Flashcards in Eyes Deck (228):
Orientation of the orbital bases and apices
Bases: directed anterolaterally
Apices: directed posteriomedially
The thickest layer of the cornea is
D. Endothelial Cells
. A distinctly red spot on the white of the eye fades to brown after several weeks. The patient has no other symptoms. The long resolution time of the spot is due to which of the following:
A. Poor venous drainage of where the spot is
B. continuing trauma to vessels in conjunctiva/sclera
C. immobility of overlying structure
D. eyeball's poor vascularity
. What is the cranial nerve for pain in the eye?
A. CN II
B. CN III
C. CN V
D. CN VII
What is the most vital consideration for the true ophthalmological emergencies?
A. Extreme eye pain
B. Development of *something* in cornea and lens
C. Extreme symptoms (excessive bleeding, referred pain)
D. Rapid permanent eye loss
The transparent mucuos membrane that lines the eyelids and the eye ball
Parts of the conjunctiva
Palpebral and bulbar conjunctiva
Conjunctiva on the eyelids
Conjunctiva on the eyeball
The recesses formed by the lines of reflection of the palpebral conjunction onto the eyeball
Superior and inferior fornices
The gap between the eyelids
The space bound by the palpebral and bulbar conjunctiva
The dense bands of connective tissue that form the "skeleton" of the eyelids
Superior and inferior tarsi (singular = "tarsus")
Which glands secrete lipids that lubricate the edges of the eyelids and prevents them from sticking together when they close?
Large sebaceous glands associated with the eyelashes
Junctions of the superior and inferior eyelids
Medial and lateral palpebral commissures
The angles of the eye
Medial and lateral canthi
Structure connecting the tarsi to the medial margin of the orbit
Medial palpebral ligament
Structure connecting the tarsi to the lateral margin of the orbit, but does not provide for direct muscle attachment
Lateral palpebral ligament
You asked a patient to look to his right. Which of the following do you expect to happen?
A. The medial rectus of his left eye contracts
B. The lateral rectus of his left eye contracts
C. The lateral rectus of his right eye relaxes
D. The medial rectus of his right eye contracts
Red eye, painless and nonblinding symptoms are associated with
D. Subconjunctival space
Large objects of similar size to a basketball are prevented from damaging the eyes when they hit the face by which of the following structures?
A. Orbital roof
B. Orbital floor
C. Orbital margin
D. Orbital apex
A patient enters a dark room. Which of the following changes in order to accommodate light?
A. Pupillary aperture
B. Orbital aperture
C. Palpebral aperture
D. None of the above
The tear film is created from the lacrimal gland and structures within this other structure:
A. medial canthus
C. nasolacrimal gland
D. lacrimal sac
Cone receptors are used for
An upside down object forms what kind of image when it passes through the retina?
A. right side up, unmirrored
B. upside down, unmirrored
C. right side up, mirrored
D. upside down, unmirrored
What is the vein that drains the eyes?
B. Central Ciliary Vein
Function of the tarsal plate
A. Attachment of SR
B. Position of lacrimal glands
C. Protects the eyeball
D. Attachment of Levator Palpebrae
Which is not a layer of the retina
A. Bowman's Layer
B. External limiting layer
C. Photoreceptor layer
D. Ganglion cell layer
Area where the lacrimal sac is situated
A. Medial wall of the orbit
B. Frontal Bone
C. Ethmoidal Bone
Which of the following is involved in the sensory relay in vision?
A. Edinger-Westphal nucleus
B. Otic ganglion
What is the function of the eyelashes?
A. Protect cornea from excess sunlight
B. Sweep off dust in air in front of eyes
C. Protect eye from sweat from the forehead
D. Marks the posterior boundary of the eyelid
Which of the following situations DOES NOT seem to indicate a true opthalmologic emergency?
A. Sudden blindness in one eye, no other symptom noted
B. A lab accident involving unknown chemicals exploding and splattering all over the face of the patient
C. Acid thrown at the patient's face by an assailant
D. Patient noticing that he is being blindsided frequently
Which structure divides the lacrimal gland into superior (orbital) and inferior (palpebral) parts?
Tendon of the levator palpebrae superioris
The accessory lacrimal glands are more numerous in the superior eyelid or inferior eyelid?
Nerve stimulation of production of lacrimal fluid
Paraympathetic impulses from CN VII
To where do the excretory ducts of the lacrimal gland open?
