EOM innervation

Question 1

Yoke muscles definition

Answer 1

Equal and simultaneous innervation

Question 2

Yoke muscle questions

Answer 2

Draw EOM diagram

Question 3

EOMs muscle to nerve ratio

Answer 3

Low muscle fiber to nerve fiber ratio

Question 4

Pupillary reflex route

Answer 4

Retinal gang cell- pretectal nucleus - ew - ciliary ganglion - short ciliary nerves - sphincter

Question 5

Oculomots - parasympathetic

Answer 5

Mitosis

Question 6

CNIII afferent fibers

Answer 6

Propioceptive

Question 7

Nerves passing through SOF

Answer 7

Throchlear 
Lacrimal 
Frontal 
Abducen
Inferior + sup oculomotor 
Nasociliary 7

Angela tiene la nariz fea, super intelligente obvio

Question 8

How many oculomotor nucleus do we have

And where are they located

Answer 8

R and L

In the midbrain ( within gray matter that surrounds cerebral aqueduct, anterior to superior colliculus

Question 9

Components of each CNIII nucleus

Answer 9

Oculomotor nuclear complex

Parasympathetic nucleus = EW

Question 10

Input into CNIII nuclei includes

Answer 10

Cerebral cortex : motor and sensory

Midbrain nuclei: MLF ( CNIV, CNVI, CNVIII nuclei)
Pretectal nucleus
Supraoculomotor area
Cerebellum

Question 11

CNIII input motor cortical regions

Answer 11

Voluntary horizontal gazes

Question 12

Saccades

Answer 12

FEF

Question 13

Pursuits

Answer 13

Occipitoparietal cortex

Question 14

CNIII input sensory cortical region

Answer 14

Visual cortex for accommodation and visual reflexes ( superior colliculus)

Visual association areas

Question 15

CNIII CN 4, 6, 8 nuclei input come via

Answer 15

MLF

Question 16

CNIII pretectal nucleus input

Answer 16

Light reflex and vertical gazes

Question 17

CNIII supraoculomotor area input

Answer 17

Acc reflex

Question 18

Each oculomotor nucleus has

Answer 18

Medial subnucleus

3 lateral subnuclei

Question 19

Medial subnucleus of oculomotor controls

Answer 19

Contralateral SR

Question 20

3 lateral subnuclei of oculomotor nucleus controls

Answer 20

3 ipsilateral EOMS

IO, IR, MR

Question 21

Parts of CNIII nucleus

Answer 21

Common central nucleus

Then each oculomotor nucleus (L and R ) - has 1 medial subnucleus, and 3 lateral subnuclei

Question 22

EW receives

Answer 22

Corticonuclear fibers for accommodation

Pretectal fibers (midbrain) for pupillary reflexes

Question 23

Where is EW located

Answer 23

Posterior to the main motor nucleus in the midbrain

Question 24

Preganglionic fibers from EW path

Answer 24

Synapse in ciliary ganglion- enter short ciliary nerves - sphincter and ciliary muscle- pupil contraction/accommodation

Question 25

Oculomotor nerve emerges from

Answer 25

Anterior aspect of midbrain medial to the cerebral peduncles and b/w posterior cerebral and superior cerebellar arteries

Question 26

Oculomotor nerve passes through which arteries

Answer 26

Posterior cerebral and superior cerebellar arteries

Question 27

Posterior cerebral artery | Superior cerebellar artery

Answer 27

CNIII nerve passes through

Question 28

CNIII progresses anteriorly parallel to

Answer 28

Posterior communicating artery

Question 29

Where does CNIII pierce the dura

Answer 29

At the level of the posterior chinoid process of the sphenoid bone and runs in the lateral wall of the cavernous sinus superiorly to CNIV

Question 30

Where are the parasympathetic fibers of CNIII located

Answer 30

On the surface of the nerve and migrate down towards orbit

Question 31

What’s incorporated into the oculomotor nerve as it progresses anteriorly

Answer 31

Sensory branch from ophthalmic | Sympathetic fibers from carotid plexus

Question 32

When does the CNIII nerve divide into sup and inferior

Answer 32

When they enter the orbit through SOF/ inside annulus of Zin

Question 33

Superior division of CNIII

Answer 33

SR and levator

Question 34

Inferior division of CNIII

Answer 34

3 branches for Other CNIII muscles (except SR) MR,IR, IO and parasympathetic fibers for Ciliary ganglion

Question 35

Where is the nucleus of the trochlear nerve

Answer 35

Inferiorly to oculomotor nucleus at the level of inferior colliculus

Question 36

Exit of SO4/ trochlear muscle

Answer 36

Leave in posterior direction and decussate before exiting the dorsal aspect of the midbrain

Question 37

Where does the trochlear nerve pierce the dura

Answer 37

It goes around the cerebral peduncle and pierces the dura close to the posterior chinois process and enters cavernous sinus

Question 38

Where does trochlear nerve pass through after going along the lateral wall of the cavernous sinus

Answer 38

Between CNIII superiorly and ophthalmic nerves inferiorly

Question 39

How does the trochlear nerve enter the orbit

Answer 39

It becomes medial to oculomotor nerve and enter orbit through SOF above the tendinous ring

Question 40

Where is the nucleus of abducens nerve located

Answer 40

In the pons beneath the floor of the 4th ventricle

Question 41

Where does abducens nerve exit

Answer 41

Within the sulcus located between the pons and the medulla

Question 42

Where does the abducens pierce the dura

Answer 42

Level of the dorsal of the sella truck a

Question 43

How does CNVI enter the orbit

Answer 43

Through SOF between the inferior and superior divisions of CNIII (inside the oculomotor foramen

Question 44

Most frequent CN palsy

Answer 44

CNVI

Question 45

Least common CN palsy

Answer 45

CNIV

Question 46

EOMs during Graves

Answer 46

Thyroid disease Enlargement of EOM causes defective ocular motility and exothalmus Proptosis

Question 47

Palsies that cause head tilt

Answer 47

6 and 4

Question 48

Do pts experience diplopia during CNIII palsies

Answer 48

Yes

Question 49

What happens if pt with CNIII palsy try’s to look down

Answer 49

SO would cause it to move inward

Question 50

What happens to pupil during CNIII palsy

Answer 50

Mydryasis

Question 51

Opthalmoplegia

Answer 51

Paralysis or weakness of EOMS

Question 52

External ophthalmoplegia

Answer 52

EOMS affected, ptosis

Question 53

Internal ophthalmoplegia

Answer 53

Paresis of ciliary body and mydryasis

Question 54

Nuclear lesion of CNIII

Answer 54

Involves contralateral superior rectus muscle

Question 55

What happens when you look nasally with a CNIV palsy

Answer 55

Affected eye goes up

Question 56

What does pt experience during CNIV palsy

Answer 56

Vertical diplopia | Fixed by tilting head to opposite side of the affected muscle

Question 57

What happens to eye when we have CNVI palsy

Answer 57

Eye is turned inward