Circulatory System Key Terms
What is the Aortic Valve
A one-way valve located between the left ventricle and the aorta that keeps blood flowing in the correct direction.
What is Arrhythmias
abnormal heart rhythms where the heart may beat too fast, too slow, or irregularly, caused by problems with the heart's electrical system
What are the Arteries
Blood vessels that carry blood away from the heart.
What is Blood
The body's circulating fluid; the average adult has about four to six quarts, composed of plasma (the fluid) and formed elements (blood cells).
What is the Capillaries
Tiny, thin-walled vessels that connect arterioles and venules, allowing for the exchange of oxygen, nutrients, carbon dioxide, and waste products between the blood and body cells.
What is the Circulatory System
Also known as the cardiovascular system, it is the body's "transportation" system, consisting of the heart, blood vessels, and blood.
What is Diastole
A period of rest in the cardiac cycle when the atria fill with blood and the ventricles relax.
What is Endocardium
The smooth inner layer of tissue that lines the inside of the heart.
What is Erythrocytes
Red Blood Cells that contain hemoglobin to carry oxygen.
What is Hemoglobin
The substance contained within erythrocytes (Red Blood Cells) that is responsible for carrying oxygen.
What is Left Atrium
An upper chamber of the heart that receives oxygenated blood returning from the lungs.
What is Left Ventricle
A lower chamber of the heart that pumps oxygenated blood into the aorta for transport to the rest of the body.
What is Leukocytes
White Blood Cells whose main function is to fight infection through phagocytosis and antibody development.
What is the Mitral Valve
A one-way valve located between the left atrium and the left ventricle that keeps blood flowing in the correct direction.
What is Myocardium
The thick muscular middle layer of tissue in the heart.
What is Pericardium
The double-layered outer sac that surrounds and protects the heart.
What is Plasma
The fluid component of blood (about 55% of the blood) that is approximately 90% water and contains dissolved substances like blood proteins and nutrients.
What is Pulmonary Valve
A one-way valve located between the right ventricle and the pulmonary artery that keeps blood flowing in the correct direction.
What is Right Atrium
An upper chamber of the heart that receives blood returning from the body.
What is Right Ventricle
A lower chamber of the heart that pumps blood to the lungs for oxygen.
What is Septum
The partition that divides the heart into a right side and a left side, which prevents blood from mixing.
What is Systole
A period of ventricular contraction in the cardiac cycle when the ventricles push blood out.
What is Thrombocytes
Platelets that are important for the clotting process by forming a sticky plug and releasing chemicals that lead to the formation of fibrin.
What is Tricuspid Valve
A one-way valve located between the right atrium and the right ventricle that keeps blood flowing in the correct direction.
What are Veins
Blood vessels that carry blood back to the heart.