Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Neuro & Special Senses > Ophthalmology Anatomy > Flashcards

Ophthalmology Anatomy Flashcards

1
Q

What bones make up the orbit?

A 
Frontal
Sphenoid
Ethmoid
Maxilla
Zygomatic
Lacrimal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which parts of the orbit are particularly susceptible to fracture?

A

Inferior and Medial parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What muscles move the eyelids and what innervates each muscle?

A

Orbicularis Oculi - facial nerve (VII)

Levator Palpabrae Superioris - oculomotor nerve (III)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What makes up the lacrimal apparatus?

A

Lacrimal glands
Lacrimal ducts
Lacrimal canaliculi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can injury to the facial nerve lead to excess tear production?

A

Orbicularis oculi paralysis –> eyelid partially open and lose protective blinking –> cornea dry and unprotected from dust –> irritation of eyeball lead to excess tear formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How may patients with a blowout fracture present?

A

Sunken orbits - pain
Reduced eye movement
Double vision
Loss of sensation to cheeks and upper gum - lose infraorbital nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is seen on X-Ray in a blowout fracture?

A

Teardrop sign

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What vasculature is important in ophthalmology?

A

Ophthalmic artery - from internal carotid
Central retinal artery - from ophthalmic artery - internal surface of retina
Ophthalmic vein - drain into cavernous sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the foramen in the orbit?

A

Optic canal - optic nerve and ophthalmic artery

Superior orbital tissue - CN III, IV, VI, ophthalmic branch of trigeminal, superior orbital vein

Inferior orbital fissure - inferior orbital vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do tears flow through the lacrimal apparatus?

A

Gland produce components of tears and secrete onto eye through the lacrimal duct

Pass through lacrimal lake at medial angle of eye

Pass to nasal cavity through nasolacrimal duct

Swallowed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the components of the tear film?

A

Surface lipid layer - secreted by meibomian glands
Middle aqueous layer - secreted by lacrimal gland and accessory lacrimal glands
Inner mucus layer - secreted by goblet cells of the conjunctiva and epithelial cell surface

Lipid layer of the tear film prevents underlying aqueous component from evaporating and drying out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the layers of the eyeball?

A

Outer protective layer - sclera and cornea
Middle - choroid, ciliary body and iris, with a rich network of blood vessels
Inner layer - retina with optic and non-visual parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the chambers of the eyeball?

A

Anterior chamber - between cornea and iris

Posterior chamber - between iris and ciliary body and lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the ciliary body secrete?

A

Aqueous humour filling the chambers of the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What contracts to change the shape of the lens?

A

Muscle fibres of the ciliary body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What contracts to change the shape of the pupil?

A

Sphincter and dilator pupillae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the vitreous humour?

A

Transparent jelly like substance

Cavity behind the lens filled with it, supports lens and holds retina in place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the structure of the retina?

A

Neural layer - light receptive
Pigmented layer

Retina supplied by the central artery of the retina
Drained by. the corresponding vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the muscles of the orbit?

A

Levator palpebrae superioris
Four recti
Two oblique - superior and inferior

Supplied by 3 (oculomotor), 4 (trochlear) and 6 (abducens)
Respectively

20
Q

What are the muscles of the orbit?

A

Levator palpebrae superioris
Four recti
Two oblique - superior and inferior

Supplied by 3 (oculomotor), 4 (trochlear) and 6 (abducens)
Respectively

Recti muscles arise from common tendinous ring - annulus of zinn.

21
Q

What are the main arteries of the orbit?

A

Ophthalmic artery - gives of central artery to the retina

Ophthalmic veins drain into cavernous sinus

22
Q

What are the roles of the cornea?

A

Maintain transparency
Ocular protection, including the corneal reflex
Refraction of incoming light, along with overlying tear film

23
Q

What are the layers of the cornea?

A

Epithelium - non-keratinised, sloughed off in tear film
Bowman’s membrane - acellular, any trauma below this level is scarring, as epithelium regenerates
Stroma - connective tissue layer, keratinocytes
Descemet’s membrane - basement membrane
Endothelium - hydration so cornea is transparent

24
Q

What innervates the cornea?

