a-short-review-of-histology

Lymphoid Tissue:

Lymphoid tissue is the general term given to accumulations of lymphocytes and other related cells
Lymphoid tissue may be found in organised structures or may be diffusely distributed in loose connective tissue around the body
Diffuse distributions of lymphoid tissue may be quite abundant in regions of the body which are exposed to the external environment and which, therefore, may be more prone to invasion by pathogens
In this context, the wall of the gut tube should be considered as part of the "external" environment
The function of the lymphoid tissue, generally, is to monitor tissue fluids for the presence of pathogens and mount immune responses against those pathogens
Details of the types of immune responses which can be mounted in the human body will be given in later courses
Organised lymphoid structures include:

Diffuse lymphoid tissue may be just a few lymphocytes or they may be large accumulations of lymphocytes and support cells grouped into an organised lymphatic nodule