Hypothalamus HY Flashcards
hypothalamus regulates ____________
via regulation of:
hypothalamus regulates WHOLE BODY HOMEOSTASIS
via regulation of:
- ANS
- endocrine system
- somatic motor activity (drive-related behaviors)
magnocellular system
- 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
lactation reflex
afferent = _________
efferent = _________
lactation reflex
afferent = NEURAL
efferent = HORMONAL (oxytocin)
-neural stimulus from baby suckling –> dorsal column –> neurohypophusis –> oxytocin released –> milk letdown
parvicellular system
- 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)
hypothalmic substances that inhibit/stimulate release of pituitary hormones (and their pituitary correlate)
GnRH --> FSH, LH GHRH --> GH Somatostatin --> GH (inhibitory) TRH --> TSH Dopamine --> prolactin (inhibitory) CRH --> ACTH
CRH
- released by hypothalamus
- in response to stress
- causes ACTH release from pituitary
- ACTH: cortisol release from adrenal gland
- feedback signal = cortisol
medial preoptic area
- TEMPERATURE regulation
- MALE sex behavior
- PARENTAL behavior
- sexually dimorphic nucleus
superchiasmatic nucleus
Circadian Rhythm Center
- master clock of brain
- day/night rhythms
- retinal input
paraventricular and supraoptic nuclei
- synthesis of oxytocin and vasopressin
- autonomic regulation
- stress axis
- metabolism
anterior nucleus
- temperature regulation
- HEAT DISSIPATION
arcuate nucleus
food intake and metabolism
-regulates feeding by responding to LEPTIN
periventricular nucleus
reproductive cycles
Korsakoff’s Syndrome
- destruction of mamillary bodies (and DMN)
- causes confabulatory amnesia)
- associated with poor diet and alcoholism
posterior nucleus
heat CONSERVATION
heat dissipation vs heat conservation
Dissipation:
- preoptic area (POA)
- anterior hypothalamic area (AH)
Conservation
-posterior hypothalamus
which nuclei control endocrine system?
- supraoptic nucleus (SON)
- PVN (periventricular)
which nuclei control ANS?
-PVN (periventricular)
descending projections to craniosacral/thoracolumbar regions
which nuclei control body temp?
- anterior (AH)
- POA (preoptic area)
which nuclei control day night rhythms?
-SCN (superchiasmatic)
which nuclei control food intake and metabolism?
- VMN (satiety)
- arcuate (response to leptin)
- DMH
- PVN
- Lateral (satiety)
which nuclei control sleep wake cycles?
- AH (anterior)
- POA (preoptic area)
- posterior hypothalamus
-melatonin
median eminence
- swelling on base on hypothalamus on ventral surface
- has rich plexus of capillaries
- connects hypothalamus to pituitary
- circumventricular organ (no BBB)
tuberoinfundibular tract
-collection of axons carrying releasing/inhibiting factors to the median eminence
VMN
satiety center
lesion = insatiable appetite
lateral nucleus
feeding center
lesion = anorexia
leptin receptors are present on _________ nucleus
leptin receptors are present on ARCUATE nucleus
mamillary bodies / dorsomedial thalamus
lesion = Korsakoff’s Syndrome
- confabulatory amnesia
- caused by alcohol, poor diet