31-Neuroendocrine Flashcards
Pituitary gland lies at base of brain in indentation of ___ bone called ___
sphenoid bone, sella turcica
anterior pituitary aka
adenohypophysis
parts of anterior pituitary
- pars tuberalis
- pars distalis
- pars intermedia (vestigial in adult human)
posterior pituitary aka
neurohypophysis
parts of posterior pituitary
- infundibular stalk (pit. Stalk)
- posterior lobe
median eminence aka
infundibulum
function of median eminence
connection between hypothalamus and pituitary gland
posterior pituitary secretes ___ and ___ into systemic circulation
vasopression, oxytocin
Vasopressin and oxytocin are synthesized in ___ neurons in ___ and ___
magnocellular, supraoptic (SON) and paraventricular (PVN) nuclei
[Magnocellular/parvocellular] neurons secrete peptides directly into systemic circulation
magnocellular
___ and ___ synapse on SON and PVN
limbic, solitary nucleus
SON
supraoptic nucleus
PVN
paraventricular nucleus
vasopressin aka
antidiuretic hormone (ADH)
ADH
antidiuretic hormone
increased blood osmolality -> …?
incr solute (NaCl) -> incr vasopressin ->
(incr. water resorption) and
(incr. vasoconstriction -> incr. blood pressure)
hypovolemia -> …?
decr blood volume -> incr. vasopressin ->
(incr. water resorption) and
(incr. vasoconstriction -> incr. blood pressure)
hypotension -> …?
decr blood pressure -> incr. vasopressin ->
(incr. water resorption) and
(incr. vasoconstriction -> incr. blood pressure)
suckling -> …?
incr oxytocin -> milk ejection
OT
oxytocin
uterine stimulation -> …?
incr oxytocin -> uterine contraction
orgasm -> …?
incr oxytocin -> contraction of sm muscle in external genitalia -> (?) incr sensation (?)
Anterior pituitary secretes three families of hormones into systemic circulation. What are they?
- somatomammotropins
- glycoproteins
- opiomelanocortin peptides
somatomammotropins and their stimuli/effects (x2)
- growth hormone (exercise, stress, sleep -> growth and metabolism)
- prolactin (suckling, stress -> dev. of mammary tissue and lactation)
glycoproteins and their stimuli/effects (x3)
- thyroid-stimulating hormone (TSH) (exposure to cold temps -> incr thyroid secretion -> incr cell metabolism -> heat production)
- follicle-stimulating hormone (FSH) (regulated by hypothalamic peptide and gonadal protein inhibin -> required for spermatogenesis or development of ovarian follicle)
- luteinizing hormone (LH) (regulated by hypothalamic peptide -> required for spermatogenesis / stimulates testosterone (male) or initiates ovulation and stimulates progesterone (female)
opiomelanocortin peptides and their stimuli/effects (x2)
- adrenocorticotropic hormone (ACTH) (stress -> incr ACTH -> incr release of cortisol from adrenal cortex)
- beta-endorphin (stress -> opiate-like peptide -> mu receptor)
GH
growth hormone
TSH
thyroid-stimulating hormone
FSH
follicle-stimulating hormone
LH
luteinizing hormone
gonadotropins: examples (x2) and the family they belong to
FSH and LH, both are glycoproteins
ACTH
adrenocorticotropic hormone
Hypothalamic releasing factors synthesized in ___
parvocellular neurons of anterior pituitary
Hypothalamic releasing factors released from nerve terminals into ___
hypophyseal portal blood vessels
TRH
thyrotropin-releasing hormone
GnRH
gonadotropin-releasing hormone
CRH
corticotropin-releasing factors
GHRH
growth hormone-releasing hormone
TRH is [excitatory/inhibitory] and causes ___
excitatory, -> incr in TSH and incr in prolactin
GnRH is [excitatory/inhibitory] and causes ___
excitatory, -> incr in FSH and incr in LH
somatostatin is [excitatory/inhibitory] and causes ___
inhibitory, -> decr in GH
CRH is [excitatory/inhibitory] and causes ___
excitatory, -> incr in ACTH and beta-endorphin
dopamine is [excitatory/inhibitory] and causes ___
inhibitory, -> decr in prolactin
GHRH is [excitatory/inhibitory] and causes ___
excitatory, -> incr in GH
What hormonal changes occur after pituitary stalk section?
- incr in prolactin
- decr in other pituitary hormones
Disorders assocatied with abnormal hypothalamic-pituitary function (x2)
- diabetes insipidus
- galactorrhea-amenorrhea hyperprolactinemia
main mechanism of effects of diabetes insipidus
loss of vasopressin secretion
etiology of diabetes insipidus
- head trauma (severing pituitary stalk)
- autoimmune -> destruction of magnocellular neurons
- ideopathic
symptoms of diabetes insipidus
- polyurea (excessive urination)
- polydipsia (excessive drinking)
treatment for diabetes insipidus
replace vasopressin w/ analogue that acts on kidneys but not blood vessels
symptoms of galactorrhea-amenorrhea hyperprolactinemia
- inappropriate lactation
- cessation of menstruation (by inhibition of FSH and LH secretion)
etiology of galactorrhea-amenorrhea hyperprolactinemia
tumor (pituitary microadenoma) -> incr prolactin
treatment for galactorrhea-amenorrhea hyperprolactinemia
- give dopamine receptor agonist
- surgery to remove tumor
