Anatomy of The Thorax 2024-2025 PDF

Block 1.3 lectures 2024-2025 Anatomy Highlighter key Writer...

Block 1.3 lectures 2024-2025 Anatomy Highlighter key Writer Reviewer Doctor explanation Abbreviation Key information Book >> >> Amal Alismail Mariyyah Al Bladi Maryam Alanazi Student explaintion 221-222-223 notes References Deleted  CARDIOVASCULAR SYSTEM STRUCTURE OF HEART AND BLOOD VESSELS Theme 14 Part A Dr. Naheed Kausar Assistant Professor Anatomy Division Biomedical Sciences College of Medicine King Faisal University 12/22/2024 (C) KFU AY 24 -25 3  The Right heart: Receives poorly The Left heart: Receives well- oxygenated (venous) blood from the oxygenated (arterial) blood from the body through the SVC and IVC and lungs through the pulmonary veins pumps it through the pulmonary and pumps it into the aorta for trunk and arteries to the lungs for distribution to the body. oxygenation SVC = Superior vena cava IVC = Inferior vena cava The superior and inferior vena cave connect in the right atrium 12/22/2024 (C) KFU AY 24 -25 4  Learning Objective 1. Orientation of heart in thoracic cavity 2.Anatomy of Heart (Layers of Wall, apex, base, chambers, cardiac skeleton, septum, fossa ovalis) 3.Valves (Functional anatomy of semilunar valves, tricuspid valve and mitral valve, papillary muscles) 4.Conducting System of Heart (structure and Function) 5. Vasculature of Heart (coronary arteries, coronary sinus) 6.Vagus nerve and Sympathetic Trunk (effects on Heart Function) 7.Pericardium (structure and function of the pericardial sac) 12/22/2024 (C) KFU AY 24 -25 5  In the heart we have four chambers they are divided into two halves The Heart The right one deal with the deoxygenated blood and the left one deal with the oxygenated blood ❑ Larger than a clenched fist A double, self-adjusting suction and ❑ pressure pump The parts work in unison to propel blood The ❑ cardiac cycle: Synchronous pumping actions of two ❑ atrioventricular (AV) pumps In theventricles first pump the two atriums will contract then the the second pump will contract , these two pumps make one cardiac cycle The cycle begins with a period of ventricular elongation and ❑ filling (diastole) and ends with a period of ventricular shortening and emptying (systole). Diastole : when the heart muscle relaxes and the ventricles fill with blood Systole : when the heart muscle contracts and pushing the blood out of the heart and into the larg blood vessels of the circulatory system The left ventricle will push The right ventricle will push the blood through the aorta the blood through the to the body pulmonary artery to the lungs 12/22/2024 (C) KFU AY 24 -25 6  This video for further understanding Heart a Pyramid One base and apex , and four faces The heart appears trapezoidal from an anterior or posterior view Apex but in three dimensions it Base is shaped like a tipped-over pyramid Anterior surface Diaphragmatic surface Also called the inferior surface Left Pulmonary Surface Right Pulmonary Surface 1. Anterior (sternocostal) surface, formed mainly by the right ventricle. 2. Diaphragmatic (inferior) surface, formed mainly by the left ventricle and partly by the right ventricle; it is related mainly to the central tendon of the diaphragm. 3. Right pulmonary surface, formed mainly by the right atrium. 4. Left pulmonary surface, formed mainly by the left ventricle; it forms the cardiac impression in the left lung. 12/22/2024 (C) KFU AY 24 -25 7  Orientation of Heart in Thoracic Cavity Apex of this pyramid projects forward, downward and to the left, deep to the left 5th intercostal space Base is opposite the apex and faces posteriorly, opposite T6-T9 when standing The left atrium in the back side 12/22/2024 (C) KFU AY 24 -25 8  The apex of the heart : The base of the heart : Is formed by the inferolateral part of the left Is formed mainly by the left atrium, with a lesser ventricle. contribution by the right atrium. usually approximately 9 cm (a hand's breadth) from the median plane. Faces posteriorly toward the bodies of vertebrae and is Sounds of mitral valve closure are maximal separated from them by the pericardium, oblique (apex beat); pericardial sinus, esophagus, and aorta. The apex beat is the impulse that results from the Extends superiorly to the bifurcation of the pulmonary apex of the heart being forced against the anterior trunk and inferiorly to the coronary sulcus. thoracic wall when the left ventricle contracts. The location of the apex beat (mitral area, M) varies in Receives the pulmonary veins on the right and left sides of position and may be located in the 4th or 5th its left atrial portion and the superior and inferior venae intercostal spaces, 6-10 cm from the AML (anterior cavae at the superior and inferior ends of its right atrial median line). portion.  