In order to visualize deeper structures, it is necessary to reflect the pectoralis major m.
from medial to lateral. Carefully cut the muscle from its attachments to the sternum and clavicle
and locate the nerves and arteries entering the muscle on its deep surface. As you reflect the
muscle laterally, remove parts of the pectoralis muscle where the nerves and
arteries enter as shown in these two videos.
The advantage of this approach is that it allows you to reflect the muscle entirely as shown in
this dissection.
This dissection shows the pectoralis major muscle
reflected exposing the
lateral pectoral nerve and pectoral arteries and the pectoralis minor muscle.
Branches of the medial pectoral nerve are seen passing through or along
the inferior border of the pectoralis minor muscle.
Now clean the thoracoacromial trunk and demonstrate its branches :
