Circulatory System

Pulmonary Circuit

Right side feeds it. It goes into the lungs and includes the lungs.

Systemic Circuit

Left side feeds it. Carries oxygenated blood through arteries.

Septum

Muscular wall separating the left and right sides of the heart. Keeps pulmonary and systemic circuits separate.

Atria

Right Atria accepts deoxygenated blood. Left Atria accepts oxygenated blood.

Atrioventricular Valves

Is flaps of tissue. Separates the atria from the ventricles. It ensures no back flow of blood. Greater blood pressure in atria than in ventricles causes the valves to open, allowing the blood to flow into the ventricles.

Chordae Tendineae

Appears as strings. Attaches AV valves to the ventricles. Prevents AV valves from inverting when ventricles contract.

Right Ventricles

They contract together to send blood out of the heart.

Pumps deoxygenated blood to the lungs. Contractions cause the AV valve to close. Pumps through the pulmonary valve to the pulmonary trunk and then pulmonary arteries (lungs)

Left Ventricle

They contract together to send blood out of the heart.

Pumps oxygenated blood to the rest of the body. Blood leaves through the aortic valve to the aorta.

Semi-Lunar Valves

Pulmonary Valves and Aortic Valve are both _____ types of valves.

Coronary Arteries

1st branches of the Aorta. Largest artery in the body. Delivers oxygenated blood into the heart muscle. Coronary veins take blood back to the vena cava when it enters the right atrium.

SA & AV Nodes

They beat in synchronization. The heartbeat is independent.

SA Node

Upper right atrium and initiates heartbeat. Sends a signal every 0.85 seconds. It causes the atria to contract and then sends a nerve impulse to the _____.

AV Node

Lower right atrium. When it accepts the electrical impulse, the _____ causes the ventricles to contract. AV nodes uses Purkinje fibers to stimulate the ventricles.

Purkinje Fibers

Nerves that begin at the AV node and send impulses through both ventricles.

Medulla Oblongada

Part of the brain that controls the heart. Sends a signal to the SA node through a nerve if it needs to accelerate contraction if more oxygen is needed in tissues or if there is low blood pressure.

Parasympathetic

Decrease in SA/AV activity. Resting and Relaxing is caused from this.

Sympathetic

Increase in SA/AV activity. Cause(d)(s) activity/ stress.

Systole

Contraction of the ventricles.

Diastole

Relaxation of the ventricles.

Hypertension

High blood pressure. 130/80

Hypotension

Low blood pressure. 90/60

Atherosclerosis

Accumulation of masses of fatty material beneath inner linings of arteries. They interfere with blood flow and increase the blood pressure. Can cause clots, then heart attacks or strokes.