Cardiac muscle cells form a highly branched cellular network in the heart. They are connected end to end by intercalated disks and are organized into layers of myocardial tissue that are wrapped around the chambers of the heart. The contraction of individual cardiac muscle cells produces force and shortening in these bands of muscle so the network help the cardiac muscle to contract faster and more stronger Not all the information is important know the cardiac muscle and read the other to differentiate  Layers of Wall of Heart The wall of each heart chamber consists of three layers. Endocardium, a thin internal layer (endothelium and subendothelial connective tissue) or lining membrane of the heart that also covers its valves. Myocardium, a thick, helical middle layer composed of cardiac muscle. The walls of the heart consist mostly of myocardium, especially in the ventricles. Epicardium, a thin external layer (mesothelium) formed by the visceral layer of serous pericardium. 12/22/2024 (C) KFU AY 24 -25 9  Layers of Wall of Heart Epicardium is covered by two layers 12/22/2024 (C) KFU AY 24 -25 9  External features of the heart Remember, this is the left atrium and it is making the whole base. It like a wall between the These grooves separate the ventricles and it contains left and the right ventricles arteries and veins 12/22/2024 (C) KFU AY 24 -25 10  External features of the heart The arch of the aorta Arches superiorly, posteriorly and to the left The aorta starts at the sternal angle 12/22/2024 (C) KFU AY 24 -25 11  4 1- The superior and inferior vena cave will carry the deoxygenated blood to the right atrium 2- the right atrium pumps the blood to the right ventricle 3 7 3- then it will pump into the lungs by the pulmonary artery 5 4- the blood will be oxygenated in the lungs 1 2 6 5- it will come back to the left atrium by the pulmonary vein 6- then it will go to the left ventricle 7- finally, it will go back through the aorta to the body 12/22/2024 (C) KFU AY 24 -25 11  External features of the heart The heart consists of four chambers Two upper chamber called atria Two lower chambers called ventricles The two upper and two lower chambers are separated by atrioventricular groove (coronary sulcus) And the atria are demarcated Simply when you determine from the ventricles the ventricles , the atria will be above them 12/22/2024 (C) KFU AY 24 -25 12  External Features of The Heart ❑ Coronary Sulcus: Separating the atria from the ventricles Contains coronary sinus right coronary artery small cardiac vein circumflex branch of the left coronary artery 12/22/2024 (C) KFU AY 24 -25 13 Right and left ventricles are demarcated from each other by anterior and posterior interventricular (IV) sulci (grooves) Posterior Interventricular Anterior Interventricular Sulcus: contains posterior Sulcus: contains anterior interventricular artery and the interventricular artery and a middle cardiac vein great cardiac vein 12/22/2024 (C) KFU AY 24 -25 14  Borders of The Heart 1. Superior border, formed by the right and left atria and auricles in an anterior view; the ascending aorta and pulmonary trunk emerge from this border and the SVC enters its right side. Line connecting the inferior border of the 2nd left costal cartilage to the superior border of the 3rd right costal cartilage 2. Right border (slightly convex), formed by the right atrium and extending between the SVC and the IVC. Line drawn from the 3rd right costal cartilage to the 6th right costal cartilage. 