Hypothalamus Flashcards

1
Q

hypothalamus regulates ____________

A

hypothalamus regulates WHOLE BODY HOMEOSTASIS

-ensures survival of individual and of species

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2
Q

hypothalamus regulates whole body homeostasis via regulation of:

A
  • ANS
  • endocrine system
  • somatic motor activity (drive-related behaviors)
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3
Q

internal parameters that the hypothalamus maintains the set point for

A
  • temperature
  • pH
  • water
  • glucose concentration
  • many others
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4
Q

behaviors that the hypothalamus affects

A
  • feeding
  • drinking
  • reproductive

SURVIVAL of individual and of species

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5
Q

anterior border of the hypothalamus

A

lamina terminalis

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6
Q

what separates the thalamus from the hypothalamus?

A

hypothalamic sulcus

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7
Q

circumventricular organs

A
  • no BBB
  • –fenestrated capillaries instead of tight junctions)
  • allow exchange of substances btwn blood and brain (imp bc hypothalamus responsible for whole body homeostasis)

w/ hypothalamus

  • median eminence
  • neurohypophysis
  • organum vasculosum
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8
Q

what causes hypothalamic disturbances

A
  • inflammation
  • tumors
  • vascular disorders
  • hydrocephalus
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9
Q

clinical disorders associated with hypothalamic lesions

A
  • hyper/hypothermia
  • obesity/wasting
  • diabetes insipidus
  • disturbances of sleep
  • emotional disorders
  • hypogonadism and early puberty
  • altered growth patterns
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10
Q

sites associated with parasympathetic function tend to be located in _________ hypothalamus

A

sites associated with parasympathetic function tend to be located in ANTERIOR hypothalamus

preoptic area, anterior hypothalamus

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11
Q

sites associated with sympathetic function tend to be located in _________ hypothalamus

A

sites associated with sympathetic function tend to be located in POSTERIOR hypothalamus

lateral and posterior hypothalamus

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12
Q

______ and ______ systems modulate hormone synthesis/release from posterior/anterior lobes of pituitary

A

MAGNOCELLULAR and PARVICELLULAR systems modulate hormone synthesis/release from posterior/anterior lobes of pituitary

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13
Q

magnocellular system

A
  • comprised of PVN (paraventricular) and SON (supraoptic) nuclei
  • LARGE diameter neurons synthesize hormones (oxytocin, ADH)
  • hormones transported to POSTERIOR pituitary for release into systemic circulation
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14
Q

vasopressin

A

water reabsorption by kidney

  • synthesized by magnocellular system
  • released by posterior pituitary
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15
Q

oxytocin

A

milk letdown, uterine contraction, pair bonding

  • synthesized by magnocellular system
  • released by posterior pituitary
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16
Q

lactation reflex
afferent = _________
efferent = _________

A

lactation reflex
afferent = NEURAL
efferent = HORMONAL (oxytocin)

-neural stimulus from baby suckling –> dorsal column –> neurohypophysis –> oxytocin released –> milk letdown

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17
Q

parvicellular system

A
  • anterior lobe
  • SMALL diameter hypothalamic neurons produce releasing and inhibiting factors that modulate synthesis and secretion of ANTERIOR pituitary hormones
  • influences the pituitary via vasculature (hypophyseal portal vessels)
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18
Q

hypophyseal portal system

A

-delivers hypothalamic releasing and inhibiting factors to the anterior pituitary

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19
Q

hypothalmic substances that inhibit/stimulate release of pituitary hormones (and their pituitary correlate)

A
GnRH --> FSH, LH
GHRH --> GH
Somatostatin --> GH (inhibitory)
TRH --> TSH
DA --> prolactin (inhibitory)
CRH --> ACTH
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20
Q

CRH

A
  • released by hypothalamus
  • in response to stress
  • causes ACTH release from pituitary
  • ACTH: cortisol release from adrenal gland
  • feedback signal = cortisol
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21
Q

______ acts as a feedback signal for CRH release

A

CORTISOL acts as a feedback signal for CRH release

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22
Q

T/F: hypothalamic nuclei stain differently and can be distinguished on a stained section

A

false. cannot distinguish them on a stained section

23
Q

medial preoptic area

A

prepotic area=rostral region of hypothalamus

  • temperature regulation
  • male sex behavior
  • parental behavior
  • sexually dimorphic nucleus
24
Q

anterior/supraoptic hypthalamic region contains which nuclei?

