THE UPPER LIMB 



305 



present, on one or both sides. It lies over the sternal fibres of the 

 pectorahs major, and is connected below with the external oblique 

 aponeurosis, whilst above it may terminate in the sternal head 

 of the stemo-cleido-mastoid, or on the presternum. 



Clavi-pectoral Fascia. — ^This is situated beneath the pectoralis 

 major. Superiorly it is disposed in two laminae, which are attached 

 to the anterior and posterior lips of the subclavian groove of the 

 clavicle, and embrace the subclavius muscle. At the lower border 

 of that muscle they unite to form the costo-coracoid membrane, 

 which, on reaching the upper border of the pectoralis minor, 

 divides to ensheathe it. At the lower border of the muscle the 

 two layers unite to form a single sheet, which joins the axillary 

 fascia, and acts as a suspensory ligament. 



Section of Clavicle 



Axillary Artery and 

 its Sheath 



Clavicular Portion of 



Pectoralis Major 



(turned up) 



-Subclavius 



-Costo-coracoid Membrane 



. Pectoralis Miwv 



■ Lower Portion of Clavi- 

 pectoral Fascia 



. Lower Portion of Pectoralis 

 Major 



Axillary Fascia 



Fig. 175. — Diagram of the Clavi-pectoral Fascia and the 

 Costo-coracoid Membrane. 



Costo-coracoid Membrane. — This name is given to that portion 



of the clavi-pectoral fascia which extends from the lower border of 



the subclavius to the upper border of the pectoralis minor. The 



lower portion of the membrane is tense and cord-like, and is known 



Eis the costo-coracoid ligament. It is attached internally to the 



ipper surface of the first rib at its sternal extremity in connection 



.vith the tendon of the subclavius, and externally it is attached to 



:he posterior part of the antero-intemal border and adjacent portion 



)f the upper surface of the coracoid process. This membrane is 



»nnected by its deep surface with the axillary sheath ; it is covered 



>y the clavicular portion of the pectoralis major ; and it is pierced 



)y the cephalic vein, the thoracic axis, and the external anterior 



uoracic nerve. 



20 