3. Inferior border (nearly horizontal), formed mainly by the right ventricle and slightly by the left ventricle. Line drawn from the inferior end of the right border to a point in the 5th intercostal space close to the left MCL (apex of the heart). 4. Left border (oblique, nearly vertical), formed mainly by the left ventricle and slightly by the left auricle. Line connecting the left ends of the lines representing the superior and inferior borders. 12/22/2024 (C) KFU AY 24 -25 15  Internal features of the heart How to identify the side of heart which one is right and which one is left? “ by thickness “ The right side is thin The left side is thick 12/22/2024 (C) KFU AY 24 -25 16  Right Atrium Has SVC, IVC, and coronary sinus openings Right auricle a conical muscular projection Smooth, thin-walled, posterior part on which the venae cavae (SVC and IVC) and coronary sinus open Rough, muscular anterior wall composed of pectinate muscles The interatrial septum has an oval, thumbprint-size depression, Fossa ovalis, a remnant of foramen ovale and its valve in the fetus. 12/22/2024 (C) KFU AY 24 -25 17  Right Atrium The right auricle (ear-like): bringing poorly oxygenated blood into the heart. Right AV orifice through which the right atrium discharges the poorly oxygenated blood it has received into the right ventricle. The SVC opens into the superior part of the right atrium at the level of the right 3rd costal cartilage. The IVC opens into the inferior part of the right atrium almost in line with the SVC at approximately the level of the 5th costal cartilage. The opening of the coronary sinus, a short venous trunk receiving most of the cardiac veins, is between the right AV orifice and the IVC orifice. 12/22/2024 (C) KFU AY 24 -25 17  Left Atrium Forms the base of the heart A larger smooth-walled part and a auricle smaller muscular and overlaps the root of the pulmonary trunk. containing pectinate muscles. Four pulmonary veins (two superior and two inferior) entering its smooth posterior wall A slightly thicker wall than that of the right atrium. A left AV orifice through which the left atrium discharges the oxygenated blood it receives from the pulmonary veins into the left ventricle. 12/22/2024 (C) KFU AY 24 -25 18  Right Ventricle Superiorly Conus arteriosus (infundibulum), leads into pulmonary trunk The tricuspid valve : The The tricuspid valve guards the inflow part of the ventricle receives blood from the right right AV, located posterior to the atrium through the right AV body of the sternum at the level (tricuspid) orifice of the 4th and 5th intercostal The bases of the valve cusps are attached spaces to the fibrous ring around the orifice. Three papillary muscles (Conical muscular projections with bases attached to ventricular wall ) Anterior Posterior Septal Papillary muscle 12/22/2024 (C) KFU AY 24 -25 19  The Papillary Muscles prevent separation of the cusps and their inversion when The interventricular septum (IVS), composed of muscular and membranous tension is applied parts, is a strong, obliquely placed partition between the right and left to the tendinous cords. ventricles , forming part of the walls of each. Because of the much higher Thus regurgitation of blood (backward flow of blood) from blood pressure in the left ventricle, the the right ventricle back into the right atrium is blocked muscular part of the IVS, bulges into the cavity of the right ventricle. A thin during ventricular systole by the valve cusps. membrane, part of the fibrous skeleton of the heart, forms the much Three papillary muscles in the right ventricle correspond to smaller membranous part of the IVS. the cusps of the tricuspid valve. The septomarginal trabecula (moderator band) is a curved muscular bundle that traverses the right ventricular chamber from the inferior part of the IVS The anterior papillary muscle, the largest and most to the base of the anterior papillary muscle. This trabecula is important prominent of the three, arises from the anterior wall of the because it carries part of the right branch of the AV bundle, a part of the right ventricle. conducting system of the heart to the anterior papillary. The pulmonary valve at the apex of the conus arteriosus is at the level of the The posterior papillary muscle, smaller than the anterior left 3rd costal muscle, may consist of several parts; it arises from the cartilage. inferior wall of the right ventricle. The septal papillary muscle arises from the interventricular septum, and its tendinous cords attach to the anterior and septal cusps of the tricuspid valve.  