1. Circulatory system

2. What are we going to learn ?
Heart
Blood circulation
Blood vessels
Blood
Blood groups

3. Heart
Acts like a pump of the circulatory system supplying blood to the whole body
Located between the lungs a little to the left; size roughly equal to a fist
Made up of muscle with a dual protective layer
Two internal sections unconnected to each other
Left section contains Oxygen-rich blood received from the lungs
Right section contains Oxygen-poor blood to be sent to lungs
Each section has two chambers
Upper chamber called Atrium; Lower chamber called as Ventricle
Atrium and ventricle connected to each other by a one-way valve

4. Heart Internal structure Pulmonary artery valve Aorta valve
Aorta (carries blood to body)
Superior vena cava (carries blood to heart)
Left pulmonary arteries (carry blood to lung)
Right pulmonary veins (carry blood from lungs)
Left atrium
Pulmonary artery valve
Aorta valve
Right atrium
Mitral valve
Tricuspid valve
Left ventricle
Right ventricle
Pericardium
Inferior vena cava (carries blood to heart)

5. How does the heart function?
Both valves close so that blood cannot go back to atria.
Ventricles contract and blood goes out to lungs through pulmonary arteries and to the rest of the body through the aorta.
Atria then expand and the cycle starts again. 3
Atria contract, both valves open and blood enters ventricles 2
Oxygen-poor blood from all over the body
Oxygen-rich blood from the lungs
Both atria expand and the blood enters right atrium through vena cava and left atrium through pulmonary veins 1

6. Heart beats
Heart beats occur due to the rhythmic expansion-contraction of the heart muscles.
Normally they range between 60 to 80 per minute.
In other words the heart expands and contracts almost one hundred thousand times day !

7. Blood circulation
Lungs
This is the process of supply of blood to all the limbs of the body and its return to the heart.
Two types
Pulmonary circulation: Oxygen-poor blood travels from the heart to the lungs and Oxygen-rich blood travels back
Systemic circulation: Oxygen-rich blood travels from the heart to the all the limbs of the body and Oxygen-poor blood travels back
Cells in the body

8. Blood circulation video

9. Blood vessels Blood circulates through blood vessels Three types
Network of vessels spread throughout the body
Circulation only in one direction
Three types
Arteries
Veins
Capillaries

10. Arteries Carry blood from the heart to various limbs No valves
Blood flows under pressure (100mm of Hg)
Other than pulmonary arteries all arteries carry Oxygen-rich blood
Walls of arteries are made of three layers of muscle. These thick walls contract and push blood forward

11. Veins
Except for pulmonary veins all other veins carry Oxygen-poor blood from various limbs to the heart
Walls are thin
Valves stop blood from flowing in reverse direction
Blood flows under low pressure (2 mm of Hg)
Valves permit flow only in one direction

12. Capillaries
Consist of a network of microscopic vessels joining arteries with veins
Extremely thin walls
Capillaries permit exchange of nutrients, gases etc. in the blood with the cells
Capillary network
Artery
Veins
Cells

13. Constituents of blood - 1
Red blood cells
Platelets
Plasma
Carbon dioxide
Nutrients (Glucose, Amino acids)
Unwanted items Ammonia, Urea
Hormones
Blood
Oxygen
White blood cells

14. Constituents of blood - 2
Plasma
Light yellow colour
Alkaline
90% water, 7% proteins, 3% non-organic matter
Blood cells
Red blood cells
White blood cells
Platelets
Plasma 54.3%
White blood cells and platelets 0.7%
Red blood cells 45%
White blood cells
Red blood cells
Platelets
Plasma

15. Red blood cells Circular shape, No nucleus, concave on both sides
Function: Supply Oxygen to body cells
Hemoglobin in the red blood cells acts as the transport of Oxygen
1 cubic mm contains 500 to 600 thousand red blood cells

16. White blood cells Colourless, amoeba-like cells with nucleus
Function: Protect body from bacteria
1 cubic mm contains 5000 to white blood cells

17. Platelets Small, irregular shape
Function: Help in coagulation of blood
After a wound platelets create a network of fibrin strings
Red blood cells are trapped in the network and form a scab on the wound
1 cubic mm = 150 to 400 thousand platelets

18. Blood groups
Blood is grouped into 4 categories based on proteins in it
A, B, O, AB
Sub-groups Rh+ and Rh- in each group
Before donating blood the blood groups have to be matched as under
Blood group of a person
Blood can be donated to
Blood can be received from A
A, AB
A, O B
B, AB
B, O AB
A, B, AB, O O

19. The end