chapter 20 Flashcards
- picks up fluid lost by blood capillaries
- consists of lymph vessels, lymph and lymph nodes
- fluid that is picked up by lymph capillaries is eventually returned to circulation
lymphatic system
- provide structural basis for immune system
- monitors body for infection
- house phagocytic cells and lymphocytes
lymphoid organs
- picks up protein containing interstitial fluid that is not reabsorbed by blood capillaries
- once it enters the lymph vessel, fluid is called “lymph”
lymphatic vessel
lymph vessels only move fluid…. the heart
toward
- blind ended vessels that weave through capillary beds
- highly permeable due to presence of two structures
- 1) lossly aggregated endothelial cells in walls of capillaries–>form flaps that open
- 2) Anchoring filaments –>increase in interstitial fluid pulls on anchoring filaments
-flaps of endothelial wall open - lymph capillaries allow intake of large proteins
- during illness/infection-capillaries become even more permeable
- pathogens transported to lymph nodes, where immune system destroys them
lymph capillaries
specialized lymph capillaries for movement of fats from small intestine to bloodstream
lacteals
Collecting lymphatic vessels
- in skin-vessels travel with superficial veins
- in trunk- vessels travel with deep arteries
lymphatic trunks
- draining areas resulting from collecting vessels uniting
drains lower extremities (legs)
lumbar trunk
drains thorax
Bronchomediastinal trunk
drains upper extremities (arm) and superficial thoracic wall
Subclavian trunk
drains head and neck
jugular trunks
drains digestive organs
intestinal trunk
lymphatic ducts
- structures that lymphatic trunks drain into
- both ducts empty into junction at internal jugualr vein and subclavian vein
- right lymphatic duct empties into veins on right side
- thoracic duct empties into veins on left side
right lymphatic duct
drains lymph from right upper limb, right side of head, and right thorax
thoracic duct
- drains any part of body that is not drained by right lymphatic duct
- usually begins at cisterna chyli
- left upper limb, left side of brain, left side of thorax
- both lumbar trunks (right and left limb)
- intestinal trunk
lymphoid tissues are made up of…
reticualr connective tissue
primary lymphoid organs
- red bone marrow and thymus
- location where B and T cells mature
- B cells mature in Bone marrow
- T cells mature in Thymus
secondary lymphoid organs
- lymph nodes, spleen, mucosa associated lymphoid tissue (MALT)
- location where mature lymphocytes first encounter antigens and become activated
lymph nodes
- forms clusters in axillary, cervical and inguinal regions
- areas where large number of collecting lymph vessels converge and form lymphatic trunks
Lymphadenopathy
- (incorrectly called “swollen glands”)
Nodes overwhelmed & blocked off due to high infection rate - Nodes become inflamed, swollen, tender, and filled with pus
- Usually necessitates use of antibiotic to assist in treatment of infection
secondary cancer sites
- Metastasizing cancer cells break free from original tumor, get “stuck” in lymph nodes in different parts of body
- lymph nodes become swollen/enlarged, but are not painful
- example: swelling of axiallry nodes indicates breast cancer
