An<unk>  is a small diameter blood vessel that extends and branches out from an artery and leads to capillaries.<unk> s have thin muscular walls (usually only one to two layers of smooth muscle) and are the primary site of vascular resistance.
This means blood pressure in the arteries supplying the body is a result of the interaction between the cardiac output (the volume of blood the heart is pumping per minute) and the vascular resistance, usually termed total peripheral resistance by physicians and researchers.
Arteriole
Artery
Deep vein
Lymph vessel
Cardiac veins
Coronary arteries
Peripheral vein
Bleb 