Health: The Cardiovascular System: Heart and Blood
How the heart, blood, and blood vessels work together
Health: The Cardiovascular System: Heart and Blood
How the heart, blood, and blood vessels work together
Health - Grade 6-8
- 1
Explain the main job of the cardiovascular system.
Think about what blood delivers and removes.
The main job of the cardiovascular system is to move blood through the body. Blood carries oxygen, nutrients, hormones, and wastes to and from cells. - 2
Name the three main parts of the cardiovascular system and describe the job of each part.
The three main parts are the heart, blood, and blood vessels. The heart pumps blood, blood carries materials, and blood vessels are tubes that blood travels through. - 3
The heart has four chambers. Identify the two upper chambers and the two lower chambers.
Atrium means upper chamber, and ventricle means lower chamber.
The two upper chambers are the right atrium and left atrium. The two lower chambers are the right ventricle and left ventricle. - 4
Describe the path blood takes from the body to the lungs and back to the body.
Blood low in oxygen returns from the body to the right side of the heart. The right side pumps it to the lungs, where it picks up oxygen. Oxygen-rich blood returns to the left side of the heart, and the left side pumps it out to the body. - 5
Compare arteries, veins, and capillaries.
Focus on the direction of blood flow and the size of the vessels.
Arteries carry blood away from the heart, veins carry blood back to the heart, and capillaries are tiny blood vessels where oxygen, nutrients, and wastes are exchanged with body cells. - 6
Why is the left ventricle usually more muscular than the right ventricle?
The left ventricle is more muscular because it must pump blood to the entire body. The right ventricle only pumps blood to the nearby lungs. - 7
List the four main components of blood and give one function of each.
Remember that blood is made of cells and liquid.
Red blood cells carry oxygen, white blood cells help fight infection, platelets help blood clot, and plasma is the liquid part that carries cells, nutrients, hormones, and wastes. - 8
A student says, "All blood in veins is low in oxygen." Explain why this statement is not always correct.
This statement is not always correct because most veins carry oxygen-poor blood, but pulmonary veins carry oxygen-rich blood from the lungs back to the heart. - 9
Explain what happens to heart rate during exercise and why.
Think about what muscles need when they are active.
Heart rate increases during exercise because working muscles need more oxygen and nutrients. The heart pumps faster to deliver these materials and remove carbon dioxide and other wastes. - 10
What is blood pressure, and why is a healthy blood pressure important?
Blood pressure is the force of blood pushing against artery walls. A healthy blood pressure helps blood move through the body without putting too much strain on the heart and blood vessels. - 11
Describe how valves help the heart move blood correctly.
Think of a one-way door.
Valves are flap-like structures that keep blood moving in one direction. They open to let blood pass and close to prevent blood from flowing backward. - 12
Identify two healthy habits that support the cardiovascular system and explain how each habit helps.
Choose habits that affect the heart, blood vessels, or blood flow.
Regular physical activity strengthens the heart and helps blood flow well. Eating a balanced diet with fruits, vegetables, whole grains, and limited unhealthy fats can help keep blood vessels healthy.