Lymphatic System Lab Flashcards
Lymphatic capillaries
Small, close ended vessels that absorb interstitial fluid, slightly larger than blood capillaries. They are interspersed around most blood capillaries but are absent in a vascular tissue, red marrow, spleen and CNS
Lacteals
Lymphatic capillaries in GI tract; absorb lipid soluble substances from GI
Movement of lymph into lymphatic capillaries
Hydrostatic pressure of IF pushes it into capillaries. Lymph moves through vessels of larger and larger size, returns to blood circulation.
Goes from…
Lymphatic capillaries —> lymphatic vessels —> lymphatic trunks —> lymphatic ducts
Lymphatic vessels
Fed by lymphatic capillaries and are located adjacent to arteries and veins. Have intima, media, and external tunicas. Have valves preventing back flow of lymph and does not have pump so it moves lymph using skeletal muscles and respiratory pumps. Some connect to lymph nodes for filtration.
Lymphatic trunks
Fed by lymphatic vessels. 5 types…
Jugular trunks: drain lymph from head and neck
Subclavian: drain upper limbs, breasts, and superficial thoracic wall
Bronchiomediastinal: drains deep thoracic structures
Intestinal: drains most abdominal structures
Lumbar: drains lower limbs, abdominopelvic wall and pelvic organs
Lymphatic ducts
Fed by lymphatic trunks and brings lymph to venous blood circulation. 2 ducts; right lymphatic duct and thoracic duct
Right lymphatic duct
Near right clavicle and drains upper right quadrant of body. Delivers lymph to junction of right subclavian and right internal jugular veins
Thoracic duct
Largest lymphatic vessel that runs from diaphragm to junction of left subclavian and jugular veins. Has saclike cisterna chyli at its base that receives lipid rich chyle from GI tract. Drain lower body and upper left quadrant.
Red bone marrow
Site of hemopoesis: production of bloods formed elements which include t&b lymphocytes
Thymus
Involved in t lymphocyte maturation. Regresses in adults
Lymph nodes
filter lymph, remove unwanted substances. They are small, encapsulated ovals that are located along lymph vessels. Occur in clusters receiving lymph from body regions
Cervical lymph nodes
Receive lymph from neck, head
Axillary lymph nodes
Receive lymph from breast, axilla, and upper limb
Inguinal lymph nodes
In groin; receive lymph from lower limb and pelvis
Afferent lymphatic vessel
Bring lymph to node
Efferent lymphatic vessel
Drains a lymph node; located in hilum
Trabeculae
Subdivide node into compartments
Lymph flow through nodes
Enters through several afferent vessels and pushes through node to efferent vessel. While being pushed, macrophages remove debris and lymphocytes can initiate immune response enlarging lymph nodes.
Spleen
Largest lymphatic organ, in LUQ. Lateral to left kidney and posterolateral to stomach.
Posterolateral side is convex and round
Anteromedial border is concave.
Surrounded by ct capsule, trabeculae extend from cortex and section off cortex
Hilum of spleen
Indentation where blood vessels and nerves enter/exit. Splenic artery supplies blood, splenic vein drains it
Spleen monitoring blood
Spleen filters and monitors blood for foreign materials and bacteria. Macrophages in sinusoids phagocytize bacteria, debris, defective RBC and platelets. Also store erythrocytes and platelets.
Path of flow: splenic artery, sinusoids, venules, splenic vein
Tonsils
3 types
Pharyngeal tonsil: in nasopharynx and called adenoids when enlarged
Palatine tonsils: in posterolateral oral cavity
Lingual tonsils: along posterior third of tongue
Lymphatic nodules
Clusters of lymphatic cells with some extracellular matrix. not completely surrounded by connective tissue capsule and is found in all body organs. Help defend against infection.
Scattered lymphatic nodules are termed
Diffused lymphatic tissue. In some areas, they group together to form larger structures
MALT
Mucosa-associated lymphatic tissue. Located in gastrointestinal, respiratory, genital, and urinary tracts. Prominent in small intestines, especially ileum
Peyer patches
Large collections of lymphatic nodules
