Cranial Nerves ppt 16 Flashcards
Mnemonic for the cranial nerves
Oh once one takes the anatomy final very good vacations are heavenly
What are the corticobulbar fibers?
serve as the source of upper motor neuron innervation of lower motor neurons in cranial nerve nuclei
What cranial nerve and muscles have corticobulbar innervation?
- Muscles of mastication (CN V)
• Muscles of facial expression (CN VII) - (partially bilateral)
• Palate, pharynx, and larynx (CN X)
• Tongue (CN XII)
• Sternocleidomastoid and trapezius muscles (CN XI)
CNI - Olfactory
Function: Smell
Origin: Olfactory bulb- cribriform plate-olfactory epithelium
Damage: Anosmia
CNII- Optic
Function: Vision
Origin: Retina-optical canal-optic chiasma- thalamus
Damage: Blindness, anopsias, papilledema, optic atrophy
CNIII- Oculomotor
Function: Movements of eye.
Origin: ventral midbrain- orbital fissures- eye
Damage: Eye rotates down and out. Ptosis. double vision
Eye Movement Mnemonic
LR6 SO4 AO3
Fibers of CNIII
- Somatic motor fibers to four of the six extrinsic eye muscles (inferior oblique and superior, inferior, and medial rectus muscles)
- Parasympathetic (autonomic) motor fibers to sphincter pupillae, and to ciliary muscle, controlling lens
- Sensory (proprioceptor) afferents
CNIV- Trochlear
Function: Superior oblique muscle
Origin: Midbrain-orbital fissure- eye
Damage: Double vision. Cannot move eye down and out
CNV1- Trigeminal Ophthalmic division
Function: Sensory forehead and eyes
Origin: Pons- orbital fissure- face
CNV2- Trigeminal Maxillary
Function: Sensory Checkbones, nose
Origin: Pons- Forament rotundum- face
CNV3- Trigeminal Mandibular
Function: Sensory jaw chin (ant. 2/3 tongue touch). muscle of mastication
Origin: through the foramen ovale
Trigeminal Neuralgia
painful afflictions known caused by a disorder of the fifth cranial (trigeminal) nerve.
CNVI- Abducens
Functions: Lateral Rectus Muscle
Origin: Pons-supirior orbital fissure- eye
Damage: eye rotates medially
CNVII- Facial
Divisions
Temporal Zygomatic Buccal Mandibular Cervical