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

Explain the parental gametes and recombinant gametes, In genetic recombinat...

In genetic recombination by crossing over what is the difference between parental gametes and recombinant gametes? Parental gametes are those gametes that keep the original lin

What is the significance of elastic capsule chromatophore, What is the sign...

What is the significance of Elastic capsule chromatophore? Specialized pigmented cells on surface of the cephalopods that, by changing their shape, expose differing amounts of

Corpus cardiacum - endocrine organs, Corpus Cardiacum - Endocrine Organs ...

Corpus Cardiacum - Endocrine Organs We before mentioned that corpus cardiacum (pl. corpora cardiaca) is a neurohemal organ in insects. It is gland of neural origin. They are c

What are the two main types of endocytosis, What are the two main types of ...

What are the two main types of endocytosis? Endocytosis can be divided as pinocytosis or phagocytosis. In pinocytosis small particles on the external surface of the membrane ex

Diagnosis of multiple myeloma, Which of the following abnormal blood work r...

Which of the following abnormal blood work results is most closely associated with a diagnosis of multiple myeloma? A. Extremely high levels of abnormal lymphocytes B. Low potassiu

Define historical example population genetic theory, Define Historical Exam...

Define Historical Example Population genetic theory? Population genetic theory, first developed by Sir Ronald Fisher, JBS Haldane and Sewall Wright, demonstrated how several ev

Define viscosity - function of proteins, Explain Viscosity of proteins ...

Explain Viscosity of proteins Viscosity reflects resistance to flow. The  main  single factor influencing the viscosity  behavior  of protein  fluids  is   the  apparent  diame

Explain thetechnique of total anomalous surgery, Explain theTechnique of to...

Explain theTechnique of total anomalous Surgery ? Corrective surgery is undertaken as an emergency procedure after diagnosis has been confirmed by two-dimensional echocardiogra

Discuss the genetics involved in the inheritance, Casein is the main protei...

Casein is the main protein in milk. There are three types of casein, one of which is beta casein. Beta casein comes in two main variants called A1 and A2. The order of amino acids

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