Blood vessels

Question 1

Arteries

Answer 1

Is a thick vessel with a small diameter. It has to be thick because the arteries carry blood at high pressure.
- Carry oxygenated blood from the heart to the body.
- Only the pulmonary arteries carry DeO2 from the hear to the lungs

Question 2

Structure of Arteries

Answer 2

3 layers of tissue: Smooth muscle tissue - Endothelium - connective tissue

Heat contracts which causes the arteries to expand to accommodate the increased pressure

Expand

Question 3

Veins

Answer 3

Large and thin vessels and they have a large inner diameter and a one way valve

• Carry deoxygenated blood under low pressure form the body to the heart
  Exception: The pulmonary vein carry 0z from the lungs to the heart

Question 4

Structure of the veins

Answer 4

The middle layer of the veins arent as thick as the arteries
- Walls are not elastic
- Greater inner diameter

Question 5

Capillaries

Answer 5

• One cell wall thick
• Inner diameter is less than 7
  micrometers
• Carry blood cells under low pressure in a single file for gas exchange to happen
• The blood in the capillaries gives carbon dioxide (waste) through the capillary walls into the alveoli and takes up oxygen form the alveoli

Question 6

Vasoconstriction

Answer 6

Nerve impulses cause the smooth muscle in the arterioles to contract - this causes the inner diameter to get smaller, which allows less blood to flow, decreases the amount of heat loss

occurs when the body is cold.

Question 7

Vasodilation

Answer 7

Nerve impulses tell the smooth muscle in the arterioles to relax, increasing the inner diameter, increase the blood flow, increase the thermal energy loss into the environment. Cooling mechanisms - happens when the body is hot