SHOULDER, ARM, FOREARM, AND HAND. 171 



They may become filled with provisional callus and bone, when a stiff joint 

 will be the result. 



Hoiv is the posterior surface of the humcrus occupied / 



By the long humeral head of the triceps above the musculo-spiral groove ; 

 by the short humeral head below the groove ; by the musculo-spiral groove, in 

 which are the musculo-spiral nerve and superior profunda artery. 



How is the outer lip of the bicipital groove occupied ? 



By the tendinous insertion of the pectoralis major muscle. 



How are the outer and inner surfaces of tlic Juuneriis occupied ? 



They are occupied by the pectoralis major, deltoid, and brachialis anticu 

 on the outer ; the teres major, latissimus dorsi, coraco-brachialis, and brachialis 

 anticus on the inner surface. 



How is the external condylar ridge occupied ? 



By the supinator longus and the extensor carpi radialis longior ; the former 

 occupies the upper two-thirds, the latter the lower one-third of the ridge. 



Name all the muscles attached to the middle one-third of the Jiuinerus wliose 

 action would tend to displace the fragments in case of fracture in this locality. 



The long and short humeral heads of the triceps, the deltoid, the coraco- 

 brachialis, the brachialis anticus muscles. 



What might be the most serious complication of 'a fracture in the middle one- 

 tJiird of the liumerus? 



Compression and paralysis of the musculo-spiral nerve, in which there would 

 be inability to extend the carpus and digits and to supinate the radius. 



What is the direction taken by the nutrient foramen of the humcrus ? 



It conforms to the rule governing the direction of these foramina in the long 

 bones of the extremities : to the elbow and from the knee being the rule. 



Hoiv many muscles and ligaments are attached to the humerus ? 



There are twenty-five muscles and eight ligaments attached. 



In this region you will find the following arrangement of 



Muscles Physiologically Grouped. 



Carpal Flexors. Flexor carpi radialis. 



Flexor carpi ulnaris. 



Palmaris longus. 

 Digital Flexors. Flexor sublimis digitorum. 



Flexor profundus digitorum. 



Flexor longus pollicis. 

 Radial Pronators. Pronator radii teres. 



Pronator radii quadratus. 

 Forearm Flexors. Flexor biceps cubiti. 



Flexor cubiti brachialis anticus. 



Flexor brachio-radialis. 

 Nerves. Median nerve and its branches. 



Ulnar nerve and its branches. 



Musculo-cutaneous nerve and its branches. 

 Arteries and Veins. Radial artery and the deep palmar arch. 



Ulnar artery and the superficial palmar arch. 



Common interosseous artery and vein. 



Anterior interosseous artery and vein. 



Posterior interosseous artery and vein. 

 Surgical Areas. The cubital fossa and its contents. 



The radial groove and its contents. 



The ulnar groove and its contents. 



