Lymphatic System: Components, Functions, and Key Structures

What are the main components of the lymphatic system?

Lymph, lymphatic vessels, lymphatic tissue, and lymphatic organs.

What are the primary functions of the lymphatic system?

Recover fluid lost from blood capillaries, guard against pathogens (immunity), and absorb lipids from the small intestine.

What is lymph?

A clear, colorless fluid similar to blood plasma but low in proteins; it supplies lymphocytes to the bloodstream.

What is chyle?

Lymph in the intestine that is rich in fats.

What is the structure of lymphatic capillaries?

They have loosely connected overlapping endothelial cells that act as flaps to ensure one-way flow of tissue fluid.

How do lymphatic vessels compare to veins?

Lymphatic vessels are similar to veins but have thinner walls and closer valves.

Describe the flow of lymph.

Lymph flows from lymphatic capillaries to collecting vessels, then to lymphatic trunks, collecting ducts, and finally into the subclavian vein.

What are the names of the lymphatic trunks?

Jugular, subclavian, bronchomediastinal, intercostal, intestinal, and lumbar.

What are the two main collecting ducts in the lymphatic system?

The right lymphatic duct and the thoracic duct.

What is the function of the right lymphatic duct?

It drains the right upper limb, right side of the head, and right side of the thorax into the right subclavian vein.

What does the thoracic duct drain?

It drains the left upper limb, left side of the head, left side of the thorax, entire abdomen, and both legs into the left subclavian vein.

What aids the flow of lymph?

Rhythmic contraction of lymphatic vessels, skeletal muscle pump, respiratory pump, and pulse pressure of neighboring arteries.

What is MALT?

Mucosa-associated lymphatic tissue, which is prevalent in the respiratory, digestive, reproductive, and urinary tracts.

What are primary lymphatic organs?

Red bone marrow and thymus, where lymphocytes become immunocompetent.

What is the role of red bone marrow in the lymphatic system?

It is the site of hematopoiesis and supplies lymphocytes and other blood cells.

What is the function of the thymus?

It houses developing lymphocytes, secretes hormones, and is necessary for the development of immunity.

What are lymph nodes?

Bean-shaped structures that cleanse lymph and serve as sites for T and B cell activation.

What regions are lymph nodes concentrated in?

Cervical, axillary, thoracic, abdominal, intestinal and mesenteric, inguinal, and popliteal regions.

What is the largest lymphatic organ?

The spleen.

What are the components of the spleen?

Red pulp (concentration of erythrocytes) and white pulp (lymphocytes and macrophages).

What are tonsils?

Patches of lymphatic tissue at the entrance of the pharynx, including pharyngeal, palatine, and lingual tonsils.

What is lymphedema?

Swelling usually in arms or legs due to obstruction of lymphatic flow.

What can cause lymphedema?

Mastectomy, blockage caused by worms (filariasis), or any other obstruction of lymph fluid flow.