anatomy and physiology of the heart

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  • CARDIOVASCULAR SYSTEM

    Anatomy & Physiology

    dr. Jeffrey Wirianta March 8th 2004

  • THE HEART

  • Lokasi Jantung

    Di dalam Pericardium di rongga mediastinum dalam rongga Thorak

    Tepat di belakang tulang dada ( sternum )

    Kurang lebih 2/3 bagian terletak di sebelah kiri dari garis tengah

  • Fungsi dan Ukuran

    Fungsi : sebagai pompa ganda agar terjadi

    aliran dalam pembuluh darah yang

    disebabkan adanya pergantian antara

    kontraksi ( sistolik ) dan relaksasi

    ( diastolik )

    Ukuran : 250 350 gram

    ( kira-kira sebesar kepalan tangan )

  • Fibrous Skeleton

    Kerangka jantung yang terdiri dari jaringan kolagen yang tebal dan kuat

    Penunjang fisik jantung

    Pegangan katup

    Mencegah kelebihan regangan otot jantung

    Electrical insulation

  • Anatomy of the Heart

    Pericardium :

    Outer fibrous sack

    Myocardium :

    Thick muscle walls

    Endocardium :

    Innermost surface

    Endothelium

    Simple squamous epithelium

  • Interventriculer Septum

    Papillary muscle

    Semilunar Valve

  • Perikardium

    Perikardium Fibrosa

    Lapisan paling luar rongga Pericardium

    Menjaga kedudukan jantung di rongga mediastinum

    Perikardium Serosa

    Lapisan parietalis

    Lapisan bagian dalam dari rongga pericardial

    Lapisan visceralis / epicardium

    Rongga Perikardium

    Cairan pericardium

    Mengurangi gesekan saat jantung bergerak

  • Anatomy of the Heart

    Heart chambers :

    Left & right atria

    Left & right ventricles

    Heart valves :

    Atrioventricular valves :

    Right : Tricuspid

    Left : Bicuspid/Mitral

    Semilunar valves

    Right : Pulmonary valve

    Left : Aortic valve

  • Anatomy of the Heart

    Aorta

    Coronary arteries

    Arterioles

    Capillaries

    Venules

    Coronary sinus

    Right atrium

    Coronary circulation

  • Tipe-tipe sel Otot Jantung

    Autoritmik autoritmik mampu berdepolarisasi spontan

    produce pacemaker potentials

    menyalurkan aksi potensial ( impulses ) melewati myocardium

    tidak berkontraksi

    Kontraktil Potensial aksi menimbulkan kontraksi

    Aliran darah ditimbulkan oleh pergantian dari

    kontraksi ( SISTOLIK ) dan Relaksasi ( DIASTOLIK )

  • Intrinsic Conducting System

    Sinoatrial node

    Electrical pace maker

    Atrioventricular node

    Receives impulses originating from SA node

    Bundle of His

    Electrical link between atria and ventricles

    Purkinje fibres

    Distribute impulses to ventricles

  • Sel Autoritmik

    Fase Depolarisasi

    Fase Repolarisasi

    Fase Istirahat

    Sel Kontraktil

    Fase Depolarisasi

    Fase Plateu

    Fase Repolarisasi

    Fase Istirahat

  • Conduction System

    SA Node Internodal branch AV Node Hiss Bundle Purkinje Fiber Contraction

  • Cardiac Action Potentials

  • Cardiac Muscle Tissue

  • The Electrocardiogram ( ECG )

    P wave : atrial depolarisation

    QRS complex : ventricular depolarisation

    T wave : ventricular repolarisation

    Atrial repolarisation hidden by QRS

    P

    Q

    R

    S

    T

  • The Electrocardiogram (ECG)

    Leads can be placed on wrists and left ankle

    ( right ankle is earthed )

    Voltages are measured across each point as shown I = L wrist to R wrist

    II = R wrist to L ankle

    III = L ankle and L wrist

    The heart sits in the centre of the triangle

    I

    II III

    +/-

    +

    -

  • The Electrocardiogram

    The three standard measurements can be used to electronically calculate the currents flowing towards each limb

    aVR

    aVL

    aVF

    +

  • The Cardiac Cycle

    Systole :

    Period of ventricular contraction

    Blood ejected from heart

    Diastole :

    Period of ventricular relaxation

    Blood filling

  • Stroke Volume

    The amount of blood ejected from the heart in one beat

    Average is 60 - 100 ml

    Depends on preload, contractile force and afterload

    Cardiac Output

    The amount of blood ejected from the heart in one minute

    Cardiac output = heart rate x stroke volume

  • Starlings Law

    The more the myocardium is stretched, the greater the stroke volume

    Has limits

    Dependent upon venous return

    Blood Pressure

    BP = cardiac output x systemic vascular

    resistance

  • Definitions

    Chronotropy Change in heart rate

    Inotropy Change in contractile force

    Dromotropy Change in conduction velocity

    Can be positive or negative