Answer:
Blood vessels. These bring blood to the lungs, where oxygen enters the bloodstream, and then to the body:
The inferior and superior vena cava bring oxygen-poor blood from the body into the right atrium.
The pulmonary artery channels oxygen-poor blood from the right ventricle into the lungs, where oxygen enters the bloodstream.
The pulmonary veins bring oxygen-rich blood to the left atrium.
The aorta channels oxygen-rich blood to the body from the left ventricle.
An electrical system that stimulates contraction of the heart muscle.
A network of arteries and veins also carry blood throughout the body:
Arteries transport blood from the heart to the body tissues.
Veins carry blood back to the heart.
Step-by-step explanation: