Occular nerve innervation Flashcards
What are the orbital motor nerves
Oculomotor (III) nerve
Trochlear (IV) nerve
Abducent nerve (VI) nerve
Facial nerve (VII) nerve
What are the orbital sensory nerves
Optic (II) nerve
Trigeminal (V) nerve
What efferent nerve fibres does the oculomotor nerve (CNIII) contain
Somatic nerve fibres
Parasympathetic nerve fibres
What are the two motor nuclei of oculomotor nerve
CN III nuclues
Edinger-Westphal nuclues
What are the two branchs of the oculomotor nerve
Superior division:
LPS and SR muscle
Inferior divion:
IR, IO and MR
Efferent parasympathetic fibres (Edinger-Westphal nuclues)
- ciliary muscles
- sphincter pupillae muscles
What does the trochlear nerve (CN IV) innervate
Superior oblique muscle only
Which nerve is the thinnest and longest nerve
trochlear nerve ( CN IV)
What does the abducent nerve (CN VI) innervate
Lateral rectus muscle
Which nerve is vulnerable to damage by the sharp edge of bones
Abducent nerve (CN VI)
What is the orbital region of the facial nerve
Temporal
Zygomatic
What does the temporal and upper buccal branch of the facial nerve innervate
Temporal:
- orbicularis oculi
- occipito- frontalis msucle
- corrugator supercilii
Upper branch branch
- procerus
Failure of this nerve causes incorrect lid closure, zygomatic also innervates ig
What does the parasympathetic nerve fibres from facial nerve innervate
Lacrimal gland
What does the sympathetic nerves of the facial nerve supply
Vessels of the lacrimal gland
What does the optic nerve do
Send afferent visual information from retina to brain
What arethe three divison of the trigeminal nerve ( CN V)
Ophthalmic, maxillary and mandibular
What type of nerve is trigemenial nerve (CN V)
Sensory nerve
What does the opthalmic divion of CN V divide into
Frontal, nasociliary and lacrimal branch
What does the frontal branch of the trigeminal nerve (CN V) divide into and which structures does itsupply
Supra orbital and trochlear nerve
Supplies
- forehead n scalp
- upper eyelid
- conjunctiva
What does the nasociliary branch of the trigeminal nerve (CN V) divide into and which structures do it supply
2 long ciliary nerve
- sclera and iris dilator and cornea
Short ciliary nerve
- cornea and choroid
Both carries sympathetic fibres
Infratrochlear nerve
- skin of nose, eyelids, conjunctiva, carruncle, canaliculi and lacrimal sac
What does the lacrimal branch of the trigeminal nerve (CN V) supply
Lacrimal gland
Upper eyelid
Conjunctiva
What muscles does the autonomic nervous system innervate
Iris
Ciliary
Smooth muscle of eyelids
Choroidal and conjunctival blood vessels
Lacrimal gland
Where does the sympathetic fibres come from
Superior cervical ganglion
How does the sympathetic nervous system suuply to orbit
Short ciliary muscles: supply orbital vessels
Long ciliary nerves: iris dilator and anerior globe
Joins oculomotor:
Muller’s muscle
What are the functions of the sympathetic nervous system
Vaso-constriction
Pupil dilation
Lid retraction
Basal secretion of lacrimal gland
This system prepares the body for an emergency
