anatomy and physiology of the heart
TRANSCRIPT
CARDIOVASCULACARDIOVASCULAR SYSTEMR SYSTEM
Anatomy & Physiology
dr. Jeffrey WiriantaMarch 8th 2004
THE HEART
Lokasi Jantung 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 SkeletonFibrous Skeleton
Kerangka jantung Kerangka jantung yang terdiri dari yang terdiri dari jaringan kolagen yang jaringan kolagen yang tebal dan kuattebal dan kuat
Penunjang fisik Penunjang fisik jantungjantung
Pegangan katup Pegangan katup Mencegah kelebihan Mencegah kelebihan
regangan otot jantungregangan otot jantung Electrical insulationElectrical insulation
Anatomy of the HeartAnatomy of the Heart Pericardium : Pericardium :
Outer fibrous sackOuter fibrous sack Myocardium :Myocardium :
Thick muscle wallsThick muscle walls Endocardium : Endocardium :
Innermost surfaceInnermost surface EndotheliumEndothelium Simple squamous Simple squamous
epitheliumepithelium
Interventriculer Septum
Papillary muscle
Semilunar Valve
PerikardiumPerikardium 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 HeartAnatomy of the Heart Heart chambersHeart chambers : :
Left & right atriaLeft & right atria Left & right ventriclesLeft & right ventricles
Heart valvesHeart valves : : Atrioventricular valves :Atrioventricular valves :
Right : TricuspidRight : Tricuspid Left : Bicuspid/MitralLeft : Bicuspid/Mitral
Semilunar valvesSemilunar valves Right : Pulmonary valveRight : Pulmonary valve Left : Aortic valveLeft : Aortic valve
Anatomy of the HeartAnatomy of the Heart
AortaAorta Coronary arteriesCoronary arteries ArteriolesArterioles CapillariesCapillaries VenulesVenules Coronary sinusCoronary sinus Right atriumRight atrium
Coronary circulationCoronary circulation
Tipe-tipe sel Otot JantungTipe-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 Intrinsic Conducting SystemSystem
Sinoatrial nodeSinoatrial node Electrical pace makerElectrical pace maker
Atrioventricular nodeAtrioventricular node Receives impulses Receives impulses
originating from SA nodeoriginating from SA node Bundle of HisBundle of His
Electrical link between Electrical link between atria and ventriclesatria and ventricles
Purkinje fibresPurkinje fibres Distribute impulses to Distribute impulses to
ventriclesventricles
Sel AutoritmikSel Autoritmik• Fase Fase DepolarisasiDepolarisasi• Fase Fase RepolarisasiRepolarisasi• Fase IstirahatFase Istirahat
Sel KontraktilSel Kontraktil• Fase Fase DepolarisasiDepolarisasi• Fase PlateuFase Plateu• Fase Fase RepolarisasiRepolarisasi• Fase IstirahatFase Istirahat
Conduction System
SA Node Internodal branch AV Node Hiss Bundle Purkinje Fiber Contraction
Cardiac Action PotentialsCardiac Action Potentials
Cardiac Muscle TissueCardiac Muscle Tissue
The Electrocardiogram The Electrocardiogram ( ECG )( ECG )
P wave : atrial P wave : atrial depolarisationdepolarisation
QRS complex : QRS complex : ventricular ventricular depolarisationdepolarisation
T wave : ventricular T wave : ventricular repolarisationrepolarisation
Atrial repolarisation Atrial repolarisation hidden by QRShidden by QRS
P
Q
R
S
T
The Electrocardiogram The Electrocardiogram (ECG)(ECG)
Leads can be placed Leads can be placed on wrists and left ankle on wrists and left ankle
( right ankle is ( right ankle is earthed )earthed )
Voltages are measured Voltages are measured across each point as across each point as shownshown I = L wrist to R wristI = L wrist to R wrist II = R wrist to L ankleII = R wrist to L ankle III = L ankle and L wristIII = L ankle and L wrist
The heart sits in the The heart sits in the centre of the trianglecentre of the triangle
I
II III
+/-
+
-
The ElectrocardiogramThe Electrocardiogram The three standard The three standard
measurements can measurements can be used to be used to electronically electronically calculate the calculate the currents flowing currents flowing towards each limbtowards each limb aVRaVR aVLaVL aVFaVF
+
The Cardiac CycleThe Cardiac Cycle Systole :Systole :
Period of ventricular Period of ventricular contractioncontraction
Blood ejected from heartBlood ejected from heart Diastole Diastole ::
Period of ventricular Period of ventricular relaxationrelaxation
Blood fillingBlood filling
Stroke VolumeStroke Volume The amount of blood ejected from the The amount of blood ejected from the
heart in one beatheart in one beat Average is 60 - 100 mlAverage is 60 - 100 ml Depends on preload, contractile force Depends on preload, contractile force
and afterloadand afterload
Cardiac OutputCardiac Output The amount of blood ejected from the The amount of blood ejected from the
heart in one minuteheart in one minute Cardiac output = heart rate x stroke Cardiac output = heart rate x stroke
volumevolume
Starling’s LawStarling’s Law
The more the myocardium is stretched, The more the myocardium is stretched, the greater the stroke volumethe greater the stroke volume
Has limitsHas limits Dependent upon venous returnDependent upon venous return
Blood PressureBlood Pressure BP = cardiac output x systemic BP = cardiac output x systemic
vascular vascular resistanceresistance
DefinitionsDefinitions
Chronotropy Change in heart rateChronotropy Change in heart rate Inotropy Change in contractile Inotropy Change in contractile
force force Dromotropy Change in conduction Dromotropy Change in conduction
velocity velocity
Can be positive or negative Can be positive or negative