PHYSICAL EDUCATION - THE HEART

The two pumps are separated by a muscular wall called the SEPTUM.

The left and right pumps each consist of two chambers, an ATRIUM and VENTRICLE, which make up the four chambers

The left and right atrium (upper) are low pressure chambers which collect and store blood before pumping it below into the left and right ventricles.

  The left and right ventricles (lower) are high pressure chambers that generate the force/ pressure required to pump blood around the whole body.

The greater force generated requires a greater contraction, therefore the muscular walls of ventricles are thicker than the atria walls.

The right ventricle only pumps blood to the lungs.

The left ventricle pumps blood around the body.

There are FOUR ONE- WAY VALVES which are situated within the heart and function to:

• Control the forward direction of blood flow through the heart
• 
• Prevent the back flow of blood within the heart chambers

Two ATRIOVENTRICULAR (AV) VALVES separate the atria from the ventricles, the right (AV) valve is called the TRICUSPID valve and the left (AV) Valve is the BICUSPID

The two remaining valves are called the SEMILUNAR (SL) VALVES. The right SL valve is called the PULMONARY VALVE, and exists the right ventricle into the pulmonary artery. The left SL valve, called the AORTIC VALVE, exits the left ventricle into the aorta.

The Heart interacts with the blood vessels of the vascular system to transport blood to and from the heart.

 This is how the blood vessels transport blood to and from the internal structures of the heart:

•Superior/ inferior vena cava- deoxygenated blood from body to right atrium.

 •Pulmonary artery- deoxygenated blood from the right ventricle to the lungs

•Pulmonary veins (x 4)- oxygenated blood from lungs to the left atrium.

•Aorta- oxygenated blood from left ventricle to whole body.

The heart wall is made of cardiac muscle and requires a good supply of blood oxygen to and from the heart for it to function as a pump.

The blood vessels supplying oxygenated blood to the heart are called the CORONARY ARTERIES, and blood vessels removing deoxygenated blood are called the CORONARY VEINS. 

CORONARY ARTERIES- left and right branches from the aorta encircle and supply the heart muscle with oxygen and glucose.

CORONARY VEINS- alongside the coronary arteries, drain deoxygenated blood directly back into the right atrium via the coronary sinus.