Circulatory System

Question 1

What are the functions of the circulatory system?

Answer 1

• Transport: of substances such as oxygen and CO2
• Control of body temperature: blood moves toward skin to cool us down, as excess heat can escape easier
• Protection: in the form of our immune system. Blood carries WBC which helps fight disease. Platelets also clot the blood to stop bleeding

Question 2

Describe the process of the blood moving through the heart

Answer 2

1. Deoxygenated blood enters right atrium
2. Moves down into right ventricle
3. Blood is pumped out of the ventricle into lungs to pick up oxygen and get rid of CO2
4. Oxygenated blood returns to the heart into the left atrium
5. Moves down into left ventricle
6. Blood is pumped out of the ventricle into the body via aorta (largest artery in the body)

Question 3

What are the 3 types of blood vessels

Answer 3

• arteries
• veins
• capillaries

Question 4

Describe arteries

Answer 4

• carry blood away from the heart
• carry oxygenated blood (except for pulmonary artery which carries deoxygenated blood to the lungs)
• thick, strong, elastic walls
• smaller arteries are called arterioles

Question 5

Describe veins

Answer 5

• carry blood back to the heart
• carry deoxygenated blood (except for pulmonary vein which carries oxygenated blood from the lungs to the heart)
• contains valves to make sure the blood travels in the right direction when under lower pressures
• thinner walls
• smaller veins are called venules

Question 6

Describe capillaries

Answer 6

• the smallest blood vessels which connect veins and arteries
• travel deep inside muscles and organs to supply nutrients and oxygen
• have walls only 1 cell thick to allow exchange of these substances

Question 7

Do arteries or veins withstand more pressure?

Answer 7

Arteries. Blood is forced into them, thicker walls. Veins have less pressure and therefore need valves to prevent blood from flowing the wrong way

Question 8

What is systolic pressure?

Answer 8

The pressure when the heart beats…slightly higher number

Question 9

What is diastolic pressure?

Answer 9

When the pressure drops due to the heart relaxing

Question 10

How is blood pressure measured

Answer 10

sphygmomanometer. ex. 120/80

Question 11

What are the 4 factors that affect blood pressure and how?

Answer 11

Age: BP increases with age as the artery walls thicken, decreasing space within them
Gender: Men often experience high blood pressure
Exercise: During exercise the heart pumps harder and faster, increasing blood pressure. In the long term, exercise decreases blood pressure
Stress: stress raises BP