1. How much do you know?
1. How many blood cells are destroyed in the human body in one second?
150,000
15,000,000
150,000,000
2. A man’s heartbeat is faster than a women’s. True or False?
True
False

2. How much do you know?
3. The adult's heart pumps about 15,140 litres of blood in what amount of time?
One day
One hour
One week

3. How much do you know?
4. How long (on average) does it take for blood to circulate around the WHOLE body?
23 seconds
23 minutes
23 hours

4. How much do you know? clear 7. Human blood on its own is in colour.
Haemoglobin, a pigment in the red blood cells, is responsible for the red colouring of the blood.
8. The average adult body contains of blood
and an has about 1 litre.
5-6 litres
infant

5. The Circulatory System

6. The Circulatory System
The function of a circulatory system is to carry blood or hemolymph into close contact with every cell in the body.
The most sophisticated circulatory systems consist of:
one or more pumps called hearts
arteries (tough, thick-walled tubes) that carry blood away from the heart under high pressure;
small vessels called capillaries whose walls are just one cell thick, allows the exchange of gases and other molecules with tissues in networks called capillary beds; and
vessels called veins that return blood to the heart under low pressure

7. Functions of the Circulatory System
Transport oxygen to cells
Transport nutrients from the digestive system to body cells
Transport hormones to body cells
Transport waste from body cells to excretory organs
Distribute body heat

8. How Are Oxygen and Carbon Dioxide Transported in Blood?
Blood : connective tissue that consists of cells in a watery extracellular matrix called plasma
Remainder of the blood is made up of formed elements: platelets, red blood cells, and several types of white blood cells:
Platelets : Cell fragments that minimize blood loss from ruptured blood vessels by releasing material that assists in the formation of clots
White blood cells: which are part of the immune system fight infections

9. RBCs Red blood cells (RBCs):
transport oxygen from the lungs to tissues throughout the body
critical role in transporting carbon dioxide from tissues to lungs
In humans, red blood cells make up 99.9% of the formed elements.
contain an oxygen-carrying molecule called hemoglobin

10. Circulation
Pulmonary Circuit
Systemic Circuit

11. How Does the Heart Work?
In animals with closed circulatory systems, the heart contains at least two chambers.
the atrium receives blood returning from circulation
the ventricle generates force to propel the blood through the system.
Atria are separated from ventricles by atrioventricular valves.
The number of distinct heart chambers has increased as vertebrates diversified.

12. How Does the Heart Work?
Vertebrates evolved two separate pumping circuits:
The pulmonary circulation is a lower-pressure circuit to the lungs.
The systemic circulation is a higher-pressure circuit to the rest of the body.

13. Right Left pulmonary vein lungs pulmonary artery head & arms aorta
main vein
Right
Left
liver
digestive system
kidneys
legs

14. Our circulatory system is a double circulatory system.
This means it has two parts parts.
Lungs
Body cells
the right side of the system
deals with deoxygenated blood.
the left side of the system
deals with oxygenated blood.

15. Components of the Human Circulatory System
The Heart Blood Vessels Blood Lymphatic Vessels Lymph

16. now lets look inside the heart
This is a vein. It brings blood from the body, except the lungs.
These are arteries. They carry blood away from the heart.
2 atria
Coronary arteries, the hearts own blood supply
2 ventricles
The heart has four chambers
now lets look inside the heart

17. The Path of Blood The heart pumps blood to the lungs
The blood gets oxygen in the lungs
The blood returns to the heart
The heart pumps the oxygenated blood to the cells in the body
The blood delivers oxygen to the body cells
The deoxygenated blood travels back to the heart

18. The Heart Artery to Lungs Artery to Head and Body
Vein from Head and Body
Vein from Lungs
Right Atrium
Left Atrium
valve
valve
Left Ventricle
Right Ventricle

19. How does the Heart work? blood from the lungs blood from the body
STEP ONE
blood from the body
blood from the lungs
The heart beat begins when the heart muscles relax and blood flows into the atria.

20. How does the Heart work? the valves open to allow blood
STEP TWO
The atria then contract and
the valves open to allow blood
into the ventricles.

21. The cycle then repeats itself.
How does the Heart work?
STEP THREE
The valves close to stop blood
flowing backwards.
The ventricles contract forcing
the blood to leave the heart.
At the same time, the atria are
relaxing and once again filling with blood.
The cycle then repeats itself.

22. Structure of the heart

23. You need to be able to label all parts of the heart

24. ? RIGHT SIDE LEFT SIDE Blood from ? Blood from lungs right atrium
valve
Left ventricle – has a thicker muscle wall than right side – why?
Right ventricle
RIGHT SIDE
LEFT SIDE

25. Body organs

26. Blood to the ?
Blood to the ?
Blood from ?
Blood from lungs
Left atrium
right atrium
valve
Left ventricle
Right ventricle
RIGHT SIDE
LEFT SIDE

28. Beating heart – blood flow
The valves prevent the backflow of blood.

30. How do the valves work?
How many can you see?

31. Can you see the 4 valves? outin in
Can you see the 4 valves?
Atrium and ventricle muscles force the blood through and out of the heart

32. blood from the heart gets around the body through blood vessels
There are 3 types of blood vessels
a. ARTERY
b VEIN
c. CAPILLARY

33. The ARTERY Arteries carry blood away from the heart.
the elastic fibres allow the artery to stretch under pressure
thick muscle and elastic fibres
the thick muscle can contract to push the blood along.