Lateral part of superior conjunctival fornix
When the cornea becomes dry, the eye blinks. T/F
DIrection of closing of the eyelids
Lateral to medial
The Optha ROD noted that the retina had a healthy yellowish color. He mentally took note that this probably meant an adequate blood supply to the retina. He recalled that the ganglion fiber layers of the retina are supplied by these vessels.
A. opthalmic artery
B. central retinal artery
C. ciliary arterial arcades
The optha ROD (resident on duty) then examined the patient’s OD using his opthalmoscope. Looking into the right eye, he observed a round structure from which vascular arcades were entering the lobe. What is this structure?
B. optic disc
C. ora serrate
D. central retinal vein
If you ask the patient to look UP & LEFT (diagonally to the left), which muscle is acting on the LEFT eye?
The patient recalled that as he was hit in the OD, he saw a flash of light even though he was able to close his eyelid. Which of the ff. structures was stimulated producing the flash of light?
Right after he was struck, the patient recalled experiencing a very sharp pain in a point below his
eye along the orbital ridge, which of the following
structures was most likely to be involved?
A. troclear nerve
B. oculomotor nerve
C. infraorbital nerve
D. optic nerve
Approximated diameter of the eyeball
All anatomical structures within the eyeball have a circular or spherical arrangement. T/F
The connective tissue layer that surrounds the eyeball to support it within the orbit
Fascial sheath of the eyeball (bulbar fascia or Tenon capsule)
This very loose connective tissue layer (a potential space) lies between the fascial sheath and the outer layer of the eyeball
The fibrous layer of the eyeball
The vascular layer of the eyeball
Choroid, ciliary body, and iris
The inner layer of the eyeball
Two main parts of the retina
Optic and non-optic
Function of the fibrous layer of the eyeball
Provides shape and resistance
The tough opaque part of the fibrous layer of the eyeball, covering the posterior five sixths of the eyeball
Part of the eyeball that provided attachment for both the extraocular and the extrinsic muscles of the eye
The anterior part of the sclera is seen through which transparent structure?
"White of the eye"
Transparent part of the fibrous layer covering the anterior one sixth of the eyeball
The convexity of the cornea is greater or less than that of the sclera?
The sclera and cornea have different collagen composition and degree of hydration. T/F
The sclera is completely avascular, while the cornea is relatively avascular. T/F
The sclera is RELATIVELY avascular, while the cornea is COMPLETELY avascular.
From where does the cornea get its nourishment?
From capillary beds around its periphery and fluids on its external and internal surfaces
Fluid on the external surface of the cornea
Fluid on the internal surface of the cornea
The lacrimal fluid provides the cornea oxygen absorbed from the air. T/F
Opthalmic nerve (V1)
The angle formed by the intersecting curvatures of sclera and cornea at the corneoscleral junction
How wide is the corneoscleral junction?
Another name for the vascular layer of the eyeball
Uvea, or uveal tract
The vascular layer of the eyeball
Choroid, ciliary body, iris
The dark reddish brown layer between the sclera and the retina
Largest part of the vascular layer of the eyeball
Vascular part that lines most of the sclera
The large vesssels of the choroid is located internally (near the sclera). T/F
They are located externally (near the sclera).
The finest vessels of the choroid
Capillary lamina of the choroid or choriocapillaris
Choriocapillaris is found in the innermost part of the choroid, adjacent to which structure?
Avascular light-sensitive layer of the retina
The choriocapillarios supply the retina with oxygen and nutrients. T/F
The choriocapillaris has the highest perfusion rate per gram of tissue of all vascular beds of the body. T/F
Layer responsible for "red eye" in flash photography
The choroid attaches firmly to which structure?
Pigment layer of the retina
The pigment layer of the retina cannot be stripped from the sclera because it is firmly attached to the choroid. T/F
It is firmly attached to the choroid, but can be easily stripped form the sclera.
The choroid is continuous anteriorly with which structure?
The ciliary body is posterior to the corneoscleral junction. T/F
The ciliary body is muscular and avascular. T/F
It is muscular and vascular.
Which structures does the ciliary body connect?
Choroid and iris
Which structure provides attachment for the lens?
The contraction and relaxation of the muscle of the ciliary body controls what?
Thickness of the lens. Therefore, focus of the lens.
The folds on the internal surface of the ciliary body
What do the ciliary processes secrete?
Which structures secrete aqueous humor?
Which areas do the aqueous humor fill?
Anterior segment of the eyeball
Which structure lies on the anterior surface of the lens?
