State the location and types of tissues in the adrenal gland.

(N/A) Location: Our body has one pair of adrenal glands,with one gland situated at the anterior part of each kidney.
Types of Tissues: The gland is composed of two types of tissues:
$1$. Adrenal Medulla: The centrally located tissue.
$2$. Adrenal Cortex: The tissue lying outside the medulla.
Functions of Adrenal Medulla:
- It secretes two hormones: adrenaline (epinephrine) and nor-adrenaline (norepinephrine),collectively called catecholamines.
- These are emergency hormones or hormones of 'fight or flight',secreted in response to stress.
- They increase alertness,pupillary dilation,piloerection,sweating,heart rate,strength of heart contraction,and rate of respiration.
- They stimulate the breakdown of glycogen,lipids,and proteins.
Functions of Adrenal Cortex:
- It is divided into three layers: zona glomerulosa (outer),zona fasciculata (middle),and zona reticularis (inner).
- It secretes hormones called corticoids,mainly glucocorticoids and mineralocorticoids.
- Glucocorticoids (e.g.,cortisol) are involved in carbohydrate metabolism,stimulate gluconeogenesis,lipolysis,and proteolysis,and suppress the immune response.
- Mineralocorticoids (e.g.,aldosterone) regulate the balance of water and electrolytes by stimulating the reabsorption of $Na^{+}$ and water,and the excretion of $K^{+}$ and phosphate ions in renal tubules.
- It also secretes small amounts of androgenic steroids,which play a role in the growth of axial,pubic,and facial hair during puberty.
- Underproduction of adrenal cortex hormones leads to Addison's disease.