CARDIOVASCLAR SYSTEM DR.M. ZAFAR QURESHI
INTRODUCTION • Cardiovascular system comprises of • Heart • Arteries • Veins • Capillaries
INTRODUCTION • Heart is a muscular organ & functions as a pump. • Works in conjunction with lungs & vascular system • Functionally two hearts & one lung • Blood from venous system Rt side of heart to lungs via pulm. trunk back to Lt side of heart via pulm. veins To the entire body via aorta back to venous system
LOCATION • Middle mediastinum • 1/3 lies on the rt & 2/3 on the left of median point of sternum. • Second to fifth rib
Skeleton of the heart • It is formed by fibrous rings around the valves • It gives origin to the whorls of the cardiac muscle • It keeps the heart valves in an un collapsible state • It acts as an insulator for the spread of electrical stimulus b/w atria & ventricles
FEATURES OF HEART • Conical Hollows organs. • Situated in the middle mediastinum enclosed with in pericardium. • Placed obliquely behind the body of sternum and adjoining part of costal cartilages. • 1/3 of heart lies to the right and 2/3 to the left of median plane of sternum. • Heart Measures about 12x9 cm or 5x3 inches (volume/ circumference) and weight about 300g in males and 250g in females.
4 Borders Upper border Lower or inferior Right border Left border Formed by border formed formed by formed by 2 atria mainly by right right artium. Mainly Left Left. Ventricle. ventricle & partly left aricle. 4 chambers 2 atria 2 ventricles
4 SURFACES Anterior Inferior surface Posterior surface left surface surface(Base) left ventricle & (left Ventricle) formed by left atrium Right atrium fommed byleft atrium & Rt ventricle).& small part of Rt atrium .
AN APEX (LEFT VENTRICLE)( In 5th intercostal space just inner to mid-clavicular line ) 3 GROOVS OR SULCI Atrio ventrienlar Inter atrial Inter ventricular (coronary) groove. groove.
ATRIO VENTRICULARGROOVE CIRCULAR SULCUS WHICH LODGES. Coronary Small Coronary Sinus. Cardiac arteries. vein. • It obliterated interiorly by ascending aorta and pulmonary trunk.
INTER ATRIAL GROOVE:- Faintly visible posteriorly while anteriorly it is hidden by the aorta and pulmonary trunk. ANTERIOR INTER VENTRICULAR GROOVE:- • Near to the left margin of the heart. • It contain anterior inter ventricular branch of the left coronary artery and great cardiac vein. • Lower end of groove separates apex from rest of the inferior border of the heart.
POSTERIOR INTER VENTRICULAR:- • Is situated on the diaphragmatic (inferior) surface of the heart. • It lodges posterior inter ventricular branch of the right coronary artery and middle cardiac vein. • Two (post & ant) inter ventricular grooves meet at the inferior border near the apex, the incisura apices cordis.
FEATURES OF RT ARTIUM:- • From Rt border, Sternocostal surface & part of base of heart. • Elongated chamber. • Receiving sup & I.V.C. • Interior is sponge like & prevent free flow of blood and favours thrombosis. • These thrombi when disloged during auricular fibrillation cause pulmonary embolism. • Suleus terminalis is a shallow vertical groove along right border b/w sup & I.V.C. It is produced by an internal muscular ridge called crista terminalis. • The upper part of suleus termanalis contains (SA) sinoatrial node which act as the pace makes of the heart. • Left atrium lies behind the right atrium.
TRIBUTARIES (INLETS) OF RT ARTIUM:- • S.V.C. ( gaurded eustachian valve) rudimentry. • I.V.C. ( Gaurded eustachian valve) rudimentry. • Coronary sinus ( Gaurded by Thebasian valve) • Anterior cardiac veins. • Venae cordis minimi( Thebasian vessels) • Some time Rt marginal veins. OUT LETS OF RT ARTIUM:- • Tricuspid valve. • Venae cordis mininmae (numerous mall pits in all 4 chambers more on right sides to ensure blood supply i.e why M.I. more common on left side.)
Interior of right atrium is DIVIDED INTO 2 PARTS (A) Smooth posterior Rough anterior Part (sinous venarum) part or Pectinate or Auricle
(A)SMOOTH PART (POSTERIOR)OR SINUS VENARUM • Derived from right horn of sinus venosus • Coronary sinus opens b/w I.V.C. and right atrioventricular openings & guarded by valve of coronary sinus (Thebasian valve). • Venae cordis minimae are numerous small pits, in all four chambers & opens through foramina venarum minimarum. These are more numerous on right side ensuring better blood supply to the myocardium than that on left side that is why M.I. is more common on left side than right.
