Question

describe the parts of the lymphatic systems and the various structures that comprise them

Answer 1

The lymphatic system is part of our circulatory system.It functions to maintain the fluid balance in the body and also acts as an aid to the immune system.

The system comprises of the following parts

1.Lymph- A fluid resembling plasma that contains all the excess proteins, salts, glucose, fats, water, and white blood cells suspended from the tissue cells as a result of pressure in the blood cappillaries.Lymph capillaries collect the interstitial fluid from body tissues transporting them through progressively larger lymphatic vessels upon enterering which the fluid is called lymph.

2.Lymphatic vessels - A network of lymphatic vessels carry the lymph from the tissue spaces   where it may accumulate for long and cause swelling, back to the blood. The fluid is carried only in one direction towards the thoracic cavity. The nutrients lost are returned to the bloodstream through 2 entry points - right lymphatic duct and the thoracic duct.

3.Lymphocytes- are subtypes of white blood cells which fight against pathogens. They are

• T- Cells
• B- Cells
• Phagocytes

4.Lymph nodes- These are tissues present along the lymphatic vessels.These are glands where bacteria from the fluid are filtered out and eliminated , a process called phagocytosis.These glands also produce antibodies. These nodes are kidney or oval shaped and range from millimeters to about 1–2 cm in length.

5.Lymphatic organs

Tonsils - are a ring of tissues present under the mucuos membrane around the mouth and back of throat.They protect the body from bacteria that may enter through nose or mouth. There are 3 types pharyngeal, located near opening of nasal cavity into pharynx, palatine tonsils , located on each side of throat and lingual , located at the base of tongue.

Peyer’s patches. These are small masses of lymphatic tissue found in the small intestine. They contain T lymphocites and B lymphocites cells that monitor the contents of the intestinal for pathogens. In case pathogens are detected, the T and B cells spread and prepare the body to fight a possible infection.

Spleen- The spleen is a flattened organ located in the upper left quadrant of the abdomen behind the stomach just below the diaphragm. The spleen is made up of red pulp which contains reticular tissues to filter damaged red blood cells from the blood. Macrophages remove any pathogens in the blood and also stores many platelets to be released in response to blood loss.

Thymus. The thymus is a small, triangular organ found in the middle of the chest just posterior to the sternum The thymus secretes a hormone called thymosin. It also stimulates the production of T- cells or T Lymphocites . T cells formed in the thymus and red bone marrow mature, develop, and reproduce in the thymus throughout childhood. The vast majority of T cells are destroyed by macrophages. The remaining T cells spread throughout the body to the other lymphatic tissues to fight infections. By puberty, the immune system strong and the thymus decreases in size and is slowly replaced by adipose tissue.