Orbital Autonomics

Question 1

where do sympathetic nerve fibres for the eye leave the spinal cord?

Answer 1

T1 spinal nerve

Question 2

where do sympathetics for the eye synapse?

Answer 2

the superior cervical sympathetic ganglion

Question 3

where do post synaptic sympathetic axons for the eye enter after they synaose?

Answer 3

the internal and external carotid nerves which pass onto the carotid arteries

Question 4

what carries the sympathetic axons into the orbit?

Answer 4

the ophthalmic artery

Question 5

where do all parasympathetic axons leave the CNS?

Answer 5

cranial nerves 3,7,9 and 10 OR via sacral spinal nerves

Question 6

what parasympathetic ganglion supplies the eye?

Answer 6

the ciliary ganglion

Question 7

what cranial nerve contributes to the ciliary ganglion?

Answer 7

CN III

Question 8

where is the ciliary ganglion located?

Answer 8

the bony orbit

Question 9

what is CN III?

Answer 9

the oculomotor nerve

Question 10

where does CN III connect with the CNS?

Answer 10

the junction of the midbrain and the pons

Question 11

where does CN III exit the cranial cavity?

Answer 11

the superior orbital fissure

Question 12

what two modalities does CN III carry?

Answer 12

somatic motor

parasympathetic

Question 13

what does CN III carry somatic motor nerve to?

Answer 13

the majority of the extraocular muscles

Question 14

what are the two divisions of CN III after it passes through the superior orbital fissure, and which is then part of the ciliary ganglion?

Answer 14

superior

inferior - this one

Question 15

what supplies sensory innervation of the face?

Answer 15

the branches of the trigeminal nerve

Question 16

where does the trigeminal nerve originate?

Answer 16

the lateral surface of the pons

Question 17

what is another name for the corneal reflex?

Answer 17

blinking

Question 18

what type of reflex is the corneal reflex?

Answer 18

sensory

Question 19

what is the function of the corneal reflex?

Answer 19

to protect the eye

Question 20

what are the three components of the corneal reflex?

Answer 20

sensory (afferent)
central
motor (efferent)

Question 21

what happens in the sensory limb of the corneal reflex?

Answer 21

AP’s conducted from the cornea via CN V1 and taken to the trigeminal ganglion

travels along CN V to the pons

Question 22

what are the central CNS connections involved in the corneal reflex?

Answer 22

connections between CN V and CN VII

Question 23

what happens in the motor limb of the corneal reflex?

Answer 23

AP’s conducted from the brain via CN VII

to the palpebral part of orbicularis oculi = a blink

Question 24

what does the vestibulo-ocular reflex do?

Answer 24

turns the eye in the opposite direction to head movement, to stabilise gaze

Question 25

what are the CNS connections in the VOR?

Answer 25

between CN 7 and CN's 3,4 and 6

Question 26

what is the oculocardiac reflex?

Answer 26

when reflex bradycardia occurs in response to tension on extraocular muscles or pressure on the eye

Question 27

what are the CNS connections in the oculocardiac reflex?

Answer 27

between CN V1 and CN X

Question 28

what happens to the eyes in the sympathetic response?

Answer 28

open wider to get more light in focus on far objects emotional lacrimation

Question 29

what happens to the eyes in the parasympathetic response?

Answer 29

get less light in focus on near objects reflex lacrimation

Question 30

what two muscles are involved in opening the eyes wider?

Answer 30

levator palpebrae superioris (LPS) | mueller's muscle

Question 31

what does the LPS do?

Answer 31

raises the upper eyelid

Question 32

what muscle type is found in the LPS?

Answer 32

skeletal and smooth

Question 33

what is another name for mueller's muscle?

Answer 33

superior tarsus muscle

Question 34

where is the mueller's muscle attached?

Answer 34

LPS

Question 35

what type of muscle is mueller's muscle and what innervates it?

Answer 35

smooth | sympathetics

Question 36

what is the function of mueller's muscle?

Answer 36

elevates the eyelid by an additional 2mm

Question 37

what effect does parasympathetic stimulation have on the pupil?

Answer 37

constricts

Question 38

what muscles are involved in the constriction of the pupil?

Answer 38

sphincter pupillae muscles - contract

Question 39

what effect does sympathetic stimulation have on the pupil?

Answer 39

dilates

Question 40

what muscle is involved in the dilation of the pupil?

Answer 40

dilator pupillae

Question 41

what is another name for a non-physiologically enlarged pupil?

Answer 41

mydriatic

Question 42

what is another name for a non-physiologically constricted pupil?

Answer 42

miotic

Question 43

what makes up the sensory limb of the pupillary light reflex?

Answer 43

CN II on the side light is shone in

Question 44

where do the CNS connections for the pupillary light reflex occur?

Answer 44

the midbrain

Question 45

what makes up the motor limb of the pupillary light reflex?

Answer 45

CN III on both sides

Question 46

where does the suspensory ligament of the lens attach?

Answer 46

the ciliary body

Question 47

what type of muscle is found in the ciliary body?

Answer 47

smooth

Question 48

what type of vision causes the ciliary body to relax?

Answer 48

far vision

Question 49

what happens when the ciliary body relaxes?

Answer 49

suspensory ligament of the lens tightens and the lens flattens this allows the eye to focus on distant objects

Question 50

what type of vision causes the ciliary body to contract?

Answer 50

near vision

Question 51

what happens when the ciliary body contracts?

Answer 51

suspensory ligament of the lens relaxes and the lens becomes spherical this allows the eye to focus on near objects

Question 52

what are the three different types of tears produced by the eyes?

Answer 52

basal reflex emotional

Question 53

when are basal tears produced?

Answer 53

all the time

Question 54

what is the function of basal tears?

Answer 54

clean and hydrate the cornea

Question 55

what immune component is found in basal tears?

Answer 55

lysozyme

Question 56

when are reflex tears produced?

Answer 56

in response to mechanical or chemical stimulation

Question 57

what is the afferent limb for production of reflex tears?

Answer 57

CN V1 from the cornea and conjunctiva

Question 58

what is the efferent limb for the production of reflex tears?

Answer 58

parasympathetic axons from CN VII

Question 59

when are emotional tears produced?

Answer 59

due to an emotion e.g. sad, scared