Hypothalamus Flashcards
hypothalamus regulates ____________
hypothalamus regulates WHOLE BODY HOMEOSTASIS
-ensures survival of individual and of species
hypothalamus regulates whole body homeostasis via regulation of:
- ANS
- endocrine system
- somatic motor activity (drive-related behaviors)
internal parameters that the hypothalamus maintains the set point for
- temperature
- pH
- water
- glucose concentration
- many others
behaviors that the hypothalamus affects
- feeding
- drinking
- reproductive
SURVIVAL of individual and of species
anterior border of the hypothalamus
lamina terminalis
what separates the thalamus from the hypothalamus?
hypothalamic sulcus
circumventricular organs
- 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
what causes hypothalamic disturbances
- inflammation
- tumors
- vascular disorders
- hydrocephalus
clinical disorders associated with hypothalamic lesions
- hyper/hypothermia
- obesity/wasting
- diabetes insipidus
- disturbances of sleep
- emotional disorders
- hypogonadism and early puberty
- altered growth patterns
sites associated with parasympathetic function tend to be located in _________ hypothalamus
sites associated with parasympathetic function tend to be located in ANTERIOR hypothalamus
preoptic area, anterior hypothalamus
sites associated with sympathetic function tend to be located in _________ hypothalamus
sites associated with sympathetic function tend to be located in POSTERIOR hypothalamus
lateral and posterior hypothalamus
______ and ______ systems modulate hormone synthesis/release from posterior/anterior lobes of pituitary
MAGNOCELLULAR and PARVICELLULAR systems modulate hormone synthesis/release from posterior/anterior lobes of pituitary
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
vasopressin
water reabsorption by kidney
- synthesized by magnocellular system
- released by posterior pituitary
oxytocin
milk letdown, uterine contraction, pair bonding
- synthesized by magnocellular system
- released by posterior pituitary
lactation reflex
afferent = _________
efferent = _________
lactation reflex
afferent = NEURAL
efferent = HORMONAL (oxytocin)
-neural stimulus from baby suckling –> dorsal column –> neurohypophysis –> 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)
hypophyseal portal system
-delivers hypothalamic releasing and inhibiting factors to the anterior pituitary
hypothalmic substances that inhibit/stimulate release of pituitary hormones (and their pituitary correlate)
GnRH --> FSH, LH GHRH --> GH Somatostatin --> GH (inhibitory) TRH --> TSH DA --> 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
______ acts as a feedback signal for CRH release
CORTISOL acts as a feedback signal for CRH release