Cardiovascular System 2

To provide an adequate circulation of blood around the body This helps to provide self with oxygen and essential nutrients and to remove waste products from these cells

The heart pumps blood twice in one cycle to help maintain a high-pressure and movement of blood

Blood flow between the heart and the whole/rest of the body

Blood flow between the heart and the lungs

The muscle which makes up the heart it never fatigues

Cardiac muscle is myogenic. This means that it can contract and relax on its own accord without the need for nerve impulses as some other muscles do

The muscular wall separating the left and right sides of the heart

the left atrium is above, receiving blood from the PV and the left ventricle is below, forcing blood out the aorta

the right atrium is above, receiving blood from the vena cava and the right ventricle is below, forcing blood out the PA

The wall of the ventricles are thicker than the walls of the atria. This is because the atria only need to pump blood down to the ventricles whereas the ventricles need to pump blood out of the heart (further distances)

The blood vessel (vein) which carries deoxygenated blood from the body to the heart (right atrium)

The blood vessel (artery) carrying oxygenated blood from the heart (left ventricle) to the rest of the body

The blood vessel carrying oxygenated blood from the lungs to the heart (left atrium)

The blood vessel carrying deoxygenated blood from the heart (right ventricle) to the lungs

Blood vessels found on the surface of the heart which provide the heart muscle with its own blood flow for essential gases & nutrients such as (oxygen and glucose)

They separate the atria and the ventricles and prevent back flow of blood from the ventricles into the atria (during ventricular systole)

Separate the ventricles and the arteries, prevent back flow of blood from the arteries into the heart (during ventricular systole)

The only open one way dependent on the pressure, when pressure is higher behind the valve it is forced open and when pressure is higher in front of a valve it is forced closed this maintains a one directional flow in the heart

Cords are attached to the atrioventricular valves from the ventricles. They stop the ventricles being forced upwards into the atria when the ventricles contract. Therefore preventing blood from back flowing

Atrial Systole Ventricular Systole Diastole

Both atria contract in unison, this decreases the volume of the atria and increases the pressure. This forces the atrioventricular valves to open and blood flows down its pressure gradient into the ventricles causing the ventricles to (slightly) increase in pressure and volume

Both ventricles contract in unison, this decreases the volume and increases the pressure in the ventricles. The higher pressure in the ventricles then the atria causes the AV valves to close The higher pressure in the ventricles then the arteries forces the semilunar valves to open, blood flows into the arteries.

All chambers of the heart relax, the arteries higher pressure than the ventricles which forces the semilunar to shut. Blood flows into the atria slowly filling them up as the veins have slightly more pressure than the atria. The increase atria pressure causes the AV valves to open and some blood passively flows into the ventricles.

Found in the right atrium, & releases an electrical signal which coordinates the cardiac cycle and initially results in atrial contraction (aka the pacemaker)