Right Ventricle Tendinous cords: (chordae tendineae) From the apices of papillary muscle to the free edges and ventricular surfaces of the cusps, like cords attaching to a parachute Prevents AV valve from reversing into the atria as papillary muscles contract 12/22/2024 (C) KFU AY 24 -25 20  Left Ventricle Forms the apex of the heart. Wall two to three times right thicker than ventricle. Two larger anterior and papillary posterior muscles. Smooth outflow leading to aortic orifice. Double-leaflet mitral valve guards the left AV orifice at the level of the 4th costal cartilage behind sternum. 12/22/2024 (C) KFU AY 24 -25 21  The left ventricle forms the apex of the heart, Left Ventricle nearly all its left (pulmonary) surface and border., The interior of the left ventricle Walls that are mostly covered with a mesh of trabeculae carneae that are finer and more numerous than those of the right ventricle. A conical cavity that is longer than that of the right ventricle. Anterior and posterior papillary muscles that are larger than those in the right ventricle. A smooth-walled, non-muscular, superoanterior outflow part, the aortic vestibule, leading to the aortic orifice and aortic valve. An aortic orifice that lies in its right posterosuperior part and is surrounded by a fibrous ring to which the right posterior, and left cusps of the aortic valve are attached;the ascending aorta begins at the aortic orifice. The mitral valve has two cusps, anterior and posterior. Left atrium and ventricle, left lateral view. Note the irregular trabeculae carneae The mitral valve is located posterior to characteristic of the ventricular wall. the sternum at the level of the 4th costal cartilage. The semilunar aortic valve, between the left ventricle and the ascending aorta, located posterior to the left side of the sternum at the 12/22/2024 (C) KFU AY 24 -25 21 level of the 3rd intercostal space.  The left ventricle forms the apex of the heart, Left Ventricle nearly all its left (pulmonary) surface and border., The interior of the left ventricle Walls that are mostly covered with a mesh of trabeculae carneae that are finer and more numerous than those of the right ventricle. A conical cavity that is longer than that of the right ventricle. Anterior and posterior papillary muscles that are larger than those in the right ventricle. A smooth-walled, non-muscular, superoanterior outflow part, the aortic vestibule, leading to the aortic orifice and aortic valve. An aortic orifice that lies in its right posterosuperior part and is surrounded by a fibrous ring to which the right posterior, and left cusps of the aortic valve are attached;the ascending aorta begins at the aortic orifice. The mitral valve has two cusps, anterior and posterior. The mitral valve is located posterior to the sternum at the level of the 4th costal cartilage. The semilunar aortic valve, between the left ventricle and the ascending aorta, located posterior to the left side of the sternum at the 12/22/2024 (C) KFU AY 24 -25 21 level of the 3rd intercostal space.  Septum of The Heart ❑ The interventricular septum (IVS) composed of muscular and membranous parts, strong, obliquely placed partition between the right and left ventricles. 12/22/2024 (C) KFU AY 24 -25 22  Cardiac Skeleton Four fibrous rings (two rings and two “coronets”), each encircling a valve. Provides attachment to cardiac muscle fibers. Keeps the valves’ orifices patent. Provides attachments for valves’ leaflets and cusps. Forms an electrical “insulator,” so that atria and ventricles contract independently. Forms an electrical “insulator,” by separating the myenterically conducted impulses of the atria and ventricles so that they contract independently and by surrounding and providing passage for the initial part of the AV bundle of the conducting system of the heart. 