CH 24 Flashcards
Lymphatic system
Lymphatic system functions
- Immunity
- Absorption of dietary fats
- Return of excess interstitial fluid to blood
Return of excess interstitial fluid
Maintains fluid homeostasis
Interstitial fluid leaked across capillaries
Blood plasma
Lymph
Fluid CT once interstitial (tissue) fluid enters lymph vessel; travels at low pressures; leaked excess blood plasma in lymph vessel
Immunity
Lymph is filtered through lymphoid structures like lymph nodes and is checked for foreign or pathogenic material like bacteria and cancer cells
Lymphoid structures contain cells that initiate an immune response to abnormal materials
Without primary immune system, the body would be unable to fight infection and stay healthy
Lymphocytes destroys pathogens, makes antibodies
Components of lymphatic system
- Lymph
- Lymphatic capillaries
- Lymphatic vessels
- Lymphatic trunks (9)
- Lymphatic ducts (2)
- Lymphatic cells
Lymphatic vessel
Vessels formed by union of lymphatic capillaries; Resorbs excess interstitial fluid and returns it to venous circulation; Similar to veins and have 3 tunics
Lymphatic capillaries
Microscopic vessel that begins network of lymphatic vessel
- Wall is endothelium
- Have overlapping endothelial cells that act as one-way valves allowing interstitial fluid into lymphatic capillaries
- Close-ended
Valve
Prevent lymph from pooling in vessel and back flow
Lymphatic trunk
- Formed by merging lymphatic vessels
- Have a L/R except for intestinal
List the lymphatic trunks
- Jugular
- Subclavian
- Bronchomediastinal
- Intestinal
- Lumbar
Jugular trunks
Drains lymph from head and neck
Subclavian trunks
Drains lymph from upper limbs, breast, superficial thoracic wall
Bronchomediastinal trunks
Drains lymph from deep thoracic wall
Intestinal trunk
Drains lymph from most abdominal structures
Lumbar trunks
Drains lymph from lower limbs, abdominopelvic wall, pelvic organs
Lymphatic ducts AKA collecting duct
Formed by fusion of lymphatic trunks; empties lymph back into venous circulation
What are the lymphatic ducts?
- Left lymphatic duct/ thoracic duct
- Right lymphatic duct
Right lymphatic duct
- Empties into right subclavian vein
- Returns lymph from right upper body only (head, neck, right upper limb and thorax)
Left/ thoracic duct
- Largest lymphatic vessel
- Receive lymph from most of body (left upper body, lower body)
- Begins inferior to diaphragm
The thoracic duct passes through ________ and empties into the _________
aortic opening in diaphragm; junction of left subclavian and left internal jugular
Cisterna chyli
Round sac-like structure at base of thoracic duct and anterior to L2; Left and right intestinal and lumbar trunks drain into
Chyle
Milky lymph from small intestine that contains dietary fats
Lacteal
Lymphatic capillaries located in wall of small intestine
Pathway of chyle
Lacteals
Lymph vessels
Intestinal trunk
Cisterna chyli
Thoracic/ left duct
Left subclavian vein