lymph
a colorless,/ yellow fluid that leaves the blood capillaries, circulates through the lymphatic vessels and returns to the circulatory system
lymph vessels/ capillaries
thin walled, microscopic tubes that carry lymph to larger vessels.
lymph nodes
small, bean shaped structures that filter foreign substances, such as viruses and bacteria from the lymph.
lymphatic tissue
tonsils, thymus, spleen, peyer’s patches (in the walls of the small
How does the lymphatic system differ from other systems
-it relies on organs and structures from several body systems
What are the lines of defense
- skin acts as a barrier against pathogens and harmful substances- primary defence-1st line
- respiratory system contains cilia and mucous membranes that trap dust, pollen, viruses, and bacteria
- digestive system the stomach produces acids to destroy invaders
- lymphatic system is a network of lymphatic cells, tissues, organs and vessels that help
How does lymph form?
- it begins when fluid leaks out of the blood vessel capillaries. FLuid inside blood vessels is called plasma. when fluid leaks out and enters the spaces between cells, it is called interstitial fluid. As fluid is absorbed from the interstitial space into lymphatic capillaries/vessels it is called lymph
where are lymphatic vessels located
throughout the body in almost all of the tissues that have blood vessels
what are lymphatic capillaries
- smallest vessels
- small, open ended lymph vessels that act like drainpipes. The lymphatic system is not a closed loop.
- join together to form larger lymphatic vessels, which pass through lymph nodes, where the lymph is filtered.
- they have valves that keep lymph flowing in a one way direction toward the thoracic cavity.
what are lymph nodes and what do they do?
- aka lymph glands
- located all over the body usually in groups
- range in size from a pin to an almond
- are small round or oval masses
- lymph vessels bring lymph to the nodes
- lymph is filtered and impurities are removed
- lymphocytes and antibodies are added before the purified lymph leaves the node through a single lymphatic vessel
what is filtered out by the lymph nodes
- carbon
- cancer cells
- pathogens (bacteria and viruses)
- dead blood cells
what are lymphocytes and what do they do?
- cells of the lymphatic system
- make up 20-30 %of WBC
- are abundant in lymphatic tissue (spleen, lymph nodes)
- are created by the bone marrow
- some migrate to the thymus where they mature and become T cells
- lymphocytes that remain in bone marrow are B cells
- B and T cells are soldier cells
what is the right lymphatic duct and what does it do
-carries all the purified lymph from the right side of the head, neck, chest, and arm and empties into the right subclavian vein
what is the thoracic duct
much larger and drains the purified lymph from the rest of the body into the left subclavian vein
what are tonsils
masses of lymphatic tissue that filter interstitial fluid. there are 3 pairs of tonsils. they trap pathogens that enter through the nose and mouth
what is a Spleen
it is the largest lymphatic organ in the body. It is located beneath the left side of the diaphragm and in back of the upper part of the stomach
- produces lymphocytes when infection detected
- destroys old RBC
- stores RBC to release if excess bleeding
- filters wastes from blood
what is thymus
mass of lymph tissue located in upper chest
- when compared to body size, the thymus is largest during childhood. Begins to shrink after puberty
- produces T-lymphocytes which help defend against infection
- produces antibodies and lymphocytes in early lifeLiver: besides its digestive functions, the liver filters the blood and stores healthy erythrocytes (RBCs)
What are peyers patches
small bundles of lymphatic tissues in the walls of the small intestine that protect against invaders in the digestive tract
