Circulatory Circulatory SystemSystem

Heart Terms

Myocardium – The muscle that forms the heart wall. Creates the “beat” of the heart.

Endocardium – A tough membrane that lines the four chambers of the heart.

Pericardium – The sac or chamber that encloses the heart.

Pericardium

MyocardiumEndocardium

More Heart Terms

Septum – The inner wall that separates the two halves of the heart.

Atrium – The upper chamber of the heart (thin wall).

Ventricle – The lower chamber of the heart (thick wall).

Pericardium

MyocardiumEndocardium

Septum

Left VentricleRight Ventricle

Right Atrium

Left Atrium

Why are the walls of the ventricles thicker than the walls of the

atriums?

Blood Vessels

Arteries – blood vessels that carry blood away from the heart.

Veins – blood vessels that carry blood back to the heart.

Capillaries – blood vessels that connect arteries to veins. Gas exchange occurs in the capillaries.

Blood Vessels of the Heart

Aorta – The largest artery, carries blood from the left ventricle to the body.

Vena Cava – Blood from the body enters the heart through this vein.

Pulmonary Artery – Carries blood from the heart to the lungs (CO2 in blood).

Pulmonary Vein – Carries blood from the lungs to the heart.

Pericardium

MyocardiumEndocardium

Septum

Left VentricleRight Ventricle

Right Atrium

Left Atrium

Pulmonary Vein

Pulmonary Artery

Aorta

Superior Vena Cava

Valves

Flaps in the heart that do not allow blood to flow backwards

Heart Valves

Tricuspid – Between right ventricle and right atrium

Mitral – Between left ventricle and left atrium Pulmonary – Between right ventricle and

pulmonary artery Aortic – Between the left ventricle and the

aorta

AorticTricuspid

Pulmonary

Mitral

The Right side of the heart carries deoxygenated blood

The left side of the heart carries oxygenated blood.

Let’s see the circulatory system in action!!!

Blood Flow Video

Basic Blood Flow Through the Heart

Complex Blood Flow Through the Heart

7th Grade - Heart