Infratrochlear nerve

Nerve: Infratrochlear nerve
Sensory areas of the head, showing the general distribution of the three divisions of the fifth nerve. (Infratrochlear nerve labeled at center left.)
Nerves of the orbit, and the ciliary ganglion. Side view.
Latin	nervus infratrochlearis
Gray's	subject #200 888
From	Nasociliary nerve
Dorlands / Elsevier	n_05/12565921

The infratrochlear nerve is given off from the nasociliary just before it enters the anterior ethmoidal foramen.

It runs forward along the upper border of the medial rectus, and is joined, near the pulley of the superior oblique, by a filament from the supratrochlear nerve.

It then passes to the medial angle of the eye, and supplies the skin of the eyelids and side of the nose, the conjunctiva, lacrimal sac, and caruncle.

Etymology

Infratrochlear means "below the trochlea". The term trochlea means "pulley" in Latin. Specifically, the trochlea referred to is a loop inside the orbit of the eye (trochlea of superior oblique), through which the tendon of the superior oblique muscle passes.

Additional images

• 

  Nerves of the orbit. Seen from above.

External links

• MedEd at Loyola GrossAnatomy/h_n/cn/cn1/cnb1.htm
• Norman/Georgetown cranialnerves (V)

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.