The Lymphatic System Flashcards
What does the high pressure in arteries cause? (In terms of the blood plasma)
Blood plasma to be forced out of the capillaries and into the tissues
What are three fluids that have the same chemical composition?
Blood plasma
Tissue fluid
Lymph
Why do these three fluids have different names?
Because of where they occur
Where does blood plasma occur?
In the blood vessels
Where does tissue fluid occur?
Between the cells of tissues
Where does lymph occur?
In the lymphatic vessels
What does the lymphatic system do?
Drains the tissue fluid between cells and transports it back to the bloodstream
Why does tissue fluid need to be drained?
Only a very small amount of it goes back into the capillaries
If left, it will accumulate and put pressure on the cells around it
It also needs to be drained because of plasma proteins
What are the smallest lymph vessels known as?
Lymph capillaries
Where do lymph capillaries occur?
They branch between the cells of tissues
What are lymph capillaries like?
They are small
They have blind-endings
What do lymph capillaries do as they get further away from the blood capillaries?
Unite
Form larger lymphatic vessels
What do lymphatic vessels eventually do?
Open into the main lymphatic vessels
How many main lymphatic vessels are there?
Two
What are the two main lymphatic vessels?
Thoracic duct
Right lymphatic duct
Which lymph vessels open into the thoracic duct?
In the lower limbs, intestines, left side of the chest, left arm, left side of the head and neck
How does the thoracic duct connect to the blood circulatory system?
By opening into the left subclavian vein
Where does lymph go?
Back into the blood circulatory system
Which lymphatic vessels open into the right lymphatic duct?
Vessels from the right side of the chest, right arm, right side of the neck and head
How does lymph from the right lymphatic duct get back into the blood circulatory system?
It opens up into the right subclavian vein
What is the pressure like in the lymphatic vessels?
Very low
Why is the pressure low in the lymphatic vessels?
There is no pumping organ to apply pressure
How is lymph moved through the lymphatic vessels?
By the movement of internal organs
By the contraction of skeletal muscles
Are there valves in the lymphatic vessels?
Yes
What kind of valves exist in the lymphatic vessels?
Semilunar
What do lymph nodes do?
Act as filters
Trap foreign particles
What are lymph nodes also known as?
Lymph glands
What do lymph nodes look like?
Small
Bean-shaped
Where are lymph nodes located?
Throughout the body
Close to the lymphatic vessels
Where can larger concentrations of lymph nodes be found?
Armpits
Groin
Neck
Give an example lymph glands
Tonsils
How do lymph nodes prevent infection?
They produce lymphocytes and antibodies
What are lymphocytes?
White blood cells
What do lymphocytes do?
Engulf and destroy bacteria
What happens to the lymph nodes when there is an infection in the body?
They swell
Why do lymph nodes swell when there is an infection in the body?
Due to the increase in lymphocytes and trapped substances
Why do plasma proteins need to be transported back to the blood circulatory system?
Large concentrations of these proteins can be life threatening
What is oedema?
Swelling that occurs when tissue fluid accumulates
Where is another place (apart from around capillaries) that lymphatic vessels occur?
In villi in the small intestine
What are lymphatic vessels in the villi called?
Lacteals
What do lacteals do?
Absorb fats and open into larger lymphatic vessels, which transports these fats back into the blood stream
Is the lymphatic system closed?
No