34. Veins carry blood towards the heart.
The VEIN
Veins carry blood towards the heart.
veins have valves which act to stop the blood from going in the wrong direction.
body muscles surround the veins so that when they contract to move the body, they also squeeze the veins and push the blood along the vessel.
thin muscle and elastic fibres

35. The CAPILLARY
Capillaries link Arteries with Veins
they exchange materials between the blood and other body cells.
The exchange of materials between the blood and the body can only occur through capillaries.
the wall of a capillary
is only one cell thick

36. The CAPILLARY A collection of capillaries is known as a capillary bed.
artery
vein
capillaries
body cell

37. what’s in BLOOD digested food red blood cells white blood cells oxygen
waste (urea)
platelets
carbon dioxide
hormones
plasma

38. The Blood
white blood cell
red blood cell
plasma
platelets

39. Red Blood Cells
contain haemoglobin, a molecule specially designed to hold oxygen and carry it to cells that need it.
a biconcave disc that is round and flat without a nucleus
can change shape to an amazing extent, without breaking, as it squeezes single file through the capillaries.

40. White Blood Cells
there are many different types and all contain a big nucleus.
the two main ones are the lymphocytes and the macrophages.
macrophages ‘eat’ and digest micro-organisms .
some lymphocytes fight disease by making antibodies to destroy invaders by dissolving them.
other lymphocytes make antitoxins to break down poisons.

41. Platelets Platelets are bits of cell broken off larger cells.
Platelets produce tiny fibrinogen fibres to form a net. This net traps other blood cells to form a blood clot.

42. Plasma It also contains useful things like; carbon dioxide glucose
amino acids
proteins
minerals
vitamins
hormones
waste materials
like urea.
A straw-coloured liquid that carries the cells and the platelets which help blood clot.

43. Types of Blood Vessels Capillaries: smallest vessels
the site where gases, nutrients, and wastes are exchanged between the blood and other tissues
The smallest veins are venules;
carry blood back to the heart after it passes through the capillaries
veins have much thinner walls and much larger interior diameters than arteries

44. Location of Heart

45. Pericardial Cavity

46. Layers of Cardiac Tissue

47. Visceral pericardium
Outer protective layer composed of a serous membrane
Includes blood capillaries, lymph capillaries, and nerve fibers.
Myocardium
Relatively thick.
Consists largely of cardiac muscle tissue responsible for forcing blood out of the heart chambers.
Muscle fibers are arranged in planes, separated by connective tissues that are richly supplied with blood capillaries, and nerve fibers.

48. Endocardium
Consists of epithelial and connective tissue that contains many elastic and collagenous fibers.
Connective tissue also contains blood vessels and some specialized cardiac muscle fibers called Purkinje fibers.
Lines all of the heart chambers and covers heart valves.

49. The Human Heart
The human circulatory system returns oxygen-depleted blood from the body to the right atrium of the heart through two large veins
the inferior and superior venae cavae.
When the right atrium contracts:
deoxygenated blood is sent to the right ventricle
it contracts and sends blood out to the lungs via the pulmonary artery
One-way valves ensure that blood follows only this path. After blood has circulated through the capillary beds in the lung’s alveoli:
it becomes oxygenated
returns to the heart through the pulmonary veins

50. The Human Heart The oxygenated blood enters the left atrium:
it contracts and pushes the blood into the left ventricle
The contraction of the left ventricle sends oxygenated blood at high pressure out the aorta and into:
the arteries
capillaries
veins
forms the systemic circulation

51. Heart Anatomy

52. Heart Anatomy

53. VALVES

54. Heart valves pulmonary semilunar valve aortic semilunar valve
bicuspid valve
tricuspid valve
Heart valves

55. The Cardiac Cycle
The contraction phase of the atria and the ventricles:
called systole
is coordinated with their relaxation phase
called diastole
A cardiac cycle:
consists of one complete systole and one complete diastole

56. systolic blood pressure :
blood pressure measured in the systemic arterial circulation at the peak of ventricular ejection into the aorta
diastolic blood pressure:
blood pressure measured just prior to ventricular ejection

57. Contraction cycle of the heart

58. Contraction Cycle of the Heart

59. Contraction Cycle of the Heart

60. Circulatory System -Gross and Cool Facts!
The body of an adult contains over 60,000 miles of blood vessels!
An adult's heart pumps nearly 4000 gallons of blood each day!
Your heart beats some 30 million times a year!
The average three-year-old has two pints of blood in their body; the average adult at least five times more!
A "heartbeat" is really the sound of the valves in the heart closing as they push blood through its chambers.

61. References
AP Biology Textbook
Addison and Wesley Biology 11
Vijay Aswathy and S Morris