1. The Heart

2. Overview of the Heart double pump
about the size of a fist - cone shaped
weight less than 1 lb.

4. located mid-thoracic cavity between the lungs
lies at an angle under the sternum
angles to the left

5. covered with double walled membrane - pericardium
outer layer is tough
inner is a serous
potential space between pericardial cavity with serous fluid to reduce friction

6. 3 Layers of Heart Wall pericardium – myocardium – endocardium – outer
cardiac muscle
bulk of the heart
contracts
endocardium –
lines chambers

8. Heart Chambers

9. Heart Chambers
4 chambers
as in all birds and mammals 2 1 3 4

10. R and L Atria Left Atrium Right Atrium receive blood
small and thin walled
Left Atrium
Right Atrium

11. R and L Ventricles RV pumps blood to the lungs
LV pumps blood to the body
large and thick walled because has hardest job to do

13. septum
divides the heart into R and L sides

14. Great Vessels

15. Great Vessels RA superior vena cava inferior vena cava
blood from superior body to heart
inferior vena cava
blood from below heart RA

16. pulmonary veins
4 total
from lungs LA

17. pulmonary trunk
to lungs RV

18. aorta
largest artery
to all organs LV

19. Heart Valves

20. Atrioventricular Valves = AV valves
between atrium and ventricle
right is tricuspid
left is the bicuspid or mitral

23. papillary muscles attached to chordae tendineae
contraction pulls valves open
when V begins to contract, blood is forced against valve and it shuts

24. Semilunar Valves Aortic Semilunar Valve between ventricle and aorta
Pulmonary Semilunar Valve
between ventricle and pulmonary trunk

26. Semilunar Valves force of blood pushes them open
attempted backflow after contraction closes them

27. Left Atrium
Right Atrium
Left Ventricle
Right Ventricle

28. Superior Vena Cava
Inferior Vena Cava

29. Pulmonary Trunk
L Pulmonary Artery
R Pulmonary Artery

30. Left Pulmonary Veins
Right Pulmonary Veins

31. Aorta
Aorta

32. Aorta
Pulmonary Trunk
Superior Vena Cava
L Pulmonary Artery
R Pulmonary Artery
Left Pulmonary Veins
Right Pulmonary Veins
Inferior Vena Cava
Aorta

33. Pulmonary Semilunar Valve Aortic Semilunar Valve
Tricuspid Valve
Bicuspid Valve

34. Septum
Chordae Tendineae
Apex

35. Circulation

36. Pulmonary Circulation
right side of heart
from body to heart to lungs for oxygen

37. Pulmonary Circulation
From body ↓
Superior and inferior vena cava
Right atrium
Tricuspid valve
Right ventricle
Pulmonary Semilunar valve
Pulmonary trunk
R and L pulmonary arteries
Capillary beds of lungs
(gas exchange)
Pulmonary veins

38. System Circulation left side of heart
supplies body with oxygenated blood

39. Aortic Semilunar valve Superior and Inferior Vena Cava
Systemic Circulation
From lungs ↓
Pulmonary Veins
Left atrium
Bicuspid valve
Left ventricle
Aortic Semilunar valve
Aorta
Arteries
Capillary beds of body
(gas exchange)
Superior and Inferior Vena Cava

40. Coronary Arteries

41. Coronary Arteries
supply the heart muscle with oxygen rich blood

42. Atherosclerosis these are clogged with plaque
contract in spasms called angina or get clots stuck in them
one cause of heart attack

43. cardiac muscles that die are not replaced dead cells = infarct
myocardial infarction or MI is proper term for a heart attack

44. coronary bypass surgery is most common surgery in USA

45. Conduction System

46. Conduction System
coordinated activity depends on gap junctions and “in house” conduction system

48. Steps:
sinoatrial node in RA near superior vena cava acts as “pace maker” by initiating each wave of nerve activity
wave moves to atrioventricular node in septum between atria

49. to the AV bundle (bundle of His) in upper ventricular region of septum
to the Pyrkinje fibers which branch down septum to ventricles

50. 5. contraction starts a bottom (apex) of ventricles to push blood up and out arteries

51. Fibrillation uncoordinated contractions
A fibs - rapid flutters and weakness

52. V fibs - fatal unless heart is defibrillated shocked back into normal

53. Electrocardiogram
ECG
measures electrical events of the heart

54. Heart Excitation Related to ECG

55. Electrocardiography

56. Cardiac Cycle

57. Cardiac Cycle
all the events associated with the flow of blood through the heart in 1 beat
Diastole - period of cardiac ventricle filling
Systole period of cardiac ventricle pumping (contracts)

58. Heartsounds LUB-dup closing of valves
LUB - AV valves closing, longer and louder
dup - Semilunar valves closing, shorter and sharper

59. Murmurs
abnormal sounds are called murmurs and are usually caused by leaky of narrowed valves