236 



ANTERIOR BRACHIAL REGION. 



Fig. 98.* 



gives passage to the dorsalis scapulae artery and veins. The quadrangular 

 space is bounded on three sides by 

 the three preceding muscles, and 

 on the fourth by the humerus. 

 Through this space pass the poste- 

 rior circumflex artery and veins, 

 and circumflex nerve. 



A few of the deep fibres of the 

 triceps, attached above to the hu- 

 merus and below to the capsule of 

 the elbow-joint, have been named 

 sub-anconeus ; they are analogous to 

 the sub-crureus. 



Relations. By its posterior sur- 

 face with the deep and superficial 

 fascia and integument. By its an- 

 terior surface with the superior pro- 

 funda artery, musculo-spiral nerve, 

 humerus, intermuscular aponeuro- 

 ses which separate it from the bra- 

 chialis anticus, and with the elbow- 

 joint. The scapular head is in 

 relation posteriorly with the deltoid 

 and teres minor ; anteriorly with 

 the subscapularis, teres major, and 

 latissimus dorsi; and externally 

 with the posterior circumflex vessels 

 and nerve. 



Actions. The triceps is an ex- 

 tensor of the fore-arm. 



Anterior Bracfiial Region. 



Superficial layer. 

 Pronator radii teres, 

 Flexor carpi radialis, 

 Palmaris longus, 

 Flexor sublimis digitorum, 

 Flexor carpi ulnaris. 



* Superficial layer of muscles of the fore-arm. 1. The lower part of the 

 biceps, with its tendon. 2. A part of the brachialis anticus, seen beneath the 

 biceps. 3. A part of the triceps. 4. The pronator radii teres. 5. The flexor 

 carpi radialis. 6. The palmaris longus. ?. One of the fasciculi of the flexor 

 sublimis digitorum ; the rest of the muscle is seen beneath the tendons of the 

 palmaris longus and flexor carpi radialis. 8. The flexor carpi ulnaris. 9. The 

 palmar fascia. 10. The palmaris brevis muscle. 11. The abductor pollicis 

 muscle. 12. One portion of the flexor brevis pollicis ; the leading line crosses 

 a part of the adductor pollicis. 13. The supinator longus muscle. 14. The 

 extensor ossis metacarpi, and extensor primi iuteruodii pollicis, curving around 

 the lower border of the fore-arm. 



