Mr. Nijaguna Mathad

Consultant Neurosurgeon, Southampton, UK

Pituitary Gland

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Pituitary gland is situated at the base of the brain within pituitary fossa.


Pituitary fossa is located at the roof of the sphenoid sinus, which is the largest air sinus at the back of the nose. Pituitary gland is of the size of a small broad bean, measuring 1.5cm X 1.0 cm. Its approximate weight is less than 0.75gm. 


Pituitary gland is called as the “master gland” of the body, as it regulates all other hormone producing (endocrine) glands. Pituitary has two lobes, the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis). Posterior pituitary lobe is connected to hypothalamus by pituitary stalk. Hypothalamus decides which regulatory hormones the pituitary gland should release.

 

 Anterior pituitary releases the following hormones in response to hormonal signal from the hypothalamus-

· GH (Growth Hormone) – which regulates the muscle and bone

· TSH (Thyroid Stimulating Hormone)-stimulates  thyroid gland to release thyroxine, which regulates metabolism

· FSH (Follicle Stimulating Hormone) & LH (Luteinizing Hormone) -  in women it stimulates ovaries to produce estrogen and in men it stimulates sperm production

· Prolactin – stimulates breast tissue

· ACTH (AdrenoCorticoTropic Hormone)- stimulates adrenal to produce steroids

 

Posterior pituitary releases the following hormones in response to neural signal from the hypothalamus-

· ADH (AntiDiuretic Hormone)- stimulates kidneys to conserve water

· Oxytocin- stimulates uterine contractions in labor and milk ejection in mother.  More info..