THE INTERNAL CAROTID ARTERY 



615 



sinuses, and, entering the cranium, gives off a dural branch which supplies the 

 adjacent dura; and nasal branches, which descend into the nose, through the slit 

 bv the side of the crista galli, and, running along the groove on the under surface 

 of the nasal bone, supply the skin of the nose. 



The internal palpebral arteries (aa. palpebrales mediates), two in number, supe- 

 rior and inferior, arise from the ophthalmic, opposite the pulley of the Superior 

 oblique muscle; they leave the orbit to encircle the eyelids near their free margin, 

 forming a superior tarsal arch (arc-its tarseus superior} and an inferior tarsal arch 

 (circus tarseus inferior), which lie between the Orbicularis muscle and the tarsal 

 plates. The superior palpebral anastomoses, at the outer angle of the orbit, with 

 the orbital branch of the temporal artery, and with the upper of the two external 

 palpebral branches from the lacrimal artery: the inferior palpebral anastomoses, 



Central 

 Fissure 



FIG. 450. Vascular area of the upper surface of the cerebrum. I. The part supplied by the external and 

 inferior frontal artery. II. The part supplied by the ascending frontal. III. The part supplied by the ascending 

 parietal. IV. The part supplied by the sphenoparietal artery. (After Duret.) 



at the outer angle of the orbit, with the lower of the two external palpebral branches 

 from the lacrimal and with the transverse facial artery, and at the inner side of the 

 lid with a branch from the angular artery. From this last anastomosis a branch 

 passes to the nasal duct, ramifying in its mucous membrane, as far as the inferior 

 meat us. 



The frontal artery (a. frontalis), one of the terminal branches of the ophthalmic, 

 leaves the orbit at its inner angle with the supratrochlear nerve, and, ascending 

 on the forehead, supplies the integument, muscles, and pericranium, anastomosing 

 with the supraorbital artery and with the frontal artery of the opposite side. 



The nasal artery (a. dorsalis nasi), the other terminal branch of the ophthalmic, 

 emerges from the orbit above the tendo oculi, and, after giving a branch to the 

 upper part of the lacrimal sac, divides into two branches, one of which crosses 



