Pituitary gland, Biology


  • 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.
Posted Date: 10/2/2012 6:36:47 AM | Location : United States

Related Discussions:- Pituitary gland, Assignment Help, Ask Question on Pituitary gland, Get Answer, Expert's Help, Pituitary gland Discussions

Write discussion on Pituitary gland
Your posts are moderated
Related Questions
Q. Define Low - density lipoprotein? Ans. LDL is the major cholesterol-rich lipoprotein carrying approximately 70 per cent of plasma cholesterol. It serves to transport ch

Goals of Computerization in Nursing Practice Improved Efficiency: Computers can rapidly process, store, and retrieve information, helping the nurse clinician in nursing

Q. What are the Causes of constipation? The most common causes of constipation are poor elimination habits, a lack of fibre in the diet, insufficient fluid intake, lack of exer

Starting at the esophagus, trace the pathway of food through the system. At each organ, indicate anatomical adaptations to the general GI tract tube structure that enhance the spec

why is cosmozoic theory considered to be true?

Explain biochemical mediators of calcium metabolism Bone physiology is controlled by an interaction of mechanical and metabolic factors. Under physiologic circumstances, bone

Pulmonary edema occurs when movement of liquid from the blood to the interstitial space and/or into the alveoli exceeds the return of liquid to the blood and its drainage through t

Define Interaction with carbohydrate, fats and proteins? Dietary carbohydrates, fats and proteins require water-soluble vitamins for their metabolism and in turn, influence the

An impermeable membrane separates one liter of a 1M KCl solution in the left compartment from one liter of 1M NaCl solution in the right compartment.  At 2 AM today the membrane be