Cardiovascular System

Physiology DepartmentMedical Faculty, Hasanuddin University

ANATOMY OF THE HEART

THE HEART WALL :• Endocardium • Myocardium• Epicardium• Pericardium

INTERNAL ANATOMYOF THE HEART : 1. Right Atrium2. Right Ventricle3. Left Atrium4. Left Ventricle

POSITION OF THE HEART :Left : linea medioclavicularis

sinistraRight : linea parasternalis

dextraTop : intercostal II

Bottom : intercostal V

• VALVES :• 1. Semilunar valves : - aortic valve• - pulmonary valve• 2. Atrioventricular valves : - bicuspid (mitral) valve• - tricuspid valve

The Conducting System

1. Sinoatrial (SA) node2. Internodal pathways3. Atrioventricular (AV)

node4. Bundle of His5. Bundle branches6. Purkinje fibers

Action Potential of the Heart

Electrocardiography (ECG/EKG)

1. P wave : atrial depolarization2. QRS complex : ventricular

depolarization- Q : septum interventricular- R : apex- S : posterobasal

3. T wave : ventricular repolarization4. U wave : late ventricular

depolarization

Electrocardiography(ECG/EKG)

Heart Cycle

Heart Cycle :1. Filling Phase

a. Rapid fillingb. Slow filling (diastasis)c. Atrial contraction

2. Isovolumetric Contraction Phase3. Ejection Phase4. Isovolumetric Relaxation

Heart Sounds

There are four heart sounds :S1 : the AV valves closeS2 : the semilunar valves closeS3 : blood flowing to the ventriclesS4 : atrial contraction

Cardiodynamics

CO = SV x HRCardiac Output (CO) : the amount of blood pumped by each ventricle in 1 minute.Stroke Volume (SV) : the amount of blood pumped out of each ventricle during a single beat.Heart Rate : the frequency of heart beats in 1 minute.

CardiodynamicsEnd-Diastolic Volume (EDV) : the amount of blood in each ventricle at the end of ventricular diastole (the start of ventricular systole)End-Systolic Volume (ESV) : the amount of blood remaining in each ventricle at the end of ventricular systole (the start of ventricular diastole)

Ejection Fraction : the percentage of the EDV represented by the ESV.

EDV – ESV = SV

Factors Affecting Cardiac Output

Regulation of heart activities

1. Instrinsic regulation :

Heterometric :the ability of heart to increase it’s pressure at different heart volume

Homeometric : the ability of heart to create different pressure at the

same volume

2.Extrinsic regulation

central nervous system- autonomic nervous system symphathetic (thoraco-lumbal) parasymphathetic (cervico-sacral)-baroreceptor reflex-vasomotor area hormonal

DYSRHYTHMIA

1. Impulses Forming

2. Electrical Conduction

Impulses Forming

1. Bradycardia

2. Tachycardia

3. Premature contraction

Electrical Conduction

1. Sinoatrial block

2. Atrioventrikuler block

3. Reentry

4. Bundle branch block