The heart is a four-chambered muscular organ located in the mediastinum protected by the pericardium. It pumps blood through two circuits - the pulmonary circuit to the lungs and systemic circuit to the rest of the body. The heart walls have three layers - epicardium, myocardium and endocardium. It has four chambers - two upper atria which receive blood and two lower ventricles which pump blood out. It uses valves to ensure one-way blood flow. The sinoatrial node initiates electrical impulses which coordinate contractions through the conduction system.

1. Heart Anatomy &
Basic Function
Presented By
Vijay Salvekar
Dept. of Pharmacology
GRY Institute of Pharmacy

2. Heart Location
• 4 chamber muscular organ
• Comparable to the size of a closed fist
• Located in the mediastinum
• (MIDLINE OF THE THORACIC CAVITY)
– Behind sternum
– Between 2nd and 6th ribs
– Between T5-T8
• Apex – base of heart
– Located at the 5th intercostal space
-300 grams (size of a fist)

3. Heart

4. Cardiovascular Function
• Cardiovascular = Heart, Arteries, Veins, Blood
• Function:
–Transportation
–Blood = transport vehicle
–Carries oxygen, nutrients, wastes, and
hormones
–Movement provided by pumping of heart

5. • PERICARDIUM – loose fitting sac surrounding the
heart.
• Function: Allows sufficient freedom of movement.
• CONSIST 2 PARTS
• 1.Fibrous pericardium 2.Serous pericardium
• 1.Fibrous pericardium
Tough, loose-fitting, inelastic thin and dense
irregular connective tissue
• Function : Helps in protection, anchors heart to
mediastinum
Coverings of the Heart

6. *2.Serous pericardium
Thinner, more delicate divided into Parietal
and visceral
i. Parietal layer: lines the inside of the fibrous
pericardium
ii. Visceral layer: adheres to outside of the heart
*Pericardial space: between parietal and visceral
layer
Filled with 10-15mL of pericardial fluid
Decreases friction

9. LAYERS OF THE HEART WALL

10. • 3 layers
• 1.Outermost = Epicardium or Epicardium
• Pericardium is a membrane anchoring heart to
diaphragm and sternum
– Pericardium secretes lubricant (serous fluid)
(imparts a slippery texture to the outer surface of
the heart)
– Epicardium is outermost muscle tissue

12. *2.Middle = Myocardium
• Contains contractile muscle fibers Myocardium
• Middle layer…thickest part
• Thick muscle layer
*3.Innermost Endocardium
• Inner lining of pumping chambers
• Continuous with endothelium
• (inner layer of blood vessels.)
• simple squamous epithelium

13. The Anatomy of the Heart
• The Heart Wall and Cardiac Muscle Tissue
Figure 12-4(a)

14. Heart’s Place in the Circulation
• Three Kinds of Blood Vessels
– Arteries
• Carry blood Away from heart and carry it to the capillaries
– Capillaries
• Microscopic vessels where exchange between cells and
blood takes place
– Veins
• Receive blood from capillaries and carry it back to the heart

15. Heart’s Place in the Circulation
• Heart Pumps Blood into Two
Circuits in Sequence
–Pulmonary circuit
•To and from the lungs
–Systemic circuit
•To and from the rest of the body
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

16. Heart’s Place in the Circulation
• Two Sets of Pumping Chambers in Heart
– Right atrium
• Receives systemic blood
– Right ventricle
• Pumps blood to lungs (pulmonary)
– Left atrium
• Receives blood from lungs
– Left ventricle
• Pumps blood to organ systems (systemic)

17. Heart’s Place in the Circulation
•Overview of the
Cardiovascular
System
Figure 12-1
Superior vena cava
inferior vena cava
aorta

19. Chambers of the Heart
• FOUR CHAMBERS
• Atria – two superior chambers
– “Receiving chambers”
– Blood from veins enters atria
• Ventricles – two inferior chambers
– “pumping chambers”
– Thick muscular walls to increase force of
pumping action
• Left > right
– Separated by interventricular septum

20. CHAMBERS OF THE HEART

21. Valves of the Heart
• Permit blood flow in one direction during
circulation
1.Atrioventricular valves (AV valves)
– Also cuspid valves
– Between atria and ventricles
2.Semilunar (SL valves)
– Between R ventricle and pulmonary arteries
and L ventricle and aorta

22. Atrioventricular Valves
• Tricuspid valve
– Between R atrium and ventricle
– 3 flaps of endocardium
– Connected to ventricular papillary muscle
via chordae tendinae
• Bicuspid valve
– Between L atrium and ventricle
– Also called mitral valve
– Two flaps of endocardium

23. Semilunar Valves
• Pulmonary semilunar valve
– Btwn R ventricle and pulmonary trunk
• Aorta semilunar valve
– Btwn L ventricle and aorta

24. The Anatomy of the Heart
• The Valves of the Heart
Figure 12-6(a)

25. • The Valves of the Heart
Figure 12-6(b)

26. Series of grooves called sulci contain fat
and coronary blood vessel
SULCUS

27. SULCUS

28. MYOCARDIAL THICKNES
• Atria : thin walled
• Ventricles :thick walled
• Lt ventricle is thicker
than the rt ventricle.
Bcz Harder job sending
blood to entire body

29. The Anatomy of the Heart

30. The Anatomy of the Heart

32. Deoxygenated
Blood
…To the
lungs
Oxygenated
Blood
…To the rest
of the body

33. Heart’s Place in the Circulation
• Heart Pumps Blood into Two Circuits in
Sequence
– Pulmonary circuit
• To and from the lungs
– Systemic circuit
• To and from the rest of the body
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

