What is Circuit?

Now, just like lightning, charges have a tendency to try to make their way to the earth if they can.

This is why if you have a conducting material and connect it to the earth with a wire or something, it is said to be grounded

Grounding is a good thing to do with circuits because if there is too much charge going through a circuit

you don't want it to stay in the circuit and fry everything, grounding a circuit is generally safe

To finish off the idea of the very basic circuit, we know that it allows a charge to build up and move through it, now we need to know that the circuit must be complete.

The ending picture of the circuit must make a complete loop so that those charges that like to move have somewhere to allways go

What happens if you hook a wire from one end of a battery to nothing else.....NOTHING. The circuit is not completed therefore the charges can't move off the end of the wire and continue to go.

Pulmonary circuits take the blood (that has no oxygen) from the heart to the lungs.

The blood travels through the veins [systemic], to the vena cava and the right atrium. From the right atrium,

it travels to the right ventricle and out to the pulmonary arteries.

From here the blood picks up oxygen and drops off the carbon dioxide.

Systemic circuits take the oxygenated blood from the lungs to the heart

The blood travels
back into the pulmonary arteries

From there the blood moves from the arteries to the left
ventricle and left atrium.

The blood then goes out of the aorta through the systemic veins.
When it gets to the systemic capillary beds it drops off the oxygenated to the rest of
the body tissues.

Pulmonary and systemic circuits both use the same types of veins and arteries

The circuits go in a loop in opposite directions. When one circuit drops off the blood, the other circuit picks it up and goes back through the heart

The pulmonary circuit goes through the right part of the heart

The systemic circuit goes through the left part of the heart.

The hear makes a lubb-dupp sound because the blood going through the heart.

The lubb is the sound of the blood going through the atrioventricular valve.

When the valves contract and the A-V valves closes, the sound is made

The dupp is the sound of the blood going through the semilunar ventricle.

When the ventricle closes and the muscles relax, the dupp sound is made.

The cardiac cycle is a complete heartbeat or it could refer to your blood rate.