1. Memmler’s The Human Body in Health and Disease 11th edition
Chapter 14
The Heart and Heart Disease
“Cheerfulness is the best promoter of health and is as friendly to the mind as to the body.” Joseph Addison

2. Location of the Heart Between the lungs
Left of the midline of the body
In mediastinum
Apex pointed toward left

3. Structure of the Heart Three tissue layers
Endocardium lines heart’s interior
Myocardium is thickest layer; the heart muscle
Epicardium is thin outermost layer

4. The Pericardium The sac that encloses the heart
Fibrous pericardium holds heart in place
Serous membrane
Parietal layer
Pericardial cavity
Visceral layer (epicardium)

5. Layers of the heart wall and pericardium
Layers of the heart wall and pericardium. The serous pericardium covers the heart and lines the fibrous pericardium.
Which layer of the heart wall is the thickest?

6. Special Features of the Myocardium
Cardiac muscles
Are lightly striated (striped)
Have single nucleus cells
Are controlled involuntarily
Have intercalated disks
Have branching muscle fibers

7. Divisions of the Heart Double pump
Right side pumps blood low in oxygen to the lungs
Pulmonary circuit
Left side pumps oxygenated blood to remainder of body
Systemic circuit

8. Four Chambers Right atrium
Receives low-oxygen blood returning from body tissue through superior vena cava and inferior vena cava
Left atrium
Receives high-oxygen blood from lungs
Right ventricle
Pumps blood from right atrium to lungs
Left ventricle
Pumps oxygenated blood to body

9. The heart as a double pump
The heart as a double pump. The right side of the heart pumps blood through the pulmonary circuit to the lungs to be oxygenated; the left side of the heart pumps blood through the systemic circuit to all other parts of the body.
What vessel carries blood into the systemic circuit?

10. The heart and great vessels.
Which heart chamber has the thickest wall?

11. Question: Which chamber of the heart receives oxygenated blood coming in from the lungs in the pulmonary veins? a. right atrium b. left ventricle c. left atrium

12. Answer: c. left atrium (upper left chamber)

13. Four Valves in Relation to Ventricles
Atrioventricular valves
Entrance valves
Right atrioventricular (AV) valve (tricuspid valve)
Left atrioventricular (AV) valve (bicuspid valve)
Semilunar valves
Exit valves
Pulmonary valve
Aortic valve

14. Valves of the heart (superior view from anterior, atria removed)
Valves of the heart (superior view from anterior, atria removed). (A) When the heart is relaxed (diastole), the AV valves are open and blood flows freely from the atria to the ventricles. The pulmonary and aortic valves are closed. (B) When the ventricles contract, the AV valves close and blood pumped out of the ventricles opens the pulmonary and aortic valves. ZOOMING IN • How many cusps does the right AV valve have? The left?

15. Pathway of blood through the heart.
Blood from the systemic circuit enters the right atrium (1) through the superior and inferior venae cavae, flows through the right AV (tricuspid) valve (2), and enters the right ventricle (3). The right ventricle pumps the blood through the pulmonary (semilunar) valve (4) into the pulmonary trunk, which divides to carry blood to the lungs in the pulmonary circuit.
Blood returns from the lungs in the pulmonary veins, enters the left atrium (5), and flows through the left AV (mitral) valve (6) into the left ventricle (7). The left ventricle pumps the blood through the aortic (semilunar) valve (8) into the aorta, which carries blood into the systemic circuit.

16. Blood Supply to the Myocardium
Coronary circulation
Right coronary artery
Left coronary artery
Coronary sinus

17. Blood vessels that supply the myocardium
Blood vessels that supply the myocardium. Coronary arteries and cardiac veins are shown. (A) Anterior view. (B) Posterior view.

18. Opening of coronary arteries in the aortic valve (anterior view)
Opening of coronary arteries in the aortic valve (anterior view). (A) When the left ventricle contracts, the aortic valve opens. The valve cusps prevent filling of the coronary arteries. (B) When the left ventricle relaxes, backflow of blood closes the aortic valve and the coronary arteries fill.

