| LEFTATRIUM | One of the four chambers of the heart (4,6) |
| VENTRICLES | The two lower chambers of the heart, left and right (10) |
| SYSTOLE | The contraction of the chambers of the heart - especially the ventricles. (7) |
| ATRIUM | One of the two upper chambers of the heart (6) |
| VENTRICLE | Each of the two main chambers of the heart that receive blood from the atrium (9) |
| SEPTUM | A partition separating two chambers, such as that between the nostrils or the chambers of the heart |
| ENDOCARDIUM | Thin membrane that lines the chambers of the heart (11) |
| ATRIAL | Pertaining to the upper chambers of the heart |
| ATRIA | Upper chambers of the heart |
| ODELSTHING | Lower chamber of the Norwegian parliament (10) |
| RAJYASABHA | Upper chamber of the Indian parliament; Sanskrit, 'state council' (5,5) |
| HEARHEAR | Words of support traditionally expressed in the chambers of the UK Parliament (4,4) |
| LEFTVENTRICLE | Chamber of the heart that pumps oxygenated blood to the arteries (4,9) |
| AURICLE | The upper chamber of the heart |
| HOUSE | One of the two chambers of parliament in the UK and Canada, ... of Commons |
| KEYS | The lower chamber of the legislature of the Isle of Man (5,2,4) |
| HOUSEOF | The lower chamber of the legislature of the Isle of Man (5,2,4) |
| DAIL | The ___ Eireann is the principal chamber of the Irish parliament, the Oireachtas |
| COD | A carved one hangs in the chamber of the Massachusetts House of Representatives |
| LANTERNS | The light-chambers of lighthouses (8) |
