The Lymphatic System
Lymph, Lymph vessel, Lymph capillaries, Lymphatic duct, Lymph organ example, spleen,thymus
Lymph node
Lymphoid tissue example, tonsils
MALT (mucosa- associated lymphoid tissue)
GALT (gut -associated lymphoid tissue)
BALT (Bronchial-associated lymphoid tissue )
1. Lymph
Lymph is a clear watery fluid, similar in composition to plasma.
Lymph originates as blood plasma that leaks the capillaries of circulating system, becoming interstitial fluid, filling the space between individual cells of tissue.
Once within the lymphatic capillaries, the fluid is called lymph ( clear water), has almost same composition as original interstitial fluid.
It also carries away larger particle example, bacteria and cells from damaged tissues, which can then be filtered out and destroyed by the lymph nodes.
Lymph contain lymphocytes which circulate in lymphatic system allowing them to patrol the different region of the body.
Amount - body contains about 3-4 litres of lymph
Appearance - clear watery fluid. Lymph formed in digestive system called Chyle is rich in fat (milky white)
Cells - cells of lymph fluid are leucocytes mainly lymphocytes, protection provide.
2. Lymph vessels and flow of lymph
Lymph capillaries
Lymph vessel
Lymphatic duct
3. Lymphatic capillaries
Lymphatic system begins in tissues as lymph capillaries.
Lymphatic capillaries are tiny thin-walled vessels that are closed at one end and are located in spaces between cells throughout body. Except in central nervous system and in non-vascular tissue.
These consist of single layer of endothelial tissue but their wall are more permeable as compare to blood capillary to all interstitial fluid constituents, including proteins and cell debris.
When pressure in greater in interstitial fluid push the wall of capillary.
Cell separate slightly, and capillary wall open
And interstitial fluid enters the lymphatic capillary
When pressure is greater inside the lymphatic capillary, cell close and lymph cannot escape back into interstitial fluid.
The tiny capillaries join up to form larger lymph vessel.
Fig, Diagram of the beginning of a lymph capillary
4. Lymph vessels
Lymphatic vessels are thin-walled valved structures that carry lymph.
Lymph travels in only one direction because of cup shaped valves with in the lymphatics vessel that do not allow fluid to flow back.
Lymph flow through lymphatic vessels, it passes through lymph nodes (mass of tissue). Lymph nodes is major site for interaction of lymphocytes.
A thin tube that carries lymph (lymphatic fluid ) and white blood cells through lymphatic system.
The ability of Lymphatic vessels to generate and regulate lymph flow is provided by the lymphatic muscle present in the vessels wall.
Lymph vessels become larger as they join with together forming two large duct ,
Right lymphatic duct
Thoracic duct
Which empty lymph into the Subclavian veins.
5. Lymphatic duct
A. Thoracic duct
This is the largest lymphatic vessel in the body. Thoracic duct is about 40 cm is long and opens into the left subclavian vein the root of the neck (left side).
It drains lymph from both legs, pelvic abdomen cavity, left thorax, left upper extremity and left side of head and.neck drain into systemic circulation at left subclavian vein and left internal jugular vein.
B. Right lymphatic duct (right thoracic duct)
This is dilated lymph vessel about 1.25cm long. It lies in the root of neck and opens into the right subclavian and right internal jugular vein.
Right lymphatic duct drains lymph fluid from right side of thorax, Right side of head and neck and right arm at right subclavian vein and right jugular vein.
0 Comments