Quiz 6

What is the organ of vision? What two things does it consist of?

eye; eyeball and optic nerve

Where do structures that protect vision lie? What about structures that move, support and innervate/vascularize the eyeballs?

anterior for protection; posterior for remaining

What area is considered the orbital region?

the face from upper eyelid-lower eyelid and lacrimal apparatus

Bony orbit margin is:

frontal, maxilla, zygomatic

Bony orbit roof is:

orbital plate of frontal and lesser wing of sphenoid

Medial wall of bony orbit is:

frontal, body of sphenoid, ethmoid, lacrimal, maxilla

Floor of orbit is:

orbital process of palantine, orbital surface of maxilla and zygomatic

Lateral wall of bony orbit is:

frontal process of zygomatic and greater wing of sphenoid

What does the maxillary nerve and inferior ophthalmic vein pass through?

inferior orbital fissure

Do the optical axes (line of gaze) coincide with orbital axes?

they do not

What are the orbits seperated by?

ethmoidal cells, upper nasal cavity and septum

What seperates the upper and lower eyelids? Where do they meet?

palpebral fissure; lateral and medial canthus (angles)

What is referred to by the glands of Zeis/ ciliary sebaceous glands?

sebaceous glands of eyelashes

What are the modified aprocine sweat glands of eyelid called?

ciliary sweat gland of Moll

What are the tarsal (meibomian) glands? What do they help eyelids to do?

modified sebaceous glands that pour oily secretion onto margin of eyelid

help closed eyelids be airtight

What is stye/external hordeolum?

inflammation of Moll glands or Zeis glands

What is chalazion/ internal hordeolum?

inflammation of tarsal glands

What does the supericial fascia of eyelid contain?

orbicularis oculi

What is the muscle that has a tendon on the eyelid?

levator palpebrae

What is the broad fibrous tissue that contains the tarsal gland in the eyelid?

tarsal plate

Is the palpebral conjuctiva deep or surperficial in the eyelid?

deep

What is there at the lid margin? What kind of glands does it contain?

a double row of eye lashes called cilia with ciliary glands

What is the fibrous framework of the eylids made up of?

orbital septum (superior and inferior)

tarsal plate (superior and inferior)

palpebral ligament (medial and lateral)

Levator Palpebrae Superioris origin

undersurface of lesser wing of spehnoid bone above optic canal

Levator Palpebrae Superioris Insertion

Anterior: tarsal plate

Posterior: upper margin of superior tarus

Where does the superior tarsal muscle come from? What nerve does it is have?

smooth muscle of levator palpebrae superioris posterior

sympathetic fibers

Levator Palpebrae Superioris nerve AND action

oculomotor

raise upper eyelid

What is horner’s syndrome?

sympathetic failure of one side of face

What are the signs of horner’s syndrome?

Anhydrosis, flushing of face/rednes, and mild ptosis

Pupillary constriction (miosis) and enophthalamos

What is enophthalamos? What is anhydrosis?

sinking eyeball

little to no sweat production

What is dacryoadenitis?

inflammation of lacrimal gland

What is dacryocystitis?

inflammation of naso lacrimal sac

Medial angle of eye is seperated from eyeball by what?

lacrimal lake (lacus lacrimalis)

What is in the center of the lacrimal lake (lacus lacrimalis)?

lacrimal caruncle

What is the plica semilunaris?

curved fold of conjuctiva which forms lateral boundary of lake

What is the elevation at each medial margin of eyelid called?

lacrimal papilla; superior and inferior

Lacrimal punctum is the summit of lacrimal papilla and leads to what?

lacrimal canal

Parasympathetic nerve supply to lacrimal gland is what mechanism?

secretomotor

Parasympathetic nerve supply to lacrimal gland is what?

superior salivary nucleus → facial n → pterygopalantine ganglion

→ maxillary n. → zygomatic n → zygomaticotemporal n → lacrimal n.

Sympathetic nerve supply to lacrimal gland is what mechanism?

vasomotor

Sympathetic nerve supply to lacrimal gland is what?

post-gg fibers from superior cervical ganglion through internal carotid plexus

→ through pterygopalantine ganglion uninterrupted→ follows PS to lacrimal gland

What is represented by the periosteum of orbital bone?

orbital fascia/periorbita

What attaches to epimysium of levator p. superioris muscle?

superior orbital septum

What attaches to inferior margin of inferior tarus?

inferior orbital septum

What is left behind during enucleation?

bulbar fascia/tenon’s capsule

Bulbar fascia/tenon’s capsule is seperated from schlera by?

episcleral space

The bulbar fascia becomes continuous with what?

epimysium of extraocular m.

epinerium of optic n.

