Platelets or Thrombocytes or Yellow Blood Veins
These are the blood vessels that carry
These are small cell fragments responsible deoxygenated blood back to the heart.
for the clotting of blood and the formation It contains about 75% of blood.
of scabs. The walls of the veins are thinner than the
They form in the red bone marrow from arteries.
large megakaryocyte cells that periodically Venules are known as the smallest of the
rupture and release thousands of pieces of veins.
membrane that become the platelets. It has no pulse and blood travels smoothly.
They do not contain a nucleus and only Capillary
survive in the body for up to a week
before macrophages capture and digest These are the smallest blood vessels in the
It contains about 5% of blood at any time,
Plasma and no pulse can be felt in one.
These blood vessels are act as a link
It is the non-cellular or liquid portion of
between arteries and veins.
the blood that makes up about 55% of the
It has a single layer of endothelial cells.
Water and other small molecule
Approximately, 90% of blood plasma is
substances can pass through this wall.
water and remaining 10% are proteins,
inclusions and waste products etc. Atrium : Either of the two (left and right)
The plasma functions as a transportation upper chambers of the heart. Also called
medium for these substances as they move auricles
throughout the body. Pulmonary : Used to describe blood vessels
that carry blood between the heart and the
These are the tubular structure carrying blood Aorta : The largest artery which directs blood
through the tissues and organs to every organ but the lungs
There are three major types of blood vessels: Lumen : The inner open space of a tubular
arteries, capillaries and veins. organ, in this case the blood vessels
Arteries Vena Cava : Either of two large veins which
carry blood into the right side of the heart
These are the blood vessels that carry the Cardiovascular : Of or involving the heart
oxygenated blood away from the heart. and blood vessels
It contains about 20% of blood at any one
Their walls are thick and elastic. It is a muscular organ about the size of a
They have small lumen (tubular cavities closed fist that functions as the body’s
inside). circulatory pump.
They also help to push the rapid flow of It takes in deoxygenated blood through the
blood when the ventricles are relaxed and veins and delivers it to the lungs for
the heart is refilling. oxygenation before pumping it into the various
Arterioles are known as the small arteries. arteries.
It has a pulse and blood travels in spurts.