The ovoid swelling in the lymph ducts is called the lymph node or lymph gland. The number of lymph nodes is 400-700. The glands are most abundant in the neck, armpits and groin. Lymph nodes are discussed.
1. Spleen: The spleen is the largest lymph gland in the human body. It is located below the ribs and above the stomach. It is soft and dark in color. It is called blood reservoir or blood bank. It consists of two types of spleen marrow. Red marrow and white marrow. It can store 300 ml of blood. Spleen measures 13×7×3 cubic cm and weighs 150 grams. The spleen acts as the main filter of blood. As most red blood cells are destroyed in the spleen, it is called the red blood cell graveyard. It destroys germs and prevents diseases.
2. Tonsil: The small ball-like structure on the right and left sides of the mouth and pharynx is called tonsil. There are three types of tonsils in the human body. Palatine, adenoid (pharyngeal) and lingual. It produces antibodies and lymphocytes to fight bacteria and viruses. Many times tonsils are infected by viruses and bacteria. It is called tonsillitis. Surgical removal of tonsils is called tonsillectomy.
3. Lymph node: Lymph node is a capsule-like part located in the lymph vessel. The number of lymph nodes in the human body is 400-700. It is filled with macrophages and lymphocytes. It removes microorganisms and foreign matter. The nodes clear the lymph.
4. Thymus: The pyramidal organ located above the heart between the trachea and sternum is called the thymus. It is soft and bifurcated. Children’s thymuses are large and active. The thymus secretes the hormones thymosin and thymopoietin. Hormones regulate lymphocyte maturation. The thymus gradually turns into fat tissue during puberty. But it disappears with age. White blood cells produced in the red bone marrow reach the thymus and become T-lymphocytes. These are any immune cells that turn into T-effector, T-killer and T-helper cells and recognize viruses and bacteria.
5. Red Bone Marrow: Red bone marrow is a spongy, semi-solid and red colored tissue. Red blood cells, white blood cells and platelets are produced from red bone marrow. Most bones in children contain red bone marrow. Adults have red bone marrow in pelvis, vertebrae, sternum, carotid, clavicle, clavicle, perscha, humerus, femur etc.