Download Basic & Clinical immunology, 2nd year Clinical Laboratory

Course name: The Cell, Subtopic: Immunology. 1st year Physiotherapy and Paramedic Students
Elements of the acquired
immune system
Lymph draining from the extracellular spaces of the body carries antigens in
phagocytic dendritic cells and macrophages from the tissues to the lymph node
via the afferent lymphatics. Lymph leaves by the efferent lymphatic in the
medulla. Naive lymphocytes enter the node from the bloodstream and leave with
the lymph through the efferent lymphatic.
The spleen collects antigen from
the blood. It also collects and
disposes of old red blood cells.
- The gut-associated lymphoid tissues(GALT), which include the tonsils,
adenoids, and appendix, and specialized structures called Peyer's patches collect
antigen from the epithelial surfaces of the gastrointestinal tract. In Peyer's
patches, the antigen is collected by specialized epithelial cells called M cells.
- Similar structures protect the respiratory epithelium and other mucosa.
- Collectively, the mucosal immune system is estimated to contain as many
lymphocytes as all the rest of the body.