Following are the main components of the cardiovascular system:
  • Heart (pump)
  • Blood vessels ( system of interconnecting tubules)

Following are the major blood vessels:
  • Aorta- largest artery in the body, leaves the heart at the left ventricle, carries oxygenated blood to the rest of the body)
  • Vena cava- major vein that returns deoxygenated blood fromm all parts of the body to the right auricle in the heart
  • Pulmonary artery- carries all the deoxygenated blood from the right ventrice to the lungs for oxygenation
  • Pulmonary vein- carries the oxygenated blood from the lungs to the left auricle in the heart

Following image is a general layout of a mammalian transport system.


It is a closed and double system as blood flows through closed paths called blood vessels and the blood flows twice through the heart, that is oxygenated blood through the left side of the heart and deoxygenated blood through the right side of the heart.

Note that there is no mixing of oxygenated and deoxygenated blood in the heart of humans.

The image below shows the main blood vessels in the human body:

Arteries branch out t form artereioles whaich further branch out to form capillaries.

All the capillaries together form a capillary network

The capillary network then join up on the other side to form venules which further join up to form the veins.

Comparison Of the Structure of an artery, vein and capillary

Structure of an Artery and Vein

Visit the following links to view the

Anatomy of heart:

Cardiac Cycle:

Blood circulation

Composition of blood:


Formation of tissue fluid and lymph

Watch the following video to understand the lymphatic system:

A few videos to watch: