Lecture_1._Cardiac_Anatomy_formatted 2024-09-27 03_50_47.pdf

CARDIAC PHYSIOLOGY FUNDAMENTALS Lecture 1 Cardiac Anatomy Paul Stoodley Contents 1 Position, Size & Shape 2 Pericardium | IVC & SVC 3 Cardiac Chambers 4 Cardiac Valves 5 Cardiac Vasculature 6 Conclusion...

CARDIAC PHYSIOLOGY FUNDAMENTALS Lecture 1 Cardiac Anatomy Paul Stoodley Contents 1 Position, Size & Shape 2 Pericardium | IVC & SVC 3 Cardiac Chambers 4 Cardiac Valves 5 Cardiac Vasculature 6 Conclusion 2 Learning Outcomes Following this lecture, you will be able to: 1. Characterise the macro anatomy of the heart 2. Describe the vascular anatomy of the heart 3. Relate essential anatomical features of the great vessels 3 1. Introductory Details readersdigest.co.uk bbc.com/news/health Heart Location: Thorax > mediastinum Base: Level of the third rib. Apex: - Level of the fifth or sixth rib space - Normally the heart is oriented leftwards. blendspace.com The long axis of the heart is oblique to the long axis of the body (the heart’s long axis is at ~30 degrees to the median). 4 1. Introductory Details Shape & Size Pinecone shaped (Broad base | narrow apex) Size: ~ fist 30o Females: 250 - 300 grams Males: 300 - 350 grams 5 1. Introductory Details Simple & complex Primary function: Pump blood Specialised components Macro & micro pintrest.com.au 6 2. Pericardium | SVC & IVC cardiosurgeon.co.uk Pericardium Peri-cardium means ‘around the heart’ Covers the heart & also the roots & mid portions of the ascending GV’s I. Hold heart in position II. Allows the heart to expand (fill) pediaa.com 7 2. Pericardium | SVC & IVC Pericardium courses.lumenlearning.com Two distinct layers: I. Fibrous (outer) II. Serous (inner) I. Fibrous Tough (CT with minimal distensibility) that protects & holds the heart in position. II. Serous A. Parietal: outer layer - fused to fibrous pericardium B. Visceral: inner layer- fused to the heart where it forms the epicardium. The pericardial cavity is lined with lubricating serous fluid. 8 2. Pericardium | SVC & IVC Superior Vena Cava (SVC) Formed by the confluence of: Right and left brachiocephalic veins from above (superior) Azygous vein from behind & below (posterior & inferior) Empties into the superior right atrium (RA) 9 2. Pericardium | SVC & IVC Inferior Vena Cava (IVC) Passes up though the diaphragm from the abdomen into the thorax. Empties into the inferior right atrium (the Eustachian valve guards it’s orifice). 10 3. Cardiac Chambers Atria The heart has four chambers: two atria (superior) & two ventricles (inferior) The atria receive blood returning to the heart (from right & left sided veins) The inter-atrial septum separates the two atria. cardiologyinstitute.co.nz 11 3. Cardiac Chambers Right atrium (RA) The right sided atrium (superior to the right ventricle) Receives blood from: I. SVC (superior) II. IVC (inferior) III. Coronary Sinus (posterior) Rough anterior wall (& appendage) & smooth posterior wall, separated by cresta terminals. 12 3. Cardiac Chambers Left atrium (LA) The left sided atrium (superior to the left ventricle) Receives blood from the four pulmonary veins - Smooth internal walls - Appendage: with rough trabeculations columbiasurgery.org 13 3. Cardiac Chambers Anterior Ventricles RV The ventricles receive blood from the atria LV The right ventricle (RV) is more anterior than the left ventricle (LV). Posterior 14 3. Cardiac Chambers Ventricles Ventricular walls: - Are significantly thicker than the atria (to enable generation of high pressure). - Composed of three layers 1. Epicardium: Outermost layer (visceral epicardium) 2. Myocardium: Middle muscular layer (majority of wall) 3. Endocardium: Innermost layer of simple squamous endothelium (to prevent blood cells from adhering). 15 3. Cardiac Chambers Ventricles Myofibrils are arranged in different orientations Circumferential fibrils predominate & are especially prominent in the outer (sub- epicardial) & mid walls The inner most fibres tend to be longitudinally oriented. Fibres arranged in different orientations promote the effectiveness of contraction. 