Cranial nerve

Identify the 12 pairs of cranial nerves and describe the endocranial course, functional composition (sensory/motor), and major functions of each nerve:
1. Optic
2. Olfactory
3. Oculomotor
4. Trochlear
5. Trigeminal
6. Abducens
7. Facial
8. Vestibulocochlear
9. Glossopharyngeal
10. Vagus
11. Accessory
12. Hypoglossal

Cranial Nerves Summary:

CN	Nerve	Endocranial Course (Slides)	Fiber Type(s)	Major Function(s)	Type
CN I	Olfactory	Olfactory epithelium → cribriform plate foramina → olfactory bulb → olfactory tract	SVA	Smell (olfaction) Olfactory sensation to cerebral cortex	Sensory
CN II	Optic	Retina → optic canal → optic chiasm → optic tract → lateral geniculate nucleus → optic radiations → visual cortex	SSA	Vision; afferent limb of pupillary light reflex	Sensory
CN III	Oculomotor	Midbrain → between PCA & SCA → cavernous sinus → superior orbital fissure→ orbit	GSE, GVE	Eye movement, eyelid elevation, pupil constriction, lens accommodation	Motor
CN IV	Trochlear	Midbrain → exits dorsally → wraps around brainstem → cavernous sinus → superior orbital fissure	GSE	Superior oblique muscle (depresses and intorts eye)	Motor
CN V	Trigeminal	Pons → divides into V1, V2, V3	GSA, SVE	Facial sensation, corneal reflex, mastication	Both
CN VI	Abducens	Pons → pontomedullary junction → cavernous sinus → superior orbital fissure	GSE	Lateral rectus muscle (abducts eye)	Motor
CN VII	Facial	Brainstem → internal acoustic meatus → facial canal → stylomastoid foramen	SVE, GVE, SVA, GSA	Facial expression, taste (anterior 2/3), tear & saliva secretion, stapedius	Both
CN VIII	Vestibulocochlear	Vestibular & cochlear nuclei → internal acoustic meatus → brainstem	SSA	Hearing and equilibrium	Sensory
CN IX	Glossopharyngeal	Medulla → jugular foramen	GSE, GVE, GVA, SVA, GSA	Swallowing, parotid secretion, taste (posterior 1/3), carotid sinus, gag reflex	Both
CN X	Vagus	Medulla → jugular foramen → carotid sheath → thorax → abdomen	SVE, GVE, GVA, SVA, GSA	Voice, swallowing, autonomic control, visceral sensation	Both
CN XI	Accessory	C1–C5 spinal roots → foramen magnum→ jugular foramen	SVE	Sternocleidomastoid & trapezius (head rotation, shoulder elevation)	Motor
CN XII	Hypoglossal	Medulla → hypoglossal canal	GSE	Tongue movement	Motor

Fiber Type	Sensory or Motor?	What It Does	Examples
GSA	Sensory	General body sensation	Pain, touch, temperature
SSA	Sensory	Vision, hearing, balance	Eyes and ears
SVA	Sensory	Smell and taste	Nose, tongue
GVA	Sensory	Internal organ sensation	Blood pressure, stretch
GSE	Motor	Skeletal muscle movement	Eye and tongue muscles
SVE	Motor	Branchial arch muscles	Facial expression, chewing, swallowing
GVE	Motor	Parasympathetic output	Glands, smooth muscle, heart