The thin contractile diaphragm with a central aperture that transmits light
Muscles that control the size of the pupil
Sphincter pupillae and dilator pupillae
The sphincter pupillae is radially arranged, while the dilator pupillae is circularly arranged. T/F
The sphincter is circular, the dilator is radial.
Parasympathetically stimulated involuntary muscle of the pupil
Sympathetically stimulated involuntary muscle of the pupil
Muscle that increases size of pupil
Muscles that decrease size of pupil
Sympathetic responses usually occur immediately, so the pupil immediately dilates. T/F
Sympathetic responses occur immediately, yet it may take up to 20 mins for the pupil to dilate.
Paraympathetic responses are usually slower than sympathetic responses yet parasympathetically stimulated papillary constriction is normally instantaneous. T/F
Part of the retina sensitive to light
Layers of the optic part of the retina
Neural and pigmented layers
Light receptive layer of the optic part of the retina
The pigmented layer helps reduce the scattering of the light in the eyeball. T/F
The non-visual retina is the anterior continuation of what part of the retina?
The non-visual retina extends over which structure anteriorly and which structure posteiorly?
Anteriorly: ciliary body
Part of the retina over the ciliary body
Ciliary part of the retina
Part of the retina over the iris
Iridial part of the retina
Posterior part of the retina where light entering the eyeball focuses
Fundus of the eyeball (ocular fundus)
The distinctive circular area of the retina where sensory fibers and vessels of the optic nerve enter the eyeball
The optic disc has no photoreceptors. T/F
The optic disc is sensitive to light. T/F
Because it has no photoreceptors.
The blind spot of the retina
When does the macula lutea appear yellow?
When the light used to examine the retina is red-free.
Special photoreceptors on the macula lutea
Depression at the center of the macula lutea
The area for most acute vision
Diameter of fovea centralis
1.5 mm approximately
Center of the fovea centralis
The foveola does not have the capillary network visible elsewhere deep to the retina. T/F
Where does the optic part of the retina terminate anteriorly?
Along the ora serrata
The irregular posterior border of the ciliary body where the optic part of the retina terminates
The central artery of the retina is from which vessel?
The central artery supplies the cones and rods of the retina. T/F
It supplies the retina except for the cones and rods.
From where do the cones and rods receive nutrients?
Venous drainage of the the retina
Central vein of the retina
The primary refractory medium of the eyeball
The cornea focuses an inverted image on what light-sensitive part of the retina?
Boundaries of the anterior chamber of the eye
Boundaries of the posterior chamber of the eye
Posterior: lens and ciliary body
Which structures do the aqueous humor nurish?
Cornea and lens
After passing through the pupil in the anterior chamber, where does the aqueous humor drain?
Scleral venous sinus
The aqueous humor is removed by the limbal plexus. T/F
The lumbal plaxus is a network of scleral veins close to the limbus. T/F
Into where does the limbal plexus drain?
Vorticose and anterior ciliary veins
Where is the lens located?
Posterior to the iris and anterior to the vitreous humor of the vitreaous body
The lens is biconcave. T/F
It is biconvex.
What anchors the capsule of the lens to the ciliary process?
The lens produces most refraction. T/F
It is the cornea that produces mos refraction.
The lens fine-tunes the focus of near or distant objects on the retina. T/F
What is the shape of the isolated unattached lens?
Which structure changes the shape of the lens?
Ciliary muscle of the ciliary body
Without nerve stimulation, the diameter of the relaxed ciliary muscle is smaller. T/F
It is larger.
Less convex lens brings more distant objects in focus. T/F
Parasympathetic stimulation of the ciliary muscle?
Oculumotor nerve (CN III)
Parasympathetic response of the ciliary muscle
Sphincter-like contraction, reducing tension on lens
Relaxed lens is for near vision. T/F
The active process of changing the shape of the lens for near vision
The thickness of the lens increases with aging. T/F
People over 40 have difficulty in near vision. T/F
Functions of the virtreous humor
Transmits light, holds retina in place and supports lens
Where is the vitreous body found?
Posterior to the lens
Transparent jelly-like substance in the posterior four-fifths of the eyeball to the lens
The watery fluid in the vitreous body
Other names for the posterior segment of the eyeball
Postremal or vitreous chamber
Extraocular muscles of the orbit
Levator palpebral superioris, the four recti (superior, infereior, medial, lateral), two obliques (superior, inferior)
Insertion of the levator palpebral superioris
Superior tarsus and skin of superior eyelid
Levator palpebral superioris is antagonistic to which muscle?
