The upcoming discussion will update you about the differences between Adrenal Cortex and Adrenal Medulla of Humans.
Difference # Adrenal Cortex:
1. It is outer firm part of the adrenal gland.
2. It forms about 75% part of the gland.
3. It is enclosed by a fibrous capsule.
4. It develops from the mesoderm.
5. It comprises three regions or zones:
(a) Outer thin zona glomeruiosa.
(b) Middle thick zona fasciculata and
(c) Inner thin zona reticularis.
6. It is essential for life. Its destruction causes death.
7. It is stimulated to release its hormones by adrenocorticotrophic hormone (ACTH) from the anterior lobe of pituitary gland.
8. It secretes three groups of hormones: mineralocorticoids glucocorticoids and gonadocorticoides.
9. There is no cooperation between adrenal cortex and sympathetic nervous system.
Difference # Adrenal Medulla:
1. It is central soft part of the adrenal gland.
2. It forms about 25% of the gland.
3. It is not enclosed by a fibrous capsule.
4. It develops from ectoderm.
5. It is not differentiated into regions. It consists of chromophil cells. The adrenal medulla is simply an extension of the sympathetic nervous system.
6. It is not so essential for life. Its destruction does not cause death.
7. It is stimulated to secrete its hormone by nerve impulses reaching through sympathetic nerve fibres.
8. It secretes two similar hormones : noradrenaline and adrenaline.
9. Adrenal medulla and sympathetic nervous system function as an integrated system called sympatheticoadrenal system.