Question

The modern idea about aging is that our body slowly loses the power of defense against the invasion of germs and pathogens. This gradual loss or decrease in the immunity can be attributed to which organ?
(a) Spleen
(b) Thymus gland
(c) Pituitary gland
(d) Parathyroid gland

Answer 1

This gland is located in the upper front part of the chest, behind the sternum, and in front of the heart. It is a specialized primary lymphoid organ of the immune system and is the site for the maturation of T cells or thymus cell lymphocytes.

Complete answer:
Our body slowly loses the power of defense against the invasion of germs and pathogens, nowadays this is considered a modern Idea of aging. This gradual loss or decrease in immunity can be attributed to the thymus gland. The thymus gland is located beneath the sternum in the upper front part of the chest, stretching upwards towards the neck. It is responsible for the maturation of T cells, which are an important part of the immune system providing cell-mediated immunity.
During the period of neonatal to pre-adolescent age the thymus grows largest in size and is highly active. The thymus begins to decrease in size, the cortex becomes thin, and activity also decreases by the early teens, and their tissues or Lymphocytes disappear and are gradually replaced by fatty tissue from the partitions between the lobules. This loss of lymphocytes will result in decreased immune power.

Additional Information:
-The thymus gland plays a very important role in the development of T-lymphocytes or T cells, which are highly important types of white blood cells that protect our body from deadly pathogens like bacteria, viruses, and fungi.
-Similar to the tonsils, adenoids, and spleen the thymus is considered as a lymphoid organ that means it is an organ of the immune system
-It has been determined in recent years that aging is not simply a process but it is actually an active process in which the body wears out.
-The involution of the thymus gland is a form of programme that leads to aging. With the involution that begins around the age of 60 years, the trigger for the deterioration of the immune system also begins.
-In most of the vertebrates the spleen is located near the stomach in the left abdominal region or near the intestine. It is a highly vascular ductless organ which is mainly concerned with the final destruction of red blood cells, filtration and storage of blood, and production of lymphocytes.
-The pituitary gland plays an important role in regulating various body functions and general wellbeing. Since the pituitary gland controls the activity of most other hormone-secreting glands, it is also called the body's 'master gland'.
-Parathyroid glands regulate the calcium in our body and is a gland of the endocrine system. The parathyroid gland is located in the neck region behind the thyroid from where it continuously monitors and regulates the calcium level in blood.

So, the correct answer is, ‘thymus gland’.

Note:
-For the maturation of the T-lymphocytes which are the most critical cells for maintaining the immunity of the body, the thymus is responsible.
-The decrease in the immunity of an individual as a result of thymus involution will increase the risk of infections and reduce the response to vaccines in adults.
-A slow process of shrinking of the thymus gland begins at the onset of puberty and this process of gradual decrease in the size continues for the rest of the life of the individual. This shrinking process of thymus is known as involution.