Why are veins superficial but arteries deep-seated?

 Why do arteries have thick walls and veins have thin walls?

what is the normal pulse rate in men and in women?

Is it possible for blood to clot under skin

What is hepatic portal vein and hepatic portal artery??

 why are the arteries are deep seated in the body?

functions of axon and dendron?

Pulse wave is caused by:

a) Systole of atria

b) diastole of atria

c) systole of left ventricle

d) systole of right ventricle

name the following

1] the mammals which has smallest rbcs

2] the site of erythropoiesis in adullts

how to make a working model of double circulatory system..

why is it so that blood flows in spurts in veins while it flows in large amounts through the arteries??

 Why do people have a common belief that the heart is located on the left side of the chest ?

why is it necessary to know the blood group before giving blood transfusions?

what is auriculo-ventricular aperture?

what is the actual colour of blood flowing through vein,arteryand capillary?