Lymphatic System Flashcards
What does the lymphatic system provide?
Return to the circulation for fluid that has leaked from capillary blood into the surrounding tissue
What is the lymphatic system?
Complex network of lymphatic vessels, lymph nodes & other lymphoid tissue
What is the name of the fluid that is found in the tissue?
Lymph fluid
What does lymph fluid contain?
Lymphocytes (white blood cells)
What do lymphocytes play a role in?
Immunity
What are the principle functions of the lymphatic system?
Bathe cells deep within tissue, providing nutrients.
Maintain fluid balance between plasma & interstitial fluid.
House lymphocytes.
Allow the absorption of fatty acids from the gut (into lacteals)
Where is the cervical lymph node located?
Neck
Where does the lymphatic thoracic duct enter?
Left subclavian vein
Where does the right lymphatic duct enter?
Right subclavian vein
Where are the axillary lymph nodes located?
Armpits
Where is the lymphatic thoracic duct located?
Bottom of thoracic cavity
What is the cisterna chyli?
Lymph junction to the legs
Where r the inguinal lymph nodes located?
Groin
What are the principle lymphatic vessels?
Thymus & spleen
Where are lymph nodes located?
Near main arteries
Where is lymph formed?
Capillary beds as blood flows through capillaries
Why does fluid tend to leave the blood & enter the interstitial space?
Due to relative pressure in blood vessels
What part of the capillary beds does the lymph tend to leave in?
Arterial part
Where does lymph tend to return to the blood?
Venous part
Even when plasma protein levels are normal how foes the fluid act?
More fluid leaves the blood than re-enters
What happens to the excess fluid in the tissue?
Drains into tiny blind ended vessels called lymphatic capillaries
What is the fluid that drains into lymphatic capillaries called?
Lymph (clear, colourless)
Why is lymph similar to plasma?
Electrolyte compsition
What does lymph contain very little of?
Protein
Define lymphatic circulation and how it works?
Tiny blind ended lymphatic capillaries drain into larger lymphatic vessels which run alongside major veins and carry lymph back to the blood
What is lymph travelling towards a lymph node called?
Afferent lymphatics
What is lymph travelling away from a lymph node called?
Efferent lymphatics
Why does the lymphatic system have valves?
Prevent backflow of lymph
What two lymphatic ducts drain back into the subclavian veins?
Thoracic & cervical ducts
What happens if lymph vessels are blocked or damaged?
Tissue can become oedematous & swollen (lymph-oedema)
How many lymph nodes does the lymphatic system consist of?
Around 500 lymph nodes (swellings)
What does the lymphoid tissue house?
Lymphocytes
What size is a lymph node?
1mm - 25mm in length
Where does lymph draining pass through before returning to the blood?
Lymph nodes
What are the regions that nodes are organised in called?
Follicles
What do the lymph nodes house?
B-lymphocytes & memory cells
What are found in large numbers between lymphatic follicles?
T-lymphocytes
Why does the lymph percolate through the node tissues?
So that any pathogens are exposed to lymphocytes in the node
What is the purpose of the lymphocytes in the nodes?
To mount an appropriate immune response
Where else do lymphocytes go?
Leave nodes via efferent lymph & return to circulation
What is the purpose of lymphocytes entering the blood stream?
So the body is continuously patrolled by immune cells
What are the secondary lymphoid tissues in the body?
Tonsils & adenoids, lymph nodes, spleen, peyers patches,
In the lymphatic system, what does older tissue house?
Large numbers of lymphocytes
What are the primary lymphoid?
Bone marrow & thymus
Where do b lymphocytes mature?
Bone marrow
Where do t lymphocytes mature?
Thymus gland
