Question

Does the lymphatic system remove bacteria and viruses from the blood?

Answer 1

No, the lymphatic system actually removes excess fluid from intercellular spaces into the circulatory system as well as removing foreign antigens from this space into lymph nodes

Explanation:

The lymphatic system consists of various small microscopic lymphatic channels/vessels, Lymph nodes and larger lymphatic trunks. The thymus and spleen are also considered parts of lymphatic system but do not play a part in lymph drainage.

The lymphatic vessels are blindly starting vessels, lined by single epithelial cells, no muscular layer which start in the interstitium/intercellular spaces.

These carry off excess fluid(aka lymph) left off during capillary exchange of blood and also carries various cells like APC (antigen presenting cells) which, as the name suggests, present foreign antigens to T-cells or B-cells (according to type of antigen) in the lymph nodes and start the immune reaction.

The lymph may also carry off bacteria, virus into the lymph nodes which start the reaction by themselves.

The Lymph nodes are home to various immune related cells and act as the 1st gate to these antigens from the periphery.

Then the lymph travels into channels which later join and form larger channels which all form or drain into the Thoracic duct which drain into the junction of left jugular and left subclavian vein.

Overview:

interstitial excess fluid `->` lymphatic vessels `->` local lymph nodes `->` lymphatic trunks/vessels `->` thoracic duct `->` venous system