Given below are the diagrammatic sketches of two kinds of blood vessels.


(a) Identify the blood vessels A and B


(b) Name the parts numbered 1 to 6.


(c) Mention any two main differences between A and B.


(a) (A) is Artery (lumen is narrow and walls are muscular) & (B) is Vein.


(lumen is wider and walls are less muscular).


Note* : Identifying artery & vein is by looking at the size of the lumen. If the lumen is large then its a vein otherwise artery.


(b) In the following diagram of the two kinds of blood vessels the parts are labelled as:



1 & 4 -- Endothelium


2 & 5 -- Tunica media


3 & 6 -- Tunica externa


(c) Two main difference between A & B


Artery



Vein



1) Arteries have thick and more muscular elastic walls.



1) Veins have thin and less muscular elastic walls.



2) They have no valves in their inner lining.



2)They have valves in their inner lining.



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