34. (4) Pulmonary Circulation
• Pulmonary = Deoxygenated Blood
• Involves Right Side of Heart
• Pathway:
1. Superior / Inferior Vena Cava
2. Right Atrium  Tricuspid Valve
3. Right Ventricle  Pulmonary Semilunar Valve
4. Left Pulmonary Artery
5. Lungs

36. (5) Systemic Circulation
• Systemic = Oxygenated Blood
• Involves Left Side of Heart
• Pathway:
1. Left Pulmonary Vein
2. Left Atrium  Bicuspid Valve
3. Left Ventricle  Aortic Semilunar Valve
4. Aorta
5. All Other Tissues

38. The Blood Supply to the Heart
. Coronary Arteries
left main coronary artery
left anterior descending artery: serves the
interventricular septum and anterior walls
of both ventricles
circumflex artery: serves the left atrium and
posterior wall of the left ventricle
Coronary Arteries
the coronary arteries arise from the base of the aorta and
actively deliver blood only when the heart is relaxed
the heart is 0.5% of body weight and receives 5% of the
body's blood supply (most to the left ventricle)

39. •Coronary Arteries
•Right main coronary artery
•posterior descending artery: serves the
posterior walls of both ventricles
•marginal artery: lateral wall of the right side
of the heart
•Cardiac Veins follow arteries and join at the
Coronary Sinus which empties blood into the
right atrium

40. •Coronary circulation meets heavy demands of myocardium for
oxygen, nutrients
•.Coronary arteries (right, left) branch from aorta base
Drainage is to right atrium
•.Great, middle cardiac veins drain capillaries into coronary
sinus

42. • The Coronary Circulation
Figure 12-7(a)

43. • The Coronary Circulation
Figure 12-7(b)

44. What causes a heart attack?
• Embolism = a blood clot in
an artery
• Build-up of “plaque” in
walls of an artery
• These can lead to restriction
or cessation of blood flow
in the afflicted artery.
• A portion of the mycardium
may die (myocardial
infarction).

46. THE CONDUCTION SYSTEM
• Inherent and rhythmical beat
is due to autorhythmic fibers
of the cardiac muscle.
• These fibers have 2 important
function
- Act as pace maker
- Form the conduction
system

47. • SA node would inititates action potential about
every 0.6 sec or 100 times/min
• The ANS alters the strength and timing of
heart beats.

48. Heart Physiology
– Electrical Events
• Intrinsic Conduction System of the Heart
– the ability of cardiac muscle to depolarize
and contract is intrinsic (no nervous
stimulation is required)
– nerve impulses can alter the basic rhythm of
heart activity set by intrinsic factors

49. Heart Physiology
– Electrical Events
• Action Potential Generated by
Autorhythmic Cells
– Sequence of Excitation
» Sinoatrial Node
» Atrioventricular Node
» Atrioventricular Bundle (bundle of
His)
» Bundle Branches
» Purkinje Fibers

50. Heart Physiology
– Electrical Events
• Extrinsic Innervation of the Heart
– fibers of autonomic nervous system
accelerate or inhibit the basic rate of
heartbeat set by the intrinsic conduction
system

51. Heart Physiology
– Electrical Events
• Electrocardiography
 electrical currents generated and
transmitted through the heart spread
throughout the body and can be
monitored
 the graphic recording of electrical
changes during heart activity is called an
electrocardiogram (ECG or EKG)

52. Heart Physiology
– Electrical Events
• Electrocardiography
 the ECG consists of series of three waves
» P Wave: atrial depolarization starting at
the SA node
» QRS Complex: ventricular
depolarization

53. Heart Physiology
– Electrical Events
• Electrocardiography
» P-R (P-Q) interval: time from the
beginning of atrial excitation to the
beginning of ventricular excitation and
includes the contraction of the atria
and the passage of the depolarization
wave through the rest of the
conduction system

54. Heart Physiology
–Electrical Events
• Electrocardiography
»T Wave: ventricular repolarization
»Q-T interval: time from the beginning of
the ventricular depolarization through
their repolarization and includes the
contraction of the ventricles

56. Coordinating the Pump: Electrical
Signal Flow
Figure 14-18: Electrical conduction in myocardial cells

57. PHYSIOLOGIC
CHARACTERISTICS OF THE
CONDUCTION CELLS
• AUTOMATICITY
• EXCITABILITY
• CONDUCTIVITY
• RHYTHMICITY
• CONTRACTILITY
• TONICITY

58. CARDIAC CYCLE

59. ATRIAL SYSTOLE
• Lasts for 0.1 sec
• Atrial depolarization causes atrial
systole
• It contributes a final 25ml of blood
to each ventricle
• End of atrial systole is also end of
ventricular diastole
• End-diastolic volume is 130 ml

60. VENTRICULAR SYSTOLE
• Lasts for 0.3 sec
• It is caused by ventricular
depolarization
• Isovolumetric contraction lasts for
0.05 seconds when both the
semilunar and atrioventricular
vlaves are closed.

61. • The sl valves open when
-the left ventricular pressures surpasses aortic
pressure(80 mm of mercury)
-The right ventricular pressure rises above
pulmonary pressure (20 mmhg)
• Sl valves open for 0.25 sec

62. • The left ventricle ejects about 70 ml into the
aorta
• The right ventricle ejects the same volume into
the pulmonary trunk.
• End systolic volume is 60ml in each ventricle .

63. RELAXATION PERIOD
• Both atria and ventricles are
relaxed .It lasts for 0.4 sec.
• When heart beats faster the
relaxation time shortens.
• Ventricular repolarization
causes ventricular daistole.

64. Thankyou