Pituitary Gland Flashcards
The anterior pituitary lobe originates from the _____ and the posterior pituitary lobe originates from the _____.
- oropharynx ectoderm
- neuroectoderm
V= 3rd ventricle
O = optic Chiasm
H = connected to hypothalamus
P = stalk/infundibulim
AP = anterior pituitary
PP = posterior pituitary
Pars distalis is also known as the _____.
anterior lobe
Cell types of the pars distalis AKA anterior lobe of the pituitary
- Chromaphils (acidophils & basophils)
- Chromophobes
- Follicular stellate cells
What are the acidophilic chroma cells of the anterior lobe of the pituitary AKA pars distalis?
- Somatotrophs
- mammotrophs
What are the basophilic cells of the anterior lobe of the pituitary AKA pars distalis?
- corticotrophs
- thyrotrophs
- gonadotrophs
Somatotrophs secrete ___.
growth hormone AKA somatotropin.
(well organized RAR with secretory granules. Unable to see under light microscopy
Mammut ropes AKA lactotrophs secrete _____.
prolactin
(development of mammary gland during pregnancy for most lactation after birth)
Basophils (subcategory of chromophils) of the pars distalis are:
- Gonadotrophs (FSH, LH)
- Corticotrophs (ACTH)
- Thyrotrophs (TSH)
Function of LH in women? In men?
- Triggers ovulation
- Stimulates steroid hormone production in the Leydig cells
Folliculostellate cells
- Non secretory cells of the pars distalis AKA anterior lobe
- Function is unknown
B = basophil (chromophil)
A = acidophil (chromophil)
Ca = capillary
Cp = chromophobe
Type of capillaries in a pituitary
fenestrated capillaries
Pars intermedia
CF= colloid
(Toluidine blue-stained)
Sounds of the pars intermedia of the pituitary gland secretes ______.
melanocyte stimulating hormone
(function is unknown)
Define pars tuberalis
- Forms a sleeve around infundibulum
- Highly vascularized composed of longitudinal chords of weekly Baeza feel like cells
Function of pars tuberalis
Secrete LH and FSH (basophils)
What is the result of a tumor that presses on the optic chiasm?
Bitemporal hemianopia
The pars nervosa is also known as the ______.
posterior pituitary gland
Herring body
Accumulation of neuro secretory granules in the dilated axon terminals
(unique to the pars nervosa)
What is the difference between oxytocin and prolactin in terms of lactation?
- Prolactin stimulates milk production
- Oxytocin stimulates mammary gland myoepithelial cells milk ejection
Neurophysin
Binding protein specific for the hormones of the neuro secretory granules
Function of pituicytes
Support on myelinated nerve fibers and pars nervosa
(Resembles neuroglial cell; possess cytoplasmic processes that terminate in the perivascular space)
(BV= blood vessel; HB = Herring body; N = Nuclei)
Divisions of the neural hypothesis
- Pars nervosa
- Infundibulum
- Median eminence
Neurosecretory hormones are synthesized by hypothalamic neurons and stored in the ______.
median eminence
Describe the blood flow to the pituitary.
Superior hypophyseal artery → primary capillary plexus → hypophyseal portal system → secondary capillary plexus
(hormones are released into the primary capillary plexus then carried to the secondary capillary plexus via the hypophyseal portal)
