anatomyphysiologyblog - Gross anatomy together with histological features of Pituitary Gland
What is pituitary gland?
Also known equally hypophysis cerebri, pituitary is an ovoid neuroglandular organ.
It is suspended from the flooring of the 3rd ventricle past times a stem known equally infundibulum.
It is located inwards a depression called hypophyseal fossa of sella turcica of trunk of sphenoid. The fossa is roofed past times the diaphragm sellae which is a bend derived from the meningeal layer of dura mater. The diaphragm sellae is pierced past times the pituitary stem or infuldibulum.
What are the presenting parts?
The gland consists of:
An anterior lobe or adeno-hypophysis in addition to
A posterior lobe or neurohypophysis
Gross anatomy of Anterior Lobe or adeno-hypophysis:
It is highly cellular in addition to occasionally presents intra-glandular cleft. The business office behind the scissure is known equally pars intermedia, which is rudimentary inwards human beings in addition to embraces the front end in addition to sides of the posterior lobe. The business office of the anterior lobe extending upward along the infudibular stem is known equally pars tuberallis. The residual of the gland inwards front end of the scissure is called pars anterior or pars distalis.
Gross Anatomy of posterior lobe or neurohypophysis:
It is continuous higher upward alongside the infundibulum. It consists of 3 parts:
Median eminence of tuber cinerium, infundibular stem in addition to pars nervosa
Relations:
Anteriorly: anterior intercavernous sinus
Posteriorly: posterior intercavernous sinus, back sellae, the basilar artery, in addition to the pons
Superiorly: eye chiasma, anterior communicating artery in addition to the flooring of 3rd ventricle separated past times the diaphragma sellae, which has a key aperture that allows the passage of the infundibulum
Inferiorly: The trunk of the sphenoid, alongside its sphenoid air sinuses
On each side: The cavernous sinus in addition to its contents
Arterial Supply:
Anterior lobe:
by superior hypophyseal artery (branch of internal carotid artery)
Breaks upward in addition to shape capillary plexus inwards the median eminence in addition to infundibular stem
Long in addition to curt portal vessels arise from these plexus in addition to provide the anterior lobe
Posterior lobe:
by inferior hypophyseal artery (branch of internal carotid artery)
Enters the posterior lobe in addition to shape capillary plexus to provide it.
Venous Drainage:
Small veins arise from the surface of the gland in addition to drain into neighboring dural sinuses
What is the construction or histological features of Pituitary gland?
Pars anterior: consists of
– chromophil cells in addition to chromophobe cells
Chromophil cells are classified into
– Acidophil cells (secrete somatotrophs, mammotrophs)
– basophil cells (secrete corticotrophs, thyrotrophs, gonadotrophs)
Chromophobe cells: they comprise rattling few granules inwards the cytoplasm
Pars tuberalis: consists of mainly undifferentiated cells in addition to roughly acidophil in addition to basophil cells
Pars intermedia: it is poorly developed inwards human.
Pars posterior:
– unmyelinated nervus fibres alongside supporting cells called pituicytes
– stores in addition to releases vasopressin (anti-diuretic hormone; ADH) in addition to oxytocin
REFERENCES:
Following resources are used patch preparing this post service (readers are strongly recommended to become through them for to a greater extent than details):
Gray's Anatomy
K. L. Moore's Clinically Oriented Anatomy
R. Snell's Clinical Anatomy
Wheater's Functional Histology: Influenza A virus subtype H5N1 Text in addition to Color Atlas
Junqueira's Basic Histology: Text in addition to Atlas