Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

58 Cards in this Set

  • Front
  • Back
What are the five layers of the eyelid?
Palpebral part of obiculus oculi m.
Tarsal fascia layer (tarsal plates and orbital septum)
Autonomic Innervation of Lacrimal Gland
Parasympathetic secretomotor fibers and vasoconstrictive sympathetic fibers.

Parasympathetic: The axons travel with VII, leave nerve as greater petrosal nerve then join lesser petrosal nerve become the nerve of the pterygoid canal (in the sphenoid bone). The pterygoid canal leads to a space in the skull called the pterygopalatine fossa where the pterygopalatine ganglion lies. This is where the synapse occurs for the parasympathetic fibers.

Sympathetic: Synapse in superior cervical ganglion, travel with the internal carotid plexus and join the deep petrosal nerve.

Both types of fibers then join the zygomatic nerve, a branch of the maxillary nerve, which brings the fibers to the lacrimal branch of the opthalmic nerve (V1), by which they enter the gland.
What are the margins of the orbit?
supraorbital - frontal bone

lateral - zygomatic bone

infraorbital - zygomatic and maxillary bones

medial - frontal process of the maxilla and a little bit of the lacrimal bone
What are the walls of the orbit?
Roof - orbital plate of frontal bone with lesser wing of sphenoid bone behind it (posterior to it)

Floor - orbital surface of the maxillary bone, with zygomatic bone and palatine process contributing some

lateral wall - greater wing of sphenoid bone and zygomatic bone

medial wall - very thin bone called the orbital plate of the ethmoid bone (also called lamina papyracia) and the lacrimal bone
Opthalmic artery
Branch from internal carotid, travels through the optic canal.
What are the branches of the opthalmic artery?
Lacrimal artery
Supraorbital artery
Posterior ethmoidal artery
Anterior ethmoidal artery
Internal palpebral artery
Supratrochlear artery, also known as the frontal artery
Dorsal nasal artery
Long posterior ciliary arteries
Short posterior ciliary arteries
Anterior ciliary artery
Central retinal artery
Muscular artery
What structures go through the inferior orbital fissure?
Infraorbital nerve, artery and vein

Zygomatic nerve
Where does the infraorbital nerve come from?
A continuation of the maxillary nerve that changes its name when it enters the orbit.

Sensory only.
Where does the opthalmic artery come from?
A branch from the internal carotid. Supplies the orbit.
Superior Orbital Fissure
CN III, IV, VI (all motor)
Branches of V1 called the nasociliary(sensory)
Opthalmic vein
Where does the zygomatic nerve come from?
Branch from V2, devides into two branches, the zygomaticotemporal nerve and zygomaticofacial nerve.

A cutaneous nerve for the skin of the face and temple.

It also carries post-synaptic parasypathetic fibers (originating in the pterygopalatine ganglion) to the lacrimal nerve via a communication. These fibers will eventually provide innervation to the lacrimal gland.
Where do the anterior and posterior ethmoidal nerves come from?
Branches from V1 from nasociliary nerve. Travel through the anterior and posterior ethmoidal foramina on the medial wall of the orbit. Sensory only.
Lacrimal Gland
Lies in the in the anterior, superolateral corner of the orbit in a small depression in the frontal bone.
Three layers/coats of the eyeball
Fibrous Layer - sclera and cronea.

Vascular layer - choroid, ciliary body, iris

Inner layer - retina (both optic and non-visual parts)

Sclera covers posterior 5/6 of eyeball. Fibrous skeleton, providing shape, resistance, attachment for the extrinsic and intrinsic muscles of the eye.

Cornea is transparent, covers anterior 1/6 of the eyeball.
Vascular Layer/Uveal Tract of they eyball
Consists of the choroid, ciliary body, and iris.
Reddish brown membrane between sclera and retina. "Red eye". Continuous with ciliary body.
Ciliary body
Muscular and vascular. Connects the choroid with the iris. Provides an attachment for the lens.

Contains smooth muscle that changes the shape of the lens.

Secrets aqueous humor, which fills the anterior and posterior chambers of the eye.
Lies on the anterior surface of the lens. Thin contractile diaphragm with a central aperture, the pupil.

Two involuntary muscles control the size of the pupil. Sphincter (parasympathetic) and dilator (sympathetic) pupillae.
Inner layer of the eyeball.
Optic Nerve (II)
Special Somatic Afferent

Surrounded by same three meninges as the brain
When the sphincter pupili contracts the pupil
When the dilator pupili dilates the pupil
What part of the nervous system controls the ciliary, sphincter and dilator muscles in the eye?
The autonomic nervous system.
Which muscles of the eye are under parasympathetic control?
Ciliary body, sphincter pupili.

Same innervation.

Cell bodies of presynaptic parasympathetic neurons are in the midbrain. The axons of these cell bodies leave in CN III (oculomotor nerve).

Presympathetic fibers travel in that root and go to the tiny ganglion in the back of the orbit called the ciliary ganglion. Divides into a superior and inferior division.

Synapse occurs in the ciliary ganglion.

The postsynaptic neurons travel through several short (5 or 6) ciliary nerves to reach the eyeball. They travel in the wall of the eyeball to reach these 2 muscles and cause constriction.
What innervates the dilator pupili muscle?
Under sympathetic control.

The presynaptic sympathetic neurons are in the lateral horn of the upper 3 thoracic cord segments. They leave the spinal nerves via white rami communicantes to ascend the cervical sympathetic trunk.

Travel up the sympathetic trunk and synapse occurs in the superior cervical ganglion at the base of the skull.

Postsynaptic sympathetic neurons travel up the internal carotid artery (ICA) and form a plexus around the ICA called the Internal Carotid Plexus.

Some of these post-synaptic fibers leave the Internal Carotid Plexus and they hitch a ride with V1.

V1 enters the orbit and gives off nerves called long ciliary nerves: They convey post-synaptic sympathetic fibers to the eyeball, which eventually reach the dilator.

Can also travel in the short ciliary nerves.
What are the components of the short and long ciliary nerves?
Short: Both parasympathetic and sympathetic fibers.

Long: Only parasympathetic fibers.
Levator palpebrae superioris muscle
Straited voluntary muscle.

Elevates the eyelid.

Innervated by the oculomotor nerve (III).

Drooping/ptosis if damage to CN III.
Superior tarsal muscle
Elevates the eyelid.

Smooth muscle under autonomic control, sympathetic fibers.

Drooping/ptosis if damage to CN III.
Which muscles ADduct the eye?
Medial rectus, superior rectus, and inferior rectus
Which muscles ABduct the eye?
Lateral rectus, superior oblique, and inferior oblique
Which muscles elevate the eye?
Superior rectus and inferior oblique
Which muscles depress the eye?
Inferior rectus and superior oblique
Which muscles cause intorsion of the eye?
Superior oblique and superior rectus
Which muscles cause extorsion of the eye?
Inferior oblique and inferior rectus
Which of the muscles will cause elevation when the eye is already ADducted?
The inferior oblique
Which muscles will cause elevation when the eye is ABducted?
The superior rectus
What is the periorbita?
Lines the bones of the orbit. Continuous with the periosteal layer of dura mater.
Which nerve provides sensory innervation to the orbit?
The opthalmic nerve, V1.


Arises from the trigeminal ganglion, travels through superior orbital fissure embedded in the dura mater of the cavernous sinus.
What are the branches of the opthalmic nerve (V1)?
Nasociliary, frontal and lacrimal nerves.
What type of fibers does the opthalmic (V1) nerve carry?
General Sensory Afferent (GSA), but other fibers travel along too.

Sympathetic fibers from the internal carotid plexus
Where do the long ciliary nerves branch from?
The opthalmic nerve (V1).

(Only sympathetic fibers)
Where do the short ciliary nerves branch from?
The oculomotor nerve (III).

(Sympathetic and parasympathetic fibers)
Frontal Nerve
Branch from the opthalmic (V1) nerve. GSA. Lies superior to the levator palpabrae superioris.

Branches into more medial supratrochlear and more lateral supraorbital nerves.
Supraorbital nerve
Branch from the frontal nerve from the opthalmic (V1) nerve. GSA.

Branches into medial and lateral supraorbital nerves.

Supply the skin of the upper eyelid, forehead, and scalp (supraorbital nerve innervates the lining of the frontal air sinus as well).
Lacrimal Nerve
From opthalmic (V1) nerve. Runs on lateral wall of orbit above lateral rectus and runs to lacrimal gland.

Small palpebral branch which innervates skin of eyelid.

Picks up parasympathetic/sympathetic fibers before reaching lacrimal gland.
How do parasympathetic fibers get to the lacrimal gland?
Presynaptic fibers conveyed from the facial nerve by the greater petrosal nerve, then the nerve of the pterygoid canal to pterygopalatine ganglion where they synapse.

Zygomatic nerve then brings fibers to the lacrimal nerve.
How do sympathetic fibers get to the lacrimal gland?
Synapse in superior cervical ganglion, travel with internal carotid plexus then deep petrosal nerve.

Join parasympathetics to form nerve of the pterygoid canal.

Zygomatic nerve then brings fibers to the lacrimal nerve.
Nasociliary Nerve
Branch from opthalmic (V1) nerve.

Deep to superior rectus running lateral to medial.

Gives off long ciliary nerves.

Gives of anterior and posterior ethmoidal nerves.

Terminates in intratrochlear nerve.
What type of fibers do the long ciliary nerves contain?
GSA from cornea and iris..

Post-synaptic sympathetic fibers from the internal carotid plexus. Supply the dilator pupillae.
What type of fibers do the short ciliary nerve contain?
Post-synaptic sympathetic fibers from the internal carotid plexus. Supply the dilator pupili.

Post-synaptic parasympathetic fibers from opthalmic (III) nerve. Supply the sphincter pupillae and ciliary muscle.

GSA from nasociliary nerve.
Ethmoidal nerves
From nasociliary (V1) nerve.

GSA from mucosa of ethmoidal air cells.

Anterior GSA from nasal cavity, becomes external nasal nerve on lower part of external nose.
Infratrochlear Nerve
Terminal branch of nasociliary (V1). Exits below the trochlea.

Innervates the lacrimal sac and general sensation for the skin on the upper half of the nose.
Ciliary Ganglion
Located in the posterior portion of the orbit, between the optic nerve (II) and the lateral rectus muscle.

Gives off short ciliary nerves to orbit.
Opthalmic artery
Main blood supply to the orbit.

Branch of the internal carotid artery just before it terminates.

Enters the orbit with the optic nerve in the optic canal.

Runs from lateral to medial with nasociliary nerve.

Numerous branches.
Which nerve runs with the opthalmic artery?
Nasociliary nerve
Branches of the opthalmic artery
Orbital Branches:
Lacrimal artery (lacrimal gland)
Supraorbital and supratrochlear arteries (forehead/scalp)
Ethmoidal arteries (nasal cavity)
Muscular branches
Dorsal Nasal artery (dorsum of nose)

Occular Branches:
Artery of the retina (pierces the optic nerve)
Posterior ciliary branches (eyeball)
Veins of the orbit
Superior and inferior opthalmic veins drain into the cavernous sinus.

Vorticose veins drain the choroids of the eye into opthalmic veins.

Opthalmic veins communicate with angular vein, this can spread infection to cavernous sinus.

The inferior ophthalmic vein also communicates through the inferior orbital fissure with the pterygoid venous plexus in the infratemporal fossa. This is another pathway for infection to spread.