Question

before you read
after you read this section, you should be able to answer these questions:

• what is the cardiovascular system?
• what are some cardiovascular problems?

what is the cardiovascular system?
your heart, blood, and blood vessels make up your cardiovascular system. the word cardio means heart. the word vascular means blood vessels. blood vessels are hollow tubes that your blood flows through. the cardiovascular system is also sometimes called the circulatory system. this is because it circulates, or moves, blood through your body.
the cardiovascular system helps your body maintain homeostasis. homeostasis is the state your body is in when its internal conditions are stable. the cardiovascular system helps maintain homeostasis in many ways:

• it carries oxygen and nutrients to your cells
• it carries wastes away from your cells
• it carries heat throughout your body
• it carries chemical signals called hormones throughout your body

the heart
your heart is an organ about the same size as your fist. it is near the center of your chest. there is a thick wall in the middle of your heart that divides it into two halves. the right half pumps oxygen - poor blood to your lungs. the left half pumps oxygen - rich blood to your body.
each side of your heart has two chambers. each upper chamber is called an atrium (plural, atria). each lower chamber is called a ventricle. these chambers are separated by flap - like structures called valves. valves keep blood from flowing in the wrong direction. the closing of valves is what makes the \lub - dub\ sound when your heart beats. the figure at the top of the next page shows how blood moves through your heart.

Explanation:

The text mentions that the cardiovascular system helps maintain homeostasis by carrying oxygen and nutrients to cells and carrying wastes away from cells. These are two of its functions.

Answer:

It carries oxygen and nutrients to your cells. It carries wastes away from your cells.