Question

Describe the working of the pituitary gland.

Answer 1

pituitary gland is basically divided into 2 parts in human being that is anterior pituitary also known as adenohypophysis and its second part is posterior pituitary also known as neurohypophysis. anterior pituitary is under direct control of hypothalamus. anterior pituitary secretes the following hormones :-

1 FSH-( follicle stimulating hormone )

2 LH-luteinizing hormone , it helps in the production of male steroid hormone -androgen

3 prolactin- helps in secretion of milk from mammary gland after parturition

4 growth hormone -responsible for growth of skeletal and smooth muscle

5 ACTH- adrenocorticotropic hormone posterior pituitary stores and releases the following hormone :-

1 ADH- antidiuretic hormone -helps in making the urine concentrated by helping the dct and collecting duct in absorption of water while the filterate is passing through them( human body has the capacity to the urine 4 times concentrated), therefore it prevents diureses , ADH is also a vasoconstrictor ,therefore it also increases blood pressure. hyposecretion of ADH causes diabetes insipidus.

2 ox ytocin- it helps in contraction of smooth muscle in females during parturition, which helps in the delivery of the baby . pituitary gland also has pars intermedia region which is rudimentary in humans and it is fused with anterior region of the pituitary gland and it secretes only one hormone known as MSH- melanocyte stimulating hormone .

Answer 2

1. The anterior pituitary secretes hormones which stimulate the secretions of other endocrine glands in the body.
2. Hence, the pituitary is called as the ‘master endocrine gland’.
3. However, the pituitary in turn is controlled by the neurosecretions of the hypothalamus, called ‘releasing factors’ which make the pituitary stimulate the secretions of other glands and ‘inhibiting factors’ which oppose the pituitary stimulation of other glands.
4. These neurosecretions reach the Pars distalis through the hypothalamo-hypophyseal portal system of blood vessels.
5. The posterior pituitary receives and stores vasopressin (ADH) and oxytocin secreted by the supra-optic nuclei and the para-ventricular nuclei respectively and secretes them as and when required.