THE INTERNAL CAROTID ARTERY. 5<if, 



Surgical Anatomy. The cervical part of the internal carotid is very rarely wounded. 

 Mr. Cripps, in an interesting paper in the Medico- Chirurgical Transactions, compares the rare- 

 ness of a wound of the internal carotid with one of the external or its branches. It is, however, 

 sometimes injured by a stab or gunshot wound in the neck, or even occasionally by a stab from 

 within the mouth, as when a person receives a thrust from the end of a parasol or falls down 

 with a tobacco-pipe in his mouth. The relation of the internal carotid with the tonsil should be 

 especially remembered, as instances have occurred in which the artery has been wounded during 

 the operation of scarifying the tonsil, and fatal haemorrhage has supervened. The indications 

 for ligature are wounds, when the vessel should be exposed by a careful dissection and tied 

 above and below the bleeding point ; and aneurism, which if non-traumatic may be treated by 

 ligature of the common carotid, but if traumatic in origin by exposing the sac and tying the 

 vessel above and below. The incision for ligature of the cervical portion of the internal carotid 

 should be made along the anterior border of the Sterno-mastoid, from the angle of the jaw to 

 the upper border of the thyroid cartilage. The superficial structures being divided and the 

 Sterno-mastoid defined and drawn outward, the cellular tissue must be carefully separated and 

 the posterior belly of the Digastric and hypoglossal nerve sought 'for as guides to the vessel. 

 When the artery is found the external carotid should be drawn inward and the Digastric muscles 

 upward, and the aneurism needle passed from without inward. 



The branches given off from the internal carotid are 



From the Petrous portion . Tympanic (internal or deep). 



( Arterise Receptaculi. 

 From the Cavernous portion < Anterior Meningeal. 



( Ophthalmic. 



f Anterior Cerebral. 



ZT ^i n i ? * I Middle Cerebral. 



rom the Cerebral portion < ^ ^ A - 



I .Posterior Communicating. 



(^Anterior Choroid. 



The cervical portion of the internal carotid gives off no branches. 



The tympanic is a small branch which enters the cavity of the tympanum 

 through a minute foramen in the carotid canal, and anastomoses with the tympanic 

 branch of the internal maxillary, and with the stylo-mastoid artery. 



The arterise receptaculi are numerous small vessels, derived from the -internal 

 carotid in the cavernous sinus ; they supply the pituitary body, the Gasserian 

 ganglion, and the walls of the cavernous and inferior petrosal sinuses. Some of 

 these branches anastomose with branches of the middle meningeal. 



The anterior meningeal is a small branch which passes over the lesser wing of 

 the sphenoid to supply the dura mater of the anterior fossa ; it anastomoses with 

 the meningeal branch from the posterior ethmoidal artery. 



The Ophthalmic Artery arises from the internal carotid, just as that vessel 

 is emerging from the cavernous sinus, on the inner side of the anterior clinoid 

 process, and enters the orbit through the optic foramen, below and on the outer 

 side of the optic nerve. It then passes over the nerve to the inner wall of the 

 orbit, and thence horizontally forward, beneath the lower border of the Superior 

 oblique muscle, to a point behind the internal angular process of the frontal bone, 

 where it divides into two terminal branches, the frontal and nasal. As the artery 

 crosses the optic nerve it is accompanied by the nasal nerve, and is separated from 

 the frontal nerve by the Rectus superior and Levator palpebrse superioris muscles. 



Branches. The branches of this vessel may be divided into an orbital group, 

 which are distributed to the orbit and surrounding parts, and an ocular group, 

 which supply the muscles and globe of the eye : 



Orbital Group. Ocular Group. 



Lachrymal. Short Ciliary. 



Supra-orbital. Long Ciliary. 



Posterior Ethmoidal. Anterior Ciliary. 



Anterior Ethmoidal. Arteria Centralis Retinae. 



Internal Palpebral. Muscular. 

 Frontal. 

 Nasal. 



