52 



A MANUAL OF ANATOMY 



from the heads to the angles ; and laterally by the ribs beyond their 

 angles. It is conical, the truncated apex being directed upwards, 

 and it is somewhat flattened from before backwards. 



The superior aperture is bounded in front by the upper border 

 of the presternum and the first costal cartilages, on either side by 



Fig. 36. — The Thorax (Anterior View). 



the first rib, and behind by the body of the first thoracic vertebra. 

 Its transverse measurement exceeds the antero-posterior, and it 

 is reniform, due to the forward projection of the first thoracic 

 body. Its plane is oblique, being sloped downwards and forwards, 

 so that the upper border of the presternum is on a level with the 

 disc between the second and third thoracic bodies. The superior 