12/22/2024 (C) KFU AY 24 -25 23  Cardiac Skeleton four fibrous rings (L. anuli fibrosi) that surround the orifices of the valves and the membranous parts of the interatrial and interventricular septa. The fibrous skeleton of the heart Keeps the orifices of the AV and semilunar valves patent and prevents them from being overly distended by an increased volume of blood pumping through them. Provides attachment for the myocardium, which, when uncoiled, forms a continuous ventricular myocardial band that originates primarily from the fibrous ring of the pulmonary valve and inserts primarily into the fibrous ring of the aortic valve 23 12/22/2024 (C) KFU AY 24 -25  Valves of the heart 12/22/2024 (C) KFU AY 24 -25 24  Valves of the heart 12/22/2024 (C) KFU AY 24 -25 25  Semilunar Valves Three semilunar cusps of the pulmonary valve (anterior, right, and left) at level of left 3rd costal cartilage. The semilunar cusps of the aortic valve (posterior, right, and left) posterior to sternum at left 3rd intercostal space. Semilunar cusps do not have How the valves close ? the closing of AV valve : by the contraction of tendinous cords to support ventriculars or papillary muscle the closing of semilunar valve? By filling of blood in them. valves (semilunar valve) The aortic sinuses and the pulmonary sinuses are spaces at the origin of the pulmonary trunk and ascending aorta. 12/22/2024 (C) KFU AY 24 -25 26  Semilunar Valves 12/22/2024 (C) KFU AY 24 -25 26  Heart Sounds Heard with a stethoscope: The heart sounds are produced by the snapping shut of the oneway valves that normally keep blood from flowing backward during contractions of the heart. Lub: (1st) sound as the blood is transferred from the atria into the ventricles (closure of AV valve) Dub: (2nd) sound as the ventricles expel blood from the heart (closure of Aortic and pulmonary valves) 12/22/2024 (C) KFU AY 24 -25 27  Surface Anatomy of Valves ❑ The valves are located posterior to the sternum ❑ The sounds produced by them are projected to the areas shown Blood tends to carry the sound in the direction of its flow; consequently, each area is situated superficial to the chamber or vessel into which the blood has passed and in a direct line with the valve orifice. 12/22/2024 (C) KFU AY 24 -25 28  Auscultatory Areas for Valves on Chest Following spaces are used to listen to the heart as; 2nd Intercostal Space R (parasternal) Aortic valve. 2nd Intercostal Space L (parasternal) Pulmonary valve. 5th Intercostal Space L (parasternal) Tricuspid valve. 5th Intercostal Space L (midclavicular) Mitral valve. 12/22/2024 (C) KFU AY 24 -25 29  Conducting system of the heart Impulse Conduction through the Heart Impulse generation and conduction can be summarized as follows: The SA node initiates an impulse that is rapidly conducted to cardiac muscle fibers in the atria, causing them to contract. The impulse spreads by myogenic conduction, which rapidly transmits the impulse from the SA node to the AV node. The signal is distributed from the AV node through the AV bundle and its branches (the right and left bundles), which pass on each side of the IVS to supply subendocardial branches to the papillary muscles and the walls of the ventricles. 12/22/2024 (C) KFU AY 24 -25 30  Conducting System of Heart 12/22/2024 (C) KFU AY 24 -25 31  Conducting System of Heart 1. SA Node (Sinoatrial Node): Location: Anterolaterally at the junction of the superior vena cava (SVC) and the right atrium, just beneath the epicardium. Function: The pacemaker of the heart; initiates and regulates electrical impulses for heart contractions. Blood Supply: Supplied by the sinuatrial nodal artery, typically a branch of the RCA (60%) or the LCA (40%). Nervous Influence: Accelerated by the sympathetic nervous system. Slowed down by the parasympathetic nervous system. 2. AV Node (Atrioventricular Node): Location: Posteroinferior region of the interatrial septum near the opening of the coronary sinus. Function: Receives signals from the SA node and relays them to the ventricles. Blood Supply: Supplied by the AV nodal artery, usually a branch of the posterior interventricular artery (a branch of the RCA in 80% of people). Nervous Influence: Conduction is accelerated by the sympathetic nervous system. Conduction is slowed by the parasympathetic nervous system. 