Pituitary Hypophysis Endocrine Gland Histology
glycoprotein hormones of the pituitary gland
FSH, LH, TSH, ACTH, POMC, Beta Endorphin located in teh basophils
paras intermedia
containes Rathke's pouch/cyst that has colloid filled vesicles that are lined with simple squamous epitleium
prepropressin separated into which two hormones?
vasopressin and neurophysin
Herring bodies of the Neurophysis store
vasopressin and oxytocin
Paras Distalsis
- majority of the anterior lobe/anterior pituitary dark stained
Acidophils
-occupies 40% of distalsis, located in the distalsis, contains protein hormones somatotrophs (secrets Growth Hormone) and lactotrophs( secrets prolactin). stain pink
Secretion of Oxytocin and Vasopressin from the Pars Nervosa steps:
1. produced by PVN and SON in the hypothalamus in BBB 2. travel outside BBB for storage in herring bodies aka constipated axons and extended axons 3. neural stimulation causes release/ secretion
Oxytocin and Vasopressin (ADH) are stored in
Posterior Pituitary AKA Neurophysis
Pars Intermedia has
Rathke's cysts lined by simple cuboidal
Ghrelin in the stomach acts as what?
a releasing hormone for somatotropin
Paras distalis contains which types of cells
acidophiles, basophils, and chromophobes
Anteriorhypophysis is also called the
anterior pituitary gland
Pituicytes of the Neurophysis
are like glial astrocytes, contain GFAP an intermediate filament protein. DO NOT SECRETE
Somatostatin is an inhibitory hormone produced by hypothalamus that inhibits which hormones of the pituitary?
growth hormone (somatotrophin) and thyrotropin
Paras nervosa is lighter and contains which types of cells and goes into which structure histologically?
herring bodies and pituicytes.. it goes into the infundibular stalk
Where does the Hypophysis sit?
in the sella turcica of the sphenoid bone
ADH aka Vasopressin does what?
increases water permeability of the collecting duct
basophils
occupies 10%, granular, darker, contain glycoprotein hormones ( gonadotrophs, corticotrophs, thyrotrophs, and other cells derived from preopiomelanocortin stuff like POMC like ACTH and B-endorphn
Chromophobes
occupies 50% does not stain bc they are degranulates
oxyphysin separates into which two hormones?
oxytocin and neurophysin
oxytocin secreted from where has what effect?
oxytocin is secreted from herring bodies and it increase prolactin
Anterior Pituitary Characteristics
paras distalsis, no BBB, paras tuberalis, paras intermedia
Posterior Pituitary Characteristics
paras nervosa,
Which cells contain GFAP which are an intermediate filament protein ?
pituicytes
ADH/ Vasopressin comes from where?
prepropressin
Dopamine is the hypothalamic inhibitory hormone of
prolactin
Which one of the hormones does not have a releasing hormone from the Hypothalamus
prolactin
The hypophysis/pituitary gland is in charge of
sex hormones, metabolism, fluid balance, growth, and lactation
neurophysin does what?
stabilizes oxytocin after exocytosis
Oxytocin
stimulates mammary gland myoepithelial cell contraction and uterine smooth muscle
Superior hypophesial arteries
supply blood to median eminance and infundibulum to form primary plexus of fenestrated capilaries. theses then branch to form secondary plexus and carry blood to distalsis
Inferior hypophysial arterioles
supply neurohypophysis
Hypothalamus + Hypophyseal Portal Circulation
there is no direct blood to the distalsis. The superior hypopheseal artery supplies the median eminance and infundibular stalk to form primary plexus of fenestration capillaries
Inhibiting Hormones come from the (IH)
Dopamine, Somatostatin
Protein hormones of the Pituitary gland
Growth Hormone and Prolactin located in the acidophiles
Oxytocin and Vasopressin are produced in
Hypothalamus
Releasing Hormones come from the (RH)
Hypothalamus