Eye H&N

robbypowell's version from 2015-04-25 21:17

Protective features of eye

Question Answer
The zygoma is considered an important protective feature because of the way that it articulates (like a tripod) with what 3 bones?Frontal bone, Maxilla, Temporal bone
Innate reflexes ensure that when trauma to the face happen, they impact from the ____side, laterally (this helps protect eye by ensuring impact from angle where there is greater protection)(bones collapse outward rather than inward toward the eye)
The zygoma rotates when it breaks... so it always breaks in how many of its 3 connections?2 out of 3
Which of the zygomatic sutures is most commonly broken with head trauma?Fronto-zygomatic suture fracture (lateral trauma most common)
What bones compose the medial part of the orbital rim?Maxilla, Frontal, Lacrimal
What bone composes the LATERAL part of the orbital rim?Zygoma
What bone composes the SUPERIOR part of the orbital rim?Frontal
The walls of the orbit are very ___ relative to other cranial bonesTHIN
The rim of the orbit is very ___ compared to the walls of the orbitTHICK, (strong and structural)
What bones break during ORBITAL BLOWOUT fracture, and why is this advantageous?Bones that line the wall of orbit. (This is advantageous because the kinetic energy will not compress the eye against walls, rather will fracture THIN walls)
Rupture of the medial ORBITAL wall would lead to what space?Ethmoidal air sinuses (not nasal cavity)
What are the AIRBAGS of orbital trauma?Ethmoidal and Maxillary air sinuses (thinnest walls that will break to protect eye)
What is the CUSHION (not airbags) that protect the eye from blunt trauma?Retro-orbital Fat
What are the weakest points of skeletal orbit?Floor and Medial wall (Maxillary and Ethmoidal walls break into sinuses)
Head-on collision would cause what type of fracture (and fracture which bones)?blow-out fracture, (floor and medial wall, maxillary & ethmoidal walls into their respective air sinuses)
Lateral collision would cause what type of fracture (and fracture which bones)?Zygomatic fracture and rotation (on tripod). (most commonly at Fronto-zygomatic suture)
After a blow-out fracture, if a recovering patient experiences double vision, what is a probable cause?Extrinsic muscles caught in fracture of medial wall

components of orbit

Question Answer
Medial wallMaxilla (inferior portion) , Ethmoid, Lacrimal, Sphenoid (lesser wing)
Lateral wallZygoma & Sphenoid (greater wing)
AirbagsEthmoid and Maxillary air sinuses
CushionRetro-orbital fat
Sling that holds eye in placeSuspensory Ligament
Collagen type 1 enclosure of orbital contentsTenon's Capsule
Component of Tenon's capsule that attaches suspensory ligament to walls of orbitCheck ligament
Central Nervous system extension surrounded by meningesOptic Nerve (CN 2)

relation of orbit. passing through this wall would take you into what space?

Question Answer
SuperiorAnterior Cranial Fossa
InferiorMaxillary air sinus
LateralTemporal Fossa
MedialEthmoidal air sinus & Nasal Cavity
PosteriorMiddle Cranial Fossa

Components of eye

Question Answer
Outside layerSclera
What layer is the WHITE of the eye?Sclera
What is the specialized anterior part of the sclera?Cornea
Middle layerChoroid
What is the VASCULAR layer of the eye?Choroid
Anteriorly, the choroid divides into what two layers (structures)?Iris (control amount of light entering) & Ciliary muscles (control accommodation of lens)
What are the 3 INTRINSIC muscles of the eye?Ciliary muscles, Sphincter pupillae & Dilator pupillae
What is the innervation of the ciliary muscles?Parasympathetic, Oculomotor (CNIII)
What is the innervation of the Sphincter pupillae muscle?Parasympathetic, Oculomotor (CNIII)
What is the innervation of the Dilator pupillae muscle?SYMPATHETIC, Superior Cervical ganglion (T1)
What is the SYMPATHETIC effect on the eye?Dilation (see more light)
What is the PARASYMPATHETIC effect on the eye?Constriction of pupil
What is the "skeleton" of the eyelid?Tarsus
What is the inner lining of the eyelid?Conjunctiva

Extraocular muscles

Question Answer
What are the 4 Rectus muscles?Superior, Inferior, Medial & Lateral
What are the 2 Oblique muscles?Superior and Inferior
What muscle elevates the Upper eyelid?Levator Palpebrae Superioris muscle
Constriction of which muscle will make you look upward and medially?Superior Rectus muscle
Constriction of which muscle will make you look laterally (abduction)?Lateral Rectus muscle
Constriction of which muscle will make you look downward and medially?Inferior Rectus muscle
All of the Rectus muscles are innervated by CN ____ except for the ____ ____ which is innervated by CN ____CN3 (Oculomotor); Lateral Rectus; CN 6 (Abducent)
What is the origin of RECTUS muscles?Tendinous ring (Posterior wall)
What is the origin of OBLIQUE muscles?
What muscle is innervated by CN VI?Lateral Rectus muscle (Abducent nerve)
What muscle is innervated by CN IV?Superior Oblique (Trochlear nerve)
Constriction of which muscle will make you look downward and laterally?Superior Oblique muscle
The Oculomotor nerve alone cannot make you look in which direction?Laterally (two muscles capable of this are supplied by other cranial nerves)
What muscles must contract to look STRAIGHT down?Superior Oblique and Inferior Rectus muscles (lateral and medial components of each muscles action counterbalance and eye looks straight down)
Oculmotor palsy causes eye to move in which directions?DOWN and OUT
Palsy of which CN causes eye to rotate downward and laterally?Oculomotor (CN III)
The Inferior Oblique muscle is supplied by which CN?Oculomotor (CN III)
What is the only extrinsic muscle of the eye that does not originate from the Tendinous ring?Inferior Oblique muscle
What muscles must contract to look STRAIGHT up?Inferior Oblique and Superior Rectus muscles (both supplied by CN III)
What is the innervation of the Levator Palpebrae Superioris?Oculomotor (CN III) & sympathetic innervation for smooth muscle component
What extrinsic muscle of the eye has an autonomic component of its innervation?Levator Palpebrae Superioris (autonomic component is sympathetic, supplied by S. Cerv. Gang)

Nerves and Vascular components

Question Answer
The Optic nerve is surrounded by ____MENINGES
What two structure pass through the optic canal?Optic nerve & Opthalmic Artery
What foramina does the Opthalmic artery pass through?Optic canal
What foramina does the Opthalmic vein pass through?Superior Orbital Fissure
The meningeal (and subarachnoid space extension) surrounding the optic nerve is important because any increase in intracranial pressure will show asEdema of the Optic Nerve
The Superior (and smaller) branch of the Oculomotor nerve supplies which muscles?Superior Rectus & Levator Palpebrae Superioris
The Inferior (and larger) branch of the Oculomotor nerve supplies and communicates to which muscles? what other important structure?Medial & Inferior Rectus and Inferior Oblique muscles; Ciliary ganglion
Which branch off of the Inferior Branch of Oculomotor nerve gives off a branch to the Ciliary ganglion?Branch to Inferior Oblique muscle
Which CN passes within the lumen of the cavernous sinus (as opposed to on the lateral wall)?CN 6 (abducent)
What are the 3 branches of the Opthalmic Nerve (V1)?Frontal, Lacrimal & Nasociliary branches
Which branch of the Opthalmic nerve (V1) passes through the Tendinous ring?Nasociliary branch
What nerve receives parasympathetic and sympathetic innervation from the Zygomaticotemporal nerve?Lacrimal nerve (V1)
What two nerves come together carrying the autonomic innervation that will eventually supply the lacrimal gland?Great Petrosal (para, Facial) & Deep Petrosal (sum, Sup Cerv Gang)
What nerve supplies sensation of the Conjuctiva and lateral part of upper eyelid?Lacrimal N. (of Opthalmic V1)
The Supratrochlear and Supraorbital nerves are branches of what nerve?Frontal N. (of Opthalmic V1)
What nerve supplies sensation to the Conjuctiva and medial part of upper eyelid?Supratrochlear N. (of Frontal N. of Opthalmic V1)
Somatic sensation of the ENTIRETY of the forehead is supplied by branches of which nerve?Frontal N. (the branches are Supratrochlear and Supraorbital)
What are the 4 branches of the Nasociliary nerve (V1)Long Ciliary, Posterior Ethmoidal, Anterior Ethmoidal, & Infratrochlear nerves
What nerve supplies sensation to the Posterior Ethmoidal air cells and the Sphenoidal Sinus?Posterior Ethmoidal nerve (of Nasociliary of Opthalmic v1)
What nerve supplies sensation to the eyeball?Long Ciliary nerve (of Nasociliary of Opthalmic V1)
What nerve supplies sensation to the medial part of the upper & lower eyelid, lacrimal sac, and skin of the upper half of nose?Infratrochlear nerve (of Nasociliary of Opthalmic v1)
What nerve supplies sensation to the anterior cranial fossa, the sinus cavity, and the lower half of the nose?Anterior Ethmoidal nerve (of Nasociliary of Opthalmic v1)
What nerve supplies sensation to upper half of nose? What nerve supplies sensation to lower half of nose?Infratrochlear nerve (upper half) Anterior Ethmoidal nerve (lower)
The external nasal nerve is a branch of which branch of the Nasociliary nerve (V1)Anterior Ethmoidal
Sympathetic innervation of the eye mainly ARISES from where?T1
Sympathetic innervation of the eye synapses where?Superior Cervical Ganglion
Parasympathetic innervation of the eye synapses where?Ciliary ganglion (arises in facial nerve, superior lacrimal nucleus)
Postganglionic fibers from the Ciliary Ganglion travel via what nerve?SHORT CILIARY nerve
What two nerves could carry Sympathetic innervation to the eye?LONG ciliary or SHORT ciliary (via ciliary ganglion) nerves
Post-ganglionic sympathetic fibers enter the orbit accompanying what structure?Opthalmic Artery
Which muscle is controlled by sympathetic innervation to the eye?DILATOR PUPILLAE muscle
The CILIARY GANGLION is associated with what branch of the Opthalmic nerve (V1)?Nasociliary
Do parasympathetic fibers that supply the Lacrimal gland pass through the Ciliary ganglion?NO! (they synapse in sphenopalatine gang and are carried to gland by Lacrimal branch)
Parasympathetic fibers that synapse in the Ciliary ganglion supply what structures?Ciliary muscles & Sphincter Pupillae muscles
Parasympathetic root of the ciliary ganglionOculomotor nerve (CN 3)
Sympathetic root of the ciliary ganglionSuperior Cervical ganglion (travel via internal carotid... then opthalmic artery... then join Nasociliary nerve)
Sensory root of the ciliary ganglionNasociliary nerve
Post-ganglionic signal from ciliary ganglion travels via what nerve?Short Ciliary nerve
MOST IMPORTANT branch of opthalmic artery, that runs with optic nerve and if it is cut patient will be blindedCentral Retinal Artery
What are the 2 terminal branches of the Opthalmic artery?Supratrochlear and Dorsal Nasal
Arteries that anastomose around the eyelid?Angular artery (facial) Transverse Facial Artery (Superficial Temporal) & Opthalmic artery branches (supratrochlear, supraorbital, lacrimal & dorsal nasal)
What 4 branches of the opthalmic artery are part of the anastomoses around the eyelid?Supratrochlear, Supraorbital, Lacrimal & Dorsal Nasal arteries
Lymphatic drainage of the eyelids and is primarily to which node?Parotid Lymph nodes