16 3. Cardiac Chambers Right Ventricle (RV) The most anterior cardiac chamber (immediately behind the sternum) ‘Triangular’ in shape: the RV curves over the LV - Coarse trabeculations - Prominent moderator band - Three (‘hidden’) papillary muscle Inlet, trabecular & outlet portions. 17 3. Cardiac Chambers Left Ventricle (LV) Posterior to the RV Normally ‘cone’ shaped, the LV forms the apex of the heart The shape helps promote efficient flow in & out (helps promote vortex formation) Fine trabeculations & two prominent papillary muscles 18 3. Cardiac Chambers Left Ventricle (LV) Base, mid & apex The Ventricular septum ‘belongs’ to the LV Anatomical differences between RV & LV: - Shape - Wall thickness - Prominent LV PM’s - Moderator band (RV). 19 4. Cardiac Valves Four Heart Valves Two atria-ventricular valves that seperate the atria & ventricles Two semi-lunar (or VA) valves that seperate the ventricles & great arteries 20 4. Cardiac Valves Mitral Valve A Complex structure with five components 1. Annulus 2. Leaflets 3. Commissures 4. Chordae tendinae 5. Papillary muscles mitralvalverepair.org Two leaflets: I. Anterior (trapezoidal shaped) II. Posterior (elliptical shaped). 21 4. Cardiac Valves Tricuspid Valve A Complex structure with five components 1. Annulus 2. Leaflets 3. Commissures 4. Chordae tendinae 5. Papillary muscles Three leaflets: I. Anterior II. Septal III. Posterior 22 4. Cardiac Valves Aortic Valve A ‘simple’ structure with three components & the most central valve 1. Annulus 2. Leaflets 3. Commissures Three leaflets (cusps): I. Left coronary cusp II. Right coronary cusp III. Non coronary cusp (Named according to the coronary artery superior). 23 4. Cardiac Valves Pulmonary Valve A ‘simple’ structure with three components & the most anterior valve 1. Annulus 2. Leaflets 3. Commissures Three leaflets (cusps): I. Anterior II. Left III. Right. 24 5. Great Vessels & Cardiac Vasculature Pulmonary Artery (PA) - The PA, which start at PV, ascends at an oblique angle (leftward) - PA is anterior to the aorta. As the PA exits the pericardium it branches Branches: - Right PA - Left PA 25 5. Great Vessels & Cardiac Vasculature Pulmonary Veins (PV’s) Two PV’s, upper and lower emerge from each lung: i.e. two from the right and two from the left Right PV’s enter the posterior left atrium (LA) from the right Left PV’s enter the posterior left atrium (LA) from the left. 26 5. Great Vessels & Cardiac Vasculature Aorta The aorta, which start at AV, ascends at an oblique angle (rightward) & is posterior to the PA. The ascending aorta has: - Sinus portion - Tubular portion Sinus are three pouches immediately superior to the AV. The left & right sinuses gives rise to the coronary arteries. (Tubular portion ascends posterior to the PA). 27 5. Great Vessels & Cardiac Vasculature Aorta At it’s arch it gives rise to three branches Right brachiocephalic trunk (right common carotid and right subclavian) Left common carotid Left subclavian The aorta descends through the thorax & into the abdomen. www.imagekb.com 28 5. Great Vessels & Cardiac Vasculature LPA RPA LUPV RUPV MPA LA LLPV RLPV PV MV RV LV TV AV RA LCA Aorta RCA IVC SVC 29 5. Great Vessels & Cardiac Vasculature Right coronary artery Origin Branches (Ostia) Is in right Marginal sinus of valsalva Superior to RCC Posterior of AV interventricular circahajournals.org 30 5. Great Vessels & Cardiac Vasculature Left coronary artery Origin Branches (Ostia) Is in left Left anterior sinus of valsalva descending Superior to LCC of AV Circumflex 31 5. Great Vessels & Cardiac Vasculature 32 5. Great Vessels & Cardiac Vasculature Venous Drainage Three (venous) systems drain the heart 1. Coronary Sinus (CS) - Most veins drain into the coronary sinus - CS empties into inferior RA 2. Anterior cardiac veins - Drain into the anterior wall of the RA 3. Thesbian veins - Drain into all four chambers. 33 Conclusions Introduction 30o Location & Orientation Size & Shape | Pericardium 34 Conclusions Chambers Atria Ventricles 35 Conclusions Valves Atrio-ventricular valves Semi-lunar valves 36 Conclusions GA | Vasculature PA / Aorta Coronary arteries and veins 37 Cardiac Physiology Fundamentals