Orbit I

Question 1

7 bones make up the orbit. Name the one not listed

Answer 1

Palatine

Question 2

Identify “a” and “b”

Answer 2

• a: superior orbital fissure
• b: inferior orbital fissure

Question 3

Identify “c”

Answer 3

optic canal

Question 4

Identify green and yellow arrows

Answer 4

Green: Infraorbital foramen

Yellow: Supraorbital foramen

Question 5

Identify blue arrow

Answer 5

nasolacrimal groove

Question 6

Identify “a” and “b”

Answer 6

• “a” Superior tarsal plate
• “b” Inferior tarsal plate

Question 7

Identify c

Answer 7

c: orbital septum

Question 8

Identify arrow

Answer 8

medial and lateral palpebral ligaments

Question 9

Identify arrows

Answer 9

green: superior tarsal plate
red: orbital septum

Question 10

Identify the green box and green arrows

Answer 10

• green box: Conjunctival sac
• green arrow: Conjunctival fornices

Question 11

Identify red and blue arrows

Answer 11

red: bulbar conjunctiva
blue: palpebral conjunctiva

Question 12

Where is the lacrimal gland located

Answer 12

superolateral region of the orbit

Question 13

List where the fluid from the lacrimal gland goes once it is in the eyeball

Answer 13

• lacrimal puncta
• lacrimal canaliculi
• lacrimal sac
• nasolacrimal duct

Question 14

Parasympathetic innervation to the lacrimal gland is

1. initiated at what cranial nerve?
2. where does it synapse?
3. How does the information from the ganglion get to the lacrimal gland: New pathway

Answer 14

CN VII -> Greater petrosal n. -> N. to pterygoid canal -> Pterygopalatine galgion (SYNAPSE) -> branches to lacrimal gland

Question 15

Sympathetic innervation to lacrimal gland

Answer 15

follows parasympathetic innervation

Question 16

Former pathway of parasympathetic innervation to lacrimal gland

Answer 16

CN VII -> Greater petrosal n. -> N. to pterygoid canal -> Pterygopalatine plexus (SYNAPSE) -> zygomatic branch of (CN V2) -> communicating branch of ophthalmic nerve (CN V1) -> Lacrimal nerve to gland

Question 17

identify purple and brown

Answer 17

purple: cornea

Brown: Sclera

Question 18

Identify blue and red

Answer 18

blue: choroid
red: retina

Question 19

identify orange

Answer 19

ciliary body

Question 20

Identify green and yellow

Answer 20

green: Fovea: strongest acuity
yellow: optic disc: blind spot

Question 21

What muscle is responsible for constricting the pupil? What innervation makes it contract?

Answer 21

Sphincter pupillae

• parasympathetic

Question 22

What muscle dilates the pupil? What innervation makes muscle contract

Answer 22

Dilator pupillae

• sympathetic innervation

Question 23

The cililary muscle contract under what innervation? What happens when it contracts?

Answer 23

paraympathetic

• When muscle contracts; it moves toward the lens and the suspensory ligaments of the lens relax, causing the lens to change shape (more spherical) allowing lens to refract light for near vision
• Accommodation: close focus

Question 24

List Pathway of light

Answer 24

1. cornea
2. iris -> pupil
3. lens
4. fovea centralis
5. optical axis

Question 25

The medial aspect of the eye gains information from what field?

Answer 25

Lateral

Question 26

Damage to the left optic tract would present with what vision loss

Answer 26

Question 27

nerves of the orbit are supplied by what nerve

Answer 27

Ophthalmic nerve (CN V1)

Question 28

Name the termianl branches of the ophthalmic nerve (CN V1)

Answer 28

* supraorbital * supratrochlear * Lacrimal * external nasal * Infratrochlear

Question 29

Branches of the opthalmic artery (branch of the internal carotid)

Answer 29

* central artery of retina * lacrimal artery * ciliary arteries * supraorbital artery * ethmoidal arteries * dorsal nasal artery

Question 30

Venous drainage from eye leaves via what 2 main branches

Answer 30

superior ophthalmic vein inferior ophthalmic vein

Question 31

Sympathetic innervation to eye

Answer 31

preganglionic axons travel sympathetic chain -\> superior cervical ganglion (**synapse**) -\> Postganglion axons follow arteries (internal carotid plexus) -\> joing ciliary nerves entering eyeball

Question 32

Parasympathtics to eyeball

Answer 32

preganglionic axons begin on inferior division of oculomotor (CN III) -\> Ciliary ganglion (**synapse**) -\> Postganglionic axons hitchhike on the short ciliary branches of the ophthalmic (CN V1)

Question 33

pupillary light reflex

Answer 33

increase in light in one eye will result in pupillary constriction of both eyes * Sensory: CN II * Motor: CN III

Question 34

Accommodation reflex

Answer 34

focus on close objects (change in lens shape) causes pupillary contraction * Sensory: CN II * Motor CN III

Question 35

Corneal blink reflex

Answer 35

Contract with the cornea causes blinking * sensory: CN V1 * Motor: CN VII