Where is the mucosal associated lymphoid tissues present in the human body and why?

Hint: Lymph nodes, spleen, tonsil, thymus and adenoids are called the lymphatic tissues. Around 50% of our body lymphoid tissue is made up of MALT. It helps in regulating the mucosal immunity.

Complete Answer:
- Mucosal associated lymphoid tissues or MALT is the secondary lymphoid tissue which aids in regulating mucosal immunity. It is scattered along the mucosal lining in the human body. It constitutes the important component of human lymph tissue. It protects the body from antigens.
- MALT are found in tonsils, Peyer patches, appendix, gastrointestinal tract, oral passage, nasopharyngeal tract, breast, lungs, salivary glands, eyes, skin etc. They have lymphocytes such as T cells, B cells, plasma, macrophages which fight against the antigens passing through mucosal epithelium.

Function of MALT:
- It plays a key role in regulating mucosal immunity. The marginal B-cell lymphoma occurs in the stomach is caused due to Helicobacter pylori infection.
- The MALT is categorised as SALT (Skin associated lymphoid tissue), GALT (Gut associated lymphoid tissue) etc.

Additional Information: The skin is considered as the first line of lymphoid organ. The epidermis is lined with the mucosal tissue which contains lymphocytes which protect the organism from the microbial invasion.

Note: All the important organs are lined with the mucosal lining because they are exposed to the external and internal environment. So, the mucosal lining serves as a defence system in protecting the delicate organs and our body from the antigens.