The Endocrine System

Adrenaline (epinephrine) and noradrenaline (norepinephrine) are hormones and neurotransmitters secreted by the adrenal medulla. They are derived from the amino acid tyrosine and belong to a class of compounds called catecholamines, characterized by a catechol group and an amine group. These hormones play a major role in the body's fight-or-flight response.
- Option (1) is incorrect: Cortisol is a glucocorticoid, not a mineralocorticoid. Aldosterone is the major mineralocorticoid.
- Option (3) is incorrect: The zona reticularis of the adrenal cortex primarily secretes androgens, not epinephrine. Epinephrine is secreted by the adrenal medulla.
- Option (4) is incorrect: Insulin is a hormone, not an enzyme, and it regulates glucose metabolism—not mineral metabolism.
Thus, the correct answer is option (2).

Sugar metabolism is primarily regulated by hormones such as insulin, glucagon, and cortisol:
- Insulin lowers blood glucose levels by promoting its uptake into cells.
- Glucagon raises blood glucose levels by promoting glycogen breakdown in the liver.
- Cortisol increases blood glucose levels by stimulating gluconeogenesis.
Aldosterone, on the other hand, is a mineralocorticoid hormone secreted by the adrenal cortex. It plays a key role in regulating sodium and potassium balance and maintaining blood pressure. It is not directly involved in carbohydrate (sugar) metabolism.
Therefore, the correct answer is Aldosterone.