Corpus: Frontal nerve

The frontal nerve is a sensory branch of the ophthalmic nerve (V₁).

Even before the ophthalmic nerve has emerged from the cranial cavity through the fissura orbitalis (carnivore, horse) or through the foramen orbitorotundum (ruminant, pig), it divides into its three terminal branches, the frontal, lacrimal and nasociliary nerves.

The frontal nerve then runs as an independent nerve over the caudomedial surface of the eye muscle pyramid. It first runs inside and then outside the perorbita to the dorsal edge of the orbit.

Course[Bearbeiten]

In the further course, the frontal nerve behaves differently depending on the animal species. In carnivores, ruminants and pigs, it wraps around the bony orbital rim and then runs as the supraorbital nerve in the skin and connective tissue in the middle area of the upper eyelid and in the forehead skin. In horses, it runs through the supraorbital foramen and also directly over the edge of the orbit to the forehead surface. In this area it participates - together with the lacrimal nerve and branches of the auriculopalpebral nerve - in the formation of the rostral auricular plexus.

In horses, ruminants and pigs, it gives off the sinuum frontalium nerve, the branches of which penetrate the frontal sinus through one or more holes in order to supply the mucous membrane with sensation. In cattle, this nerve can also branch off from the zygomaticotemporal ramus of the zygomatic nerve. In pigs, a supratrochlear nerve is also formed, which enters the skin and conjunctiva of the medial corner of the eye via the bony orbital rim and is also involved in the innervation of the upper eyelid.

Innervation[Bearbeiten]

The nerve branches of the frontal nerve behave as follows in the individual animal species:

• Nickel, Richard, Schummer, August, Seiferle, Eugen. Lehrbuch der Anatomie der Haustiere, Band IV: Nervensystem. Parey Verlag, 2003.