Lymphatic System Flashcards
Function(s) of lymphatic system
- returns lost fluids to circulatory system
-constantly on the lookout for foreign invaders (absorbs bacteria and viruses with fluid it collects) (identifies foreign materials and “sounds the alarm”
Organization of LS
resembles the cardiovascular system
-lymphatic vessels (small to large)
- not a loop; only moves fluid in one direction
Lymphatic fluid =?
lymph
Lymphatic Formation and Flow
plasma leaks from capillaries and becomes interstitial fluid around cells, becomes lymph when absorbed into lymphatic capillary
Lymphatic vessels (small to large)
lymphatic capillaries join to form lymphatic vessels, vessels join to form lymphatic trunks
Lymph Movement
system has no pump
-moves lymph by contracting vessels, squeezed by muscles of body
Lymphatic trunks
all named for the body region they drain
- lead 2 major lymphatic ducts
Thoracic duct
collects/drains from MOST of the body
Right lymphatic duct
collects/drain from right upper body only
Where do ducts return the fluid?
return fluid to circulation in subclavian veins (large veins under each clavicle)
Immune System Cells (White blood cells)
cells of the lymphatic system = lymphocyte (type of WBC)
Where are WBCs made?
made in bone marrow
T lymphocytes (T-cells)
mature in thymus (that’s why called T-cells)
B lymphocytes (B-cells)
stay/mature in bone marrow
Natural Killer cells (NK cells)
destroy foreign or diseased (cancer) cells
Macrophages
a phagocytic cell that consumes old worn-out blood cells as well as disease - causing agents
-(easily damaged, especially when enlarged from illness)
Lymphatic Organs
Lymphatic tissues, lymph nodes, spleen, and thymus
Lymphatic Tissue
present in tissue open to the outside world, removes pathogens from food and air
What lymphatic tissues are open to the outside world?
Digestive, respiratory, urinary, and reproductive
-ex: tonsils
Lymph Nodes
located along lymph vessels, cleanse the lymph passing through
house T-cells and B-cells to fight infection
Spleen
- Largest lymphatic organ
acts like a lymph node but scans and cleans BLOOD - can be removed and lead normal life
Thymus
- found near the heart (part of endocrine system)
- nursery for T-cells, largest in childhood, stops growing after puberty
- starts shrinking therefore less production of T-cells(bad immune system with age)
