1. BLOOD CIRCULATORY SYSTEM

2. Cardiovascular System
Every cell in the body needs oxygen to survive and there is only one way they can get it – through the blood.
Blood has three main functions;-
Transportation
Regulation
Protection
(Tommy Prays Regularly)

3. Transportation Blood transports: Oxygen from the lings to the cells
Carbon dioxide from the cells to the lungs
Nutrients from the gastrointestinal tract to the cells
Heat and waste away from cells
Hormones from glands to cells

4. Regulation Blood regulates: The PH of the body
The temperature of the body
The water content of cells

5. Protection
Blood protects the cells against foreign microbes and toxins and also has the ability to clot and so protect the body against excessive blood loss.

6. THE BLOOD
Blood is composed of 55% straw-coloured fluid called plasma and 45% is made up of cells
Three main types of blood cells:
Erythrocytes Red blood cells
Leucocytes White blood cells
Thrombocytes Platelets

7. RED BLOOD CELLS Most numerous of all the blood cells.
No nucleus and the cytoplasm is filled with haemoglobin which carries oxygen.
Bi-concave shape
Their membranes allow for the exchange of oxygen.
Produced in the bone marrow.

9. WHITE BLOOD CELLS Leucocytes
Primarily for protection of the body against foreign microbes.
They live between a few hours to a few days and are pale whitish in colour.
Can be categorised into granulocytes and agranulocytes.

10. Granulocytes
Neutrophils – engulf and digest foreign particles through phagocytosis.
Eosinophils – destroy certain parasitic worms and combat the effects of some inflammatory complexes.
Basophils – contain histamine which causes dilation of blood vessels. They release histamine at sites of inflammation

11. Agranulocytes
Lymphocytes – play an important role in immune response and are present in lymphatic tissue such as the lymph nodes.
Monocytes – some circulate in blood and are phagocytic others migrate to the tissues to become macrophages which clean up infection.

12. Thrombocytes
Thrombocytes function in heamostasis, which is the process by which bleeding stops.
Thrombocytes form a platelet plug and release chemicals that promote blood clotting.

13. Clotting
Platelets will clot a damaged area where blood loss has occurred.
Clotting prevents excess blood loss and protects against microbe entry.

14. BLOOD VESSELS
Blood flows around the body by the pumping action of the heart and is carried in vessels known as :-
Arteries
Veins
Capillaries

15. ARTERIES Carry blood under pressure away from the heart.
Thick muscular walls to withstand pressure.
No valves
Carry oxygenated blood, except for the pulmonary artery.
Lie deeper than veins

16. VEINS Carry blood back to the heart under low pressure.
The walls are less thick and elastic.
Valves prevent backflow.
Carry deoxygenated blood except for the pulmonary vein.

17. CAPILLARIES Smallest vessels.
They join the arterioles and the venules.
Only one cell thick to allow for the transfer of substances between the cells and the capillaries.
Have no valves

19. CAPILLARY EXCHANGE
The exchange of substances between tissue cells in the body and the blood in the capillaries.
Oxygen, nutrients, vitamins and minerals pass into the tissue fluid to nourish the cells.
Carbon dioxide and waste products pass out of the cell and back into the blood to be excreted.

21. THE HEART Made up of cardiac muscle tissue.
Lies in the centre of the thorax under the sternum
Made up of three layers
Pericardium, outer layer that
encloses the heart
Myocardium, middle layer of
strong muscle
Endocardium, inner layer
which lines the heart cavities

22. FUNCTION OF THE HEART Acts as a pump.
To maintain a constant circulation of blood in the body.
The heart rate will speed up or slow depending on the volume of blood required by the body.

24. MAIN BLOOD VESSELS OF THE HEART
MAIN ARTERIES
AORTA
Takes oxygenated blood to the body
PULMONARY ARTERY
Takes deoxygenated blood to the lungs
MAIN VEINS
SUPERIOR AND INFERIOR VENA CAVI
Brings deoxygenated blood from the body back to the heart.
PULMONARY VEINS
Brings oxygenated blood from the lungs to the heart

25. BLOOD FLOW THROUGH THE HEART
Deoxygenated blood flows through the right side of the heart and is pumped to the lungs to pick up oxygen. It then travels back to the left side of the heart where it is pumped around the body.

26. CONTRACTION OF THE HEART
The atria contract together to force the blood into the ventricles. The atria then relax and the ventricles contract to push the blood out of the heart and around the body

27. BLOOD CIRCULATION
There are two main divisions to the blood circulation
Pulmonary circulation
Systemic or general circulation

28. PULMONARY CIRCULATION
The circulation of the blood to the lungs, where carbon dioxide is removed and oxygen obtained before it returns to the heart.

29. SYSTEMIC CIRCULATION
The circulation of oxygenated blood around the body and the return of deoxygenated blood to the heart.
Blood leaves the heart via the aorta which divides into branches to supply the different areas of the body

30. BRANCHES OF THE AORTA
The ascending arch supplies the head, neck and top of arms.
Descending thoracic supplies the organs of the thorax.
Descending abdominal supplies the legs, renal, digestive and reproductive systems.

32. ARTERIES TO THE HEAD
Facial artery
Occipital artery
Carotid artery

33. VEINS FROM THE HEAD
External Jugular
Internal Jugular

34. BLOOD SHUNTING
The system of diverting blood from some areas of the body to other areas where it is in need.
For example, blood is diverted to the muscles during exercise where it is required and away from the digestive system where it is not vital.

35. BLOOD PRESSURE
The force with which blood is pumped through the vessels.
The maximum (systolic) pressure is when the blood has just been pushed into the arteries.
The minimum (diastolic) pressure is when the
heart relaxes and blood flows into the heart from the veins.

36. FACTORS AFFECTING BP
Anything that makes the heart beat faster will raise the blood pressure.
Excitement Anger
Stress Fright
Pain Exercise
Smoking and drugs

37. THE PULSE
The pulse is the wave of blood as it passes through the arteries.
It can be felt at positions on the body where the arteries pass close to the surface.

38. The Cardiac Cycle Systole – contraction Diastole - relaxation
The cardiac cycle lasts approximately 0.8 seconds and is involved with the contraction and relaxation of both atria and ventricles.
Systole – contraction
Diastole - relaxation

39. ECG trace

40. Cardiac diastole
This occurs at the end of the heartbeat and all four chambers relax.

41. Atrial systol
The SA node stimulate the contraction of the atria. They contract simultaneously and empty all their contents into the ventricles.

42. Ventricular systole
Ventricular contraction is then triggered by the AV node and as the ventricles contract blood is pushed up against the AV valves, forcing them shut.

43. Cardiac diastole
After ventricular contraction both the atria and ventricles are relaxed, therefore starting another cycle.

44. END OF SLIDE SHOW