pituitary + hypothalamus Flashcards
pituitary gland is aka
hypophysis
the pituitary gland is derived from ______
2 diff embryological pouches - adenohypophysis and neurohypophysis
discuss adenohypophysis
forms anterior pituitary - from ectoderm cells from roof of pharynx = rathke’s pouch
the anterior pituitary contains ______
glandular cells that secrete hormones
release of hormones by anterior pituitary is controlled by ______
hypothalamus
discuss the neurohypophysis
forms posterior pituitary from floor of ventricular system
the posterior pituitary contains ______
axons and axon terminals from cells in hypothalamus
the posterior pituitary secretes ______
oxytocin and vasopressin
the hypothalamus is ____ to optic chiasm
posterior to optic chiasm but some portions are dorsal to optic chiasm
bulge between optic chiasm and mammillary bodies
tuber cinereum
the infundibulum arises from the _____
tuber cinereum
the infundibulum continues inferiorly as the _____
pituitary stalk
significance of median eminence
region where hypothalamic nuc release regulating factors
regulating factors released by median eminence are carried by _____ to _____
carried by portal vessels to the anterior pituitary
pituitary gland lies within the ______
pituitary fossa
saddle shaped depression on the sphenoid bone
sella turcica
the sella turcica houses the ______
pituitary gland
found beneath the floor of sella turcica
sphenoid sinus
dura covering the superior portion of the pituitary fossa
Diaphragma Sella
_____ traverses the diaphragma sella
pituitary stalk
the pituitary fossa is bound laterally by _____
cavernous sinus
the pituitary fossa lie behind and inferior to the _____
optic chiasm
from optic chiasm to lamina terminalis and anterior commissure
preoptic area
the preoptic area merges caudally c _____
midbrain tegmentum
how does the hypothalamus maintain homeostasis
by interacting with and exerting regulatory influences over other systems
how does hypothalamus have endocrine control
via pituitary gland
3 areas of hypothalamus from medial to lateral
periventricular
medial
lateral
lies closest to the 3rd ventricle
Periventricular Nucleus
fibers of the _____ pass through hypothalamus otw to _____
fornix pass through the hypothalamus otw to mammillary body
fibers of the fornix pass through the hypothalamus on the way to the mammillary body, dividing it to
medial and lateral hypothalamic area
what is found in the lateral hypothalamic area
lat hypothalamic nucleus, medial forebrain bundle and other nuc
it runs through the lateral hypothalamic area in rostrocaudal direction
medial forebrain bundle
the medial forebrain bundle carry connection to and from _____
hypothalamus
4 regions of medial hypothalamic area from anterior to posterior
preoptic
anterior or supraoptic
midlle hypothalamic (tuberal)
posterior hypothalamix
what is found on preoptic region
lateral and medial preoptic nucleus
continuations of lateral and medial hypothalamic area rostrally
what is found on the anterior region
supraoptic and paraventricular nucleus
suprachiasmatic nucleus
the supraoptic and paraventricular nucleus contain
oxytocin or vasopressin to project to the posterior pituitary
function of suprachiasmatic nucleus
“master clock” for circadian rhythms
suprachiasmatic nucleus receive inputs from
retinal ganglion cells
what does the middle hypothalamic region contain
arcuate nucleus
function of arcuate nucleus
project to median eminence to control pituitary
structure responsible for hypothalamic control of ANS
paraventricular nuc - mainly
dorsomedial hypothalamic nuc, lateral and posterior hypothalamus
discuss connections of ANS control
medial forebrain bundle to dorsolateral brainstem and periaqueductal gray matter
MFB synapse c _____ in brainstem
preganglionic PSY nuclei
MFB synapse c ____ in sacral spinal cord
intermediate zone
MBF synapse c _____ in intermediolateral cell column of thoracolumbar SC
preganglionic sympathetic neurons
discuss hypothalamic-limbic pathway
hippocampal formation to mammillary body via fornix
then mammillary body to anterior thalamic nucleus
discuss mammillary body to anterior thalamic nucleus
via mammillothalamic tract then to cingulate gyrus
amygdala has _____
reciprocal connections
amygdala has reciprocal connections via
stria terminalis and ventral amygdalofugal pathways
function of hypothalamic-limbic pathways
emotional influence on autonomic and homeostatic pathways and immune system
physical expression of emotion
nucleus found in hypothalamic-limbic pathway
lateral hypothalamic and ventromedial
function of lateral hypothalamic nucleus in ANS
rage
function of ventromedial nucleus in ANS
passivity
function of lateral hypothalamus
hunger center - appetite
lesion on lateral hypothalamus
cause decrease body weight
function of medial hypothalamus
satiety center - inhibits appetite
what specific nucleus inhibits appetite
ventromedial nucleus
lesion in medial hypothalamus
cause obesity
hormone released by adipose tissue
leptin
leptin binds to _____ in hypothalamus
Ob receptors
function of leptin
reduce appetite
secreted by gastric mucosal cells
ghrelin
ghrelin binds to _____
hypothalamus
function of ghrelin
stimulates appetite
exp how thirst is felt
activation of osmoreceptors in anterior regions of hypothalamus
regions of hypothalamus responsible in thermoregulation
anterior and posterior hypothalamus
discuss role of anterior hypothalamus in thermoregulation
detects inc in body - activates heat dissipation, vasodilation and sweating
discuss role of posterior hypothalamus in thermoregulation
conserves heat - heat production, vasoconstriction, inhib sweating, shivering
hormone for sexual desire and motivational states
oxytocin
oxytocin is produced in _____ and released in _____
produced in hypothalamus and released in posterior pituitary
function of oxytocin in mothers
Increase nurturing behaviors
anterior pituitary hormones
o Adrenocorticotropic hormone (ACTH)
o Growth hormone (GH)
o Prolactin (PRL)
o Thyroid-stimulating hormone (TSH)
o Luteinizing hormone (LH)
o Follicle-stimulating hormone (FSH)
what controls anterior pituitary
hypothalamus via releasing or release inhibiting factors thereby controlling hormone production of anterior pituitary
posterior pituitary hormones
oxytocin
vasopressin - arginine vasopressin or antidiuretic hormone
release of anterior pituitary hormones is controlled by hypothalamus through _______
hypophysial portal system
pituitary gland receives arterial blood from _____
inferior and superior hypophysial arteries
neurons lying adjacent to the 3rd venticle project to the
median eminence
what are the neurons adjacent to 3rd vent
arcuate nucleus, periventricular nucleus, medial parvocellular portions of the paraventricular nucleus
hormones in hypophyseal portal system are carried by _____ to anterior pituitary
hypophysial portal veins
hormones from pituitary area picked up by _____ of the portal system
secondary capillary plexus
from secondary capillary plexus it is then carried by _____ to ______
draining veins to cavernous sinus
oxytocin is synthesized in which nuclei
supraoptic and paraventricular nuclei
discuss hypothalamohypophyseal tract
for oxytocin and vasopressin
pass along axons the absorbed in fenestrated capillaries of post lobe of pituitary then secreted dun din
vasopressin is synthesized in which nuclei
supraoptic nucleus
function of vasopressin
vasoconstriction and anti-diuretic
inc absorption of water
relate supraoptic nuc and kidneys
supraoptic nuc acts as a osmoreceptor; high osmotic BP = inc vasopressin = inc water reabsorption of kidney
function of oxytocin
contraction of smooth muscles in uterus and myoepithelial cells in alveoli and breast duct for milk
regulates release of hormones
Hypothalamic – Pituitary Axis
