Parts Of Lymphatic system Flashcards
Reticular connective tissue containing lymphocytes
Lymphatic tissue
interstitial fluid in lymphatic vessels
Lymph
Lymphatic System function
- Drains excess interstitial fluid.
- Transports dietary lipids. - lipid-soluble vitamins
(A, D, E, and K) absorbed by the GIT. - Carries out immune responses.
n Begin at lymphatic capillaries
q Slightly larger than blood capillaries q Overlapping cells like one-way valve q Pressure will force fluid in
n Merge to form larger & larger vessels q Thin walled and more valves than veins
n Periodically have lymph nodes
q Lymphocytes in capsuled structure
n à thoracic duct à L subclavian vein q At junction with jugular
n à R. lymphatic duct à R. subclavian vein
Lymphatic Vessels
n From tissue to veins
n Pumped by muscle & respiratory pumps like venous return
Lymphatic Flow
site where stem cells divide & become immunocompetent.
Primary lymphatic organs
q develop into mature B & T-cells
q Red bone marrow
q Thymus
Primary lymphatic organs
site for most immune responses
occur
Secondary organs
q Lymph nodes
q spleen
q lymphatic nodules (follicles)
Secondary organs
n Two lobed organ (bilobed)
n located in the mediastinum between the sternum and the aorta
n T-cells divide & mature
q Self reactive cells are removed
Thymus
n Scattered throughout the body
q Concentrated near mammary glands, axilla &
groin
n Contain mature B-cells, T-cells, dendritic cells and macrophages
n Function as a type of filter, trap foreign substances q macrophages destroy some foreign
substances by phagocytosis
q lymphocytes destroy others by immune responses.
Lymph Nodes
n Between stomach & diaphragm
n Contains blood filled venous sinuses and RBCs, macrophages, lymphocytes plasma cells & granular leukocytes
n Performs three functions related to blood cells:
n (1) removal by macrophages of ruptured, worn out,
or defective blood cells and platelets;
n (2) storage of platelets, up to one-third of the body’s supply; and
n (3) production of blood cells (hemopoiesis) during fetal life.
Spleen
n egg-shaped masses of lymphatic tissue that are not surrounded by a capsule.
n occur in multiple large aggregations in specific parts of the body.
n Includes tonsils in the pharyngeal region and the aggregated lymphatic follicles (Peyer’s patches) in the ileum of the small intestine
n Tonsils are strategically positioned to participate in immune responses against inhaled or ingested foreign substances.
Lymphatic Nodules
