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

Requirement of folic acid and vitamin b12 during pregnancy, Determine Requi...

Determine Requirement of Folic acid and vitamin B 12 During pregnancy? Folic acid and vitamin B 12 are important for production of new cells. DNA must replicate and transmit

Microorganisms on basis of oxygen requirement for growth, Q. Microorganisms...

Q. Microorganisms on basis of oxygen requirement for growth? On basis of oxygen requirement for growth: - Obligate Aerobes: Require oxygen for growth and multiplication e.g

Sequencing of dna fragments, Q. If a fragment of nucleic acid has a nucleot...

Q. If a fragment of nucleic acid has a nucleotide sequence TAC can one assert that it is an anticodon or a codon? A nucleic acid having a TAC sequence surely is not tRNA it is

Roles of glycogen metabolism, Glycogen is a huge polymer of glucose residue...

Glycogen is a huge polymer of glucose residues linked by α1-4 glycosidic bonds with branches every 10 residues or so by α1-6 glycosidic bonds.  Glycogen gives an significant energy

Embryogenesis, Phenomenon of embryogenesis is not confined to the reproduct...

Phenomenon of embryogenesis is not confined to the reproductive system

What anatomical direction with respect to occipital cortex, The frontal cor...

The frontal cortex is in what anatomical direction with respect to the occipital cortex? a. anterior b. posterior c. sagittal d. inferior

What are atherosclerosis, Atherosclerosis, the most common part of hardenin...

Atherosclerosis, the most common part of hardening of the arteries, is characterized by the presence of cholesterol-rich arterial thickenings (atheromas).  This progressive  diseas

Gibberellins in plant growth , Gibberellins in plant growth  Gibbere...

Gibberellins in plant growth  Gibberellins were first isolated from the culture of a fungus Gibberella fujikuori. Gibberellins has a significant effect on stem elongation

State about the latent squint disease, State about the Latent squint diseas...

State about the Latent squint disease Latent squint is seen commonly as exophoria in infancy and presbyopic age and esophoria in childhood. Hypermetropes can have esophoria and

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