thyrotropin-releasing hormone

25

Arcuate nucleus; lesion

neuroendocrine and feeding dysfunction

26

Dorsomedial nucleus; function

control feeding & body wt

27

Dorsomedial nucleus; lesion

feeding & wt dysfunction

28

Anterior supraoptic region; consists of

Anterior nuc
Suprachiasmatic nuc
Paraventricular nuc
Supraoptic nuc
Lateral hypothalamus

29

Anterior nuc; function

control of Parasymp
Thermoregulation (dissapation of heat)
(ant supraoptic region)

30

Anterior nuc; lesion

deficit in parasymp function
hyperthermia
(ant supraoptic region)

31

Suprachiasmatic nuc; function

Circadian rhythms
(bio clock & modulates pineal gland function)
(ant supraoptic region)

32

how does the suprachiasmatic nuc control circadian rhythms?

receives light info from retinal ganglion cells
via; Retinohypothalamic tract

info relayed via desc symp fibers from hypothal -> intermediolat nuc -> sup cervical ganglia -> pineal gland

Inhibits prod of Melatonin during day
(melatonin = sleep-promoting hormone)

33

Suprachiasmatic nuc; lesion

disturb cyclic variations of body functions
blood pressure
hormone levels
body temp
sleep & wakefulness

34

Paraventricular nuc; function

water retention (vasopressin secreting)
milk letdown, uterine contraction (oxytocin secreting)
control ant pituitary function (ACTH, TSH)

35

milk letdown & water retention

paraventricular nuc
magnocellular neurosec neurons project to Posterior Pituitary;
release Oxytocin or Vasporessin (ADH) in to general circulation

Vasopressin - inc water perm in collecting duct, activated by inc in osmolarity, circ levels of angiotensin, dec BP, hypovolemia

Oxytocin - stim of nipple -spinal pathways->hypothalamus = act of these neurons -> Oxytocin release => contraction of myoepithelial cells

36

paraventricular nuc; control of Ant Pituitary function

parvocellular neurosec neurons project to the median eminence/portal sys to control ant pituitary function;

Corticotropin-RH N - enhance adrenocorticotropic hormone (ACTH)

Thyrotropin-RH N - enhance thyroid-stimulating hormone (TSH) release

Somatostatin-R N - inhibit growth hormone secretion

37

Supraoptic nuc; function

water retention
milk letdown
uterine mm contraction
(ant supraoptic region)

38

Supraoptic nuc - how it works

paraventricular nuc
magnocellular neurosec neurons project to Posterior Pituitary;
release Oxytocin or Vasporessin (ADH) in to general circulation

- Just like the Paraventricular nuc (except doesn't alter secretions of ACTH, TSH, or GH)

39

Orexin

orexen (hypocretin)
neuropeptide
regulator of sleep/wake states, feeding behav, reward process
deficiency = narcolepsy
* esp imp for maintenance of wakefulness
admin of orexin stimulates appetite

40

Paraventricular nuc; lesion

diabete insipidus (same as Supraoptic nuc)
endocrine deficits (unique to it)

(ant supraoptic region)

41

Supraoptic nuc; lesion

diabete insipidus (same as Paraventricular)
- drink drink pee pee

(ant supraoptic region)

42

Anterior Preoptic region; consists of

lateral preoptic nuc
medial preoptic nuc

of telencephalic orgiin, but functionally associated w/ hypothalamus

*only part that the lateral hypothalamus isn't present

43

nucleus basalis of Meyner

rich in cholinergic neurons w/ wide projections to neocortex
compromised in Alzheimer disease

located laterally to the Lateral preoptic nuc - the Substancia Inominata (in the Ant preoptic region)

44

Lateral preoptic nuc; function

Inhibits wakefulness
promotes non-REM sleep

(ant preoptic region)

45

Lateral preoptic nuc; lesion

hyposomnia

46

Lateral preoptic nuc; mechanism

GABAergic neurons in ventrolat preoptic inhibit wake-promoting;

Orexinergic neurons - lateral hypothalamus
Histaminergic neurons - posterior hypothalamus
Cholinergic, Serotonergic, & Noradrenergic Neurons - brainstem
= control global brain activity & promote non-REM sleep

47

Medial preoptic nuc; function

thermoregulation set point
release of gonadotrophic hormones (into med eminence) & sexual behavior

(ant preoptic region)

48

Medial preoptic nuc; lesion

hyperthermia
amenorrhea & impotence

(ant preoptic region)

49

body temp below the set-point

Medial Preoptic neurons activate Posterior hypothalamus (Symp)
= heat conservation via shivering and vasoconstriction

50

body temp above the set-point

Medial Preoptic Nuc activate Anterior Hypothalamic nuc
= sweating and vasodilation (Para)

51

Fever

set-point to a higher temp

triggered by pyrogens (cytokines) -> PGE2 (prostaglandin) -> act on Medial Proptic neurons to reset the set-point to a higher temp
Aspirin works by inhibiting the enzyme cyclooxygenase involved in prod of PGE2

52

Stria terminalis

connects reciprocally the hypothalamus and amygdala

53

hypothalamic-hypophyseal portal system

system where factorsl controlling the hormonal secretion of the Anterior Pituitary gland are released and reach their target via a portal venous system

54

supraoptico-hypophyseal tract

contains axons from the paraventricular and supraoptic nuclei projecting to the posterior pituitary gland

55

retinohypothalamic tract

carries light info from retinal ganglion cells to the Suprachiasmatic nuc

56

dorsal longitudinal fasiculus

1. contains afferent hypothalamic fibers - carring visceral and tast sens; relayed to the hypoth via the solitary and parabrachial nuc
2 contains efferent hypoth fibers innervating; preganglionic parasym neurons, pregang symp neurons in spinal cord, autonomic reg centers in medulla, periaqueductal gray (pain modulation)

57

hypophyseal portal system links;

the hypothalamus and pituitary gland
allows endocrine signalling between the two structures

58

arteris of pituitary gland

superior and inferior hypophyseal arteries

59

superior hypophyseal artery

forms a capillary plexus, primary portal plexus, that penetrates the median eminence and infundibulum
primary portal plexus drains via long portal veins to the secondary portal plexus in the ant pituitary

60

inferior hypophyseal artery

forms capillary network within the posterior pituitary
venous drainage via hypophyseal veins

61

nuclei of Neuroendocrin control

paraventricular
supraoptic
arcuate
medial preoptic

62

nuclei of Weight Control, Feeding, Drinking

ventromedial
lateral hyp
arcuate
dorsomedial

63

nuclei of Temp Reg and Fever

medial preoptic
posterior
anterior

64

nuclei of Osmoreg, Water Balance, BP, B volume

posterior
anterior
paraventricular
supraoptic
CVO's

65

nuclei of Reproductive function

paraventricular
supraoptic
medial preoptic

66

nuclei of Sleep/Wake cycle

suprachiasmatic
tuberomammillary
ventrolateral preoptic nuc