eye autonomics

Question 1

where does sympathetic innervation exit the spinal cord?

Answer 1

T1-L2 spinal nerves

Question 2

where do pre synaptic axons from CNS exit the spinal cord and travel in the head and neck?

Answer 2

-they exit spinal cord in T1 spinal nerve then ascend within the sympathetic chain and synapse in superior cervical sympathetic ganglion

Question 3

where do post synaptic sympathetic axons travel in head and neck?

Answer 3

• enter the internal and external carotid nerves
• pass onto the surface of the internal and external carotid arteries
• are carried to the organs of the head and neck on the surface of the branches of these arteries
• the ophthalmic artery carries the sympathetic axons into the orbit

Question 4

where do all parasympathetic axons leave the CNS?

Answer 4

-via cranial nerves III, VII, IX and X via sacral spinal nerves

Question 5

is the ciliary ganglion sympathetic or parasympathetic?

Answer 5

-parasympathetic ganglion

Question 6

where is the ciliary ganglion located?

Answer 6

-in the bony orbit

Question 7

which division of the Oculomotor nerve relates to the ciliary ganglion?

Answer 7

-inferior division

Question 8

Answer 8

Question 9

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

what does CNV1 sensory innervate in the face?

Answer 13

• upper eyelid
• cornea
• conjunctiva

Question 14

which divisions of the trigeminal nerve are only sensory?

Answer 14

CNV1 and CNV2 (ophthalmic and maxillary)

Question 15

what does CNV2 sensory innervate in the face?

Answer 15

• skin of the lower eyelid

- skin her maxilla

Question 16

what does CNV3 innervate sensory of the face?

Answer 16

• skin over mandible and TMJ (temporomandibular joint)

- except angle of mandible

Question 17

what nerve opens the eyelid?

Answer 17

oculomotor

Question 18

what is the orbiculares oculi?

Answer 18

-muscle located on the eyelids

Question 19

what is the most densely innervated part of the face?

Answer 19

cornea

Question 20

role of corneal reflex?

Answer 20

-stop any irritants from entering the eye, protecting the cornea

Question 21

what nerve is involved in the afferent (sensory) part of the corneal reflex?

Answer 21

CNV1 (ophthalmic division of trigeminal)

Question 22

what nerve is involved in the efferent (motor) part of the corneal reflex?

Answer 22

CNVII (facial) (closes it)

Question 23

what us the vestibulo ocular reflex?

Answer 23

• turns the eyes in the opposite direction to a head movement
• stabilises gaze on an object during head movement

Question 24

what cranial nerves control the vestibulo ocular reflex?

Answer 24

CN VIII for vestibular part

CN III, IV and VI for move the eye

Question 25

what is the oculocardiac reflex?

Answer 25

• reflex bradycardia in response to tension on extra ocular muscles or pressure on the eye
• basically pulling on the eye muscles can cause bradycardia, patients can get syncope from it

Question 26

what encircle the pupil causing it to constrict when there is bright light?

Answer 26

sphincter papillae fibres which are around the circumference of the iris

Question 27

is constriction of the pupil parasympathetic or sympathetic?

Answer 27

parasympathetic

-in bright light ‘rest and digest’

Question 28

is dilation of the pupil sympathetic or parasympathetic?

Answer 28

-sympathetic

Question 29

what fibres causes the pupil to dilate?

Answer 29

dilator papillae fibres

Question 30

what’s a myadritic pupil?

Answer 30

-when myadriatic drugs induce dilation of the pupil

Question 31

what’s a non physiologically constricted pupil called?

Answer 31

miotic pupil (this is a feature of Horner’s syndrome_