Hypothalamus Flashcards
GHIH
Growth hormone-inhibiting hormone(inhibiting)
- from hypothalamus
- to anterior pituitary
- inhibits secretion of GH
GHRH
Growth hormone-releasing hormone(excitatory)
- from the Hypothalamus
- to the anterior pituitary
- Action = stimulates secretion of GH
CRH
corticotropin-releasing hormone(excitatory)
- from the hypothalamus
- to the anterior pituitary
- stimulates release of adrenocorticotropic hormone(ACTH)
TRH
thyrotropin-releasing hormone(excitatory)
- from the hypothalamus
- to anterior pituitary
- stimulates release of thyroid-stimulating hormone(TSH)
GnRH
Gonadotropin-releasing hormone(excitatory)
- from the hypothalamus
- to anterior pituitary
- stimulates release of gonadotropins(FSH and LH)
PRH
Prolactin-releasing hormone(excitatory)
- from the hypothalamus
- to the anterior pituitary
- stimulates secretion of prolactin
PIH
prolactin-inhibiting hormones(inhibitory)
- from the hypothalamus
- to the anterior pituitary
- inhibits secretion of prolactin
GH
growth hormone
- from the anterior pituitary
- promotes growth by stimulating protein anabolism and fat mobilization
PRL
prolactin
- from the anterior pituitary
- mammary glands
- promotes milk secretion
TSH
thyroid stimulating hormone
- from the anterior pituitary
- to thyroid gland
- stimulates development and secretion of the thyroid gland
ACTH
adrenocorticotropic hormone
- from the anterior pituitary
- to adrenal cortex
- promotes development and secretion in the adrenal cortex
LH
Leuteinizing hormone
- from the anterior pituitary
- to the gonads
- female = triggers ovulation; promotes development of corpus luteum
- male = stimulates production of testosterone
ADH
antidiuretic hormone
- from posterior pituitary
- to kidney
- promotes water retention by kidney tubules; raises blood pressure by stimulating muscles in walls of small arteries
OT
oxytocin
- from the posterior pituitary
- to the uterus and mammary glands
- stimulates uterine contractions; stimulates ejection of milk into ducts of mammary glands
Melatonin
produced by pineal gland
- production and secretion mediated largely by postganglionic retinal nerve fibers that pass through the retinohypothalamic tract to the suprchiasmatic nucleus, then to the superior cervical ganglion, and to the pineal gland
- activated by darkness and suppressed by light
anterior pituitary
master gland
1) pars distalis = major endocrine part
2) pars tuberalis = extension contacting the infundibulum
- derived from pharyngeal epithelial tissue
anterior pituitary gland cells
1) acidophils
- somatotrophs and lactotrophs
2) basophils
- corticotrophs, thyrotrophs, and gonadotrophs
posterior pituitary
- neural part
- continuation of the 3rd ventricle
- derived from a down growth of the hypothalamus
- consists of pars nervosa
Hypothalamus –> anterior pituitary
hypthalamus –> hormones produced and released –> tuberoinfundibular tract –> 2 capillary beds(superior hypophyseal artery) –> portal vein –> anterior pituitary –> produce or inhibit hormones –> circulatory system
hypothalamus –> posterior pituitary
paraventricular and supraoptic nuclei –> supraoptic-hypophyseal tract –> capillaries(inferior hypophyseal artery) –> hypophyseal vein
Functions of the hypothalamus
1) body temperature
2) cardiovascular system
3) food intake and body weight
4) thirst and water balance
5) involved in sleep and wakefulness
6) involved in emotional reactions
7) involved in reactions to stress
8) controls ovarian secretions during ovarian cycle
9) controls testicular secretions
hypothalamus reaction to stress
stress–> hypothalamus(CRH) –> anterior pituitary(ACTH) –> adrenal gland –> release of cortisol and adrenaline
- chronic stress maintains high levels of cortisol and adrenaline
