Pituitary gland, Biology

Assignment Help:

PITUITARY GLAND (HYPOPHYSIS CEREBRI) -

  • It develops from ectoderm of the embryo.
  • The pituitary gland is located just below the hypothalamus. The pituitary gland is situated in a depression the sella turcica of sphenoid bone of the skull.
  • The pituitary gland is the smallest endocrine gland. It is about 1.3 cm in diameter and weighs about half a gram.
  • The gland is attached to the brain by a stalk the infundibulum which is continuous with the hypothalamus above.
  • Adenohypophysis or pars distalis and the posterior lobe or neurohypophysis or pars nervosa.
  • Adenohypophysis originates as Rathke's pouch from dorsal wall of stomodaeum in the embryo, but later its connection with the stomodaeum disappears.
  • The neurohypophysis originates as an outgrowth from the floor of the diencephalon.
  • A third lobe, called the intermediate lobe or pars intermedia is a part of adenohypophysis.

1108_pituitary gland.png

  • Adenohypophysis comprises about 75% part of the pituitary gland.
  • The hypophysial portal veins carry blood containing neurohormones (releasing factors) from the hypothalamus to tbe adenohypophysis.
  • Neurohypophysis comprises about 25% part of the pituitary gland. The axons of neurosecretory cells (secretory neurons) extend into the neurohypophysis where these axons terminate as axon terminals. These terminals are embedded in a neuroglial tissue formed of large and branched cells called pituicytes.
  • No hormones are synthesized in neurohypophysis but two hormones, synthesized in the hypothalamic neurosecretory cells remain stored in very small vesicles in the axons and terminals. These vesicles are called Herring bodies.

Related Discussions:- Pituitary gland

Determine protein needs during pregnancy period, Determine Protein needs du...

Determine Protein needs during pregnancy period? Altogether, 925 g of protein are deposited in a normal foetus and maternal accessory tissues and considering the dietary protei

State the term in detail hydrostatic skeleton., State the term in detail hy...

State the term in detail hydrostatic skeleton. Formed from a fluid-filled and closed cavity surrounded by a body wall comprising muscles oriented in different directions. Muscu

Define traditional cycle of root canal treatment, Define Traditional Cycle ...

Define Traditional Cycle of Root Canal Treatment The traditional cycle of Root Canal Treatment a) Dig in the tooth to make a big hole b) Then, look through this hole to f

How can a child become infected with gonorrhoea, How can a baby become infe...

How can a baby become infected with (a) gonorrhoea, (b) syphilis   (a)  During birth, a baby might be become infected with gonorrhoea bacteria as it passes by t

Difference between striated, DIFFERENCE S BETWEEN STRIATED, NON-STRIATED A...

DIFFERENCE S BETWEEN STRIATED, NON-STRIATED AND CARDIAC MUSCLE FIBRES -                      Striated                                                              Non-striat

Which are the heart chambers, Which are the heart chambers respectively whe...

Which are the heart chambers respectively where the entrance and the exit of blood occur? The heart chambers by which blood enters the heart are the atria. There are the right

Importance of behaviour change communication, Importance of Behaviour Chang...

Importance of Behaviour Change Communication BCC is an in built part of a diabetes prevention, care and support program. Importance of BCC: · Increase knowledge. BCC can en

Winter stratification - thermal stratification, Winter Stratification - The...

Winter Stratification - Thermal stratification During extremes of winter the surface layer of the lake freezes or attains a temperature close to 0° Celsius. Under these condit

Louping ill, Louping ill This is an infectious encephalomyelitis of sh...

Louping ill This is an infectious encephalomyelitis of sheep and man occurring during spring and summer when the vectors like ticks are active. It is reported from British Isl

What is an oligopeptide, Q. What is an oligopeptide? How is it differing fr...

Q. What is an oligopeptide? How is it differing from a polypeptide? Peptide is the molecule formed by the union of amino acids through the peptide bond. Oligopeptide is a pepti

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd