Lab 2 - Eye and Orbit Flashcards
Which structure is labeled by #7?
What nerve runs through this structure?
Infraorbital groove
Contains the infraorbital nerve (from V2)
(on its way to exit the infraorbital foramen)
Which structure is labeled by #13?
Which nerves meet up here?
Ciliary ganglion
- Pre-ganglionic parasympathetics from the oculomotor nerve (CN III) (-> pupil sphincter and cilliary body) and
- Sympathetics (-> pupil dilator and superior tarsus) jump onto the
- Ophthalmic nerve (CN V1)
Which bone is labeled by #13?
Nasal
Describe the clinical presentation of Horner’s Syndrome
What is the etiology?
Ptosis, Miosis, loss of hemifacial sweating
Caused by loss of sympathetic tone to the eye
1
- Muscle:
- Action:
- Innervation:
1
- Muscle: Medial rectus
- Action: Adduct the eye
- Innervation: Oculomotor nerve (CN III)
Which structure is labeled by #12?
Oculomotor nerve (CN III)
Which nerves are labeled by #7?
Long ciliary nerves
What pathology does the lower eyelid show?
What causes this?
Ectropian
Caused by lack of tendon support
Which bone is labeled by #11?
Lacrimal
Which structure is labeled by #6?
Which nerves pass through this structure?
Inferior orbital fissure
(Infraorbital groove (6) is anterior)
Anterior branches of the maxillary nerve (V2)
- Infraorbital nerve
(-> infraorbital groove, infrorbital foramen) - Zygomatic nerve
(Splits into zygomaticotemporal and zygomaticofacial)
Which muscle is labeled by #11?
What innervates it?
Levator palpebrae superioris
Innervated by the oculomotor nerve (CN III)
Which part of which bone is labeled by #9?
Lesser wing of the sphenoid
Which nerve is labeled by #8?
Trochlear nerve
(Innervates the superior oblique, #2)
Note: Sneaky sneaky nasociliary (#5) looks like it could innervate the superior oblique based on this picture, but it provides sensory innervation, sympathetics, and parasympathetics (from CN III) to the eye
Which bone is labeled by #10?
Ethmoid
13
- Artery:
- Nerve:
13
- Artery: Supraorbital artery
- Nerve: Supraorbital nerve
Which structure is labeled by #6?
Vitreous humor
Enough of this pushes the pigemented retina against the visual retina so we can see
8
- Muscle:
- Action:
- Innervation:
8
- Muscle: Superior rectus
- Action: Elevate and adduct the eye
- Innervation: Oculomotor nerve (CN III)
Note: Superior rectus is deep to levator palpebrae superioris (#12)
Which structures are labeled by #15?
Lacrimal nerve (branch of CN V1) for sensory innervation*
Lacrimal artery
Lacrimal gland
*Note: Lacrimal gland secretions are under parasympathetic control from the facial nerve (CN VII) that jump onto the lacrimal nerve in the pterygopalatine ganglion
What is the vascular layer of the eye?
The choroid, #8
Which nerve is labeled by #4?
Where does it exit the skull?
Trochlear nerve (CN IV)
Exits the skull through the superior orbital fissure (Between the lesser and greater wings of the sphenoid)
Which structure is labeled by #15?
Ethmoidal air cells
9
- Muscle:
- Action:
- Innervation:
9
- Muscle: Lateral rectus
- Action: Abduct the eye
- Innervation: Abducens (CN VI), #7 in this image
Which structure is labeled by #9?
Infraorbital foramen
(This is where the infraorbital nerve V2) exits the skull
Which nerves are labeled by #10?
Short ciliary nerves
Which structure is labeled by #1?
Which nerve this structure?
Suprorbital foramen (may also be a notch)
Supraorbital nerve (branch of V1)
Note - Frontal incisure (17) is medial to the supraorbital foramen
Which part of the eye is labeled by #3?
Anterior chamber
(filled with aqueous humor)
Which structure is labeled by #2?
Superior oblique muscle
Which structure (bone and part) is labeled by #8?
Orbital surface of the maxilla
4
- Nerve:
- Action:
4
- Nerve: Trochlear
- Muscle supplied: Superior oblique, #2 in this image
- Action: Depress and abduct the eye
The _______ is the anterior extent of the neural retina
Ora serrata
(not labeled here, but look at the line between 5 and 6)
3
- Nerve:
- Action:
- Parasympathetics that hitch-hike on: [nerve origin + destination]
- Sympathetics that hitch-hike on: [destination]
3
- Nerve: Nasociliary (Branch of V1)
- Action:
- *Sensory innervation to the structures surrounding the eye**
- Parasympathetics that hitch-hike on:
- *From oculomotor (CN III) via ciliary ganglion -> pupil sphincter, ciliary body**
- Sympathetics that hitch-hike on:
- *From sympathetic outflow -> pupil dilator, superior tarsal muscle**
Note: Nasociliary is superficial to the orbital nerve
7
- Nerve:
- Action:
7
- Nerve: Abducens (CN VI)
- Muscle supplied: Lateral rectus, #9 in this image
- Action: Abducts the eye
Which structure is labeled by #10?
Frontal nerve
(Branch of the ophthalmic nerve V1)
Branches into the supraorbital and supratrochlear nerves
Which nerve is labeled by #8?
Where does it exit the skull?
Trigeminal nerve (CN V)
Splits into its 3 branches before leaving the skull
- Ophthalmic nerve (V1) -> Superior orbital fissure
- Maxillary nerve (V2) -> Foramen rotundum
- Mandibular nerve (V3) -> Foramen ovale
Which structure is labeled by #9?
