What is diffuse lymphoid tissue?
Diffuse lymphatic tissue is a constituent of lymphatic organs and also is widely dispersed along mucous membranes. It appears as a rather loose aggregate of cells and shows no distinct demarcation from surrounding tissue with which it gradually merges.
Where are lymphoid nodules located?
Lymphoid nodules are characteristic features of lymphoid organs. They occur most typically in the cortex of normal lymph nodes, in the spleen, in the tonsils, and in the Peyer’s patches of the ileum. As concerns the spleen, lymphoid nod- ules appear in this organ in forms from fishes to mammals.
What is the name of the lymphatic nodules found in the ileum of the small intestine?
Peyer patch, any of the nodules of lymphatic cells that aggregate to form bundles or patches and occur usually only in the lowest portion (ileum) of the small intestine; they are named for the 17th-century Swiss anatomist Hans Conrad Peyer.
Which of the following is a function of lymph nodes?
A small bean-shaped structure that is part of the body’s immune system. Lymph nodes filter substances that travel through the lymphatic fluid, and they contain lymphocytes (white blood cells) that help the body fight infection and disease. There are hundreds of lymph nodes found throughout the body.
Where is diffuse lymphatic tissue found?
The most diffuse lymphoid tissue is found in the loose connective-tissue spaces beneath most wet epithelial membranes, such as those that line the gastrointestinal tract and the respiratory system.
Where is diffuse lymphatic tissue not found?
Diffuse lymphatic tissue is not found in the central nervous system.
What is located in the center of the lymph node?
A lymph node contains lymphoid tissue, i.e., a meshwork or fibers called reticulum with white blood cells enmeshed in it. The regions where there are few cells within the meshwork are known as lymph sinus. It is lined by reticular cells, fibroblasts and fixed macrophages.
Do lymph nodes have lymphatic nodules?
Lymph nodes are more organized organs than are nodules. They have a capsule , subcapsular sinus , hilus , supporting connective tissue trabeculae , and trabecular sinuses . Arteries, veins, and efferent lymphatics are all located at the hilus.
Where is lymph derived?
Lymph is a fluid similar in composition to blood plasma. It is derived from blood plasma as fluids pass through capillary walls at the arterial end. As the interstitial fluid begins to accumulate, it is picked up and removed by tiny lymphatic vessels and returned to the blood.
What part of the small intestine has the most lymph nodes?
Although the lymphatic nodules are located throughout the small intestine, they are most abundant in the ileum.
Where in the neck are lymph nodes located?
Cervical lymph nodes are located in the sides and back of the neck. These glands are usually very small. However, when a lymph node is greater than 1 centimeter in diameter, it is enlarged. The cervical lymph nodes sit deep inside the neck.
Where are armpit lymph nodes located?
The subscapular axillary lymph nodes are located on the lower part of the armpit’s posterior (rear) wall. The apical and pectoral nodes are located respectively on the upper and lower parts of the pectoralis minor, a thin, flat muscle of the chest.