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 the internal carotid, but in some 
eases with that artery by a common trunk of variable 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 cay- 
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 
1The relation to the guttural 
pouch is not constant. In some cases— 
especially when the head and neck are 
extended—the artery lies behind the 
ouch. The backward extension of the 
atter is variable. 
*The branch to the mandibular 
gland (A. glandule mandibularis dor- 
salis) may come from the external caro- 
tid or the posterior meningeal artery. 
‘It is also known as the preverte- 
bral; it often comes from the posterior 
meningeal artery. 
4 Also termed the mastoid artery. 
Fic. 559.—VeEssEts AND Nerves OF BAsE OF BRAIN OF Horse. 
13, Cerebro-spinal artery; 14, ventral spinal artery; 15, basilar 
artery; 16, posterior cerebellar artery; 17, anterior cerebellar ar- 
tery; 18, internal auditory artery; 19, posterior cerebral artery; 
20, deep cerebral artery; 21, stump of internal carotid artery; 22, 
anterior chorioid artery; 23, anterior meningeal artery; 24, middle 
cerebral artery; 25, artery of corpus callosum; 26, anterior com- 
municating artery; 1, 1’, 1’, olfactory strie; 1’, olfactory 
tract; 2-12, cranial nerves; a, olfactory bulb; 6, trigonum olfac- 
torium; c, lamina perforata anterior; d, fossa lateralis; e, piri- 
form lobe; f, cerebral peduncle; g, tractus tramsversus; h, corpus 
mammillare; i, tuber cinereum; fk, lateral fissure (of Sylvius); 
1, presylvian fissure; m, pons; 0, pyramid; p, facial eminence; 
g, corpus restiforme; r, cerebellum; s, middle peduncle of cerebel- 
lum. (After Ellenberger-Baum, Top. Anat. d. Pferdes.) 
