Within the blood circulation the heart plays a key role. How well the heart function depends on the lifestyle of an individual and heart disease can be linked to a person’s diet and level of physical activity.

Function

Before you can understand how the heart functions important to know the structure of the heart.

As you can see from the diagram, the heart is composed of a number of parts:

• chambers
  • right atrium
  • left atrium
  • right ventricle
  • left ventricle
• nodes
  • sinoatrial node
  • atrioventricular node
• valves
  • tricuspid valve
  • mitral valve
  • semilunar valves

There are also four main blood vessels connected to the heart:

• the anterior vena cava transports blood from the upper body
• the inferior vena cava transports blood from the lower body
• the pulmonary artery carries deoxygenated blood from the rest of the body to the lungs
• the pulmonary vein carries oxygenated blood from the lungs to the rest of the body

Coninue to read below for additional A level biology revision on the heart:

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Heart disease

As people have become less active and due to changes in diet, heart disease has been on the increase. There are a number of different reasons for people to develop a heart condition and sometimes these can eventually lead to myocardial infarction (heart attack).