Adrenal gland :
The adrenal glands are present in pairs, one at the anterior part of each kidney. The adrenal gland is made of two kinds of tissues namely
i. Adrenal medulla.
ii Adrenal cortex.
Parts of Adrenal gland :
1. Adrenal cortex : It is the outer part of the adrenal gland. It is further differentiated into three parts :
(a) Zona glomerulosa (Outer zone)
(b) Zona fasciculata (Middle zone)
(c) Zona reticulosa (Inner zone outer to adrenal medulla).
Hormones secreted - Adrenal cortex secretes the following three hormones derived from steroids :
(i) Aldosterone or mineralocorticoids.
(ii) Cortisol or glucocorticoids.
(iii) Sexcorticoids or androgens.
2. Adrenal medulla : It lies inner to cortex.
Hormones secreted- It secretes two hormones namely:
(a) Epinephrine
(b) Norepinephrine.
Explain the following :
(a) Insulin lowers the blood sugar level.
(b) Hypothalamus and pituitary function as an integrated and coordinated system.
(c)Body growth is greatly accelerated at puberty in the male.
(d) Adrenal medulla and the sympathetic nervous system function as a closely integrated system.
(e) Pituitary gland regulates the reproductive system.
Write notes on the following :
i. Hypothyroidism
ii. Melatonin
