Lymph capillary
Encyclopedia
Lymph capillaries or lymphatic capillaries are tiny thin-walled vessels that are closed at one end and are located in the spaces between cells throughout the body, except in the central nervous system
, and in non-vascular tissues. The main purpose of these vessels is to drain excess tissue fluids from around the cell ready to be filtered and returned to the venous circulation. This tissue fluid upon entering the lumen
(elongated cavity of a tubular structure) is known as the lymph
.
Lymphatic capillaries are slightly larger in diameter than blood capillaries and have a unique structure that permits interstitial fluid
to flow into them but not out. The ends of endothelial cells that make up the wall of a lymphatic capillary overlap. When pressure is greater in the interstitial fluid than in lymph, the cells separate slightly, like the opening of a one-way swinging door, and interstitial fluid enters the lymphatic capillary. When pressure is greater inside the lymphatic capillary, the cells adhere more closely, and lymph cannot escape back into interstitial fluid. Attached to the lymphatic capillaries are anchoring filaments, which contain elastic fibers. They extend out from the lymphatic capillary, attaching lymphatic endothelial cells to surrounding tissues. Lymph capillaries have a greater oncotic pressure
, which is due to the greater concentration of plasma proteins in the lymph.
The lymphatic capillary becomes the afferent lymphatic vessel and carries the lymph into a lymph node
.
When excess interstitial fluid
accumulates and causes tissue swelling, the anchoring filaments are pulled, making the openings between cells even larger so that more fluid can flow into the lymphatic capillary.
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
, and in non-vascular tissues. The main purpose of these vessels is to drain excess tissue fluids from around the cell ready to be filtered and returned to the venous circulation. This tissue fluid upon entering the lumen
Lumen (anatomy)
A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...
(elongated cavity of a tubular structure) is known as the lymph
Lymph
Lymph is considered a part of the interstitial fluid, the fluid which lies in the interstices of all body tissues. Interstitial fluid becomes lymph when it enters a lymph capillary...
.
Lymphatic capillaries are slightly larger in diameter than blood capillaries and have a unique structure that permits interstitial fluid
Interstitial fluid
Interstitial fluid is a solution that bathes and surrounds the cells of multicellular animals. It is the main component of the extracellular fluid, which also includes plasma and transcellular fluid...
to flow into them but not out. The ends of endothelial cells that make up the wall of a lymphatic capillary overlap. When pressure is greater in the interstitial fluid than in lymph, the cells separate slightly, like the opening of a one-way swinging door, and interstitial fluid enters the lymphatic capillary. When pressure is greater inside the lymphatic capillary, the cells adhere more closely, and lymph cannot escape back into interstitial fluid. Attached to the lymphatic capillaries are anchoring filaments, which contain elastic fibers. They extend out from the lymphatic capillary, attaching lymphatic endothelial cells to surrounding tissues. Lymph capillaries have a greater oncotic pressure
Oncotic pressure
Oncotic pressure, or colloid osmotic pressure, is a form of osmotic pressure exerted by proteins in blood plasma that usually tends to pull water into the circulatory system.Throughout the body, dissolved compounds have an osmotic pressure...
, which is due to the greater concentration of plasma proteins in the lymph.
The lymphatic capillary becomes the afferent lymphatic vessel and carries the lymph into a lymph node
Lymph node
A lymph node is a small ball or an oval-shaped organ of the immune system, distributed widely throughout the body including the armpit and stomach/gut and linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all through the body, and act as...
.
When excess interstitial fluid
Interstitial fluid
Interstitial fluid is a solution that bathes and surrounds the cells of multicellular animals. It is the main component of the extracellular fluid, which also includes plasma and transcellular fluid...
accumulates and causes tissue swelling, the anchoring filaments are pulled, making the openings between cells even larger so that more fluid can flow into the lymphatic capillary.