Cranial Nerves Flashcards
What is the name of cranial nerve I?
Olfactory
What does CN I do?
Sense of smell
What is the route of CN I?
Olfactory mucosa
Cribriform plate
Olfactory bulb
Olfactory tract
1.Lateral olfactory stria
Olfactory area of cerebral cortex
2. Medial olfactory stria - carries olfactory nerves to the contralateral olfactory bulb. Crosses the anterior commissure.
Which olfactory stria carries olfaction to the cerebral cortex?
Lateral olfactory stria
Where do 1st order olfactory neurons synapse with 2nd order neurons?
Olfactory bulb
What is the name of the 2nd order cell in the olfactory bulb?
Mitral cell
The olfactory nerve fibres synapse with the mitral cells, forming collections known as synaptic glomeruli
How to you test for CN I damage?
Test each nostril separately with a familiar smell
When can a loss of smell be due to?
Early signs of Parkinson’s/Alzheimer’s
Viral infection
Anterior cranial fossa #
Cribriform plate #
What is the name of CN II?
Optic
How does CN II enter the skull?
Optic canal
What is the route of CN II?
Retina
Optic nerve
Optic chiasm
Optic tract
Lateral geniculate nucleus of thalamus
Primary visual cortex (occipital lobe)
What can cause damage to CN II?
Pituitary adenoma
Pituitary gland is close to the middle cranial fossa
What exits the skull via the cribriform plate?
CN I
What can cause damage to CN II?
Pituitary adenoma
Pituitary gland is close to the middle cranial fossa
Cavernous sinus compression
Posterior cerebral artery aneurysm
Infection causing thrombosis
Lesion to interpeduncular fossa
What travels through the cavernous sinus, and what is near the cavernous sinus?
Through:
Internal carotid artery CN III CN IV CN Va CN Vb CN VI
Near:
Pituitary gland
Sphenoid sinuses
Where are the 2 cavernous sinuses?
They sit either side of the sella turcia
Sella turcia contains the PITUITARY GLAND
Which muscle opens your eyelid?
Which CN innervates it?
Levator palpebrae
CN III
What is the name of CN IV?
Trochlear
What is the function of CN IV?
Motor innervation to superior oblique muscle
What is the route of CN III?
Oculomotor nucleus (anterior midbrain)
Cavernous sinus
Superior orbital fissure
What is the route of CN III?
Oculomotor nucleus (anterior midbrain)
Cavernous sinus
Superior orbital fissure
4/6 extraocular eye muscles
Levator palpebrae superioris (eyelid)
Sphincter pupilae (lens accommodation)
Ciliary eye muscle (constrict pupil)
Which artery runs next to CN VI?
Internal carotid artery
Which artery runs next to CN III?
Posterior cerebral artery
Where is the trigeminal sensory nucleus?
Across the entire brainstem
Where is the trigeminal motor nucleus?
Pons
Describe the route of CN Va
Trigeminal sensory nucleus
Trigeminal ganglion
Cavernous sinus
Superior orbital fissure
Sensation to upper portion of face
Where does CN Va exit the skull?
Superior orbital fissure
Where does CN Vb exit the skull?
Foramen rotundum
Where does CN Vc exit the skull?
Foramen ovale
Describe the route of CN Vb
Trigeminal sensory nucleus
Trigeminal ganglion
Cavernous sinus
Foramen rotundum
Sensation to middle portion of face
