1. Circulatory System
Noadswood Science, 2016

2. Thursday, February 22, 2018
Circulatory System
To describe the circulatory system and the function it provides

3. Precise Learning
The body contains three different types of blood vessel:
arteries
veins
capillaries
Students should be able to explain how the structure of these vessels relates to their functions.
Students should be able to use simple compound measures such as rate and carry out rate calculations for blood flow.
Blood is a tissue consisting of plasma, in which the red blood cells, white blood cells and platelets are suspended.
Students should know the functions of each of these blood components (evaluate risks related to use of blood products)
Students should be able to recognise different types of blood cells in a photograph or diagram, and explain how they are adapted to their functions.

4. Circulation
What is the function of the circulatory system? What does it transport?
The circulatory system is the body's main transport system, carrying food and oxygen to the cells and taking waste products (carbon dioxide) away
It consists of the heart; arteries; veins; and capillaries

5. Circulatory System

6. Oxygen
Oxygen is initially absorbed into the blood within the lungs (via diffusion)
It will now travel through a variety of systems in order to get to the cell, where it is needed for respiration

7. Traveling
Blood travels through three types of vessel - arteries, veins and capillaries with have specific properties: -
Arteries are thick-walled muscular tubes which carry blood away from the heart - fast flowing!
Veins are thin walled tubes which carry blood back to the heart – they have a large diameter and valves as the blood flows slower
Capillaries are extremely narrow tubes which carry blood through our tissues: their walls are just one cell thick - so thin that oxygen, food and waste products can easily pass through them

8. narrow central tube (lumen)
Blood Vessels – Artery
Arteries are thick-walled muscular tubes which carry blood away from the heart - fast flowing!
thick outer wall
thick inner layer of muscle and elastic fibres
narrow central tube (lumen)

9. wide central tube (lumen)
Blood Vessels – Veins
Veins are thin walled tubes which carry blood back to the heart – they have a large diameter and valves as the blood flows slower
thin outer wall
thin inner layer of muscle and elastic fibres
wide central tube (lumen)

10. Blood Vessels – Capillaries
Capillaries are extremely narrow tubes which carry blood through our tissues: their walls are just one cell thick - so thin that oxygen, food and waste products can easily pass through them
wall only one cell thick

11. Blood Vessels blood to the heart blood from the heart
Artery
Carries blood away from the heart
Vein
Carries blood back into the heart
carries blood to and from the body’s cells

12. Blood
Blood is a liquid tissue whose function is to fight disease and to transport materials around the body
Blood plasma (liquid) containing glucose, amino acids, nutrients, hormones, as well as waste materials like urea
Red blood cells contain haemoglobin, a protein which picks up oxygen molecules in the lungs
White blood cells fight disease by making antibodies and fighting germs
Platelets are cell fragments. Together with fibrinogen they form clots to repair cuts or tears in nearby tissue

13. Blood Plasma
Blood plasma is the liquid which carries everything in the blood (a pale straw-coloured liquid)
Red and white blood cells; nutrients such as amino acids and glucose; carbon dioxide; urea; hormones; antibodies and antitoxins are all carried in the blood plasma

14. Red Blood Cells
Red blood cells carry oxygen from the lungs to all the cells in the body – they have a doughnut shape to maximise their surface area and they contain no nucleus at maturity
They contain the red pigment haemoglobin which combines with oxygen at the lungs (becoming oxyhaemoglobin)
In body tissues the oxygen and haemoglobin split (which releases the oxygen to the cells)

15. White Blood Cells
White blood cells defend against disease – they can change shape to consume unwelcome microorganisms (they do contain a nucleus)
White blood cells also produce antibodies to fight microorganisms and antitoxins to neutralise any toxins produced by harmful microorganisms

16. Platelets Platelets are small fragments of cell and have no nucleus
They help the blood to clot at a wound stopping blood loss (and microorganisms entering)
A lack of platelets can cause excessive bleeding and bruising

17. Heart
What do you know about our heart? How does it work? How is it specialised?
The heart pumps blood around the body – in humans this is a four chambered pump
The right side of the heart pumps deoxygenated blood to the lungs to pick up oxygen
The left side of the heart pumps the oxygenated blood from the lungs around the rest of the body (which is why it is more muscular)

