What Is the Purpose of Thymus Tissue?

It is located in the upper part of the anterior mediastinum behind the sternal stalk. The glands are attached to the pericardium and the large blood vessels in the front. They are made of asymmetric left and right leaves. Infants and young children are large, 10-15 grams, the maximum sexual maturity is 25-40 grams, and then they begin to shrink and gradually become smaller. The elderly only have 10-15 grams, which are mostly replaced by adipose tissue. It is light yellow.

It is located in the upper part of the anterior mediastinum behind the sternal stalk. The glands are attached to the pericardium and the large blood vessels in the front. They are made of asymmetric left and right leaves. Infants and young children are large, 10-15 grams, the maximum sexual maturity is 25-40 grams, and then they begin to shrink and gradually become smaller. The elderly only have 10-15 grams, which are mostly replaced by adipose tissue. It is light yellow.

Chinese name

Thymus

Foreign name

thymus

Attributes

Important lymphoid organs

Weight

10-15 g

Location

Behind the sternum

colour

Gray red

Shape

Flat oval

Features

Is the first organ in the human body to age

Overview of the thymus

The surface of the thymus is covered with connective tissue capsules and extends into the parenchyma of the gland, dividing it into a number of thymus leaflets, each of which is divided into two parts, the cortex and the medulla:

1. Thymus 1. Cortex:

In the periphery of the thymus leaflets, the staining is deeper, and it consists of many dense lymphocytes and reticulocytes. Lymphocytes are small, called thymus cells, and they constantly undergo mitosis and proliferation. Observation under the electron microscope showed that the cytoplasm contained dispersed RNA particles and a small amount of endoplasmic reticulum. Reticulocytes are also called reticuloepithelial cells, which are relatively small in size, large in size, have protrusions, have large nuclei, and have nucleoli. Observed under the electron microscope, the cytoplasm contained abundant endoplasmic reticulum, mitochondria and dispersed RNA and a small amount of lysosome. Such cells can become phagocytes when the thymus degenerates, phagocytosing senescent or dead lymphocytes.

2. Thymus 2. Medulla:

In the center of the thymic lobules, it is composed of most reticular epithelial cells and a small number of lymphocytes. One can also see a round or oval-shaped thymus body, which varies in size, and is composed of a cluster of degenerate epithelial cells.

Thymosin immunomodulators:

1. Thymosin 1:

A small molecule biologically active peptide isolated and purified from thymosin 5 component (TF5) in the late 1970s, is a thermostable acidic peptide with similar biological activity as thymosin. It consists of 28 amino acids, with an isoelectric point of 4.2, a relative molecular mass of 3.108, and a structural formula of Ac-Ser-Asp-Ala-Ala-Val-Asp-Thr-SerSer-Glu-Ile-Thr-Thr-Lys-Asp- Leu-Lys-Glu-Lys-Lys-GluVal-Val-Glu-Glu-Ala-Glu-Asn-OH.

2. Thymic pentapeptide:

It is a polypeptide fragment composed of 5 amino acids with a structural formula of NH2-Arg-Lys-Asp-Val-Tyr-COOH. Researchers found that it is the immunoactive center of thymosin II and is located at positions 32 to 36 of the polypeptide. It retains the effective biological activity of thymosin, is an immune modulator, and has two-way regulation of the body's immune function. It is clinically used to treat various malignancies, hepatitis B, infections, autoimmune diseases, and type 2 diabetes , Menopausal syndrome, senile failure, and decreased immune function.

Thymosin, thymosin 1, and thymopentin are the active components of thymosin, all of which have immunomodulatory activity, which can make the immune response that is too strong or suppressed tend to be normal, meanwhile, it has low immune function to the thymus and the body, and autoimmunity The disease has a good regulatory effect, and is mainly used clinically for primary and secondary immunodeficiency, such as the treatment of chronic hepatitis B, severe hepatitis B, antiviral, treatment of AIDS, etc., and is used as a variety of malignant tumors Adjuvant drugs for early chemotherapy and radiotherapy. The clinical application results show that thymosin 1 and thymosin have good curative effect and safety, and thymosin has many adverse reactions.