N5315 Advanced Pathophysiology
Neurologic System
Module 7
Examine the anatomy and physiology of the Central Nervous System.
1. Discuss the anatomy
... [Show More] and physiology of the brain and brain stem.
a. Explain the function of the twelve cranial nerves
I – Olfactory (Smell)
Function: Sensory, carries impulses for sense and smell
Sign of Dysfunction: Loss or disturbance in the sense of smell.
II – Optic (Sight)
Function: Sensory, carries impulses for vision
Sign of Dysfunction: decreased visual acuity and contrast sensitivity, impaired color vision,
and an afferent pupillary defect. (blindness)
III – Oculomotor
Function: Contains motor fibers to interior oblique and to superior, inferior, ad medial rectus
extraocular muscles that direct eye ball; levator muscles of eyelid; smooth muscles of iris and
ciliary body; and proprioception (sensory) to brain from extraocular muscles
Sign of Dysfunction: Drooping of the eyelid, eyeball moves outward, dilation of the pupil,
double vision.
IV – Trochlear
Function: Propioceptor and motor fibers for superior oblique muscle of eye (extraocular
muscles)
Sign of Dysfunction:
Rotation of eyeball upward and outward, double vision
V Trigeminal
(facial muscles including chewing, facial sensation)
This is the largest cranial nerve
Function: Both motor and sensory for face; conducts sensory impulses from mouth, nose,
surface of eye, and dura mater; also contains motor fibers that stimulate chewing muscles
Sign of Dysfunction: Sensory root – Pain or loss of sensation in the face, forehead, temple
and eyes. Motor root – affecting the jaw, trouble chewing
VI Abducens (moves eyeballs)
Function: Moves the eyeballs outwards by sending nerve impulses to the lateral rectus
muscles
Sign of Dysfunction: Deviation of the eyes outward; double vision
2
VII Facial
(taste, tears, saliva and facial expressions)
Function: Mixed: 1. Supplies motor fibers to muscles of facial expression and to the lacrimal
and salivary glands. 2. Carries sensory fibers from taste buds of anterior part of tongue
Sign of Dysfunction: Paralysis of all the muscles in one side of the face, inability to wrinkle the
forehead, close the eye, whistle, deviation of the mouth. Bell’s Palsy
VIII [Show Less]