18. Heart
The right side of the heart pumps deoxygenated blood to the lungs to pick up oxygen
The left side of the heart pumps the oxygenated blood from the lungs around the rest of the body (which is why it is more muscular)

19. Heart lungs body’s cells
Deoxygenated blood is pumped from the heart to the lungs through the pulmonary artery
Oxygenated blood returns to the heart through the pulmonary vein
Oxygenated blood is pumped at high pressure from the heart to the body through the aorta
Deoxygenated blood returns to the heart through the vena cava
body’s
cells

20. Double Circulation lungs body’s cells
The pulmonary circulation carries: -
Deoxygenated blood from the heart to the lungs
Oxygenated blood back from the lungs to the heart, ready to be pumped out to the body
body’s
cells
The systemic circulation carries: -
Oxygenated blood to the rest of the body through the arteries
Deoxygenated blood back to the heart through the veins

21. blood flow = volume of blood ÷ time
E.g ml of blood passed through an artery in 4.5 minutes
1464 ÷ 4.5 = 325 ml/min

22. Cells
Oxygen and glucose leak out of the capillaries and the cells close by absorb the required oxygen and glucose
The waste products (including carbon dioxide) pass out of the cells and into this fluid, that is then re-absorbed by the blood
Capillaries do not join up to every cell - instead fluid is passed out of them, with cells close by absorbing what they need

23. Summary Oxygen enters the body in the lungs, via breathing
It is absorbed into the blood, where it passes through the heart and then throughout the body (via the circulatory system)
It travels through arteries, veins and capillaries
Cells and blood exchange materials in the fluid, which is released adjacent to the capillaries
The cells then use this oxygen for respiration

24. Stents
Stents keep arteries open (tubes inserted inside arteries keeping them opening allowing blood to pass)
Stents lower the risk of a heart attack, especially for individuals who suffer coronary heart disease (fatty deposits blocking the blood supply to the heart)

25. Worksheet
Match the circulatory key words with their function

26. Worksheet Complete the circulatory system worksheet Arteries Heart
Veins
Capillaries
One cell thick

27. Donation

28. Donation

29. Practice Questions Describe the structure of an artery
What type of blood vessel has walls that are only one cell thick?
Describe how substances in the blood pass into body cells
Give two differences between the structure of a vein and the structure of an artery

30. Answers
Describe the structure of an artery – artery has thick walls in comparison to its lumen (thick muscle and elastic fibres)
What type of blood vessel has walls that are only one cell thick – capillary
Describe how substances in the blood pass into body cells – capillaries carry blood close to the cells which allows substances to diffuse in/out
Give two differences between the structure of a vein and the structure of an artery – vein thinner walls / bigger lumen / valves

31. Practice Questions – Application
Alan has a condition known as SVCS – it is very serious as it obstructs blood flow going into the heart. Which type of blood vessel do you think SVCS affects
The graph below shows the relative pressure inside two different blood vessels (a vein and artery). Which blood vessels contains a higher proportion of muscle

32. Practice Questions – Application
In a particular artery in the body the average rate of blood flow should be between 270 and 315 ml/min. A doctor measured this blood flow and in five minutes 1075 ml had passed – the doctor thought there may be a blockage. Calculate the blood flow and say if you agree or not with the doctor

33. Practice Questions – Application
Alan has a condition known as SVCS – it is very serious as it obstructs blood flow going into the heart. Which type of blood vessel do you think SVCS affects – vein (carry blood to heart)
The graph below shows the relative pressure inside two different blood vessels (a vein and artery). Which blood vessels contains a higher proportion of muscle – arteries at higher pressure (A) due to more muscular walls

34. Practice Questions – Application
In a particular artery in the body the average rate of blood flow should be between 270 and 315 ml/min. A doctor measured this blood flow and in five minutes 1075 ml had passed – the doctor thought there may be a blockage. Calculate the blood flow and say if you agree or not with the doctor
1075 ÷ 5 = 215 ml/min
*Yes may be a blockage as this is lower than the average