Lymphoid Tissue

Lymph node, Monkey

Examine your section with the naked eye. Identify the medulla(paler central area) and the cortex(periphery with lymphatic nodules). Under X10 objective, look at the connective tissue capsule surrounding the entire mass of the lymphatic tissue. Trabeculae(pinkish fibrous bundles) are seen extending from the capsule into the substance of the lymph node to form part of the supporting stroma. The hilum is on the concave side; blood vessels and efferent lymphatic vessels are present. The lymphatic vessels may be difficult to identify unless their valves are also included in the section. Try to identify the afferent lymphatic vessels in the capsule. Adipose tissue is also present at the hilar region. Look at one of the lymphatic nodules. Can you recognize the germinal centre? Identify also the subcapsular sinus(next to the capsule), cortical sinus and medullary sinus. What cell types are present in these? Identify also the medullary cords. What are their component cells?