19. Function of the Heart
Left and right sides of heart work together in cardiac cycle (heartbeat)
Systole (active phase, contraction)
Diastole (resting phase)

20. The cardiac cycle.
ZOOMING IN • When the ventricles contract, what valves close? What valves open?

21. Cardiac Output Calculating cardiac output Cardiac output (CO)
Stroke volume (SV)
Heart rate (HR)
CO = HR X SV

22. The Heart’s Conduction System
Electrical energy stimulates heart muscle
Nodes
Sinoatrial (SA) node (pacemaker)
Atrioventricular (AV) node
Specialized fibers
Atrioventricular bundle (bundle of His)
Bundle branches
Purkinje fibers (conduction myofibers)
Intercalated disks

23. Conduction system of the heart
Conduction system of the heart. The sinoatrial (SA) node, the atrioventricular (AV) node, and specialized fibers conduct the electrical energy that stimulates the heart muscle to contract.
What parts of the conduction system do the internodal pathways connect?

24. The Conduction Pathway
Sinus rhythm
Sinoatrial (SA) node
Atria
Atrioventricular (AV) node
Internodal pathways
Bundle of His
Bundle branches and Purkinje fibers
Ventricles

25. Control of the Heart Rate
Influences that allow heart to meet changing needs rapidly
Autonomic nervous system (ANS)
Sympathetic nervous system
Parasympathetic system
Cranial nerve X

26. Variations in Heart Rates
Bradycardia
Tachycardia
Sinus arrhythmia
Premature beat (extrasystole)

27. Heart Sounds
Lub
Dup
Murmurs
Organic
Functional

28. Classifications of Heart Disease
Anatomical classification
Endocarditis
Myocarditis
Pericarditis
Causative factors classification
Congenital heart disease
Rheumatic heart disease
Coronary artery disease
Heart failure

29. Congenital Heart Disease
Congenital heart disease often results from fetal development defects
Atrial septal defect
Patent (open) ductus arteriosus
Ventricular septal defect
Coarctation of the aorta
Tetralogy of Fallot

30. Rheumatic Heart Disease
Streptococci release toxins during infection
Antibodies that combat toxin also attack heart valves
Heart valves become inflamed
Valve cusps thicken and harden
Pulmonary congestion occurs

31. Coronary Artery Disease
Coronary arteries can degenerate
Myocardial infarction
Creatine kinase released upon any muscle damage. Tests for certain forms of CK indicate whether an MI occurred.
Angina pectoris
Abnormalities of heart rhythm
Treatment of heart attacks

32. Heart Failure
Heart is unable to pump sufficient blood for the body’s needs
Heart chambers enlarge
Blood backs up into lungs
Ventricular muscles have decreased ability
Fluid accumulates in lungs, liver, abdomen, legs

33. The Heart in the Elderly
How the heart can age
Heart shrinks
Decreased contraction strength
Valves become less flexible
Murmur develops
Cardiac output decreases
Abnormal rhythms
Heart block

34. Prevention of Heart Disease
Risk factors that cannot be modified
Age
Gender
Heredity
Body type
Risk factors that can be modified
Smoking
Physical inactivity
Weight
Diet
Blood pressure
Diabetes, gout

35. Heart Studies Stethoscope Electrocardiograph (ECG or EKG) Electrodes
Catheterization
Fluoroscope
Echocardiography (ultrasound cardiography)
Oscilloscope

36. Treatment of Heart Disease
Medical approaches
Surgical approaches
Combined approaches

37. Medications Digitalis Nitroglycerin
Beta-adrenergic blocking agents (beta-blockers)
Antiarrhythmic agents
Slow calcium-channel blockers
Anti-platelet aggregates
Plavix, Aspirin
Anticoagulants
Heparin, Lovenox, Coumadin

38. Correction of Arrhythmias
Artificial pacemaker
Set rate
Only when heart skips beat
Adjustable pacing rate
Implantable cardioverter-defibrillator (ICD)

39. Heart Surgery Coronary artery bypass graft (CABG) Angioplasty
Valve replacement
Surgical transplantation of heart or heart and lungs
Artificial heart