Component of lymphatic system

Lymphatic system :

Component of lymphatic system : 

1. lymph vessels:

• lymphatic capillary,
• afferent & efferent lymph vessels,
• thoracic duct,
• right lymphatic duct

2. Lymphatic organs:

Primary lymphatic organs :

• bone marrow
• thymus

Secondary lymphatic organs :

• spleen,
• tonsil,
• lymph nodes,
• mucosa associated lymphatic tissue:

               BALT : bronchus associated lymphatic tissue ,

               GALT: gut associated lymphatic tissue

Lymphatic capillary : 

it has some unique character

1.  overlapping of endothelium
2. discontinuous basal lamina
3. anchoring filaments (elatic fibres) attach the endothelium with surrounding tissue 

Due to these features interstitial fluid enter in to lymphatic capillary like one way gate

Why bone marrow and thymus consider as primary lymphatic organ?

Ans: In these organs, the cells of immune system became mature and differentiate so they are known as primary lymphatic organ.

After maturation and differentiation an immune cells (lymphocyte) can distinguish between self antigen and non-self antigen. So a mature lymphocyte destroy non-self antigen but not react with self antigen.

What is the function of secondary lymphatic organs?

Ans : They only proliferate the cells of immune system ( lymphocytes)  but maturation and differentiation is not possible in secondary lymphatic organ