Model 3 Flashcards
Lymphatic vessels
Transport fluids that have escaped from blood vascular system back into the blood.
Lymphoid organs
House phagocytize cells and lymphocytes (body defense and resistance to disease)
Edema
Fluid accumulation in the tissues which impairs the ability of tissue cells to make exchanges with the interstitial fluid and blood.
What is the function of the lymphatic vessels
Pick up excess tissue fluid (lymph)and return it to the bloodstream.
One way system (lymph only flows toward the heart) - massage in the right direction.
Adventitia
Outermost connective tissue covering of an organ, vessel, or other structure.
Also called tunica adventitia or tunica externa.
What does the lymphatic system consist of?
2 semi-independent parts:
1) a meandering network of lymphatic vessels
2) various lymphoid tissues and organs scattered throughout the body
Afferent
Going in
Efferent
Going away
Hills
Entrance
Thymus
- primary lymphatic organ
- provides environment for stem cells to convert into T-lymphocyte
- reaches max size at puberty
- never disappears completely
- very sensitive to radiation and infection
Thymus structure
Comprised of lobes surrounded by a capsule
1) Capsule
2) Cortex (no lymphatic nodules but more lymphocytes than medulla)
3) Medulla (Hassall’s corpuscle and form thymus corpuscles)
Spleen
1) blood rich organ that filters blood
2) doesn’t filter lymph, but cleanses blood of bacteria viruses and other debris
3) destroy worn-out RBCs and return some of their breakdown products to liver
4) stores platelets and acts as blood reservoir (like the liver does)
Peyer’s Patches
- lymphoid tissues found in wall is small intestine
- AKA aggregated nodules
- part of mucosal-associated lymphoid tissue (MALT) and gut associated lymphoid tissue (GALT).
- macrophages of peyers patches are in ideal position to capture and destroy bacteria (always present in tremendous amounts in the intestine)
Bone marrow
Network of connective tissue fibers, fat cells, blood vessels, and blood producing cells.
Produces both red and white blood cells including lymphocytes and T-lymphocytes and B-lymphocytes.
Young T-cells move into Thymus for development, but B-cells stay in bone marrow until mature and then go out into circulation.
B-cells
Produced in bone marrow
Are white blood cells that are sensitive to antigens and produce antibodies against them.
When antigen is present, Bcells activate and produce antibodies against that antigen.
Once a Bcell makes antibodies against an antigen it keeps a memory of that antigen preventing a second infection of same antigen.
Antigen
Any chemicals that produce an immune response in the body (toxins, foreign proteins, particulate matter, bacterial cells)
Antibodies
Special proteins that bind to antigens and mark them for destruction
2 systems that defend our bodies
1) Non specific defense systems
2) specific defense systems
Non specific defense system
Responds immediately to protect body from all foreign substances.
Provided by intact skin and mucous membranes, inflammatory response, a number of proteins produced by body cells.
Reduces workload of second protective arm, the specific dense system, by preventing entry and spread of microorganisms throughout the body