Dissection 14

Question 1

What bones make up the ocular orbit?

Answer 1

Question 2

Where are the sinuses that line the orbits?

Answer 2

Question 3

Name and locate the foramina of the orbit

Answer 3

Question 4

Name and locate the bones that make up the medial wall of the orbit

Answer 4

Question 5

Name the four layers of fascia in the orbit

Answer 5

1. Periorbita
2. Fascia of extraocular muscles
3. Bulbar fascia
4. Optic nerve sheath

Question 6

Periorbita fascia

Answer 6

Lines the bony orbit

Continuous with periosteal dura in the skull

Fuses with optic nerve sheath at optic canal

Question 7

Optic Nerve Sheath

Answer 7

• Continuous with meningeal dura
• Encloses arachnoid and pia mater

Question 8

Two types of conjunctiva

Answer 8

1. Bulbar on the eye
2. Palpebral on the inside of the eyelid

Question 9

Three muscles of the eyelids

Answer 9

• Levator Palpebrae Superioris
  
  • Skeletal
  • Opens eye
  • CN III
• Superior Tarsal Muscle
  
  • Smooth
  • Opens eye
  • Sympathetics that run with CN III
• Orbicularis Oculi
  
  • Closes eye and spreads tears
  • CN VII

Question 10

Where is the lacrimal gland?

Answer 10

Superior lateral orbit

Question 11

Pathway for tears

Answer 11

1. Drains into lacrimal puncta
2. Lacrimal sac in lacrimal groove
3. Nasolacrimal duct to nasal cavity
4. Out of nose

Question 12

What muscle changes the shape of the lens?

Answer 12

Ciliary muscle; under parasympathetic control

Question 13

What dilates the pupil?

Answer 13

Pupillary Dilator; radial fibers; sympathetic control

Question 14

What constricts the pupil?

Answer 14

Pupillary Sphincter; Circular fibers; parasympathetic control

Question 15

What muscles do NOT attach to the common tendinous ring?

Answer 15

Levator Palpebrae Superioris

Superior Oblique

Both attach above the ring

Question 16

Name and locate the extraocular muscles (picture)

Answer 16

Question 17

What eye muscles only act around the vertical axis?

Answer 17

Medial Rectus- adduction

Lateral Rectus- Abduction

Question 18

What muscles act around all three axes?

Answer 18

• Superior Rectus
  
  • Elevates, adducts, medially rotates
• Inferior Rectus
  
  • Depresses, Adducts
  • Laterally rotates
• Superior Oblique
  
  • Depresses, abducts, medially rotates
• Inferior Oblique
  
  • elevates, abducts, laterally rotates

Question 19

What muscles serve to adduct the eye?

Answer 19

• Medial Rectus
• Superior Rectus
• Inferior Rectus

Question 20

What muscles abduct the eye?

Answer 20

1. Lateral rectus
2. Superior Oblique
3. Inferior Oblique

Question 21

What muscles elevate the eye?

Answer 21

• Superior rectus
• Inferior Oblique

Question 22

What muscles depress the eye?

Answer 22

• Inferior rectus
• Superior Oblique

Question 23

What muscles are involved with eyeball intorsion?

Answer 23

Superior Rectus

Superior Oblique

Question 24

What muscles are involved with extorsion?

Answer 24

Inferior Rectus

Inferior Oblique

Question 25

Name the cranial nerves that send innervation to the orbit

Answer 25

III, IV, V1, VI, VII, sympathetics

Question 26

What innervates the orbicularis oculi?

Answer 26

CN VII

Question 27

Branches of V1 in the orbit from medial to lateral

Answer 27

1. Nasociliary Nerve 2. Frontal Nerve 3. Lacrimal Nerve Come from trigeminal ganglion; Lacrimal and Frontal split

Question 28

Most superficial layer of fascia in the orbit

Answer 28

Periorbita fascia

Question 29

What does the frontal nerve split into after the lacrimal nerve splits off?

Answer 29

Supratrochlear nerve Supraorbital nerve

Question 30

Difference between short and long ciliary nerves

Answer 30

Short nerves go from the ciliary ganglion to the eye while long nerves go straight from the nasociliary nerve to the eye

Question 31

Parasympathetic nerve targets in the orbit

Answer 31

Pupillary sphincter Ciliary muscle Lacrimal gland Travel with branches of trigeminal nerve

Question 32

Targets of sympathetic nerves in the orbit

Answer 32

* Pupillary dilator * Superior tarsal muscle * Lacrimal gland * Travel with blood vessels and cranial nerves

Question 33

How do parasympathetic fibers get from the pterygopalatine ganglion to the lacrimal gland?

Answer 33

Zygomatic branch of V2 to communicating branch to V1 to lacrimal gland

Question 34

How do sympathetic fibers get to the pupillary dilator?

Answer 34

1. Lateral horn of spinal cord (presynaptic cell body) 2. Superior cervical ganglion (postsynaptic) 3. Carotid plexus 4. Ciliary Ganglion

Question 35

How do sympathetic fibers get to the superior tarsal muscle?

Answer 35

1. Lateral horn of spinal cord (presynaptic cell body) 2. Superior cervical ganglion (postsynaptic) 3. Carotid Plexus 4. Superior branch of III

Question 36

How do sympathetic fibers get to the lacrimal gland?

Answer 36

1. Lateral horn 2. Superior cervical ganglion 3. Carotid plexus 4. Deep petrosal nerve 5. Pterygopalatine ganglion 6. V2 7. Lacrimal gland

Question 37

What do short ciliary nerves carry that long ciliary nerves don't?

Answer 37

Parasympathetics Both carry sympathetics and somatosensory

Question 38

What main artery carries blood to the orbits?

Answer 38

Ophthalmic Artery

Question 39

Branches of ophthalmic artery that leave the orbit

Answer 39

1. Ethmoidal Artery 2. Supratrochlear Artery 3. Dorsal Nasal Artery 4. Supraorbital Artery

Question 40

Branches of ophthalmic artery that stay in the orbit

Answer 40

1. Central artery of retina 2. Posterior ciliary arteries 3. Lacrimal arteries 4. Muscular arteries

Question 41

What does the ophthalmic artery anastomose with?

Answer 41

Middle Meningeal Artery Branches of Facial Artery

Question 42

How does the cornea get oxygen?

Answer 42

Diffusion only; that area is avascular!!!

Question 43

What veins drain blood from the eye?

Answer 43

1. Superior ophthalmic vein 2. Inferior opthalmic vein Into pterygoid plexus or cavernous sinus