Anatomy of heart Cardiac chambers anulus fibrosus cardiac

Anatomy of heart Cardiac chambers, anulus fibrosus, cardiac valves Ágnes Nemeskéri 2018 Semmelweis University Department of Anatomy, Histology and Embryology nemeskeri. agnes@med. semmelweis-univ. hu

Human heart Latin: cor 1. 2. 3. 4. 5. 6. Greek: kardia Location of heart Cardiac size, shape, external features Chambers of heart – internal features Valves of heart Connective tissue, fibrous skeleton of heart Arrangement of cardiac muscle fibers

1. Location of heart Thoracic cavity -mediastinum cardiacum -above the diaphragm – anterior slope -between mediastinal pleurae R L -1/3 of the cardiac mass lies to the right of the midline

Heart X-ray - posteroanterior https: //i. pinimg. com/564 x/20/89/b 5/2089 b 5471 adcd 287 f 0 d 22 c 8963 d 8 b 571 --cardiac-anatomy-heart-failure. jpg

Axis of the heart: from the apex to center of the base projecting posterolaterally: emerges near the right midscapular line http: //www. vhlab. umn. edu/atlas/anatomy-tutorial/graphics/Article-3_Fig 2. jpg

Lateral X-ray (chest –lateral view http: //2. bp. blogspot. com/-Ppda. VYB 28 I 4/VTXIVh. LXs. I/AAAABSo/x. IDQMDI 56 rg/s 1600/a 517 d 01679 b 356_2 HEART-Lateral. jpg

Left lateral radiograph with an esophagogram https: //radiologykey. com/wp-content/uploads/2015/12/9783131493316_c 001_f 010. jpg Bal pitvar megnagyobbodás

base: facing posteriorly, to the right 2. Cardiac shape pyramid-shaped: base - apex – oblique orientation in the thorax -apex: facing anteriorly and to the left -base: facing posteriorly, to the right Four chambers - muscular pumps - 2 atria -weakly contractile reservoirs -receive venous blood - 2 ventricles -powerful contractility, force the blood into the main arterial trunks apex

2. Cardiac size, external features auricles Size -from apex to base: ~ 12 cm -broadest transverse diameter: 8 -9 cm, 6 cm ant-post -weight: 280 g – 340 g in males (~ 0, 45 % of body weight) 230 g – 280 g in females (~0, 40 % of b. w. ) Pulm. tr. Surfaces, borders LV 1. sternocostal surface (anterior) -facing forwards and upwards -right & left ventricles + right atrium & left auricle -left margin (obtuse) RV -inferior margin (acute) Grooves -anterior interventricular groove -coronary groove -notch of cardiac apex

Surfaces • Anterior (or sternocostal) – Right ventricle. • Posterior (or base) – Left atrium. • Inferior (or diaphragmatic) – Left and right ventricles. • Right pulmonary – Right atrium. • Left pulmonary – Left ventricle 1. sternocostal surface (anterior) - facing forwards and upwards - right & left ventricles + right atrium & left auricle - left margin (obtuse) - inferior margin (acute)

2. Diaphragmatic surface 3. Posterior suface -upper border of the heart 2. Diaphragmatic surface (inferoposterior) -largely horizontal -more flat -mainly on the central tendon of diaphragm -coronary groove: border between inferior and posterior s. -slopes down and forwards -ventricles (chiefly the left) -posterior interventricular groove traverses obliquely LA 3. Posterior (cardiac base) -faces back and to the right -mainly the left atrium, posterior part of the right atrium -through the pericardium: esophagus! RA LV RV -posterior interventricular groove CRUX -point of junction of coronary groove (atrioventricular groove) + interatrial groove + posterior interventricular groove

diaphragmatic surface

4. posterior surface of the heart Base of heart - portion of the heart opposite the apex - superior and medially located - forms the upper border of the heart - lies just below the second rib - primarily involves the left atrium, part of the right atrium, and the proximal portions of the great vessels