Superior half of orbicularis oculi
The drooping of the upper eyelid
Action of the levator palpebral superioris
Elevates superior eyelid
The origin of the four recti muscles
Common tendinous ring (annulus tendineus)
Insertion of the four recti muscles
Sclera, just posterior to corneoscleral junction
Actions of the superior rectus
Adduction, elevation, medial rotation of eyeball
Actions of the inferior rectus
Adduction, depression, lateral rotation of eyeball
Actions of the medial rectus
Adduction of the eyeball
Actions of the lateral rectus
Abduction of the eyeball
Muscles that adduct the eyeball
Superior, inferior, medial rectus muscles
Origin of the superior oblique
Body of sphenoid
The superior oblique is deep to what muscle?
Insertion of the superior oblique muscle?
Actions of the superior oblique
Abducts, depresses, medially rotates
When does the IR and SR produce only depression and elevation, respectively?
When the line of gaze coincides with the plane of the IR and SR, i.e., when the eyeball is abducted by the LR
Action of the superior oblique when acting alone
Medial rotation of the eyeball
Insertion of the inferior oblique
Sclera, between lateral rectus and inferior rectus
Action of the inferior oblique when acting alone
Lateral rotation of the eyeball
Actions of the inferior oblique
Elevates, abducts, laterally rotates eyeball
The only muscle to originate from the anterior part of the orbit, immediately lateral to the lacrimal fossa
Primary lateral rotator of the eyeball
Primary medial rotator of the eyeball
Which direction should a person's gaze be directed to test the elevation and depression of the rectus muscles?
Which direction should a person's gaze be directed to test the elevation and depression of the oblique muscles?
No single muscle can act to elevate the pupil directly from the primary position. T/F
No single muscle can act to depress the pupil directly from the primary position. T/F
Muscles that depress the eyeball
Muscles that elevate the eyeball
Adductors of the eyeball
MR, SR, IR
Abductors of the eyeball
SO, IO, LR
Lateral rotators of the eyeball
Medial rotators of the eyeball
Muscles that act when gazing to the right
Left MR, right LR
Muscles the act when gazing to the left
Right MR, left LR
Why is the superior eyelid further elevated out of the line of vision when the gaze is directed superiorly?
Because the superior rectus and the levator palpebral superioris share the same muscles sheath
The triangular expansions from the sheaths of the medial and lateral rectus ligaments
Medial and lateral check ligaments
To which bones are the check ligaments attached?
Lacrimal and zygomatic
Which actions do the check ligaments limit?
Adduction and abduction
The hammock-like sling from the blending of the check ligaments with the fascia of the IR and IO
Suspensory ligaments of the eyeball
The suspensory ligament of the eyeball is from the fascial sheath of which muscles?
Which structures act against the posterior pull on the eyeball produced by the rectus muscles?
Check ligaments, obliques and retrobulbar fat
CN II is part of the central nervous system. T/F
Where do the optic nerves begin?
Lamina cribrosa of the sclera
CN II exits the orbit via which structure?
Nerves of the orbit and the eyeball
CN II, CN III, CN IV, CN VI
Motor innervation of LR
Motor innervation of SO
Motor innervation of IO
Motor innervation of MR
Motor innervation of SR
Motor innervation of IR
Muscles innervated by CN IV
Muscles innervated by CN VI
Muscles innervated by CN III
IO, SR, IR, MR
Motor innervation of levator palpebral superioris
The oculomotor nerve divides into superior and inferior division. Which muscles are supplied by each division?
Superior: SR, levator palpebral superioris
Inferior: IR, MR, IO
Which nerve carries parasympathetic and sympathetic fibers to ciliary body and iris?
Short ciliary nerves
Short and long ciliary nerves are from which cranial nerve?
Which nerve carries postsynaptic sympathetic fibers to the dilator pupillae and afferent fibers from the iris and cornea?
Long ciliary nerves
The blood supply of the orbit is mainly from which branch of the internal carotid artery and which branch of the external carotid?
Opthalmic artery, from internal carotid
Infra-orbita artery, from external carotid
The central artery of the retina is from which artery?
Branches of the opthalmic artery that supply the choroid
Short posterior ciliary arteries
Branches of the opthalmic artery that supply the ciliary plexus
Long posterior ciliary arteries and anterior ciliary arteries
Venous drainage of the orbit
Superior and inferior opthalmic veins
The central vein of the retina enter directly the cavernous sinus. T/F
The vorticose veins drain into which vessel
Inferior opthalmic vein
Vascular structure through which the aqueous humor is returned to the blood circulation
Scleral venous sinus