Lymph nodes have an outer layer called the cortex in an inner layer called the medulla, true or false
The Correct Answer and Explanation is:
True.
Lymph nodes are crucial components of the lymphatic system, which is involved in immune defense. They function as filters, trapping harmful substances like pathogens and foreign particles, and house immune cells that help fight infections.
The structure of a lymph node consists of two main regions: the cortex (outer layer) and the medulla (inner layer).
- Cortex: The cortex is the outer layer of the lymph node and is divided into two sub-regions: the outer cortical zone and the deep cortical zone, also called the paracortex. The cortex is rich in follicles, which contain B lymphocytes (a type of white blood cell that is involved in antibody production). The follicles often have a germinal center where B cells proliferate and differentiate into plasma cells upon activation.
- Medulla: The medulla is the inner part of the lymph node and consists mainly of medullary cords and medullary sinuses. The medullary cords are rich in plasma cells, B cells, and macrophages, which help in producing antibodies and fighting infections. The medullary sinuses, which are spaces between the cords, allow for the movement of lymph fluid as it passes through the node.
Lymph enters the lymph node through afferent lymphatic vessels, and it is filtered as it flows through the sinuses. Afterward, the lymph exits the node through the efferent lymphatic vessels.
In summary, the structure of a lymph node, with its cortex and medulla, plays a crucial role in its function as a filter and immune surveillance system.
