Functions of the Lymphatic System

Key Components of the Lymphatic System

afferent lymphatic vessel:
- Definition: Tube transporting lymphatic fluid into a lymph node.
anchoring filaments:
- Definition: Structures that prevent the collapse of lymphatic capillaries, particularly important during tissue swelling.
appendix:
- Function: Stores and releases healthy intestinal bacteria when needed.
- Additional Role: Stores lymphocytes which are thought to filter out pathogens from the large intestine.
axillary lymph nodes:
- Function: Filter lymph fluid coming from the upper limb and breast.
capsule:
- Definition: A layer of connective tissue that surrounds lymphatic organs such as the lymph node, thymus gland, and spleen.
cervical lymph nodes:
- Function: Filter lymph fluid that comes from the head and neck.
collecting duct:
- Definition: Tubes that receive lymph fluid from the lymphatic trunks and send it to the bloodstream.
collecting vessels:
- Definition: Tubes that receive lymph fluid from the lymphatic capillaries and transport it to the lymphatic trunks.
hilum:
- Definition: The region of an organ where blood vessels, nerves, and other structures enter and exit the organ.
inguinal lymph nodes:
- Function: Filter lymph fluid that comes from the lower limb.
efferent lymphatic vessel:
- Definition: Tube that transports lymphatic fluid out of a lymph node.
intercellular clefts:
- Definition: Openings between overlapping endothelial cells of a lymphatic vessel that allow excess tissue fluid to enter a lymphatic capillary.
lymph nodes:
- Definition: Small organs located along a lymphatic vessel that function to filter lymph fluid.
lymphatic capillaries:
- Definition: Small tubes, closed at one end, responsible for removing excess fluid from tissues and sending it to the collecting vessels.
- Notable Absence: Lymphatic capillaries are not present in cartilage, bone marrow, bone, or the cornea.
lymphatic trunks:
- Definition: Tubes that receive lymph from the collecting vessels and transport it to the lymphatic ducts.
lymphatic vessels:
- Definition: Tubes of the lymphatic system that are responsible for transporting lymph fluid.
right lymphatic duct:
- Definition: A large tube that receives lymph fluid from the right upper body including the head, neck, thoracic cavity, shoulder, arm, and hand.
spleen:
- Functions:
- Collects healthy red blood cells (RBCs) in red pulp and can later release them back into circulation.
- Old RBCs enter the spleen, where they are removed from circulation and broken down by macrophages in white pulp.
- The white pulp of the spleen also contains lymphocytes, and both lymphocytes and macrophages monitor blood passing through the spleen for foreign antigens.
- Can produce new RBCs during extreme anemia.
splenic artery:
- Definition: Blood vessel that transports blood into the spleen.
splenic vein:
- Definition: Blood vessel that transports blood out of the spleen.
thoracic duct:
- Definition: A large tube that receives lymph fluid from all of the body below the diaphragm, as well as from the left upper body.
thymus gland:
- Function: The organ where T lymphocytes mature.
tonsil:
- Function: Protects the body against pathogens that enter through inhaled air or ingested food.