Question

The gland X which is located just below the brain in the human head secretes a chemical substance Y which controls the development of ones and muscles in the body of a person. Secretion of too little of substance Y as well as the secretion of too much of substance Y by the gland X leads to abnormal development of the body of a person.
(a) Name the gland X.
(b) What is the chemical substance Y?
(c) What happens if too little of substance Y is secreted?
(d) What happens if too much of substance Y is secreted?
(e) Name the system of glands in the human body of which gland X is a part.

Answer 1

1. X is the pituitary gland. It is located just below the brain.
2. The chemical substance (Y) released from the pituitary gland is human growth hormone.
3. Under-secretion of growth hormone leads to a condition known as dwarfism. In dwarfism, the person remains very short.
4. Over-secretion of growth hormone causes a condition known as gigantism. In gigantism, the person grows very tall.
5. The pituitary gland (X) is a part of the endocrine system.