Lecture 22: eye and orbit II

Question 1

what cranial nerves are in the orbit

Answer 1

CN II-optic
CN III- oculomotor
CN IV- trochlear
CN V1- ophthalmic division of trigeminal
CN VI-Abducens

Question 2

where does CN II enter the orbit

Answer 2

optic canal

Question 3

what four nerves go through orbital fissure

Answer 3

III- oculomotor
IV- trochlear
V1-ophthalamic
VI- abducens

Question 4

what structures are located in the optic canal

Answer 4

optic nerve, internal ophthalmic artery and vein

Question 5

what muscles heavily surround the optic nerve

Answer 5

extraoccular muscles

Question 6

what seven muscles attach to eye to move it

Answer 6

dorsal, ventral, lateral, and medial rectus
ventral and dorsal obliques
retractor bulbi

Question 7

what eye muscle pulls eye back into orbit

Answer 7

retractor bulbi

Question 8

what cranial nerve distributes sensory innervation to the cornea, sclera, nasal cavity and face

Answer 8

V1- ophthalmic

Question 9

what are the branches of V1 ophthalmic CN

Answer 9

nasociliary, frontal, lacrimal

Question 10

what nerve provides sensory innervation from nasal cavity, cornea and sclera

Answer 10

nasociliary nerve

Question 11

what nerve provides sensory innervation from skin of forehead and scalp

Answer 11

frontal nerve

Question 12

what nerve provides sensory information from lacrimal gland, conjunctiva and upper eyelid

Answer 12

lacrimal nerve

Question 13

what are the branches of the nasociliary nerve

Answer 13

long ciliary nerves, anterior and posterior ethmoidal nerve

Question 14

what branch of the nasociliary provides sensory from cornea and sclera

Answer 14

long ciliary nerve

Question 15

what branch of the nasociliary nerve provides sensory information from nasal cavity

Answer 15

anterior and posterior ethmoidal (think methoidal- snort via nasal cavity)

Question 16

what branch of the CN III provides parasympathetics to pupillary sphincter and ciliary muscle

Answer 16

short ciliary nerve
(think im gonna sh(ph)rink you down small)

Question 17

what delivers parasympathetic innervation to the lacrimal gland

Answer 17

postganglionic parasympathetic axons travel directly from the pterygopalatine ganglion to lacrimal gland through the orbital fissure

Question 18

Cranial Nerve III: Oculomotor provides motor innervation to what muscles

Answer 18

ventral oblique, dorsal, medial and ventral rectus and levator palpebrae superiosis

Question 19

what cranial nerve innervates the ciliary ganglion

Answer 19

CN III- oculomotor

Question 20

what neural modality is the ciliary ganglion part of

Answer 20

site of synapse for PNS that travel along short ciliary branches to travel to eye to innervate pupillary sphincter and ciliary muscle

Question 21

what are the parasympathetic branches of cranial nerve III-oculomotor and are these pre or post ganglion

Answer 21

short ciliary- PNS to pupillary sphincter and ciliary muscle, post-ganglionic

Question 22

what is the pathway from the midbrain to the pupillary sphincter and ciliary muscle

Answer 22

1. preganglionic PNS cell bodies in Edinbger-Westphal nucleus (midbrain)
2. CN III
3. synapse at ciliary ganglion
4. hitchhike on short ciliary nerves-innervate pupillary sphincter and ciliary muscle

Question 23

what muscle does CN IV (trochlear) innervate in the eye

Answer 23

dorsal oblique

Question 24

what muscle does CN VI (abducens) innervate in the eye

Answer 24

lateral rectus and retractor bulbi (causes nictitating membrane to partially cover eye)

Question 25

what four cranial nerves provide parasympathetic innervation

Answer 25

oculomotor III facial VII glossopharyngeal IX vagus X

Question 26

what ganglion does the oculomotor nerve innervate and what is the function

Answer 26

ciliary ganglion site of synapse and then travel to short ciliary nerves to provide PNS to sphincter and ciliary muscle

Question 27

what ganglion does the facial nerve innervate and what is the function

Answer 27

pterygopalatine- provide PNS to lacrimal gland submandibular- salivaiton

Question 28

what ganglion does the glossopharyngeal nerve innervate and what is the function

Answer 28

otic ganglion- provide PNS to parotid gland for salivation

Question 29

mnemonic to remember ganglia associated with each cranial nerve

Answer 29

3, 9, 7, 7 COPS ocoulomotor (III)- ciliary Glossopharyngeal (IX)- otic facial (VII)- ptyergopalatine and submandibular

Question 30

where is the site of synapse for sympathetics to the eye and head

Answer 30

cranial cervical ganglion

Question 31

what provides sympathetic innervation to dilator pupillae muscle and superior tarsal muscle

Answer 31

internal carotid periarterial plexus

Question 32

what provides sympathetic innervation to face

Answer 32

external carotid periarterial plexus

Question 33

what is the order of cells passed through in visual pathway

Answer 33

photoreceptors--->bipolar neurons--> retinal ganglion cells--> lateral geniculate nucleus of thalamus--> primary visual cortex/occipital lobe

Question 34

what are the steps in the pupillary light reflex

Answer 34

1. optic nerve fibers synapse at pretectal area 2. pretectal nerve fibers synapse bilaterally at edinger-westphal nuclei 3. E-W nerve fibers (preganglionic PNS) synapse at ciliary ganglia 4. ciliary ganglia nerve fibers (postganglionic PNS) synapse on pupillary sphincter muscles and cause it to contract

Question 35

what is the pupillary dilation reflex

Answer 35

1. preganglionic sympathetic nerve fibers synapse in the superior portion of the sympathetic trunk 2. postganglionic sympathetic nerve fibers synapse on pupillary dilator muscle

Question 36

what artery supplies the orbital contents

Answer 36

short ciliary arteries anastomosis between external and internal carotid artery

Question 37

where does venous drainage of the orbital contents occur

Answer 37

drainage to the cavernous sinus via the ventral and dorsal external ophthalmic veins

Question 38

what receives venous drainage from the brain

Answer 38

sinuses and then the blood is drained to vertebral and internal jugular veins

Question 39

what muscle adducts the eye

Answer 39

medial rectus

Question 40

what muscle abducts the eye

Answer 40

lateral rectus

Question 41

what muscle adducts and elevates the eye

Answer 41

dorsal rectus

Question 42

what muscle adducts and depresses the eye

Answer 42

ventral rectus

Question 43

what muscle abducts and elevates the eye

Answer 43

ventral oblique

Question 44

what muscle abducts and depresses the eye

Answer 44

dorsal oblique

Question 45

what muscles are involved in the action of looking up

Answer 45

dorsal rectus and ventral oblique

Question 46

what muscles are involved in looking down

Answer 46

ventral rectus and dorsal oblique