1. Higher Human Biology Unit 2: Physiology and Health
Chapter 11 Structure of the cardiovascular system
1. Vessels of the cardiovascular system

2. What you should know
The differences in structure of arteries, capillaries and veins
Direction of blood flow from and to the heart
What happens to blood pressure as blood moves away from the heart?
What is the role of vasoconstriction and vasodilation in controlling blood flow?

3. Arteries Endothelium lines the inner surface of the artery
Elastic fibres allow artery to stretch with each high pressure surge in blood flow from heart
Smooth muscle enable vessel to stretch and recoil with each heart beat
Connective tissue anchors the arteries to other tissue
The lumen is the central core of the artery where the blood flows

4. Capillaries Endothelium very thin, one cell thick
Thinness allows efficient diffusion of materials from and to cells
Connect arteries to veins
Blood pressure decreasing

5. Veins Endothelium Valve to prevent backflow of blood at low pressure
Elastic tissue
Smooth muscle
Connective tissue
Lumen

6. Connecting arteries to veins
Arteries become smaller arterioles
Arterioles become smaller capillaries
Capillaries become larger venules
Venules join to larger veins

7. Fine control of blood distribution
Vasoconstriction and vasodilation occur in both arterioles and venules
Enables blood flow to be regulated during different circumstances
Revision – sympathetic and parasympathetic nervous systems

8. The cardiovascular system

9. What do I know?
The differences in structure of arteries, capillaries and veins
Direction of blood flow from and to the heart
What happens to blood pressure as blood moves away from the heart?
What is the role of vasoconstriction and vasodilation in controlling blood flow?