Lymphatic vessel

The lymphatic vessels are tiny, thin channels that carry waste material and immune system cells in a fluid called lymph.

They are distributed throughout the body, filling the interstitial spaces of the cells and emptying into small stations called lymph nodes until they end up in the systematic venous circulation.

The lymphatic vessels form a network of ducts that begin in the interstitium and progressively flow into other larger ducts, forming collectors that drain into the bloodstream at the base of the neck, at the angle formed by the internal jugular and subclavian veins. Lymphatic vessels have different sizes, shapes, and functions. The lymphatic vessels unite to form larger collecting trunks that empty into regional lymph nodes. The lymphatic vessels that carry lymph to the lymph nodes are called afferent lymphatics.

Pre-lymphatic channels

Actually they are not lymphatic vessels, but due to their conductive function of prelymph (interstitial fluid) even the lymphatic capillaries are included in this section. They are present in the field of connective tissue; Their mission is to provide, rather quickly, to the lymphatic capillaries, the carbohydrates that come out of the blood capillaries. The diameter of these channels is less than that of the final capillaries or lymphatics.

Lymphatic capillaries

They are the smallest conducting vessels of the lymphatic system. Lymphatic capillaries begin in the tissues in the shape of a glove finger; they are thin-walled tubes made up of a single layer of overlapping endothelial cells, held together by filaments attached to the surrounding connective tissue. The existence of these filaments allows that, by increasing the amount of fluid in the interstitial space, the lymphatic capillaries do not collapse or collapse, but rather a part of the cell edges give way and fluid enters the interior of the lymphatic capillaries, while the edges held with the filaments remain firm.

This opening and closing mechanism allows rapid entry of the lymphatic load into the lymphatic capillaries and of large molecular size particles (proteins, cell debris, debris, etc.) that could not otherwise exit the lymphatic capillaries. fabrics where they are produced.

The lymphatic system, from the lymphatic capillaries, is transformed into lymphatic vessels of increasing caliber. The lymphatic capillaries intercommunicate with each other and with the lymphatic pre-collectors, forming a kind of network. These new structures already have valves inside that will give rise to the lymphangions or lymphatic angions.

Thoracic duct

It is the largest vessel in the human body. It originates in the abdomen, at the upper end of the cistern of Pecquet, an elongated sac located in the lumbar region between the 10th thoracic and 4th lumbar vertebra (level of the deep umbilical region) and ascends anterior to the spine. vertebral, crosses the diaphragm and, after making an arc to the left, at the level of the sterno-clavicular joint, ends at the so-called "venous angle".