Right atrium

Right atrium - receives and holds deoxygenated blood from the superior vena cava, inferior v. cava, vv. cardiacae ant. , sinus coronarius, small cardiac vein, which it then sends down to the right ventricle (through the tricuspid valve) https: //s 3. amazonaws. com/classconnection/191/flashcards/8294191/ png/screen_shot_2015 -09 -21_at_175837 -14 FF 0 D 7 F 93378 B 94528. png Sinuatrial node - is located in posterior aspect of the right atrium, next to the superior vena cava. - pacemaker cells which spontaneously depolarize to create an action potential - cardiac action potential spreads across both atria causing them to contract, forcing the blood they hold into their corresponding ventricles

3. Chambers of heart – right atrium -pectinate muscles -crista terminalis (terminal crest) -smooth muscular ridge -ostium of coronary sinus ssa ovalis epression -anteroinferior part of right atrium: -large oval vestibule leading to the orifice of the tricuspid valve -interatrial septum -right auricule (muscular pouch) -posterior vertically elongated part: sinus venarum cavarum -smooth-walled -right atrioventricular orifice

In fetal life, eustachian valve (valve of inf. v. cava) helps direct flow of oxygen-rich blood through the right atrium into left atrium and away from right ventricle Right atrium - from the interatrial septum inferiorly and to the right to the inferomedial part of the inferior vena caval valve - connective tissue fibers, fibroblasts http: //theanatomymap. com/wp-content/uploads/2017/04/Learning-Tendon-Of-Todaro-Heart. Anatomy-37 -with-Tendon-Of-Todaro-Heart-Anatomy. jpg Triangle of Koch: helps the surgical orientation!

Interatrial septum – right side http: //heart. bmj. com/content/heartjnl/103/6/456/F 2. large. jpg? width=800&height=600&carousel=1 Oval fossa - its floor is represented by septum primum - its limbus or margin is represented by septum secundum

3. Chambers of heart – left atrium - smaller in volume than the right, roughly cuboidal - left part of it is concealed by the initial segments of pulmonary trunk and aorta - thicker walls (~3 mm) - posterior aspect forms most of the base, quadrangular - receives two pulmonary veins from each lung, they open into upper posterolateral surface - left auricle – pectinate muscles – longer , narrower than the right auricle - vestibule leads to mitral valve -septum has a crescentic ridge (valve of the embyonic foramen ovale) valve of foramen ovale bal pitvar https: //classconnection. s 3. amazonaws. com/469/flashcards/919469/jpg/ left_atrium 1321061595114. jpg http: //content. onlinejacc. org/data/Journals/JAC/23051/08038_gr 2. jpeg

3. Chambers of heart – ventricles http: //www. med. uottawa. ca/patho/eng/public/cardio/nheartshort. gif

3. Chambers of heart – right ventricle RA septomarginal trabecula -„V” –shaped chamber -the anterosuperior cusp of tricuspid valve attaches to the posterolateral aspect of the crest -apical component is coarsly trabeculated -outlet component is smooth -irregular muscular ridges and protrusions: trabeculae carneae, papillary muscles -a protrusionfrom the septum: septomarginal trabecula supports the anterior papillary muscle, then crosses to the parietal wall

Right ventricle – inlet - outlet http: //www. revespcardiol. org/imatges/255 v 63 n 09/255 v 63 n 09 -13155686 fig 1. jpg 1. inlet component: surrounding the tricuspid valve; 2. apical component; 3. outlet or infundibulum (conus arteriosus) -inlet and outlet components are separated in the roof by the supraventricular crest – highly arched from the interventricular septum to the anterolateral right ventricular wall Supraventricular crest separates the inlet and outlet

3. Chambers of heart – left ventricle https: //www. researchgate. net/profile/Ismail_El. Hamamsy/publication/264163917/figure/fig 2/AS: 203027085565953@1425416837335/Photogra ph-of-an-open-aortic-root-showing-its-structural-components-annulus-cusps. png -wall is 3 x thicker than that of right ventricle (8 -12 mm) -cone-shaped, longer and narrower than the right ventricle, transversly nearly circular -1. inlet region guarded by the mitral valve; 2. outlet region guarded by the aortic valve; 3. apical trabecular component -in contrast to orifices in right ventricle, in the left: orifices are in close contact, with fibrous continuity -interventricular septum : muscular and membranous septum -trabeculae carneae are finer

4. Cardiac valves 1. Atrioventricular – cusped valves 2. Arterial – semilunar valves -they arise from the skeleton of the heart

