The Circulatory System

Question 1

5 Major functions

Answer 1

1. Carries nutrients to cells
2. brings waste (CO2) away from cells
3. sends chemical messengers from cells in one part of the body
4. distribute heat throughout the body
5. maintains acceptable level of body fluids (with kidneys)

Question 2

What’s it composed of?

Answer 2

Heart, veins, and arteries

Question 3

Blood vessels

Answer 3

blood flows from heart via the blood vessels and back to the heart

Question 4

Arteries

Answer 4

A for Away from the heart.
- carries blood under HIGH pressure
- thick, elastic, muscular walls
- Aorta = largest artery
- increase O2, decrease CO2

Question 5

Arterioles

Answer 5

• smaller than arteries
• less elastic, no change in diameter as much when blood flows through

Question 6

Capillaries

Answer 6

• smallest blood vessels (1 cell thick)
• no elastic or muscular layers
• connect arteries and veins

Question 7

Venules

Answer 7

V. Small veins
- carry blood from capillaries to larger veins
- structure like veins

Question 8

Veins

Answer 8

TO THE HEART
- thin walled, no muscle
- carry blood under LOW pressure
- has valves to prevent back flow (1 way flaps)
- largest vein = vena cava
- decrease O2, increase CO2

Question 9

Vasoconstriction

Answer 9

• decrease diameter of the blood vessel
• decrease blood flow and amount of oxygen to tissue
• looking pale

Question 10

Vasodilation

Answer 10

• increase diameter of blood vessel
• increase blood flow and amount of oxygen to tissues
• blushing