CHAPTER 12: HEART

Chapter 12: HEART Heart Chambers

 Four Chambers:
The Cardiovascular System  Left Atrium (LA)
 the heart is a muscular organ that is essential for life because  Right Atrium (RA)
it pumps blood through the body.  Left Ventricle (LV)
 the heart is a member organ of the cardiovascular system,  Right Ventricle (RV)
which consists of the heart, blood vessels, and blood.
 the heart of a healthy adult, at rest, pumps approximately 5  Coronary sulcus:
liters (L) of blood per minute.  separates atria from ventricles
Functions of the Heart  It contains:
 the right coronary artery
 generates blood pressure
 the small cardiac vein
 routes blood
 the coronary sinus
 ensures one-way blood flow
 the circumflex artery
 regulates blood supply
Pericardia
Heart Characteristics
 Pericardium
 double-layered sac that anchors and protects
heart

 Parietal pericardium
 membrane around heart’s cavity

 Visceral pericardium
 membrane on heart’s surface

 Pericardial cavity
 space around heart

 Size
 size of a fist and weighs less than 1 lb.
 Location
 between lungs in thoracic cavity
 Orientation Blood Flow Through Heart
 apex (bottom) towards left side

Ventricles
 inferior chambers
 pumping chambers
 thick, strong walled
 contract forcefully to propel blood out of heart

 Interventricular septum
 separates right and left ventricles.

The Atria
 superior chambers
 holding chambers 1. Right Atrium 5. Pulmonary 9. Left Atrium 13. Aorta
 small, thin walled trunk
2. Tricuspid valve 6. Pulmonary 10. Bicuspid 14. Body
 contrast minimally to push blood into ventricles
arteries valve
3. Right Ventricle 7. Lungs 11. Left Ventricle
 Interatrial septum
 separates right and left atria 4. Pulmonary 8. Pulmonary 12. Aortic
semilunar valve veins semilunar valve

Precious Faith Rodriguez

CHAPTER 12: HEART
Semilunar Heart Valves Electrocardiogram (ECG/EKG)
 the semilunar valves have three half-moon shaped cusps, and  record of electrical events in heart
are valves between the pulmonary trunk and aorta.  diagnoses cardiac abnormalities
 uses electrodes
 Pulmonary valve  contains P wave, QRS complex, T wave
 between RV and pulmonary trunk

 Aortic valve Components of ECG/EKG

 between LV and aorta  P wave
 depolarization of atria
Atrioventricular Heart Valves
 valves between the atria and ventricles  QRS complex
 depolarization of ventricles
 Tricuspid valve  contains Q, R, S waves
 AV valve between RA and RV
 3 cusps  T wave
 repolarization of ventricles
 Bicuspid valve
 AV valve between LA and LV
 2 cusps Heart Sounds
 heart sounds are produced due to the closure of heart
Heart Wall valves
 a stethoscope is used to hear heart sounds
 the first heart sound makes a ‘lubb’ sound
 the second heart sound makes a ‘dupp’ sound
 the first heart sound is due to the closure of the
atrioventricular valves
 the second heart sound is due to the closure of the
semilunar valves

Heart Disease
 Coronary Artery Disease
 due to decrease blood supply to the heart
 Epicardium  coronary arteries are narrowed for some reason
 surface of heart (outside)
 Myocardial Infarction (heart attack)
 Myocardium  due to closure of one or more coronary arteries
 thick, middle layer composed of cardiac muscle  area(s) of cardiac muscle lacking adequate blood
supply die, and scars (infarct)
 Endocardium
 smooth, inner surface Heart Procedures
 Angioplasty
Action Potential Path through Heart  procedure opens blocked blood vessels
1. SA node
2. AV node (atrioventricular)  Stent
3. AV bundle  structures inserted to keep vessels open
4. Right and Left Bundle branches
5. Purkinje fibers  Bypass
 procedure reroutes blood away from blocked
Conduction System of the Heart
arteries

Cardiac Cycle
 Atrial systole
 contraction of atria

 Ventricular systole
 contraction of ventricles

 Atrial diastole
 relaxation of atria

 Ventricular diastole
 relaxation of ventricles

Precious Faith Rodriguez