574 



284. 



ARTERIES OF THE HUMAN 

 FORE-ARM. 



1, Lower part of biceps ; 2, 

 Inner condyle of humerus ; 

 3, Deep portion of pronator 

 radii teres ; 4, Supinator 

 longus; 5, Flexor longus 

 pollicis; 6, Pronator quad- 

 ratus ; 7, Flexor profundus 

 digitorum; 8, Flexor carpi 

 ulnaris ; 9, Annular liga- 

 ment ; 10, Brachial artery; 

 11, Anastomotica longus 

 magna, inosculating above 

 with the inferior profunda, 

 and below with the anterior 

 ulnar recurrent ; 12, Radial 

 artery; 13, Radial recurrent 

 inosculating with the supe- 

 rior profunda ; 14, Super- 

 ficial is volae; 15, Ulnar ar- 

 tery ; 16, Superficial palmar 

 arch, giving off digital 

 branches to three fingers 

 and a half; 17, Magna 

 pollicis and radialis indicis ; 

 20, Posterior interosseous. 



THE AETEEIES. 



four branches the palmar or collateral of the digits. 

 These are at first situated between the perforatus and 

 perforans tendons, and reach the superior extremity of 

 the interdigital spaces, where they receive the metacarpal 

 interosseous arteries, and comport themselves in the fol- 

 lowing manner : the internal goes to the thumb ; the 

 second counting from within outwards gains the con- 

 centric side of the index ; the third, the largest, divides 

 into two branches which lie alongside the great digits; 

 the last goes to the external digit. 



COMPARISON OP THE AXILLARY ARTERIES IN MAN WITH 

 THOSE OF ANIMALS. 



The arteries of the thoracic limbs and head arise sepa- 

 rately from the arch of the aorta ; consequently, in Man 

 there is no anterior aorta. 



The vessel of the limb that represents the axillary of 

 animals is here resolved into two portions : the subclavian 

 artery and axillary artery. 



The SUBCLAVIAN ARTERY has not the same origin on 

 both sides ; on the right it arises from the aorta by a trunk 

 common to it and the carotid of that side the brachio- 

 cephalic trunk (arteria innominata) ; while the left is 

 detached separately from the most distant part of the 

 aortic arch. The subclavian vessels extend to the in- 

 ferior border of the clavicles, and furnish seven important 

 collateral branches, which are present in the domesticated 

 animals. They are : 



1. The vertebral artery, situated in the vertebral fora- 

 mina of the cervical vertebrae, as far as the axis ; there it 

 anastomoses, as in Solipeds, with a branch of the carotid, 

 enters the spinal canal by the foramen magnum, and 

 unites with its fellow at the lower border of the pons 

 Varolii to form the basilar artery which, in the Horse, 

 comes from the cerebro-spinal artery of the occipital. 



2. The inferior thyroid, whose origin and some branches 

 we find in the ascending branch (ascending cervical) of 

 the inferior' cervical artery in the Horse. 



3. The internal mammary artery divides into two 

 branches at the xiphoid appendix of the sternum. 



4. The superior intercostal artery, whose analogue we 

 see in Solipeds, in the subcostal branch of the dorsal. 



5. The superscapular artery, present in all animals 

 and disposed in the same manner. 



6. The transverse cervical (transversa colli), represented 

 by the extra-thoracic branches of the dorsal artery. 



7. The deep cervical (cervicalis pro/undo) corresponds 

 to the superior cervical in the Horse. 



The AXILLARY ARTERY, or exti a-thoracic portion of the 

 subclavian trunk, extends to the external border of the 

 pectoral muscle, where it is continued by the humeral 

 artery. The axillary gives off: the thoracica acromialis, 

 resembling the descending branch of the inferior cervical 

 artery of large quadrupeds ; the external mammary , sub- 

 scapular ; and posterior and anterior circumflex, branches 

 of the preceding in Solipeds. 



HUMERAL (BRACHIAL) ARTERY. This artery extends 

 from the external border of the pectoral muscle to the 

 bend of the elbow; here it divides into two terminal 

 branches the ulnar and radial. 



In its course it gives off several muscular branches, 



18, Posterior ulnar recurrent i 19, Anterior interosseous ; 



