The diagram of thymus gland shows its location in the chest and demonstrates its lobular structure consisting of cortex and medulla regions. The thymus gland is a crucial organ of the immune system. The simple thymus gland diagram shows how it plays a central role in T-cell maturation and secretes hormones supporting immune function.

The labelled diagram of thymus gland is given below:

What is Thymus Gland?

The thymus gland is an important organ of the immune system located in the chest region behind the sternum and between the lungs. It plays a crucial role in the development and maturation of T lymphocytes (T cells), a type of white blood cell that is essential for adaptive immunity. During childhood, the thymus is particularly active, but it gradually shrinks in size as we age. Despite its small size, the thymus holds great significance in maintaining overall health by supporting the body’s immune defenses.

Also Read: Difference between Adaptive and Innate Immunity

Structure of Thymus Gland

The structure of thymus gland diagram consists of two lobes, each composed of lobules made up of epithelial cells and lymphocytes. It is divided into two main regions: the cortex and the medulla. The cortex contains immature T cells (thymocytes) and is where T cell maturation primarily occurs. The medulla contains more mature T cells and specialized epithelial cells called thymic epithelial cells (TECs), which play a role in the selection of T-cells.

The process of T cell maturation in the thymus is highly regulated and involves several stages. Initially, hematopoietic stem cells from the bone marrow migrate to the thymus and differentiate into immature thymocytes. These thymocytes undergo positive and negative selection processes, ensuring that only T cells capable of recognizing foreign antigens without attacking the body’s own tissues (self-tolerance) survive.

• Positive selection involves the recognition of self-major histocompatibility complex (MHC) molecules by thymocytes,
• While negative selection eliminates thymocytes that strongly bind to self-antigens.

Once mature, T cells leave the thymus and enter the bloodstream to populate various lymphoid organs and tissues, where they play critical roles in immune surveillance and defense against pathogens. Additionally, the thymus secretes hormones such as thymosin, thymulin, and thymopoietin, which support T cell development and function. Thymus gland serves as a central organ for the selection of T cells, contributing significantly to the maintenance of immune homeostasis and the body’s ability to mount effective immune responses.

Function of Thymus Gland

The diagram of thymus glands shows its structure which helps us learn about its various function. Some of these functions are given below:

• T cell maturation: The thymus gland is the primary site for the maturation of T lymphocytes (T cells), which are essential for adaptive immunity.
• Positive selection: Thymic epithelial cells (TECs) present self-major histocompatibility complex (MHC) molecules to developing T cells, promoting the survival of those capable of recognizing self-antigens.
• Negative selection: Thymocytes that strongly bind to self-antigens undergo apoptosis, preventing the development of self-reactive T cells and ensuring self-tolerance.
• Hormone secretion: The thymus secretes hormones such as thymosin, thymulin, and thymopoietin, which support T cell development and immune function.
• Immune surveillance: Mature T cells produced in the thymus migrate to various lymphoid organs and tissues, where they contribute to immune surveillance and defense against pathogens.
• Involution: After puberty, the thymus gradually decreases in size and activity, but it continues to play a role in immune function throughout life.

Conclusion – Diagram of Thymus Gland

The thymus gland diagram shows its crucial role in the immune system and also its location in the chest. The thymus gland is important for T cell maturation and immune function. Its consists of cortical and medullary regions, helps in positive and negative selection of T cells. Hormone secretion and immune surveillance are important functions, shows its significance in maintaining immune homeostasis and overall health.

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