Orbit

Question 1

What bones make up the outer rim of the orbit?

Answer 1

Frontal, zygomatic, and maxilla bones

Question 2

What bones make up the inner part of the orbit?

Answer 2

Sphenoid (greater & lesser wings), ethmoid, lacrimal, and palatine bones

Question 3

What bones makeup the floor of the orbit?

Answer 3

Maxilla, zygomatic, palatine bones

Question 4

What bones makeup the roof of the orbit?

Answer 4

Frontal, sphenoid bones

Question 5

What bones makeup the medial wall of the orbit?

Answer 5

Ethmoid, lacrimal, frontal, maxillary, palatine bones

Question 6

What bones makeup the lateral wall of the orbit?

Answer 6

Zygomatic, sphenoid, frontal, maxilla bones

Question 7

What lies at the apex of the orbit?

Answer 7

Optic canal

Question 8

What makes up the base of the orbit?

Answer 8

Orbital margin

Question 9

What is the axis of the orbit?

Answer 9

45 degrees from sagittal

Question 10

What is the name for the space b/w the upper and lower eyelids?

Answer 10

Pelpebral fissure, bound by the upper and lower palpebral margins (palpebrae = eyelids)

Question 11

The upper and lower palpabral margins meet at the ___________.

Answer 11

Canthus (medial and lateral canthi)

Question 12

How many layers does a palpebra have associated w/it?

Answer 12

7

Question 13

What is the major m. of the eyelid?

Answer 13

Levator palpabrae superioris m.

Question 14

What is the lacrimal lake?

Answer 14

The larger medial angle of the eyelid

Question 15

What is the fleshy elevation seen in the medial eye (next to the lake)?
What’s contained in it?

Answer 15

• Lacrimal caruncle

- Sweat glands, sebaceous glands, cilia

Question 16

What is the name of the CT band found just lateral to the lacrimal caruncle?

Answer 16

Plica semilunaris (separates sclera from lacrimal lake)

Question 17

Where are lacrimal glands located?

What do the ducts of the lacrimal gland drain directly into?

Answer 17

• Superolateral aspect of eye

- Superior palpebral fornix (of upper lid. aided by blinking)

Question 18

What is the function of the puncta lacrimali?

Where are they located?

Answer 18

• Drain opening for the tears

- Medial side of upper and lower lid

Question 19

What is the function of the lacrimal canaliculus?

Where are they located?

Answer 19

• It’s a duct from the puncta lacrimali to the lacrimal sac

- Upper and lower palpebrae

Question 20

What is the lacrimal sac?

Where is it located?

Answer 20

• Collection of fluids

- Fossa of lacrimal bone

Question 21

Where does the nasolacrimal duct drain?

Answer 21

Nasal sinus

Question 22

What do the recti mm. originate?

Answer 22

Anulus tendineus (fibrous ring encircling inf and sup orbital fissures + optic canal)
- Placed medially, so mm. travel laterally and anteriorly to reach eye

Question 23

Where does the superior oblique m. originate?

Answer 23

Sphenoid

Question 24

Where does the inferior oblique m. originate?

Answer 24

Maxilla

Question 25

Where does the levator palpebrae superioris m. originate?

Answer 25

Sphenoid

Question 26

What are the vertical axis actions of each of the 6 eye mm.?

Answer 26

``` Medial rectus: none Lateral rectus: none Superior rectus: elevates Inferior rectus: depresses Superior oblique: depresses Inferior oblique: elevates ```

Question 27

What are the horizontal axis actions of each of the 6 eye mm.?

Answer 27

``` Medial rectus: adducts Lateral rectus: abducts Superior rectus: adducts Inferior rectus: adducts Superior oblique: abducts Inferior oblique: abducts ```

Question 28

What does the superior division of the oculomotor n. innervate?

Answer 28

Superior rectus and levator palpebrae superioris mm.

Question 29

What does the inferior division of the oculomotor n. innervate?

Answer 29

Medial and inferior recti, inferior oblique mm.

Question 30

Besides the optic n., what travels through the optic canal?

Answer 30

Ophthalmic a.

Question 31

What are the 3 primary branches that V1 divides into?

Answer 31

"NFL" - Nasociliary n. - Frontal n.--> Supratrochlear and supraorbital nn. - Lacrimal n.

Question 32

What is the pw of the nasociliary n. across the eye? What branches does it give off (just kind of know them)

Answer 32

- Lateral to medial | - Short ciliary nn., long ciliary nn., posterior ethmoidal n., anterior ethmoidal n., infratrochlear n.

Question 33

How does the communicating branch of the ciliary ganglion reach the eye?

Answer 33

Runs thru the ciliary ganglion w/o synapsing, then reaches eye by running w/short ciliary nn.

Question 34

What are the only types of fibers that synapse w/ciliary ganglion? What other fibers run directly thru it?

