Gross Anatomy:Cranial Nerve Introduction

(Grays, pages 807; 848-854)

Vocabulary REVIEW

1. Afferent:• sensory• primary afferents• axons entering the CNS• cell bodies in sensory ganglia• CN versus spinal nerves

2. Efferent:• motor• leaving the CNS• innervate skeletal muscle or

viscera• visceral efferent pathways always

involve 2 neurons [one in the CNS and one in a peripheral ganglia]

CNS

Functional Components

• Special – cranial nerves only; olfaction, vision, taste, balance and hearing • General – touch, pressure, proprioception, vibration, pain and temperature• Somatic – body wall • Visceral – smooth and cardiac muscle, glands and arrector pili

General Somatic Afferent (GSA): sensation from body wall General Visceral Afferent (GVA): sensation from visceraSpecial Visceral Afferent (SVA): taste and olfaction Special Somatic Afferent (SSA): DON’T NEED TO KNOW YETGeneral Somatic Efferent (GSE): motor; to skeletal muscleGeneral Visceral Efferent (GVE): motor to “viscera” Branchial Efferents (BE [SVE]): motor (skeletal muscle from pharyngeal arches)

CRANIAL NERVE SUMMARY

1. Olfactory CN I (SVA) Sensory2. Optic CN II (SSA) Sensory3. Oculomotor CN III (GSE, GVE-P) Motor4. Trochlear CN IV (GSE) Motor5. Trigeminal CN V (GSA, BE) Both6. Abducens CN VI (GSE) Motor7. Facial CN VII (BE, GSA, SVA, GVA, GVE-P) Both8. Vestibulocochlear CN VIII (SSA, SSE) Sensory9. Glossopharyngeal CN IX (BE, GSA, SVA, GVA, GVE-P) Both

10. Vagus CN X (BE, GSA, SVA, GVA, GVE-P) Both11. Accessory CN XI (GSE) Motor12. Hypoglossal CN XII (GSE) Motor

Cranial Nerves along the Cranial Fossa

I. OlfactoryII. OpticIII. OculomotorIV. TrochlearV. TrigeminalVI. AbducensVII. FacialVIII. VestibulocochlearIX. GlossopharyngealX. VagusXI. AccessoryXII. Hypoglossal

12 Cranial Nerves:

To the “intra” and extraocular muscles:CN III – OculomotorCN IV – TrochlearCN VI - Abducens

Brain stem (CNS)

Brain stem (CNS)

Brain stem (CNS)

CN V - Trigeminal

CN V - Trigeminal Nerve

NOTE: The mesencephalic nucleus is involved in proprioception from muscles of mastication, the TMJ, extraocular muscles and muscles of the face.

Ophthalmic

Maxillary

CN V - Trigeminal

CN V1 - Ophthalmic

CN V2 - Maxillary

CN V3 - Mandibular

CN VII - Facial

CN VII - Facial Nerve

CN VII - Facial

Cranial Nerve VII

CN IX – Glossopharyngeal

CN X - Vagus

CN IX - Glossopharyngeal

CN IX - Glossopharyngeal

CN X - Vagus Nerve

CN X - Vagus Nerve

CN XI – Spinal AccessoryCN XII - Hypoglossal

CN XI - Spinal Accessory

CN XII - Hypoglossal