A

Rich nerve supply mainly from ophthalmic branch of trigeminal via long ciliary nerve

25
What maintains intraocular pressure?
Balance between rate of production of aqueous and rate of drainage. Aqueous humour is responsible for maintaining an adequate pressure in the eye.
26
What is the flow of aqueous humour?
Produced by ciliary body Flows up between iris and anterior surface of lens Through the pupil Flows out through the drainage angle of the eye Between cornea and peripheral iris Through trabecular meshwork Into canal of schlemm Drains into episcleral vessels and into the systemic venous circulation
27
What is the normal IOP?
Intraocular pressure Measured by determining force needed to flatten pre-determined area of the corneal surface using a tonometer Greater force needed = higher pressure Normal - 11-21mmHg Above 21 - ocular hypertension Does not necessarily equate to diagnosis of glaucoma (can have normal IOP too)
28
What receptors control IOP?
Adrenergic Alpha 2 - reduces IOP by reducing aqueous production, increase uveoscleral outflow Beta 2 - increases IOP by increasing aqueous production
29
What is the function of timolol?
Beta blocker | Reduces production of aqueous
30
What is the function of apraclonidine/brimonidine?
Alpha agonists Reduces aqueous production Small increase in drainage
31
What is the function of latanoprost?
Prostaglandin analogues | Increases uveoscleral outflow of aqueous
32
What is the function of dorzolamide?
Carbonic anhydrase inhibitors | Reduces production of aqueous
33
What is the function of pilocarpine?
Parasympathetic | Increases outflow of aqueous by ciliary muscle contraction, opening trabecular meshwork
34
How can the pupil change size?
Mydriasis - conditions of low light or sympathetic activation - dilation by dilator pupillae Bright light - miosis, constricts by sphincter pupillae Stimulated by parasympathetic activation, fibres by inferior division of 3rd nerve
35
What drugs can have an effect on the pupil?
Tropicamide - antimuscarinic - mydriasis Phenylephrine - sympathomimetic - mydriasis Pilocarpine - muscarinic agonist - miosis
36
What is the function of the ciliary body?
Accommodation, aqueous humour production secreted into the posterior chamber, providing attachment for the lens zonules (suspensory ligaments)
37
What is the function of the choroid?
Allows nerves and vessels to reach anterior eye Removes waste products from outer retina Supplies essential nutrients to outer half of retina Absorbs any light passing through the retina, preventing it from reflecting back and interfering with vision
38
How does the choroid attach to the retina?
Basement membrane - Bruch's membrane | Important in age related macular degeneration
39
What supplies blood to the outer half of the retina?
Rich capillary bed of the choroid - choriocapillaris
40
What is the vitreous cavity?
Fills 2/3 volume of the eye Attached to posterior lens capsule and retina 99% water, 3x more viscous than water
41
What are the layers of the retina?
Inner neural layer and outer retinal pigment layer Subretinal space fuses during foetal life, and attached to Bruch's membrane Neural retina attached to optic nerve head and anteriorly at termination - ora serrata Retinal detachment causes separation to reform
42
What are the components of the neural retina?
Inner retina - photoreceptors (but many neural cell types) Rods - contrast, motion Not good for detail Black and white To see in darker environments Cones - finer detail Colour vision
43
What is the blood supply of the retina?
Inner 2/3 central retinal artery Outer 1/3 supplied by choroidal blood supply Central retinal artery divides into 4, each supplies a segment of the retina - end-arteries
44
What is the visual pathway?
Light striking temporal retina comes from nasal field, and vice versa Temporal and nasal fibres come together at optic nerve, to optic chiasm Nasal retinal fibres (temporal visual field) decussate at chiasm Optic tract synapses at lateral geniculate nucleus Then forms optic radiations through the temporal and parietal lobes Terminates at occipital visual cortex
45
What is the pathway of pupil reflexes?
Afferent pupillary fibres travel with retinal fibres up until the LGN Then synapse with pretectal nucleus and travel to both Edinger-Westphall nuclei (3rd nerve nucleus) Meaning stimulation causes a bilateral response Efferent fibres leave EWN and gravel to ciliary ganglion via inf division of oculomotor to sphincter pupillae - constriction of pupil.

Neuro & Special Senses (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions