5. Apex/Cervicoaxillary Canal
• It is directed upwards and medially towards the root of the neck.
• It is truncated (not pointed).
• The Apex is bounded by 3 bones:
posterior surface of clavicle Anteriorly
superior border of the scapula Posteriorly
outer border of the first rib Medially
6. BASE OR FLOOR
• It is directed downward
Formed by
skin
Superficial
Axillary fasciae
base
9. Medial
It is convex laterally and formed by the following.
Serratus anterior muscle
Upper 4-5 ribs and intercostal muscle
10. Lateral
It is very narrow because the anterior and posterior
walls converge on it.
intertubercular groove of the
humerus
Coracobrachialis
Biceps brachii