Circulatory System

What are capillaries? What is the significance of their size?

Capillaries are the tiny blood vessels that transport blood to and from the cells of the body. Capillaries are so small (one cell thick) that blood cells have to move through them in a single file; materials are also diffused easily in and out of them.

What are the main parts of the circulatory system?

The main parts of the circulatory system are the heart, the blood, and the blood vessels.

What do the blood vessels of the circulatory system do?

They keep oxygen-poor blood from mixing with oxygen-rich blood.

What are veins?

Veins are blood vessels that carry blood from the rest of the body back to the heart.

How are arteries and veins connected?

By a system of capillaries.

What are arteries?

Arteries are blood vessels that carry blood away from the heart to the rest of the body.

What kind of blood do arteries carry? What kind of blood do veins carry?

Arteries carry oxygen-rich blood, and veins carry oxygen-poor blood.

How does the circulatory system help the cells?

It brings vital supplies to the cells and carries away their wastes.

Where does blood inside the circulatory system stay? What kind of system is this?

The blood in the circulatory system stays inside the vessels; it's a closed system.

What does the circulatory system do with oxygen?

The circulatory system carries oxygen to all of the body's cells and transports carbon dioxide from the rest of the body to the lungs, where it is exhaled.

Other than transporting vital supplies to cells, what does the circulatory system do?

The circulatory system collects waste materials produced by digestion and cell metabolism, and delivers them to the liver and kidneys to be filtered out of the body. It helps maintain body temperature by distributing the heat that cells produce in the muscles and internal organs.

What are the three types of blood vessels in the circulatory system?

The circulatory system has three types of blood vessels: arteries, veins, and capillaries.

What is the circulatory system?

The circulatory system is the body system that transports blood and other materials.

What is the function of the circulatory system? How does the circulatory system accomplish this?

The function of the circulatory system is to transport O2 and nutrients to body cells and to carry oxygen-poor blood and CO2 back to the heart and lungs. To do its job, the system must keep blood constantly circulating.

What is the heart? What does it do?

The heart is a muscular pump, about the size of your fist, that keeps the blood moving to every part of the body.

What do your heart and blood vessels do when you're active? In cold weather?

When you are active, your organs and muscles produce more heat. The heart pumps harder, and the blood vessels dilate to bring excess heat to the skin, where it can escape. In cold weather, the blood vessels constrict to conserve heat.