The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphoid organs, lymphoid tissues and lymph. Lymph is a clear fluid carried by the lymphatic vessels back to the heart for re-circulation..
In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the aortic arch, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.
In human anatomy, the thoracic duct is the larger of the two lymph ducts of the lymphatic system. The thoracic duct usually begins from the upper aspect of the cisterna chyli, passing out of the abdomen through the aortic hiatus into first the posterior mediastinum and then the superior mediastinum, extending as high up as the root of the neck before descending to drain into the systemic (blood) circulation at the venous angle.
Lymph is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues to be recirculated. At the origin of the fluid-return process, interstitial fluid—the fluid between the cells in all body tissues—enters the lymph capillaries. This lymphatic fluid is then transported via progressively larger lymphatic vessels through lymph nodes, where substances are removed by tissue lymphocytes and circulating lymphocytes are added to the fluid, before emptying ultimately into the right or the left subclavian vein, where it mixes with central venous blood.
Chylomicrons, also known as ultra low-density lipoproteins (ULDL), are lipoprotein particles that consist of triglycerides (85–92%), phospholipids (6–12%), cholesterol (1–3%), and proteins (1–2%). They transport dietary lipids from the intestines to other locations in the body. ULDLs are one of the five major groups of lipoproteins that enable fats and cholesterol to move within the water-based solution of the bloodstream. A protein specific to chylomicrons is ApoB48.
The celiacartery, also known as the celiac trunk or truncus coeliacus, is the first major branch of the abdominal aorta. It is about 1.25 cm in length. Branching from the aorta at thoracic vertebra 12 (T12) in humans, it is one of three anterior/ midline branches of the abdominal aorta.
The small saphenous vein is a relatively large superficial vein of the posterior leg.
The superior thoracic aperture, also known as the thoracic outlet, or thoracic inlet refers to the opening at the top of the thoracic cavity. It is also clinically referred to as the thoracic outlet, in the case of thoracic outlet syndrome. A lower thoracic opening is the inferior thoracic aperture.
The cisterna chyli or receptaculum chyli is a dilated sac at the lower end of the thoracic duct in most mammals into which lymph from the intestinal trunk and two lumbar lymphatic trunks flow. It receives fatty chyle from the intestines and thus acts as a conduit for the lipid products of digestion. It is the most common drainage trunk of most of the body's lymphatics. The cisterna chyli is a retroperitoneal structure.
The anterior jugular vein is a vein in the neck.
The intercostal space (ICS) is the anatomic space between two ribs. Since there are 12 ribs on each side, there are 11 intercostal spaces, each numbered for the rib superior to it.
The right lymphatic duct is an important lymphatic vessel that drains the right upper quadrant of the body. It forms various combinations with the right subclavian vein and right internal jugular vein.
The jugular trunk is a lymphatic vessel in the neck. It is formed by vessels that emerge from the superior deep cervical lymph nodes and unite to efferents of the inferior deep cervical lymph nodes.
The efferent vessels of the tracheobronchial lymph nodes ascend upon the trachea and unite with efferents of the internal mammary and anterior mediastinal glands to form the right and left bronchomediastinal trunks.
The parasternal lymph nodes are placed at the anterior ends of the intercostal spaces, by the side of the internal thoracic artery.
The following outline is provided as an overview of and topical guide to human anatomy:
The pretracheal lymph nodes are lymph nodes located anterior to the trachea in the neck.
A lymph duct is a great lymphatic vessel that empties lymph into one of the subclavian veins. There are two lymph ducts in the body—the right lymphatic duct and the thoracic duct. The right lymphatic duct drains lymph from the right upper limb, right side of thorax and right halves of head and neck. The thoracic duct drains lymph into the circulatory system at the left brachiocephalic vein between the left subclavian and left internal jugular veins.
Lymph sacs are a part of the development of the lymphatic system, known as lymphangiogenesis. The lymph sacs are precursors of the lymph vessels. These sacs develop through the processes of vasculogenesis and angiogenesis. However, there is evidence of both of these processes in different organisms. In mice, it is thought that the lymphatic components form through an angiogenic process. But, there is evidence from bird embryos that gives rise to the idea that lymphatic vessels arise in the embryos through a vasculogenesis-like process from the lymphangioblastic endothelial precursor cells.