3. AV Bundle (Bundle of His): Function: The only electrical connection between the atria and ventricles. Path: Passes through the fibrous skeleton of the heart and divides into: Right and Left Bundles: These branches travel along the interventricular septum and end in Purkinje fibers, which transmit signals to the ventricular walls. Key Points: The SA node generates the initial signal. The AV node regulates and relays the signal to the ventricles. The AV bundle and Purkinje fibers ensure the signal reaches the ventricles for contraction. 12/22/2024 (C) KFU AY 24 -25 31  ARTERIAL SUPPLY TO HEART 12/22/2024 (C) KFU AY 24 -25 32  ARTERIAL SUPPLY TO HEART The right coronary artery (RCA) arises from the right aortic sinus of the ascending aorta and passes to the right side of the pulmonary trunk, running in the coronary sulcus. Branches are: SA nodal supply Pulmonary trunk and SA node Right marginal supply Right ventricle and apex of heart Posterior interventricular supply Right and left ventricles and posterior third of IVS AV nodal supply AV node Typically, the RCA supplies The right atrium. Most of right ventricle. Part of the left ventricle (the diaphragmatic surface). Part of the IV septum, usually the posterior third. The SA node (in approximately 60% of people). The AV node (in approximately 80% of people). The left coronary artery (LCA) arises from the left aortic sinus of the ascending aorta (Fig. 1.58), passes between the left auricle and the left side of the pulmonary trunk, and runs in the coronary sulcus. Branches are: SA nodal supply Left atrium and SA node Anterior interventricular supply Right and left ventricles and anterior two thirds of IVS Circumflex supply Left atrium and left ventricle Left marginal supply Left ventricle Posterior interventricular 33% supply Right and left ventricles and posterior third of IVS Typically, the LCA supplies: The left atrium. Most of the left ventricle. Part of the right ventricle. Most of the IVS (usually its anterior two thirds), including the AV bundle of the conducting system of the heart, through its perforating IV septal branches. 12/22/2024 (C) KFU AY 24 -25 33 The SA node (in approximately 40% of people).  ARTERIAL SUPPLY TO HEART Branch Distribution Right coronary (RCA) Right atrium and ventricle, SA and AV nodes, and posterior part of IVS SA nodal Pulmonary trunk and SA node Right marginal Right ventricle and apex of heart Posterior interventricular Right and left ventricles and posterior third of IVS AV nodal AV node Left coronary (LCA) Most of left atrium and ventricle, IVS, and AV bundles; may supply AV node SA nodal Left atrium and SA node Anterior interventricular Right and left ventricles and anterior two thirds of IVS Circumflex Left atrium and left ventricle Left marginal Left ventricle Posterior interventricular 33% Right and left ventricles and posterior third of IVS 12/22/2024 (C) KFU AY 24 -25 34  Venous Drainage of the Heart The great, middle, and small cardiac veins; the oblique vein of the left atrium; and the left posterior ventricular vein are the main vessels draining into the coronary sinus. The coronary sinus, in turn, empties into the right atrium. The anterior cardiac veins drain directly into the auricle of the right atrium. 12/22/2024 (C) KFU AY 24 -25 35  Blood supply of the heart The heart is drained mainly by veins that empty into the coronary sinus and partly by small veins that empty into the right atrium. The coronary sinus, the main vein of the heart, is a wide venous channel that runs from left to right in the posterior part of the coronary sulcus. The coronary sinus receives the great cardiac vein at its left end and the middle cardiac vein and small cardiac veins at its right end. The left posterior ventricular vein and left marginal vein also open into the coronary sinus. 