Ch 15 - Cranial nerves

What are the 12 cranial nerves

in cerebrum

• CN I(1) Olfactory nerve

• CN II(2) Optic nerve

  in midbrain

• CN III(3) Oculomotor nerve

• CN IV(4) Trochlear nerve

in pons

• CN V(5) Trigeminal nerve

• CN VI(6) Abducens nerve

• CN VII(7) Facial nerve

• CN VIII (8) Vestibulocochlear nerve

  in medulla oblongata

• CN IX(9) glossopharyngeal

• CN X(10) Vagus

• CN XI (11) Accessory

• CN XII (12) Hypoglossal

CN I (1) - olfactory nerve

sends sensory info about olfaction (smell) to temporal lobe

passes through: olfactory foramina of cribriform plate of ethmoid bone

CN II (2) - optic nerve

sends sensory info about light (vision) from eye to occipital lobe

Passes through: optic canal of sphenoid bone

CN III(3) - oculomotor nerve

sends motor output info to levator palpebrae superioris, superior rectus, inferior rectus, and inferior oblique muscles of the eye

passes through: superior orbital fissure of sphenoid bone

CN IV(4) - trochlear nerve

sends motor output info to superior oblique muscle in eye

passes through: superior orbital fissure of sphenoid bone

CN V1(6) - abducens nerve

sends motor output info to lateral rectus muscle of eye

passes through: superior orbital fissure of sphenoid bone

why is CN V(5)- trigeminal nerve unique

includes BOTH sensory and motor functions; has three branches:

• V1 - opthalmic n.

• V2 - maxillary n.

• V3 - mandibular n.

CN V1(5₁)- opthalmic nerve

sends sensory (touch) info from top of head, forehead, and nose to parietal lobe

passes through: superior orbital fissure of sphenoid bone AND supraorbital foreamen

CN V2(5₂)- maxillary nerve

sends sensory info (register touch) from middle of face (between eyes, lips, and teeth) to parietal lobe

passes through: foreamen rotundum AND infraorbital foreamen

CN V3(5₃)- mandibular nerve

sends sensory info (touch) fro lower jaw and anterior 2/3rds of tongue to parietal bone

sends motor output from frontal lobe during chewing (control muscles elevate jaw)

passes through: foreamen ovale AND enters mandibular foreamen AND exits mental foreamen

CN VII(7) - facial nerve

Sends taste sensations for anterior 2/3rds of tongue to insula lobe; sends motor output from frontal lobe to facial expression muscles; parasympathetic function rest and digest

passes through: sits in internal acoustic meatus of temporal bone and exits stylomastoid foramen

CN VIII(8) - vestibulocochlear nerve

branch one where sensory receptors monitor balance and position of the head and is sent to insula lobe

branch two where vibrational sound sensing cells are located and info is sent to temporal lobe

passes through: internal acoustic meatus of temporal bone (DOES NOT EXIT SKULL)

CN IX(9) - glossopharyngeal nerve

sends sensory info from pharynx, tonsils, and posterior 1/3 of tongue to parietal lobe; sends taste for posterior 1/3 of tongue to insula lobe

receive motor output from frontal lobe to stylopharyngeus muscle (swallowing)

exits through: jugular foramen

CN X(10) - vagus nerve

sends taste and touch info from pharynx and larynx to parietal and insula lobe; sends visceral sensory info from ventral body organs (heart, lungs, digestive system) to insula lobe

motor output from frontal lobe to medulla oblongata to ventral body organs

exits through: jugular foramen

CN XI(11) - spinal accessory

receives motor output from frontal lobe an is sent to sternocleidomastoid and trapezuis

exits through: jugular foreamen

CN XII(12) - hypoglossal

sends motor output from frontal lobe to tongue muscles to help with movement during chewing, swallowing and talking

exits through: hypoglossal canal of occipital bone