Ophthalmic artery
Describe the pathway of the infraorbital nerve
(From its parent nerve leaving the brainstem to its exit from the skull)
Infraorbital nerve is a branch of the maxillary nerve (V2)
- Foramen rotundum (as the maxillary nerve)
- Pterygopalatine fossa
- Inferior orbital fissure (As the infraorbital nerve)
- Infraorbital groove
- Infraorbital foramen
What pathlogy does the lower eyelid have?
Entropian
2
- Muscle:
- Action:
- Innervation:
2
- Muscle: Superior oblique
- Action: Depress and abduct the eye
- Innervation: Trochlear nerve (CN IV), #4 in this image
Which structure is labeled by #2?
Cornea
Which structure is labeled by #3?
(Artery and nerve)
Anterior ethmoidal artery and nerve
Which structure is labeled by #10?
Optic disc
This is where the optic nerve sends neurons into the retina - this is the blind spot of our visual field
Which structure is labeled by #9?
Sclera
(The whites of the eye)
What is the most common casue of orbital cellulitis?
Spread from the sinuses (especially ethmoid sinus) through the anterior or posterior ethmoidal foramen
Which structure is labeled by #14?
Which nerve runs thorugh this structure?
Optic canal (of the sphenoid bone)
The optic nerve
(Also ophthalmic artery)
Which structure is labeled by #5?
Common tendinous ring
Which nerve is labeled by #7?
Where does it exit the skull?
Abducens (CN VI)
Exits the skull through the superior orbital fissure (between the greater and lesser wings of the sphenoid)
Which artery is labeled by #2?
Internal carotid artery
(#1 is the ophthalmic artery)
Which structure is labeled by #3?
Optic chiasm (Part of the optic nerve CN II)
Which foramen is labeled by #3?
Zygomatico-orbital foramen
Which structure is labeled by #7?
Retina
Which structure is labeled by #8?
Choroid
(Vascular layer)
Which structure is labeled by #6?
Cavernous sinus
Which structure is labeled by #11?
Ocular conjunctiva
Which structure is labeled by #16?
Posterior ethmoidal foramen
11
- Structure:
- Innervation:
11
- Structure: Lacrimal gland
- Innervation:
- Sensory: Lacrimal nerve (Branch of V1)
- Secretion: Parasympathetics from facial nerve (VII) that hitch-hike on in the pterygopalatine ganglion
Note - All other parasympathetics to the orbit/eye originate from the oculomotor nerve (III) and hitch-hike onto V1 in the ciliary ganglion
Which nerve is labeled by #12?
Supraorbital nerve
(Branching: ophthalmic (V1) -> frontal -> supraorbital)
10
- Nerve:
- Action:
- Parasympathetics that hitch-hike on: [nerve of origin, action]
10
- Nerve: Lacrimal Nerve (Branch of V1)
- Action: Sensory innervation to the lacrimal gland
- Parasympathetics that hitch-hike on:
- *Facial nerve (CN VII) via pterygopalatine ganglion, lacrimal gland secretion**
Which structure is labeled by #4?
Which nerves pass through this structuer?
Superior orbital fissure
Everything going to the eye/orbit except the optic nerve and ophthalimc artery
- Oculomotor nerve (CN III)
- Trochelar nerve (CN IV)
- Ophthalmic nerve (CN V1)
- Abducens (CN VI)
Which structure is labeled by #1?
Lens
Which structure is labeled by #4?
Superior ophthalmic vein
Describe the clinical presentation of 3rd nerve palsy.
Ptosis, dilated pupil, eye in the “down and out” position
Note: the only oculomotor nerves that are working are the superior oblique (IV) and the lateral rectus (VI)
Which structure is labeled by #6?
(Artery and nerve)
Posterior ethmoidal artery and nerve
Which numbers label ciliary nerves?
Long ciliary nerves: #7
Short ciliary nerves: #10
Ciliary ganglion: #13
Which structure is labeled by #5?
Nasociliary
(Note: looks like it innervates the superior oblique (#2), but actually provides sensory, sympathetic, and parasympathetics (from CN III via ciliary ganglion) to the eye
Which bone is labeled by #5?
Zygomatic
Which structure is labeled by #15
Anterior ethmoidal foramen
Which structure is labeled by #14?
Inferior ophthalmic vein
Which artery is labeled by #1?
Where does it exit the skull?
Ophthalmic artery
(Branch off of internal carotid #2)
Exits the skull through the optic canal, along with the optic nerve (3)
Which structure is labeled by #5?
What is its function?
Ciliary body
(Hard to tell here, but it encircles the lens)
Contracts to put slack in the suspensory ligments, allowing the lens to round out. This enables us to accomodate for close-up vision
Which nerve is labeled by #13?
Supratrochlear nerve
(Branching: ophthalmic (V1) -> frontal -> supratrochlear)
6
- Nerve:
- Action:
- Relevant branches:
6
- Nerve: Frontal nerve (Branch of V1)
- Action:
- *Cutaneous innervation to the forehead, eyelid, and nose**
- Relevant branches: Supraorbital, supratrochlear
Which nerve is labeled by #11?
Optic nerve (CN II)
Which structure is labeled by #1?
Medial rectus muscle
Which structure is labeled by #17?
Frontal incisure
Which structure is labeled by #5?
Where does it exit the skull?
Oculomotor nerve (CN III)
Exits the skull through the superior orbital fissure (between the greater and lesser wings of the sphenoid)
12
- Muscle:
- Action:
- Innervation:
12
- Muscle: Levator palpebrae superioris
- Action: Elevate the eyelid
- Innervation: Oculomotor nerve (CN III)
Note: Levator palpebrae superioris is superficial to the superior rectus
Which structure is labeled by #4?
Chamber angle
(Angle of the anterior chamber of the eye - if this is too narrow, the aqueous humor accumulates, resulting in narrow-angle glaucoma)
