Right Ventricle overview

• Wraps around one-third of the left ventricle (LV)

• Muscle fibers continues with those of the LV

• Components

  •  Inferoposterior inflow (sinus)

  •  Anterosuperior outflow (infundibular)

  •  Inflow and outflow components divided by the crista supraventricularis (definition: a ridge on the inner wall of the right ventricle, marking off the conus arteriosus: supraventricularis also called supraventricular crest)

    •  Crista supraventricularis:  joins interventricular septum and LV to the right ventricular free wall (may assist left and right ventricular function integration)

  • Inflow component:

    •  Prominent muscle bands:

      • Moderator

      • Septal

      • Parietal

    •  Muscle bundle

      • Trabeculae carneae

Pulmonary Artery and Peripheral Pulmonary Circulation

• Pulmonic valve (a trileaflet valve) separates:

  •  Right ventricular infundibulum from the main pulmonary artery (PA).

  •  Trileaflet (right, anterior, left cusps)-- 4 cm² in area.

  •  Origination -- superior portion of the right ventricle

    • 11: anterior semilunar cusp (pulmonic valve)

    • 12: left semilunar cusp (pulmonic valve)

    • 13: right semilunar cusp (pulmonic valve)

    • Reference: Rohen, J.W. and Yokochi, C.,Color Atlas of Anatomy:  Photographic Study of the Human Body, third edition, Ikaku-Shoin, New York, Tokyo, p. 240, 1993.

    • 

  •  Path:

    1. Under the aorta

    2. Bifurcation into the right and left pulmonary artery (upper part of bifurcation is attached to the inferior aortic surface by the ligimentum arteriosum - a remnant of the ductus arteriosus)

  •  Pulmonary arteries →  pulmonary arterioles →  pulmonary capillaries that spread over alveolar surfaces between two alveolar endothelial layers.

  •  Pulmonary vessels size:

    •  Left-to-right shunt: prominent main pulmonary artery and hillar vessels: prominent.

    •  Pulmonary hypertension: main pulmonary artery dilation, followed by tapering of peripheral pulmonary vessels.

 Left Atrium

• Larger than right atrium

• Receives one or two pulmonary veins on left side

• Receives two or three pulmonary veins  on right side

• Blood flow path:

  • Left atrium left ventricle through the mitral valve

  • Mitral valve composition:  (area = 6-8 cm²)

    • Two major anteromedial and posterolateral leaflets

    • Papillary muscles

    • Chordae tendineae

  • Mitral chordae tendineae and papillary muscle: sensitive to reduced blood supply  

Left Ventricle (LV)

• Thicker (8-15 mm) > right ventricle

• Internal dimension (4.5 cm) > right ventricle (3.5 cm)

• Division of right ventricle from left ventricle:

  • Interventricular septum

• Ventricular layered structures (common to both left and right ventricles)

  •  Inner layer-endocardium covered with endothelium

  • Muscle layer (myocardium)

  • Outer layer (epicardium)

Aortic valves

• Adjacent to mitral valves within the left ventricle

• Cusps-unequal sizes; area = 3-4 cm².

  •  Right and left (coronary) cusps

  •  Posterior (non-coronary) cusp

  •  At the level of the valve, the aorta dilates to form the sinuses of Valsalva (location of the coronary ostia)

  • Reference: Rohen, J.W. and Yokochi, C.,Color Atlas of Anatomy:  Photographic Study of the Human Body, third edition, Ikaku-Shoin, New York, Tokyo, p. 240, 1993.

  • Left image 1: superior vena cava 9: chordae tendineae 10: anterior papillary muscle 11: myocardium 12: pulmonary trunk 13: ascending aorta 19: left atrium 20: aortic valve 21: left ventricle 22: pulmonary veins 23: fossa ovalis 24: left atrium 25: left atrioventricular left and bicuspid or mitral) valve 26: coronary sinus 27: left coronary 28: posterior papillary muscle

    Right Image 1: superior vena cava 9: chordae tendineae 10: anterior papillary muscle 11: myocardium 13: ascending aorta 18: heart apex 20: aortic valve 21: left ventricle 22: pulmonary veins 23: fossa ovalis 24: left atrium 25: left atrioventricular left and bicuspid or mitral) valve 26: coronary sinus 29: left subclavian artery 30: descending aorta 31: left pulmonary artery