Lymphatic System Flashcards

Flashcards covering the anatomy and function of the lymphatic system.

What is one lymphatic system function

Returns lymph to blood, regulates blood volume, and prevents tissue swelling (edema).

What is another lymphatic system function

Transports lipids and lipid-soluble vitamins (A, D, E, and K) to veins via lacteals.

Lymphatic Vessels

Vessels that hold lymph and transport it to veins, including ducts, trunks, vessels, and capillaries.

Lymphatic Nodes

Structures clustered along lymphatic vessels that filter lymph and hold specific leukocytes.

Lymphatic Capillaries

Weave between body tissue and blood capillaries, collecting water, solutes, and leukocytes from the interstitial space to create lymph.

Mini-valves in Lymphatic Capillaries

Overlapping cells in lymphatic capillaries that open with increased interstitial fluid to allow fluid entry and close with increased capillary fluid.

Lacteals

Specialized lymph capillaries in the small intestine villi that absorb lipids/fats.

Lymphatic Trunks

Major vessels in the neck, thorax, and abdomen that drain lymph from specific regions.

Right Lymphatic Duct

Collects lymph from the upper right limb, thorax, head, and neck on the right side.

Thoracic Duct

Collects lymph from the lower limbs and abdominopelvic regions, as well as the upper left limb, thorax, head, and neck on the left side.

Cisterna Chyli

An enlarged sac where the thoracic duct arises, anterior to the L1-2 vertebrae.

Edema

Swelling caused by fluid trapped in the interstitial space or lymphatic vessels.

Lymphatic System Function 3

Provides immunity by preventing entry of and removing antigens and pathogens.

Antigens

Substances that cause an immune response.

Pathogens

Infectious agents that can cause disease

Leukocytes

True cells with a nucleus that protect the body from infectious materials; include granulocytes and agranulocytes.

Neutrophils

Granulocytes that migrate quickly to infection sites and phagocytize (eat) and destroy bacteria.

Eosinophils

Granulocytes that attack objects covered in antibodies, like large parasitic worms, and help control inflammation.

Basophils

Granulocytes that start the inflammation process by releasing histamines to dilate blood vessels and heparin to prevent blood clotting.

Monocytes

Agranulocytes that transform into macrophages and become phagocytic cells, attracting other phagocytic cells and fibroblasts.

Lymphocytes

Agranulocytes, including T-cells (kill virus-infected and tumor cells) and B-cells (produce antibodies).

Primary Lymphatic Organs

Organs (red bone marrow and thymus) where immune cells divide and mature.

Secondary Lymphatic Organs

Organs (lymph nodes, spleen, tonsils, Peyer's patches, appendix) where lymphatic cells are stored and immune responses occur.

Red Bone Marrow

Connective tissue and blood stem cells that produce all formed elements, including leukocytes, and where B lymphocytes mature.

Thymus

Bilobed organ that matures lymphocytes into T lymphocytes and produces thymosin and thymopoietin.

Lymph Node Anatomy

Includes locations in the groin, axilla, neck, thorax, and along the gut tube, with clusters near mammary glands in women.

Afferent Lymphatic Vessels

Lymph enters the lymph node through these.

Efferent Lymphatic Vessels

Lymph exits the lymph node through these at the hilum.

Spleen

The largest lymphatic organ, located on the left side of the abdominal cavity, that filters and cleanses blood.

Red Pulp

Connective tissue and veins in the spleen where old red blood cells are destroyed.

White Pulp

Mostly lymphocytes in connective tissue within the spleen that cleanse the blood of bacteria and viruses.

Tonsils

Lymphoid nodules around the pharynx that collect pathogens entering through the mouth and nasal cavity.

Peyer’s Patches

Lymphoid nodules in the wall of the small and large intestines.

Appendix

An offshoot of the cecum containing lymphoid nodules that destroy bacteria, preventing them from breaching the intestinal wall.

Appendicitis

Inflammation of the appendix caused by an increase in bacteria present.