THE OCCIPITAL ARTERY 



639 



THE OCCIPITAL ARTERY 



The occipital artery (A. occipitalis) is usually the second in size of the terminals 

 of the carotid. It arises commonly just in front of theinternal carotid, but in some 

 cases with that artery by a common trknk of "variaA)le length. It pursues a some- 

 what flexuous course to the fossa atlantis, where it divides into anterior and posterior 

 branches. It is related superficially to the mandibular gland and the brachio- 

 cephalicus, and deeply to the guttural pouch and the rectus capitis ventralis major.^ 

 The internal carotid artery, the 

 ventral cerebral vein, and the ac- 

 cessory, vagus, and sympathetic 

 nerves cross its deep face. It 

 gives off twigs to the mandibular 

 gland, the ventral straight mus- 

 cles of the head, the guttural 

 pouch and the adjacent lymph 

 glands, and two named collateral 

 branches.^ The condyloid artery 

 (A. condyloidea) is a small vessel 

 which passes upward and forward 

 on the guttural pouch, and divides 

 into muscular and meningeal 

 branches. The latter enter the 

 cranium through the foramen 

 lacerum and hypoglossal foramen 

 and are distributed to the dura 

 mater. This artery is very vari- 

 able in its origin.^ The posterior 

 meningeal artery (A. meningea 

 aboralis)* is a much larger vessel 

 which runs upward and forward 

 between the obliquus capitis an- 

 terior and the paramastoid proc- 

 ess, passes through the mas- 

 toid foramen into the temporal 

 canal, enters the cranial cav- 

 ity, and is distributed to the 

 dura mater. It gives collateral 

 branches to the atlanto-occipital 

 articulation and the adjacent 

 muscles. 



The posterior or recurrent 



iThe relation to the guttural 

 pouch is not constant. In some cases — 

 especially when the head and neck are 

 extended— the artery lies behind the 

 pouch. The backward extension of the 

 latter is variable. a 



2 The branch to the mandibular 

 gland (A. glandulae mandibularis dor- 

 salis) may come from the external caro- 

 tid or the posterior meningeal artery. 



3 It is also known as the preverte- 

 bral; it often comes from the posterior 

 meningeal artery. 



* Also termed the mastoid artery. 



Fig. 559. — Vessels and Nekves of Base of Brain of Hobse. 

 J S, Cerebrospinal artery; J4, ventral spinal artery; i,5, basilar 

 artery; 16, posterior cerebellar artery; 17, anterior cerebellar ar- 

 tery; IS, internal auditory artery; 19, posterior cerebral artery; 

 W, deep cerebral artery; il, stump of internal carotid artery; ^3, 

 anterior chorioid artery; «3, anterior meningeal artery; 2i, rmddle 

 cerebral artery; 25, artery of corpus callosum; 26, anterior com- 

 municating artery; 1, 1', 1", olfactory strise; J'", ^factory 

 tracfr^=Wrcranial nerves; a, olfactory bulb; b, trigonu-n olfac- 

 torium; c, lamina perforata anterior; d, fossa lateralis; t,, piri- 

 form lobe; /, cerebral peduncle; g, tractus transversus; h, corpus 

 mammillare; i, tuber cinereum; k, lateral fissure (of Sylvius); 

 I, presylvian fissure; m, pons; o, pyramid; p, facial eminence; 

 q, corpus restiforme; r, cerebellum; s, middle peduncle of cerebel- 

 lum. (After Ellenberger-Baum, Top. Anat. d. Pferdes.) 