Intervenous tubercle of lower is a very small projection, visible on the posterior wall of Rt atrium just blow the opening of S.V.C. • During embryonic life it directs the superior caval blood to the right ventricle
(B)ROUGH ANTERIOR PART PECTINATE PART (AURICLE) • Devlopmentally derived from Primitive atrial chamber. • It presents a series of transverse muscular ridges called musculi pectinati. They raise from crista teaminalis and run forward and downward towards the atrioventricular orifice, giving appearance of teeth of comb. • Muscles in auricle are interconnected to form reticular network.
Septal wall • From the centeral part of posterior wall. • Developmentally derived from septum primum and septum secondum. • Present fossa ovalis, a shallow saucer –shaped depression, in the lower part, formed by septum primum.
RIGHT VENTRICLE (triangular chamber) • It form inferior border & large part of sernocostal surface and a small part of the diaphragmatic surface of heart. • It receives blood from right atrium and pumps it to the lungs.
Externally has two surface Anterior (sternocostal ) Inferior (diaphragmatic)
Interior has 2 parts Inflowing part is rough Outflowing part or infundibulnm due to musclular ridges is smooth and form the upper called trabeculae carnae one inch conical part of right ventricle develop from primitive which gives rise pulmonary trunk ventricle heart tube. ( develops from the bulbs cordis).
Septomarginal trabecula (musclar ridges) contains right branch of bundle of his & prevents over distension of right ventricle. Right ventricle is (cresent) shaped due to bulging of interventricular septum. Wall of right ventricle is thinner than left ventricle Ratio 1:3
Left atrium (feature) • Quadrangular chamber. • Situated posteriorly • Interiorly overlaped by right auricle.
LEFT ATRIUM • Posterior surface from anterior wall of oblique sinus of pericardium. • Anterior wall from the interatrial septum. • 2 pulmonary veins open on each side of posterior wall. • Greater part is smooth wall derived from the absorption of pulmonary veins which open into it. • Muscli pectinati (muscular part (rough ) present only in the auricle. • Septal wall shows fossa lunata correspond to fossa ovalis of left atrium
Left ventricle ( features ) • Receives qxygenated blood from left atrium. • From apex of heart.
Externally forms(3 surfaces) Anterior part form left surface forms most of left Sternocostal border inferior surface forms 2/3 of left diaphragmatic surface of heart
Interior of left ventricle -Lower rough part with -upper smooth part (aortic vestibule) Trabeculae corae, Develops which gives origin to ascending aorta, From primitive ventricle of develops from bulbus cordis. Heart tube. -Vistibule lies between membranous part of the inter ventricuar septum and anterior (aortic) cusps of mitral valve.
2 orifices Left A.V orifice (bicuspid) aortic orifice (guarded by Mitral valve aortic valve) (tricuspid)
2 papillary muscles Ant post Both attached to cusps of mitral valve by chordae tendinae -Wall of left ventricle is 3 time thicker then those of right ventricle.
Blood supply of heart • Supplied by 2 coronary arteries arises from ascending aorta Right coronary artery left coronary -smaller than left -larger than right -origin=Int aortic sinus -origin=post aortic sinus
Right coronary branches Large branches small branches 1-Marginal 1-Nodal in 60% 2- Posterior 2-Right Atrial interventricular 3-Infundibular 4-Terminal
Left coronary branches Large branches small branches 1-Anterior ventricular 1-Left atrial 2-Diaphragmatic 2-pulmonary branches branches to 3-Terminal branches Left venricle
Right C.A (course) It passes forward & to the right to emerge b/w the root of pulmonary trunk and right auricle. 2ndit runs downwards in the right anterior cornerary sulcus to the junction of the right and inferior border of heart Next it winds round and continuous in the posterior coronary sulcus upto the posterior interventicular groove. On entering the left coronary sulcus it terminates by anastomosing with the left coronary artery. Left C.A. (course) It passes forward & to the left to emerge b/w the pulmonary trunk and left auricle & gives interventricular branch which runs down in its groove & continuation of left coronary artery is called as circumflex artery Then it runs towards the left anterior coronary sulcus Next it winds round and continuous in the left posterior coronary sulcus upto close to posterior interventericular grooves where it terminate by anastomosing with right coronary artery Course
INTERNAL STRUCTURE OF HEART • Four chambers in the heart • Rt atrium with rt auricle • Rt ventricle • Lt atrium with lt auricle • Lt ventricle
INTERNAL STRUCTURE OF HEART • Rt atrium: Cuboidal chamber, smooth (sinus venarum) & rough (musculi pectaniti) parts, four openings • Rt auricle • SVC • IVC • Coronary sinus
Rt ventricle • Occupies most of the ant surface • Tapers above into conus arteriorus which is the outflow part • Inside of the inflow part is rough due to trabeculae carnae • Tricuspid AV valve b/w rt atrium & rt ventricle • It is crescent shaped in cross section