Canonical Question
CVS – Anatomy
Master answer
RIGHT
VENTRICLE
LEFT
VENTRICLE
| Pathway | |
| RA → tricuspid valve → RV → pulmonary valve → Pulmonary trunk | LA → Mitral valve → LV → Aortic valve → Aorta |
| Valves | |
| TV: 3 triangular cusps (medial anterior, inferior) attached by the base to fibrous ring of TV orifice. Papillary muscles connect trabeculae to cusps PV: 3 cusps (posterior, right anterior, left anterior) | MV: large anterior and small posterior cusp Attach to 2 large papillary muscles (anterolateral, posteromedial) by chordae tendinae AV: 3 semilunar cusps (Rt posterior, left posterior, anterior). Aortic sinuses above |
| Portions | |
| Septal portion: 1) the inflow tract: supports the tricuspid valve, Inferior aspect have ‘trabeculae carnae’ 2) Infundibuloventricular crest: muscular, lies between AV and pulmonary orifices – separates inflow and outflow 3) the outflow tract (infundibulum) – smooth walled, directed up+right towards pulm trunk | Portions: 1) Large trabeculated sinus portion with MV 2) Small smooth outflow tract that supports AV located anterior to the anterior mitral leaflet and is part of the atrioventricular (AV) septum. |
| Rest | |
| Rest of RV wall is trabecular Moderator band: muscular bundle crossing ventricular cavity from Intrerventricular septum to anterior wall – conveys right branch of AV bundle to the ventricular muscle | Wall: thick trabeculae carnae mostly. Exception of fibrous vestibule immediately below aortic orifice The free wall and apical half of the septum contain fine internal trabeculations. |
| Dimension | |
| The wall of the right ventricle is thinner than that of the left (1/3rd) Thickest at base, thinner towards apex Cavity size 85ml (=LV) | Wall 3x the size of RV Cavity size equal |
| Functions | |
| Receives deoxygenated blood from RA Pumps into pulmonary circulation | Receives oxygenated blood from LA Pumps into aorta → systemic circulation |
| Main Function | |
| maintain adequate pulmonary perfusion pressure to deliver desaturated venous blood to the gas exchange membranes of the lungs maintain low systemic venous pressure to prevent tissue and organ congestion | Maintain adequate systemic perfusion pressure to deliver oxygenated blood to tissue |
| Pressures | |
| RV Sys 15-30 | LV Sys 100-140 |
| RV Dias 4-12 | LV Dias 3-12 |
| RVEDD 10-26mm | LVEDD 36-56mm |
| RVESD 10-26mm | LVESD 20-40mm |
Sources: Last’s Anatomy, Aneskey.com, Anatomy for anaesthetists
JC 2019
RIGHT
VENTRICLE
LEFT
VENTRICLE
- Supply:
- Right coronary artery and its branches
- conus artery supplies the infundibulum
- acute marginal arteries supply the anterior free wall
- posterior descending artery via septal branches supply the posterior 1/3 IV septum (PDA arises from RCA in Right dominant circulation and LCx in Left dominant circulation
- the other 2/3 of the IV septum is supplied by septal branches of the left anterior descending artery
- Supply: Left Main Coronary
- LAD (supplies the free wall and most of the papillary muscles)
- Diagonals
- Septal perforators
- LCx: inferolateral LV wall
- Obtuse Marginal branches
- LAD (supplies the free wall and most of the papillary muscles)
- RV Coronary blood flow
- RV pressures are low during both systole and diastole.
- flow during both systole and diastole
- LV Coronary blood flow
- The pressure inside the left ventricle is slightly higher than in the aorta during systole.
- Flow predominantly during diastole.
- Subendocardial flow ceases during systole.
Sources: Last’s Anatomy, Aneskey.com, Anatomy for anaesthetists
JC 2019
Exam appearances
| Exam | Exact wording | Relationship | Success |
|---|---|---|---|
| 2019B Q16 | Compare the structure, function and coronary circulation of the right and left ventricles. | historical_member | — |
| 2023B Q02 | Outline the anatomy of the cardiac ventricles including the chambers, valves and conduction elements. | historical_member | — |