A
  • superchiasmatic nucleus
  • paraventricular/supraoptic nuclei
  • anterior nucleus
25
Q

superchiasmatic nucleus

A
  • master clock of brain
  • day/night rhythms
  • retinal input
26
Q

paraventricular and supraoptic nuclei

A
  • synthesis of oxytocin and vasopressin
  • autonomic regulation
  • stress axis
  • metabolism
27
Q

anterior nucleus

A
  • temperature regulation

- heat dissipation

28
Q

tuberal region of the hypothalamus contains which nuclei?

A
  • VMN (ventromedial)
  • DMN (dorsomedial)
  • LH (lateral hypothalamic)
  • arcuate
  • periventricular
29
Q

arcuate nucleus

A

food intake and metabolism

30
Q

periventricular nucleus

A

reproductive cycles

31
Q

bilateral lateral hypothalamic (LH) lesion causes

A

-anorexia

32
Q

bilateral VMN lesion

ventromedial hypothalamic nuclei

A
  • no satiety (voracious appetite)

- rage

33
Q

leptin

A
  • hormone produced by fat tissue
  • acts in brain to modulate food intake
  • functions in feedback loops that regulate metabolism and body weight
34
Q

decreased leptin levels

A
  • increased orexigenic peptides
  • stimulation of feeding behavior (LH)
  • decreased metabolism
35
Q

elevated leptin levels

A
  • stimulation of anorexic peptides
  • inhibition of feeding behavior (LH)
  • increase in metabolism
36
Q

posterior region of hypothalamus contains which nuclei?

A
  • mamillary bodies
  • posterior nucleus
  • subthalamic nucleus
  • lateral hypothalamic nucleus
37
Q

Korsakoff’s Syndrome

A
  • destruction of mamillary bodies (and DMN)
  • causes confabulatory amnesia
  • associated with poor diet and alcoholism
38
Q

posterior hypothalamic nucleus

A

heat conservation

39
Q

centers for heat dissipation vs heat conservation

A

Dissipation:

  • preoptic area (POA)
  • anterior hypothalamic area (AH)

Conservation
-posterior hypothalamus

40
Q

afferents to hypothalamus

A
  • hippocampus
  • amygdala
  • septal nuclei
  • other limbic structures
  • retina
  • spinothalamic
  • visceral nuclei
  • physical stimuli
41
Q

which nuclei control endocrine system?

A
  • supraoptic nucleus (SON)
  • PVN (periventricular)

(synthesize oxytocin and vasopressin)

42
Q

which nuclei control ANS?

A

-PVN (periventricular)

descending projections to craniosacral/thoracolumbar regions

43
Q

which nuclei control body temp?

A
  • anterior (AH)

- POA (preoptic area)

44
Q

which nuclei control day night rhythms?

A

-SCN (superchiasmatic)

45
Q

which nuclei control food intake and metabolism?

A
  • VMH
  • arcuate
  • DMH
  • PVN (paraventricular nucleus)
  • LHA (lateral hypothalamic area)
46
Q

which nuclei control sleep wake cycles?

A
  • AH (anterior)
  • POA (preoptic area)
  • posterior hypothalamus

-melatonin

47
Q

median eminence

A
  • swelling on base on hypothalamus on ventral surface
  • has rich plexus of capillaries
  • connects hypothalamus to pituitary
  • circumventricular organ (no BBB)
48
Q

tuberoinfundibular tract

A

-collection of axons carrying releasing/inhibiting factors to the median eminence

49
Q

VMN

A

satiety center

50
Q

lateral hypothalamic (LH) nucleus

A

feeding center

51
Q

leptin receptors are present on _________ nucleus

A

leptin receptors are present on ARCUATE nucleus

52
Q

hypothalamus sits just superior and posterior to the

A

optic chiasm

53
Q

efferents from hypothalamus

A

amygdala
septal nuclei
other limbic

thalamus (anterior nucleus, also dorsomedial)

pituitary gland

visceral motor nuclei (P,S)