Question Answer
Eye is deviated down and out, Pupil is dilated, Eyelid depressedOculomotor Palsy (muscles and parasympathetic failure)
Pup is constricted, Eyelid is partially depressedHorner's Syndrome (sympathetic failure)
Term for inability to constrict pupilMydriasis
Term for inability to dilate pupilMyosis
Term for depressed upper eyelidPtosis
Term for lack of sweatingAnhydrosis
Myosis, Ptosis & AnhydrosisHorner's Syndrome
Ptosis & MydriasisOculomotor (CN 3) Palsy
Most common cause of Horner's SyndromeApical Lung Tumor (or tumor in root of neck)
Blockage of the Tarsal glands, inside eyelidChalazion
Blockage of the Sebacous glands of eyelashes, outside eyelidStye


Question Answer
What nerves supply the external ear?Auriculotemporal (V3) (superior/anterior) Great Auricular nerve (C2 & C3) Lesser Occipital nerve (C2), Facial nerve (inner part of external ear) & Vagus (inner part of external ear)
What is the name of the SENSORY FIBERS of the FACIAL NERVE?Nervous Intermedius
What is the fancy name for earwax?CERUMEN
What is the arterial supply to the external ear?Posterior divisions of External Carotid (Occipital and Posterior Auricular)) & Superficial Temporal
Nerve supply of the external tympanic membraneV3 (Auriculotemporal), 7, 9 & 10
Nerve supply of the internal tympanic membraneGlossopharyngeal
What bone is attached to the inner surface of the tympanic membrane?Malleus
This nerve from the Tympanic plexus leaves to connect with the Auriculotemporal nerve and provide parasympathetic innervation to the Parotid glandLesser Petrosal nerve
The middle ear communicates with what two other spaces?Mastoid space & Pharyngotympanic tube (eustachian)
Parasympathetic innervation from Tympanic plexus goes on to supply which gland and synapse in which ganglion?Parotid gland, Otic ganglion
Sympathetic innervation that passes through the Tympanic plexus goes on to become what nerve (carrying only sympathetic innervation) ?DEEP petrosal nerve
Which petrosal nerve does NOT pass through the middle ear?GREATER Petrosal nerve
The greater petrosal nerve carries what two types of innervation?Parasympathetic (to Lacrimal Gland) & Taste (palate)

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