Orbit

Question 1

Boundaries of the orbit
Roof
Lateral
Floor

Answer 1

Roof=frontal
Lateral=zygomatic/sphenoid
Floor=maxillary

Question 2

Medial wall of he orbit

Answer 2

Maxillary, lacrimal, ethmoid, frontal and sphenoid bones

Question 3

What passes through the superior orbital fissure

Answer 3

Contains CN 3,4,V1 and 6 as well as the ophthalmic veins

Question 4

What passes through the supraorbital notch and wat bone is it in

Answer 4

In the frontal bone and it contains the suprorbital nerve, artery, vein from V1 and the opthalmic A/V

Question 5

What is contained by the infraorbital foramen and what bone is it in

Answer 5

In the maxillary bone and contains the infraorbital N/V/A from V2 and the max artery

Question 6

What is contained by the ant/posterior ethmoidal foramina and what do they do

Answer 6

They connect the orbit and nasal cavities and contain V1 and the ophthalmic A/v

Question 7

What is contained by the nasolacrimal duct and what bones compose it

Answer 7

The maxillary and lacrimal bone and continues the membranous nasolacrimal duct and tears

Question 8

Location of the orbital fissure, bones composing it, and the contents

Answer 8

Slit below the superior orbital fissure between the sphenoid and maxillary bones. It connects the ptergopalatine fossa and infratemporal fossa with the orbit. It contains the infraorbital and zygomatic N/A/V (V2 and the maxillary artery

Question 9

Layers of the eye from superficial to deep

Answer 9

Skin (eyelashes, opening of sebaceous/sweat glands)

Subcutaneous layer (CT and sebaceous glands)

Orbicularis occuli (palpebral part)
Skeletal muscle innervated by VII and it closes the eye

Tarsal plate- keeps tears in eye

Question 10

Result in the obstruction of the sebaceous gland of the eye

Answer 10

A stye or hordoleum

Question 11

Result if the obstruction of the tarsal plate of the eye

Answer 11

Chalazion

Question 12

What is the orbital septum of the eye

Answer 12

A CT layer that runs continuous with the periosteum of the orbit and connects to the tarsal plate

Question 13

Elevator palpebrae superioris
O
And what makes it unique
Clinical correlate

Answer 13

Originates from the tendonous ring and its composed of skeletal muscle(CN III) and smooth sympathetics
Damaging either the skeletal or the smooth muscle causes eyelid droop

Question 14

What is the conjunctiva and what does it do

Answer 14

Covers the inside of the lid and fuses to the sclera can become infected and inflamed

Question 15

Where do tears form and where do they go to

Answer 15

They form in the lacrimal gland, drain through the lacrimal puncta to the nasal lacrimal duct to the inferior meatus of the nasal cavity

Question 16

What CN innervates the lacrimal gland

Answer 16

CN VII

Question 17

What two developmental structures meet to form the nasolacrimal duct

Answer 17

It develops as a fold between the maxillary process and the frontonasal processes

Question 18

What isn’t he function of the medial and lateral check ligaments

Answer 18

They prevent excessive rotation

Question 19

Function of the sclera in the eye

Answer 19

It maintains the shape of the eye and serves as an attachment for muscles

Question 20

Function of the cornea and clinical correlation

Answer 20

Aids in focusing light and irregularities in the cornea cause astigmatism

Question 21

What is the main blood supply to the orbit

Answer 21

The ophthalmic artery

Question 22

What are the major branches of the ophthalmic artery

Answer 22

1. Posterior ciliary arteries(pierce the sclera and supply the choroid/photoreceptors)
2. Central artery of he retina blood to the neural retina and it is an end artery

Question 23

What is the function of the choroid

Answer 23

It provides O2 and nutrients to the photoreceptors but not the ganglion cells of the retina that form the optic nerve

Question 24

What is the function of the ciliary body

And what is the cranial nerve that supplies them parasympathetically

Answer 24

Contains smooth muscles that attach to suspensory ligmaments that control the thickness of the lens.

Relaxed ciliary muscles=normal lens
Constricted ciliary muscles=thick lens

CN III

Question 25

What innervates the dialator pupil muscles and what type of muscle are they

Answer 25

Radial smooth muscle and sympathetics

Question 26

What type of muscle is the constrictor pupil muscle and what innervates it

Answer 26

Circular smooth musc nd CN III

Question 27

What would the result be if there were an occlusion to the central artery of the retina and what would be the most common cause of that

Answer 27

Blindness most of the time unless the ciliary arteries had a cilioretinal branch

Carotid artery atherosclerosis

Question 28

What is papilledema and what is the reason this would occur

Answer 28

Swelling of the optic disc and an increase in CSF pressure can affect vision

Question 29

Damage to CN VI and its effect on the eye

Answer 29

Medial strabismus(cross eye) due to damage/paralysis of the lateral rectus

Question 30

Damage to the trochlear nerve and its effect on the eye

Answer 30

Patient can not look out and down causing the patient to tilt their head to the opposite side so both eye are rotated

Question 31

Damage to the oculomotor nerve and its effect on the eye

Answer 31

At rest

1. Lateral strabismus (wall eye) due to paralysis of the medial rectus
2. Ptosis-paralysis of the lavatory palpebrae superioris
3. Dilated pupil- paralysis of the pupillary constrictor

Question 32

Ciliary ganglion CN and clinical correlate

Answer 32

CN III which are parasympathetic ganglion to the occulomotor nerve and damage to this=blown pupil indicating a catastrophe