Key Words
Aortic valve
Valve between the left ventricle and the aorta that prevents blood from flowing backward.
Circulatory system
Body system responsible for transporting oxygen, nutrients, and waste through the blood.
Left atrium
The upper left chamber of the heart that receives oxygenated blood from the lungs.
Pericardium
A double-layered membrane that surrounds and protects the heart.
Septum
A muscular wall that separates the right and left sides of the heart.
Arrhythmias
Abnormal heart rhythms caused by improper electrical impulses in the heart.
Diastole
The phase of the heartbeat when the heart muscle relaxes and the ventricles fill with blood.
Left ventricle
The lower left chamber that pumps oxygenated blood into the aorta.
Plasma
The liquid portion of blood that carries cells, nutrients, hormones, and waste.
Systole
The phase of the heartbeat when the ventricles contract and pump blood out.
Arteries
Blood vessels that carry blood away from the heart.
Endocardium
The smooth inner lining of the heart.
Leukocytes
White blood cells that fight infection.
Pulmonary valve
Valve between the right ventricle and pulmonary artery that prevents backflow.
Thrombocytes
Platelets that help the blood clot.
Blood
The fluid that circulates through the vessels to carry oxygen and nutrients to the body.
Erythrocytes
Red blood cells that carry oxygen.
Mitral valve
Valve between the left atrium and left ventricle that prevents backflow.
Right atrium
The upper right chamber that receives deoxygenated blood from the body.
Tricuspid valve
Valve between the right atrium and right ventricle that prevents backflow.
Capillaries
Tiny blood vessels that connect arterioles to venules and allow the exchange of oxygen and wastes.
Hemoglobin
Iron-containing protein in red blood cells that carries oxygen.
Myocardium
The thick muscular middle layer of the heart.
Right ventricle
The lower right chamber that pumps blood to the lungs.
Veins
Blood vessels that carry blood toward the heart.