Question

Explain the structure and functions of different endocrine glands found in the human body.

Answer 1

Endocrine glands:

1. The endocrine glands can be defined as the glands which are ductless and responsible for the secretion of chemical messengers called hormones, directly into the bloodstream.

Different types of endocrine glands with their structures and functions are as follows:

1. Hypothalamus:
   • The hypothalamus is a small gland located near the pituitary gland at the base of the brain.
   • It is helpful in coordinating the whole endocrine system and keeping the body stable.
2. Pituitary gland:
   • The pituitary gland is a tiny pea-sized gland located in the lower part of the brain.
   • It is divided into two parts: anterior and posterior.
   • It is known as a master gland as it is responsible for the stimulation and functioning of other endocrine glands.
   • Its job is to produce hormones that are necessary for the manufacturing and secretion of other hormones to perform various activities.
   • The growth hormones released by the anterior pituitary help in the growth and development of the individual.
   • It also helps in maintaining the water balance of the body.
3. Pineal gland:
   • The pineal gland consists of a small mass of glandular tissue in the shape of a pine cone.
   • It secretes a hormone called melatonin which helps in maintaining the sleep-wake cycle of human beings.
4. Thyroid gland:
   • The thyroid glands are responsible for the production of a hormone called thyroxine.
   • Iodine plays an important role in the production of thyroxine.
   • This hormone stimulates the proper functioning of the thyroid glands.
   • Its underproduction can cause hypothyroidism and its overproduction can cause hyperthyroidism.
5. Parathyroid glands:
   • Parathyroid glands are small ductless glands present on the backside of the thyroid gland.
   • It is four in number.
   • A hormone called the parathyroid hormone is released by this gland which helps in maintaining the levels of calcium in the blood.
6. Adrenal glands:
   • The adrenal glands are tiny glands attached to the top of both kidneys on either side. It is also known as the suprarenal glands. This gland has two parts:
   • Medulla: It is the innermost part that is responsible for producing two hormones adrenaline and noradrenaline.
   • Cortex: It is the outer part of the glands that are responsible for producing hormones called aldosterone, and cortisol.
   • The hormones released by this gland help control heart rate, and blood pressure.
   • It maintains the level of minerals in the blood like sodium and potassium.
   • These hormones are secreted during stress conditions.
7. Pancreas:
   • The pancreas is a heterocrine gland that works as both an endocrine gland and exocrine gland.
   • The endocrine part of the pancreas is responsible for releasing two hormones called insulin and glucagon.
   • These two hormones are responsible for maintaining and balancing the blood glucose level.
8. Gonads:
   • It includes testes in males and ovaries in females which are responsible for the production of sex hormones.
   • Testes are pair of reproductive organs in males, which are found in the sac-like structure called the scrotum. It produces a hormone called testosterone.
   • The ovaries are a pair of almond-shaped structured located on either side of the female reproductive system. They produce two hormones, progesterone, and estrogen.
9. Thymus:
   • The thymus is a triangular-shaped gland found in the chest.
   • It is a ductless gland that produces a hormone called thymosin.
   • This hormone creates resistance to diseases in children.
   • This gland functions from the embryonic stage to childhood and becomes inactive from the period of adolescence.