Right Ventricle

Heart Anatomy

Right Ventricle

Position, external features, internal features and interventricular septum.

1

Position

  • The right ventricle is a triangular chamber.
  • It receives blood from the right atrium.
  • Pumps blood to the lungs through:
  • Pulmonary trunk
  • Pulmonary arteries

It forms:

  • Inferior border of the heart
  • 2/3rd part of sternocostal surface
  • 1/3rd part of inferior surface of the heart.
2

External Features

1 Surfaces

Externally, the right ventricle has 2 surfaces:

  • Anterior or sternocostal
  • Inferior or diaphragmatic

2 External Separation

The right ventricle is separated externally:

  • From the right atrium → by the atrioventricular groove.
  • From the left ventricle → by anterior and posterior (inferior) interventricular grooves.
3

Internal Features

1

Parts of Right Ventricle

The interior has 2 parts:

a. Inflowing Part

  • Rough due to the presence of muscular ridges called trabeculae carneae.
  • Develops from the proximal part of bulbus cordis of the heart tube.

b. Outflowing Part / Infundibulum

  • Smooth.
  • Forms the upper conical part of the right ventricle.
  • Gives rise to the pulmonary trunk.
  • Develops from the midportion of bulbus cordis.
Separation of the Two Parts

The two parts are separated by a muscular ridge called:

  • Supraventricular crest
  • Infundibuloventricular crest

It is situated between the:

  • Tricuspid orifice
  • Pulmonary orifice.
2

Orifices

The interior shows 2 orifices:

a. Right Atrioventricular / Tricuspid Orifice

  • Guarded by the tricuspid valve.

b. Pulmonary Orifice

  • Guarded by the pulmonary valve.
3

Trabeculae Carneae / Muscular Ridges

The inflowing part shows trabeculae carneae or muscular ridges of 3 types:

  1. Ridges / Fixed Elevations
  2. Bridges
  3. Papillary Muscles (Pillars)
  • One end is attached to the ventricular wall.
  • Other end is connected to the cusps of the tricuspid valve by chordae tendineae.
  • Chordae tendineae = Latin: strings to stretch.

There are 3 papillary muscles in the right ventricle:

1. Anterior muscle

Largest.

2. Posterior / inferior muscle

Small and irregular.

3. Septal muscle

Divided into a number of little nipples.

  • Each papillary muscle is attached by chordae tendineae to the contiguous sides of two cusps.
4

Septomarginal Trabecula / Moderator Band

  • A muscular ridge extending from the ventricular septum to the base of the anterior papillary muscle.
  • Contains the right branch of the AV bundle.
5

Cavity

  • The cavity of the right ventricle is crescentic in section.
  • This is because of the forward bulge of the interventricular septum.
6

Wall Thickness

  • The wall of the right ventricle is thinner than that of the left ventricle.
  • Ratio = 1 : 3.
4

Interventricular Septum

  • The septum is placed obliquely.
  • One surface faces:
  • Forwards
  • To the right
  • The other surface faces:
  • Backwards
  • To the left

It has 2 parts:

a. Membranous Part

  • Upper part of the septum.
  • Thin and membranous.
  • Separates:
  • The two ventricles
  • Right atrium and left ventricle

b. Muscular Part

  • Lower part.
  • Thick and muscular.
  • Separates the two ventricles.
  • Its position is indicated by the:
  • Anterior interventricular groove
  • Posterior interventricular groove.
Right Ventricle — Study Notes