Question

the gross structure and function of:
-Lymphatic vessels (capillaries, trunks & ducts)
-Lymph (including how it flows)
-Lymph nodes
-Lymphoid organs e.g. spleen, thymus gland, tonsils?

Answer 1

Gross anatomy??? and function??? well u asked for it

Lymphatic vessels are similar to blood vessels with muscular wall, simple squamous epithelial lining of the lumen, valves to prevent backflow but with blind end cappillaries (which are slightly larger than blood capillaries) which unite forming the lymphatic vessel trunk,the lymph ducts are only two in number...the right lymphatic duct and the thoracic duct, these are the final relay points of the lymph vessels fom whence the lymph is emptied back into blood stream

The lymph is a clear fluid similar in composition to blood plasma, it is made up of lymphocytes(a type of white blood cell) which fight infection, protein, fat, water, electrolytes...harmful microorganisms which have invaded body tissue are also carried in this lymph to be destroyed at the lymph nodes...all lymph flow towards the ducts which are located in the thoracic region.

Lymph nodes are round nodular junctions along the lymph vessel, they are secondary lymphoid organs found all over the body, they contain lymphocytes which they produce, and other white blood cells(T and B cells) which attack and kill invading organisms(antibodies) hence it serves as a filter for lymph just like the spleen filters blood....

whew finally the lymphoid organs, they are either pry or sec, the central or primary organs generate all the immune cells, they are the BONE MARROW and the THYMUS. all blood cells and immune cells are formed in the bone marrow, some mature in the bone marrow(B Cells), while some as in the case of the T cells leave the bone marrow and mature in the Thymus....After maturation they go to sec lymphoid organs and wait for the arrival of antibodies, these include the lymph nodes which filter the lymph, the spleen which filters the blood, the tonsils, etc

thats why during a major infection, these organs are usually inflammed.

ciao

Answer 2

thanx :D