Answer 34

- Parasymp fibers from CN III | - Sensory and symp fibers

Question 35

What m. causes constriction of the pupil via parasympathetic stimulation?

Answer 35

Sphincter pupillae m.

Question 36

What m. causes allows eye to focus on nearby objects via parasympathetic stimulation?

Answer 36

Ciliary m. contraction

Question 37

After passing thru ciliary ganglion, how to sympathetic fibers enter the eye? What m. do they innervate and what's its function?

Answer 37

- Short and long ciliary nn. | - Dilator pupillae mm. --> dilate pupil

Question 38

What are the 7 branches of the ophthalmic a. that Dr. Frystak cares about?

Answer 38

``` Lacrimal (taggable) Central retinal Long and short ciliary (choroidal) Supraorbital (taggable) Anterior ethmoidal Posterior ethmoidal Supratrochlear ```

Question 39

What veins drain the orbit? What hole do they pass thru? Where do they drain to?

Answer 39

- Superior and inferior ophthalmic vv. - Superior orbital fissure - Cavernous sinus

Question 40

What are the 3 layers of the eye, outside to inside?

Answer 40

Schlera, choroid, retina

Question 41

What are responsible for the production of the eye's aqueous humor?

Answer 41

``` Ciliary processes (in the ciliary body). - Distributed to ant and post compartments ```

Question 42

What attaches the ciliary body to the lens?

Answer 42

Zonular fibers

Question 43

What is the cause of Glaucoma?

Answer 43

Increasing IOP (intraocular pressure). Aqueous humor drainage is less than its production (produced in ciliary body) - Compresses retina, optic n., BV's - Caused be decreased outflow thru canal of schlemm or increased production in aqueous humor - Can dmg retina, painful, eventually can cause blindness - Sx: blurred vision, halos around bright objects

Question 44

Where is the constrictor pupillae m. located?

Answer 44

Pupillary aspect of the eye, circumferentially. (parasymp)

Question 45

Where is the dilator pupillae m. located?

Answer 45

Deep to constrictor pupillae, oriented radially. (symp)

Question 46

Where is the vitreous body contained?

Answer 46

Postremal chamber

Question 47

What are the functional layers of cells in the retina, in the order that light hits them?

Answer 47

1. Ganglion cells (cell bodies, pass to optic n.) 2. Interneurons and bipolar cells 3. Photoreceptors (lie adjacent to pigmented epithelium)

Question 48

What are Muller cells, basically?

Answer 48

Supporting cells of the retina

Question 49

Do rods or cones have higher amplification?

Answer 49

Rods

Question 50

Which has higher temporal resolution, rods or cones?

Answer 50

Cones

Question 51

Which take more light to saturate, cones or rods?

Answer 51

Cones

Question 52

Which have more pw convergence (lower acuity), rods or cones?

Answer 52

Rods

Question 53

Describe what's present at the fovea.

Answer 53

Avascular zone consisting mainly of just a cone layer.

Question 54

Where does the optic n. leave the sclera?

Answer 54

Lamina cribrosa (of the sclera)

Question 55

What is the name of the retina overlying the lamina cribrosa?

Answer 55

Optic papilla/optic disc/blind spot

Question 56

Where do the central a. and v. of the retina run thru?

Answer 56

Center of the optic n.

Question 57

Where does the central v. of the retina normally drain to?

Answer 57

Cavernous sinus

Question 58

Do the oblique mm. insert on the medial or lateral side of the eyeball?

Answer 58

Lateral

Question 59

What does the outer-most layer of the retina consist of? (resting on the choroid)

Answer 59

Pigmented epithelial cells

Question 60

What forms the blood-retinal barrier?

Answer 60

Tight junctions b/w Muller cells (of the retina)

Question 61

What is responsible for the yellow and white secretion sometimes found in the eye upon arising after a night's sleep?

Answer 61

The lacrimal caruncle (contains the sweat glands, sebaceous glands, and cilia)

Question 62

What accounts for the "sniffling" which is necessary to keep the draining tears within the nasal cavity during crying.

Answer 62

Anterior drainage of the nasolacrimal duct | - "overflow" from the ductal system

Question 63

Describe the pathway of tears from the lacrimal gland.

Answer 63

Lacrimal gland (ducts-->) Superior palpebral fornix --> Puncta lacrimali (drain opening, sup and inf medially) --> Lacrimal canaliculus (sup and inf) --> Lacrimal sac (fossa of lacrimal bone) --> Nasolacrimal duct --> nasal sinus

Question 64

What is the flow of aqueous humor? What does it go through?

Answer 64

Post --> ant | - goes thru pupil

Question 65

What are the major nn. found in the orbit?

Answer 65

- CN II - CN III - CN IV - CN V-1 - CN VI (all travel through SOF) - Sympathetics & parasympathetics

Question 66

What types of information do short ciliary nn. carry to the eye?

Answer 66

- Postganglionic symp - Postganglionic parasymp - General sensory (afferent) fibers