Page 225 - Anatomy and Physiology of Farm Animals, 8th Edition

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Table 10-4. Synopsis of Cranial Nerves
VetBooks.ir Number Name Type Arises From Function and Distribution

Olfactory
Olfaction (smell); nasal mucosa
Olfactory bulb
I
Sensory
II Optic Sensory Diencephalon Vision; retina
III Oculomotor Motor Midbrain Motor to extraocular eye muscles;
parasympathetic innervation to iris sphincter
and ciliary muscles
IV Trochlear Motor Dorsal Midbrain Dorsal oblique muscle of eye
V Trigemina Mixed Pons
Ophthalmic Sensory Sensory to eye and dorsal parts of head
division
Maxillary division Sensory Sensory to maxillary region, nasal cavity,
palates, upper teeth
Mandibular Mixed Sensory to tongue, lower teeth and jaw; Motor
division to muscles of mastication
VI Abducens Motor Medulla Lateral rectus and retractor bulbi muscles of eye
VII Facial Mixed Medulla Sensory (taste) to rostral two‐thirds of tongue;
parasympathetic to salivary and lacrimal
glands; motor to muscles of facial expression
VIII Vestibulocochlear Sensory Medulla Hearing (cochlear division) and sense of
acceleration (vestibular division)
IX Glossopharyngeal Mixed Medulla Sensory (taste) to caudal third of tongue;
parasympathetic to salivary glands; motor to
pharyngeal muscles
X Vagus Mixed Medulla Sensory to pharyngeal, laryngeal mucosa,
most viscera; parasympathetic to cervical,
thoracic and most abdominal viscera; motor to
pharyngeal, laryngeal muscles
XI Accessory Motor Medulla & Motor to cervical, shoulder muscles (e.g.,
cervical spinal trapezius)
cord
XII Hypoglossal Motor Medulla Motor to muscles of tongue

the vagosympathetic trunk synapse in the The sympathetic innervation to the
cranial cervical ganglion, found ventral adrenal gland (see Chapter 11) is unique
to the base of the skull, and from this gan- in that preganglionic sympathetic fibers
glion the postganglionic fibers spread to synapse directly on the chromaffin cells of
the glands and smooth muscle of the head. the adrenal medulla without an interven-
No sympathetic preganglionic cell bod- ing ganglion. Sympathetic stimulation
ies exist caudal to the midlumbar region, so causes this tissue to release catechola-
sympathetic innervation to pelvic organs mines (epinephrine and norepinephrine)
(rectum and urogenital organs) arrives via into the bloodstream, producing a wide-
the right and left hypogastric nerves, a spread, pronounced, and prolonged fight‐
continuation of the caudal parts of the or‐flight response. This is a physiologically
sympathetic trunk. The fibers of the important site at which the rapid commu-
hypogastric nerve become admixed with nication system of the body (the nervous
parasympathetic fibers in a diffuse network system) is integrated with the slow, more
of autonomic nerves on the lateral surface lingering communication system of the
of the rectum called the pelvic plexus. body (the endocrine system).