Page 391 - Clinical Anatomy

ECA6 7/18/06 6:54 PM Page 376

376 The central nervous system

Fig. 263◊Distribution of the facial nerve within the temporal bone.

Fig. 264◊Distribution of
the facial nerve: T,
temporal; Z, zygomatic;
B, buccal; M, mandibular;
C, cervical; and P,
posterior auricular
branch.
and malleus, exits via the fissure between the tympanic and petrous parts
of the temporal bone to enter the infratemporal fossa where it joins the
lingual nerve. Hence its taste fibres reach the anterior two-thirds of the
tongue and its secretomotor fibres are conveyed to the submandibular gan-
glion, thence to the submandibular and sublingual salivary glands.
On emerging from the stylomastoid foramen, the nerve supplies the
stylohyoid and the posterior belly of digastric muscle. It then enters
the parotid gland where it divides into five divisions for the supply of
the facial muscles: the temporal, zygomatic, buccal, mandibular, and cervi-
cal branches (see Figs 208, 209, 264).

Clinical features

1◊◊It is important to distinguish between ‘nuclear’ and ‘infranuclear’ facial