5. Cardiovasulcar system

The heart

The heart is a 'double pump' organ responsible for transporting blood and its constituting parts around the body. It is a specialised type of muscle that contracts to produce the force to push blood around the body.  The technical term for the heart muscle contraction is 'systole'. Once contracted, the heart muscle relaxes to allow more blood to refill it's chambers. The technical term for heart muscle relaxation is 'dyastole'.

The heart is described as a double pump because one pump, pushes blood to the lungs to collect oxygen. Blood traveling between the lungs and heart is passing through the pulmonary circulation.  A separate pump pushes oxygenated blood to all the other tissues of the body. Blood travelling between the rest of the body and heart is passing through the systemic circulation.

Watch  to see how blood passes through the heart. 

   

Check your knowledge of some key anatomical features of the heart with this interactive labelling activity.

This article maybe helpful for the labelling activity. 

Blood vessels.

The heart pumps blood around the body through blood vessels called arteries, veins and capillaries.

Watch this to check your knowledge of the function of blood vessels and their relationship to each other.