Cranial Nerves Flashcards
What are the functional components of the oculomotor nerve?
Somatic and visceral efferents
also contains preganglionic parasympathetic fibers
What structures are innervated by the oculomotor nerve?
Most of the eye muscles (except the dorsal oblique, lateral rectus, and retractor bulbi muscles)
Parasympathetics- pupillary constrictor muscle and ciliary body
What are the clinical signs of a lesion in the oculomotor nerve?
Pupillary dilation, lateroventral strabismus, and ptosis (drooping of the upper eyelid)
What are the functional components of the mandibular division of the trigeminal nerve?
Somatic afferent and efferents
Where does the mandibular division of the trigeminal exit the skull?
The oval notch of the foramen lacerum
The lingual branch of the mandibular division of the trigeminal provides general sensation to which structure or region?
The rostral two-thirds of the tongue
The mandibular or inferior alveolar branch of the mandibular division of the trigeminal provides general sensation to which structure or region?
The lower teeth
The buccal branch of the mandibular division of the trigeminal provides general sensation to which structure or region?
The mucosa of the inner cheek
Which muscles are innervated by the mandibular division of the trigeminal?
Muscles which close the jaws, including the masseter, temporalis, and pterygoid muscles
Rostral belly of the digastricus
Mylohyoideus
The mental and auriculotemporal branches of the mandibular division of the trigeminal provide general sensation to which structures or regions?
The skin on the lower half of the face and the temporomandibular joint
What are the clinical signs of a lesion in the mandibular division of the trigeminal?
Jaw drop- may be unilateral or bilateral
What are the functional components of the maxillary division of the trigeminal?
Somatic afferents
The infraorbital branch of the maxillary division of the trigeminal provides general sensation to which structures or regions?
Upper lip, and the upper half of the face
The zygomatic branch of the maxillary division of the trigeminal provides general sensation to which structures or regions?
Lower eyelid, lateral canthus, and the skin rostral to the ears
The caudal and internal nasal branches of the maxillary division of the trigeminal provide general sensation to which structures or regions?
Ectodermal lining of the nasal cavity, except the ethmoturbinates
The maxillary or superior alveolar branch of the maxillary division of the trigeminal provide general sensation to which structures or regions?
The upper teeth
The palatine branch of the maxillary division of the trigeminal provide general sensation to which structures or regions?
The hard palate
Where does the maxillary division of the trigeminal exit the skull?
The round foramen
What are the functional components of the ophthalmic division of the trigeminal?
Somatic afferents
Where does the ophthalmic division of the trigeminal exit the skull?
The orbital fissure
The lacrimal, frontal, and infratrochlear branches of the ophthalmic division of the trigeminal provide general sensation to which structures or regions? Which additional structure do these nerves innervate in the cow?
The skin of the forehead
In cows, it also innervates the horns
The long ciliary and infratrochlear branches of the ophthalmic division of the trigeminal innervate which structures or regions?
The cornea and the conjunctiva
Which nerve provides general sensation to the mucosa covering the large and small ethmoturbinates?
The ethmoidal nerve (branch of the ophthalmic division of the trigeminal)
What are the clinical signs of a lesion in the ophthalmic division of the trigeminal?
Loss of sensation in the areas it innervate, lack of a corneal reflex?
What are the functional components of the facial nerve?
Somatic afferents and efferents
Where does the facial nerve exit the skull?
The stylomastoid foramen
The skeletal muscles of the face are innervated by which branches of the facial nerve?
Dorsal buccal, ventral buccal, auriculopalpebral, and caudal auricular
What kind of innervation does the chorda tympani branch of the facial nerve provide the tongue? Which region of the tongue?
Provides taste fibers to rostral two-thirds of the tongue
Which salivary glands are innervated by parasympathetics from the facial nerve?
The mandibular and sublingual salivary glands
Which structures have parasympathetic motor innervation from branches of the facial nerve?
Glands of the nasal cavity and the lacrimal gland
The internal auricular branch of the facial nerve provides somatic afferent innervation to which structures or regions?
The skin on the inside of the ear
In addition to the muscles controlling facial expression, which muscles are innervated by the facial nerve?
The caudal belly of the digastricus and the occipitomandibularis
What are the clinical signs of a lesion in the facial nerve?
Facial nerve paralysis- mouth hangs, eyelid drops, loss of symmetry in the face
Halitosis from food remaining in mouth- can’t be moved or chewed
What are the functional components of the glossopharyngeal nerve?
Somatic afferent and efferents
Where does the glossopharyngeal nerve exit the skull?
The foramen lacerum
The lingual branch of the glossopharyngeal nerve provides what kind of innervation to which structures or regions?
General sensation and taste to the caudal one-third of the tongue
The pharyngeal branch of the glossopharyngeal nerve provides sensory innervation to which structures or regions? Which reflex depends on the sensory information it carries?
The pharynx
Swallowing or gagging reflex
The pharyngeal branch of the glossopharyngeal nerve provides motor innervation to which muscles?
The skeletal muscles of the pharynx
What are the receptors innervated by the carotid sinus branch of the glossopharyngeal nerve?
Chemoreceptors for blood pH and CO2 in the carotid body
Baroreceptors in the carotid sinus
Which salivary gland is innervated by parasympathetics from the glossopharyngeal nerve?
The parotid salivary gland
What are the clinical signs of a lesion in the glossopharyngeal nerve?
Dysphagia
What are the functional components of the vagus nerve?
Mixed
Afferent and efferents
Somatic afferents from the vagus nerve innervate which structures or regions?
Pharynx, larynx, esophagus, upper GI tract
Baroreceptors, stretch receptors, and chemoreceptors in the heart
Which reflexes depend in part on the vagus nerve?
Swallowing or gagging, cough or choke, vomiting, and regurgitation in the ruminant
The vagus nerve innervates which group of muscles?
The skeletal muscles of the larynx via the recurrent laryngeal nerve
What are the clinical signs of a lesion in the vagus nerve?
Dysphagia, laryngeal hemiplegia
Infection in the guttural pouch can damage which nerve?
The glossopharyngeal nerve
