Lymphatic System Flashcards
Why do we need it?
bring back and restore lymph that leaks from the capillary beds that are very thin
What is lymph?
- all of blood plasma material that leaks out of capillary beds
- fluid connective tissue
- recovered interstitial fluid
- lymphocytes (T,B cells)
- macrophages
Functions of the lymphatic system:
- return interstitial fluid to veins
- distribute lymphocytes made in red marrow, spleen, and thymus
- transport lipids absorbed by small intestine using “lacteals”
- take in bacteria, viruses, or cancer cells
Components of lymphatic system:
- lymphatic vessels
- lymphoid nodules
- lymphoid organs
Lymphatic vessels
- vessels have beaded appearance (from one-way valves; low pressure in vessel)
- locomotion powers lymph
What are the 2 lymphatic ducts that drain into veins and which veins?
- right lymphatic duct - into right subclavian vein (1/4)
- thoracic duct - into left subclavian (3/4)
Lymphoid nodules
swelling/node where there are many lymphocytes in reticular fiber framework
What is the MALT?
mucosa-associated lymphoid tissue (makes sure everything is “safe” - they detect antigens entering body)
Where are lymphoid nodules located?
- digestive
- respiratory
- urinary
- reproductive tracts
(everything in contact with outside world)
What are two types of MALTs?
- Tonsils
- Peyer’s patches
What do tonsils do and where are they located?
remove pathogens in pharynx (pharyngeal, palantine, lingual)
What are Peyer’s patches and where are they located?
detect foreigners in feces - aggregate lymphoid nodules in the ileum
What are the lymphoid organs?
- lymph nodes
- thymus
- spleen
What are the locations of the lymph nodes?
- cervical lymph nodes
- axillary
- lumbar
What are lymph nodes?
“check station” - check identity before allowing into the circulatory system - filter returning fluid
What are the functions of lymph nodes?
filter antigens from lymph
Why do my lymph nodes hurt when I’m sick?
nodes swell with lymphocytes & macrophages fighting infection
How are lymph nodes used to detect metastatic cancer?
cancer cells enter lymphatic capillaries - lymph nodes are way-stations of metasiss
Why does cancer spread?
- cancers are not cohesive tissue
- cancer cells get stuck in narrow ducts in lymph nodes
TNM staging
t= tumor (how big)
n= node (in nodes or not in nodes)
m= metastasis (how far it spread)
a- arteriole
b- lymphatic capillary
c- capillary bed
d- venule
a- interstitial fluid
b- opening
c- lymph
a- capillary
b- lacteal
c- lymph vessel
anatomy of lymph nodes
a- lymph nodules
b- lympocytes
c- efferent lymph vessel
d- cortex
e- afferent lymph vessel