Atrioventricular valvular complex -orifice its associated anulus, cusps, 4. Cusped valves supporting chordae tendineae, papillary muscles Cusps -reduplication of endocardium – collagenous core (fibrosa), fibroelastic tissue surrounds it -continuous at the margin and on the ventricular aspect with the chordeae tendineae -basally confluent with the anular connective tissue 1. basal zone: 2 -3 mm, thicker, more connective tissue, vascular, innervated 2. clear zone: smooth, translucent, thinner fibrous core 3. rough zone: thick, opaque, uneven on its ventricular aspect where cordae tendineae attach Chordae tendineae -fibrous collagenous structures, arise from on the tips of papillary muscles -attach to ventricular aspect or free margins of cusps (to fibrosa) -they hold the cusp in position to prevent it from flapping back into the atrium Papillary muscles (musculi papillares) -strong muscular columns – 6 -12 tendinous cords arise from the tip

4. Tricuspid valve -roughly triangular orifice -anular connective tissues around the orifice separate the atrial and ventricular myocardium completely except: at the point of penetration of atrioventricular bundle -3 cusps: anterosuperior (largest), septal, inferior) -anterior papillary m. is the largest -posterior papillary m. -septal papillary m. is small

4. Bicuspid (mitral) valve -cuspis anterior (aortic, septal, greater, anteromedial), posterior (fali, ventricularis, smaller, posterolateral) -anterior cusp is placed between the inlet and outlet -posterior cusp: wider attachment to the anulus -circular orifice smaller than the tricuspid orifice -mitral, tricuspid and aortic orifices are connected centrally at the central fibrous body -anterolateral + posteromedial papillary m. intimately

Semilunar valves 4. Semilunar valves -pulmonary valve -nodular thickening at the center of the free edge of each cusp: nodule -lunula: both sides of nodule the edges of cusp are thin, translucent -below the lunula: fibroelastic thickening: linea alba http: //www. e-heart. org/Photos/01_Cardiac_Structure _Photos/%C 2%A 9 Aortic%20 Valve%20 Gross%20640%20 x%20440. jpg Pulmonary valve -anterior, right and left cusps Aortic valve -aortic valve -posterior, right, left cusps -at the level of semilunar valves the vessel wall bulges outward: sinus of aorta -coronary arteries arise in the depth of right and left aortic sinuses

5. Fibrous skeleton of heart old statement Cusps of pulmonary valve are supported on a free-standing sleeve of right ventricular infundibulum!! Not all four valves are contained within the fibrous skeleton!!

6. Wall of the heart 1. Epicardium -1. flat mesothelial cells (visceral pericardium) -2. underlying loose connective tissue, contains elastic fibers -arteries, veins of heart, adipose tissue, nerves , ganglia 2. Endocardium -1. innermost layer: flat endothelial cells -2. middle layer: collagen and elastic fibers are compact and arranged in parallel in the deepest part, it contains bundles of smooth muscles -3. subendocardial layer: irregular collagen fibers that merge with the collagen surrounding the cardiac muscle fibers -this layer contains the fibers of the conducting system 3. Myocardium

6. Myocardium

6. Myocardium Atria: 2 layers -inner longitudinal, outer circular Ventricles: 3 layers -outer spiraling longitudinal: arising from the cardiac skeleton (mainly fibrous trigones) fibers run towards the apex – they form a whorl: vortex of the heart -inner spiraling longitudinal fibers: trabeculae carneae, papillary muscles -middle circular: strong fibers

6. Myocardium

Spatial organization of the ventricular myocardial fibers Invited paper Towards new understanding of the heart structure and function Francisco Torrent-Guaspa, Mladen J. Kocicab, *, Antonio F. Cornoc, Masashi Komedad, Francesc Carreras-Costae, A. Flotatsf, Juan Cosin-Aguillarg, Han Wenh „The problem of the macroscopic structure of the ventricular myocardium has remained unsolved since the XVI century, ” „Ventricular myocardial band concept (VMB)” „the concept of active diastole”

„Torrent-Guasp proposed a challenging and very important anatomic concept in which both ventricles are considered to consist of a single myocardial band extending from the right ventricular muscle just below the pulmonary artery to the left ventricular muscle where it attaches to the aorta, twisted and wrapped into a double helical coil during evolutionary and embryological development, capable of highly efficient sequential contraction responsible for ventricular ejection and filling „