How do you identify the thymus histology?

The thymus is an encapsulated primary lymphoid organ. Histologically, it is divided into subcapsular cortical, cortical and medullary regions within each lobule, created by the intervening connective tissue septae extending from the capsule.

What is the capsule of the thymus?

The capsule is composed of an outer and inner layer of collagen and reticular fibres between which are occasional clusters of lymphocytes. This inner layer invaginates to form the septae. Fine trabeculae also extend from the capsule or septae into the centre of the lobules.

Does the thymus have a connective tissue capsule?

Thymus is covered by a connective tissue capsule, the septa of which penetrate into the tissue and divides it into incomplete lobules. Each lobule has a peripheral dark zone called cortex and middle lighter zone called medulla.

What are the characteristics of the thymus?

The thymus gets its name from its silhouette. It is shaped much like a thyme leaf, a common cooking herb. It has two separate lobes divided by a central medulla and a peripheral cortex and is formed with lymphocytes and reticular cells. The reticular cells form a mesh that is filled with lymphocytes.

Are there B cells in the thymus?

Thymic B cells are a unique population of B lymphocytes that reside at the cortico-medullary junction of the thymus, an organ that is specialized for the development and selection of T cells. These B cells are distinct from peripheral B cells both in terms of their origin and phenotype.

Which cell is found in thymus?

The thymus makes white blood cells called T lymphocytes (also called T cells). These are an important part of the body’s immune system, which helps us to fight infection. The thymus produces all our T cells before we become teenagers.

What is the structure of thymus?

The thymus consists of two lobes, merged in the middle, surrounded by a capsule that extends with blood vessels into the interior. The lobes consist of an outer cortex rich with cells and an inner less dense medulla.

What type of cells are in the thymus?

The two major categories of thymus cells are thymic epithelial cells and thymocytes. Thymic epithelial cells appear in the thymic cortex, or the outermost layer of the organ, as well as in the inner thymic medulla. TECs create two types of cytokeratin, K5 and K8, and play a major role in thymocyte development.

What type of tissue is in the thymus?

The thymus tissue is distinguishable into an outer zone, the cortex, and an inner zone, the medulla. The organ is composed principally of two types of cells, called, respectively, lymphocytes (see lymphocyte) and reticular cells.

Which lymphocyte matures in thymus?

T-cells
The T Cell: T-cells mature in the thymus gland or in the lymph nodes. Since the thymus is only 10-15% functional in the adult, the lymph nodes take on greater importance in the maturation process.

Does the thymus activate B lymphocytes?

The thymus of MG patients contains activated B cells undergoing clonal proliferation and hypermutation and plasma cells that produce autoantibodies against the acetylcholine receptor (AChR) (83–85).

What type of tissue is the thymus made of?

By late adulthood, most of the thymus is made up of fat tissue.