12/22/2024 (C) KFU AY 24 -25 36  Autonomic innervation Parasympathetic stimulation From Vagus nerve Force of contraction ↓ Saving energy between Sympathetic stimulation periods of increased From superior 5-6 thoracic demand segments of the spinal cord. Rates of depolarization Force of contraction ↑ of the pacemaker cells ↓ Impulse conduction ↑ Atrial contractility ↓ Atrial and ventricular Atrioventricular conduction ↓ contractility ↑ Heart rate ↓ Heart rate ↑ Coronary arteries constrict Blood flow through the Coronary vessels ↑ 12/22/2024 (C) KFU AY 24 -25 37  Autonomic innervation Sympathetic innervation: Preganglionic neurons from T1 to T6 spinal cord segments send fibers to synapse on postganglionic neurons in the cervical and upper thoracic sympathetic ganglia. The three cervical cardiac nerves and thoracic cardiac branches contribute to the cardiac plexus. Parasympathetic innervation: Preganglionic neurons and fibers reach the heart via cardiac branches, some of which also arise in the cervical region. They synapse on postganglionic neurons near the SA node and along the coronary arteries. The subendocardial branches of the right bundle stimulate the muscle of the IVS, the anterior papillary muscle through the septomarginal trabecula (moderator band), and the wall of the right ventricle. The left bundle divides near its origin into approximately six smaller tracts, which give rise to subendocardial branches that stimulate the IVS, the anterior and posterior papillary muscles, and the wall of the left ventricle. 12/22/2024 (C) KFU AY 24 -25 31  Nerves of the thorax 12/22/2024 (C) KFU AY 24 -25 38  Pericardium (A fibro-serous membrane) Covers heart and beginning of its great vessels. Composed of two layers; Fibrous layer: Tough external layer Fibrous layer Prevent heart over expansion of Serous layer (mesothelium): 1. Parietal layer, (glistening) lining fibrous pericardial layer 2. Visceral layer, on the heart as epicardium and extends onto beginning of great vessels. Serous layer secreting the fluid allowing the lobrication of the heart because the heart continuously 12/22/2024 (C) KFU AY 24 -25 contracting,protecting it from damaging 39  Pericardium The pericardial cavity: A potential space between parietal and visceral layers of serous pericardium, contains a thin film of fluid for lubrication for heart to move and beat. Transverse pericardial sinus Oblique pericardial sinus The pericardial sinuses are spaces formed during the folding of the primitive heart tube. They are two main types: 1. Transverse Pericardial Sinus: A passage within the pericardial cavity. Located between the aorta and pulmonary trunk (anteriorly) and the superior vena cava (SVC), inferior vena cava (IVC), and pulmonary veins (posteriorly). Important in cardiac surgery, as surgeons can insert a finger through this sinus to access major vessels behind the aorta and pulmonary trunk. 2. Oblique Pericardial Sinus: A pocket-like space behind the base of the heart (posteriorly). Formed by the reflection of the serous pericardium around the SVC, IVC, and pulmonary veins. Positioned near the left atrium. 40 12/22/2024 (C) KFU AY 24 -25  Pericardium Video for further understanding Involved in several disease processes: Pericarditis: Inflammation of the pericardium. Pericardial effusion: Passage of fluid from pericardial capillaries into the pericardial cavity, or an accumulation of pus. Hemopericardium:Blood in the pericardial cavity. Pneumopericardium: Air or gas enter the pericardial sac. Pericardiocentesis: Drainage of fluid from the pericardial cavity (needle may be inserted through the left 5th or 6th intercostal space near the sternum) Pericardiocentesis: Drainage of fluid from the pericardial cavity, pericardiocentesis, is usually necessary to relieve cardiac tamponade. To remove the excess fluid, a wide- bore needle may be inserted through the left 5th or 6th intercostal space near the sternum. 12/22/2024 (C) KFU AY 24 -25 41  Summary Heart has four surfaces, borders, chambers and valves. Blood supplied by coronary arteries and venous drainage by coronary sinus. Clinicians' interest in the surface anatomy of the heart and valves results from their need to listen to heart sounds. The conducting system of the heart produces coordinated contraction of the atria and ventricles. Pericardium is composed of fibrous (tough) external layer and inner serous(mesothelium) a double layer. 12/22/2024 (C) KFU AY 24 -25 42 REFERENCES: Clinically Oriented Anatomy (8th ed.) 1/22/2024 (C) KFU AY 24 -25 43 THANK YOU 12/22/2024 (C) KFU AY 24 -25 44  team Wishes you the best