Transport & Circulation System

The internal cavity of this structure is divided into four separate chambers.

• heart

• lungs

• liver

• aorta

Systemic circulation is initiated with every contraction of this very muscular chamber.

• left atrium

• left ventricle

• right ventricle

• right atrium

All vessels that carry blood away from the heart can be classified as this.

• aorta

• vessels

• arteries

• veins

The exchange of material between blood and body cells occurs across the walls of these vessels.

• venules

• arteries

• veins

• capillaries

The pacemaker of the heart, the sinoatrial node (SA node), is found in the wall of this chamber.

• right atrium

• left atrium

• right ventricle

• left ventricle

Blood from the lungs is collected here. The blood only needs to be squeezed into the ventricle so its walls are relatively thin.

• left vein

• left atrium

• right atrium

• aorta

To prevent backflow and to keep low-pressure blood moving in one direction, these larger vessels contain one-way valves.

• arterioles

• capillaries

• veins

• arteries

Made up of cardiac muscle. Cardiac muscle and smooth muscle are under involuntary control. Meaning, you cannot consciously control the movement of these muscles in your body.

• liver

• spleen

• lungs

• heart

This vessel carries oxygenated blood to the heart. Blood here has the highest oxygen concentration and lowest carbon dioxide concentration in the circulation.

• pulmonary vein

• left atrium

• arteries

• pulmonary artery

The “Inferior” one collects blood from the lower portion of the body (feet, legs, pelvis, and abdomen).

• heart

• vena cava

• aorta

• pulmonary