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Flashcards in Ophtha Deck (25):
1

CN II
[M/S/Mix, origin, pathway, function]

>Sensory
>Origin: ganglionic layer of retina
>Optic nerves unite to form optic chiasma -- pass thru lateral geniculate body -- optic radiation -- visual cortex
*Midline fibers of optic nerve cross to opposite side; temporal fibers stay on same side

2

CN III
[M/S/Mix, origin, pathway, function]

>Motor
>Origin: ant. surface of midbrain
>Divides into superior/inferior rami, both enter orbit via superior orbital fissure
>Supply: SR, MR, IR, IO; levator palepebrae superioris; pupillary constrictor muscles (via ciliary ganglion and short ciliary nerves)
>Fxn: up, down, medial movement; pupillary constriction; accomodation

3

CN IV
[M/S/Mix, Origin, pathway, function]

>Motor
>Origin: post. midbrain (after decussating)
>Enters via superior orbital fissure
>Supply: SO
>Fxn: downward and lateral movement

4

CN VI
[M/S/Mix, origin, pathway, function]

>Motor
>Origin: anteriorly, b/w pons and medulla
>Passes thru cavernous sinus w/ internal carotid
>Enters orbit via Superior orbital fissure
>Supply: LR
>Fxn: Lateral movement

5

CN V (ophthalmic branch)
[M/S/Mix, origin, pathway, supply/function]

>Sensory
> 3 branches: lacrimal, frontal nasociliary
>Enters via Superior orbital fissure
>Supply: lacrimal gland, conjunctivae, skin of upper eyelid; frontal sinus, skin of forehead; tip of nose, skin of eyelids, pupillary dilators, cornea, ethmoid and sphenoid sinuses

6

Supraorbital foramen transmits...

Supraorbital nerve and blood vessels

7

Infraorbital canal transmits...

Infraorbital nerve and blood vessels

8

Nasolacrimal canal transmits...

Nasolacrimal duct

9

Inferior orbital fissure transmits...

Maxillary nerve and its zygomatic branch
Inferior ophthalmic vein
Sympathetic nerves

10

Superior orbital fissure transmits...

Lacrimal nerve, Nasociliary nerve
Frontal nerve
Trochlear nerve
Oculomotor nerve
Abducent nerve
Superior ophthalmic vein

11

Optic canal transmits...

optic nerve
ophthalmic artery

12

Superior Rectus (movement)

Upward, medially

13

Inferior Rectus (movement)

Downward, medially

14

Medial Rectus (movement)

Medially

15

Lateral Rectus (movement)

Laterally

16

Superior Oblique (movement)

Downward, laterally
(assists inferior rectus)

17

Inferior Oblique (movement)

Upward, laterally
(assists superior rectus)

18

Sphincter pupillae of the iris (fxn)

Constricts pupil
(fibers arranged around the pupil; uses short ciliary fibers)

19

Dilator pupillae of the iris (fxn)

Dilates pupil
(radial fibers; uses long ciliary nerves)

20

Ciliary muscle (fxn)

Controls shape of lens
Accommodation

21

How is the lens kept flat for the eye to focus on distant objects?

The periphery of the lens is attached to ciliary processes of the ciliary body by the suspensory ligament. The radiating fibers of the suspensory ligament pull the lens flat.

22

Where does the optic nerve enter the eye?

The optic nerve leaves the retina at the optic disc. The optic disc is pierced by the central artery of the retina.

23

What secretes aqueous humor, and where is aqueous humor drained?

>Secreted by Ciliary body into the posterior body, then flows through the pupil and into the anterior chamber.
>Drained in the Venous sinus of the sclera (Schlemm's canal)

24

What is the fovea?

It's a pit in the macula of the retina that provides the clearest vision. This region has exclusively cones that are more densely packed than anywhere else. Has no blood vessels to interfere with vision.
*Maximum visual acuity, maximum color sensitivity

25

Where does the optic nerve exit the eye?

The lamina cribrosa is found at the base of the optic disc, through where retinal fibers leave the eye to form the optic nerve, which then goes on to form the optic chiasma