Bulbar fascia sends what to medial and lateral walls of orbit?

medial and lateral check ligaments

Layers of the eyeball:

External fibrous coat (tunica fibrosa)

Middle vascular coat (tunica vasculosa)

Internal nervous layer (tunica nervosa)

External fibrous coat (tunica fibrosa) parts:

sclera: white, 5/6 of coat; lamina cribrosa

cornea: 1/6 of coat, convex transparent; evokes corneal reflex to close eyelid

What liquids are in the tunica fibrosa?

lacrimal fluid and aqueous humor(behind cornea)

Parts of middle vascular coat:

choroid: largest part

ciliary body: connects choroid to iris; has ciliary processes; ciliary muscle

iris (color): anterior to lens; has pupil

iris muscles:

spinchter pupillae:miosis (constrict)

dilator pupillae: mydriasis (dilate)

Ciliary process does what?

produce aqueous humor

Parts of internal nervous layer:

retina

optic disc

Layers of internal nervous coat(retina):

outer pigmented cell layer: columnar epithelial cells containing melanin

inner neural layer: contains 3 neuron types

inner neural layer- contains 3 neuron types:

rods and cones

bipolar cells

ganglion nerve cells→ make optic nerve

What can we identify at the posterior end of the retina?

optic disc - blind spot

macula lutea

fovea centralis at center of macula

Does the number of cones decrease or increase further from the middle?

decrease

What is the fovea centralis?

location of best vision (most cones here)

What is the wavy anterior margin or border of the retina behind the ciliary body?

ora serrata

What presents with hour glass shape vein?

A-V nicking

What is papilledema?

swelling of optic n cause by increased intercranial pressure

What are the chambers of the eye?

anterior and posterior segments

Anterior segment features:

filled with aqueuous humor and divided into:

• anterior chamber

• posterior chamber

Anterior chamber of eye is bounded by what anteriorly and posteriorly?

anterior: cornea

posterior: iris/pupil

Posterior chamber of eye anterior and posterior boundary:

anterior: iris/pupil

posterior: ciliary body

Posterior segment(vitreous chamber) of eye location?

posterior 4/5ths of eyeball posterior to lens filled with vitreous body

Where aqueous humor produced? Where is it absorbed?

ciliary processes of posterior chamber

iridocorneal angle into scleral venous sinuses

intraocular tension increase may cause what?

glaucoma

What is humor removed by?

limbal plexus

Lens is what relation to iris and vitreous humor?

posterior to iris

anterior to vitreous humor

Highly elastic capsule of lens is anchored by?

zonula fibers (suspensory ligament of lens)

Most refraction is produced by what?

cornea

Convexity of the lens does what to refraction of light?

varies to fine tune the focus of near or distant objects on retina

Pupillary direct and consensual light reflex sensory parts:

light enters pupil

retina

optic nerve

Pupillary direct and consensual light reflex center parts:

light reflex center in pretectal region

Pupillary direct and consensual light reflex motor parts:

oculomotor nuclear complex

oculomotor n

ciliary ganglion

short ciliary n

pupilloconstrictor muscle

Pupillary dilation reflex is what type of reflex?

sympathetic reflex

Accommadation reflex is what type of reflex?

parasympathetic reflex

Accommodation reflex parts:

convergence of eyeballs

pupillary constriction

increased convexity of lens

What is the accommodation reflex?

when our eyes focus on near objects

Accommodation reflex, nerve reflex pathway:

1. perception of near object

2. optic n.

3. occipital cortex

4. coritcotectal fibers

5. Accommodation center in superior colliculus and pretectal area

6. Oculomotor complex

What does Oculomotor complex of the accommodation reflex consist of?

edinger westphal nucleus - changes in lens and pupil

somatic nuclei - LMNs for contraction of medial rectus muscles

What is argyll robertson pupil?

light reflex lost but accommadation reflex is preserved

What is the corneal reflex known as?

red reflex

What is the corneal reflex

What muscles are for eye movement?

superior and inferior rectus -GSE

medial and lateral rectus -GSE

What are the movements of the eye?

abduction- adduction

elevation- depression

extorsion- intorsion

Recti muscles O and I

O: common fibrous ring around optic canal

I: diverge and insert into sclera of eye

Recti muscles N

SO- CN 4

LR - CN 6

All others -CN 3

Superior Rectus A

A: upwards and medial movement of eye

Inferior Rectus A

A: downwards and medial movement of eye

Medial Rectus A

A: adduction

Lateral Rectus A

A: abduction

Superior Oblique A

A: downwards and lateral rotation

Inferior Oblique A

A: elevation and lateral rotation

Superior Oblique O and I

O: body of sphenoid above and medial to optic canal

I: tendon through trochlea then curves back and laterally into sclera at postero-superior quadrant of eye

Inferior Oblique O and I

O: antero-medial part of floor of orbit

I: into sclera at lateral aspect of postero-inferior quadrant of eye

What movement does the inferior oblique and inferior rectus make?

extorsion