PNUR 101 LYMPHATIC SYSTEM
LYMPHATIC SYSTEM FUNCTIONS - ANS-Fluid balance - extra interstitial fluid (exits from
capillaries) enters lymphatic vessels - fluid now called lymph (water and substances found in
blood plasma)
Fat absorption - fat from digestive tract moves into lacteals
Defense - microorganisms and other foreign substances in the lymph are filtered by lymph
nodes
LYMPHATIC CIRCULATION - ANS-One-way circuit from tissues to circulatory system,
consisting of:
Lymphatic Capillaries
one cell layer (endothelium), allows easy passage of soluble materials and water
lacteals - lymph capillaries in the small intestine, designed to absorb digested fats
Lymphatic Vessels - thin walled with valves
superficial (immediately below the skin, often near
superficial veins)
deep (larger, follow deep veins)
LYMPH PATHWAY - ANS-Lymphatic capillaries → lymphatic vessels → lymph nodes → right
lymphatic duct or thoracic duct → subclavian veins into bloodstream
Right lymphatic duct
receives only lymph from superior right quadrant
empties into right subclavian vein
Thoracic duct (left lymphatic duct)
receives lymph from the rest of the body
empties into left subclavian vein
LYMPH NODES - ANS-Small, round nodules distributed along lymphatic vessels - lymph
passes through before entering blood
Surrounded by a connective tissue capsule
Divided into compartments of lymphatic tissue (lymphocytes) and lymph sinuses (spaces
containing macrophages)
As lymph travels through the node:
immune system may be activated to produce more lymphocytes
removal of microorganisms by macrophages
THYMUS GLAND - ANS-Location: superior mediastium, deep to the sternum
Key role in immune system in fetus and newborn
T lymphocytes mature in the thymus
Secretes hormone - thymosin (development of T-cells)
Shrinks after puberty
LYMPHATIC SYSTEM FUNCTIONS - ANS-Fluid balance - extra interstitial fluid (exits from
capillaries) enters lymphatic vessels - fluid now called lymph (water and substances found in
blood plasma)
Fat absorption - fat from digestive tract moves into lacteals
Defense - microorganisms and other foreign substances in the lymph are filtered by lymph
nodes
LYMPHATIC CIRCULATION - ANS-One-way circuit from tissues to circulatory system,
consisting of:
Lymphatic Capillaries
one cell layer (endothelium), allows easy passage of soluble materials and water
lacteals - lymph capillaries in the small intestine, designed to absorb digested fats
Lymphatic Vessels - thin walled with valves
superficial (immediately below the skin, often near
superficial veins)
deep (larger, follow deep veins)
LYMPH PATHWAY - ANS-Lymphatic capillaries → lymphatic vessels → lymph nodes → right
lymphatic duct or thoracic duct → subclavian veins into bloodstream
Right lymphatic duct
receives only lymph from superior right quadrant
empties into right subclavian vein
Thoracic duct (left lymphatic duct)
receives lymph from the rest of the body
empties into left subclavian vein
LYMPH NODES - ANS-Small, round nodules distributed along lymphatic vessels - lymph
passes through before entering blood
Surrounded by a connective tissue capsule
Divided into compartments of lymphatic tissue (lymphocytes) and lymph sinuses (spaces
containing macrophages)
As lymph travels through the node:
immune system may be activated to produce more lymphocytes
removal of microorganisms by macrophages
THYMUS GLAND - ANS-Location: superior mediastium, deep to the sternum
Key role in immune system in fetus and newborn
T lymphocytes mature in the thymus
Secretes hormone - thymosin (development of T-cells)
Shrinks after puberty
