1. Unit 2b: The Cardiovascular System

2. What words do you associate with …
Cardio
Vascular
Cardiac
Veins
Heart
Vascularisation of the endometrium
Activity
Vessels
Exercise / work out

3. B – The Cardiovascular System Key areas:
The structure and function of arteries, capillaries and veins
The structure and function of the heart
Pathology of cardio vascular disease (CVD)
Blood glucose levels and obesity

4. KA 1: The structure and function of arteries, capillaries and veins
Subtopics:
Structure and function of blood vessels
Exchange of materials between tissue fluid and cells
This used to be in a spider diagram format!

5. KA1: Learning Outcomes
Describe the blood flow around the body (in general basic terms)
Describe the structure of arteries and veins using the following terms:
Endothelium
Central lumen
Connective tissue
Elastic fibres
Smooth muscle
Valves
State the role of arteries, veins and capillaries
State the function of valves
Describe what happens to blood pressure as blood moves away from the heart
State what is meant by vasoconstriction and describe how it is caused
State what is meant by vasodilation and describe how it is caused

6. Blood flow around the body (basic)
You need to the order in which blood flows through the vessels:
Capillaries
Artery
Veins
Artery
Veins
Capillaries

7. Blood flow around the body (basic)
Blood circulates from the heart through the arteries to the capillaries to the veins and back to the heart.
HEART
arteries
VEINS
capillaries
capillaries
veins
arteries
HEART

8. Re-cap: what do you already know about the blood vessels
Arteries
Veins
Capillaries
FUNCTION
Description of wall
Valves present?
Pulse present?
EACH GROUP COULD HAVE 3 SHOW ME BAORDS (ONE FOR EACH VESSEL) AND TRY TO WORK TOGETHER TO COMPLETE THE TABLE
TASK: use your show me boards to complete the table

9. Arteries carry blood away from the heart.
The ARTERY
Arteries carry blood away from the heart.
The endothelium lining of the central lumen.
This lining is then surrounded by layers of tissue.
Outer layer:
Connective tissue containing elastic fibres
Middle layer:
Contains smooth muscle with more elastic fibres
The endothelium lining the central lumen of blood vessels is surrounded by layers of tissue.
Central lumen
The elastic walls of the arteries stretch and recoil to accommodate the surge of blood after each contraction of the heart.

10. The VEIN Veins carry blood towards the heart.
The endothelium lining of the central lumen.
Outer layer:
Connective tissue containing elastic fibres
Middle layer:
Contains a much thinner muscular wall than arteries (also has elastic fibres)
Central lumen (much wider than the artery lumen)
Veins also contain VALVES. Valves prevent the BACKFLOW of blood
A LOT more on valves in the next Key Area!!

11. VIDEO CLIP: Valves in action

12. TASK: Demonstrating the emptying of part of a vein in the arm

13. CAPPILARIES
RED BLOOD CELLS
THIN CELL WALL
BODY CELLS

14. Arteries, Veins and Capillaries
Capillaries have a wall which is ONE CELL THICK. This allows for the exchange of substances such as glucose and oxygen with the body tissues.
Arteries carry high pressure blood away from the heart.
Veins carry low pressure blood back to the heart.

15. Summary

16. Vasodilation

17. VIDEO CLIP: vasodilation vasoconstriction

18. Vasodilation Vasoconstriction
This is the widening of blood vessels
Caused by smooth muscle cells relaxing
This results in the lumen becoming wider and blood flow increasing
(To parts of the body such as skeletal muscles during exercise)
This is the narrowing of blood vessels
Caused by smooth muscle cells contracting
This results in the lumen becoming narrower and blood flow decreasing
(To parts of the body such as the small intestine during exercise)

19. KA1: Learning Outcomes
Describe the blood flow around the body (in general basic terms)
Describe the structure of arteries and veins using the following terms:
Endothelium
Central lumen
Connective tissue
Elastic fibres
Smooth muscle
Valves
State the role of arteries, veins and capillaries
State the function of valves
Describe what happens to blood pressure as blood moves away from the heart
State what is meant by vasoconstriction and describe how it is caused
State what is meant by vasodilation and describe how it is caused