Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Block 6 > 6.2 Histology of the eye > Flashcards

6.2 Histology of the eye Flashcards

1
Q

What are the 3 layers of the eye?

A

Corneoscleral
Uveal
Retinal

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

What is the conjunctiva

A

mucous membrane which covers the exposed part of the eye (sclera and inner surface of the eyelids)

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

What is the function of the conjunctiva

A

Mucinous secretions add to the protective layer covering the eye
Allow eyelids to move freely over the eye

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

What is the histology of the conjunctiva?

A

non keratinzing stratified squamous epithelium with goblet cells and scattered melanocytes

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

What is the common presentation of conjunctiva pathology?

A

Inflammation bilaterally with a red appearance and hyperaemic vesses

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

What divides the eye into chambers?

A

The lens and iris

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

What do teh anterior and posterior chamber contain?

A

Aqueous humour

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

How does the aqueous humour circulate?

A

Produced by the ciliary processes, secreted into the posterior chamber by the ciliary body, circulates through the pupil and drains into the canal of schlemm into the anterior chamber

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

What is the function of the cornea?

A

Allow entry of light and the principle mechanism for focusing images on the retina

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

What is the junction of the cornea and sclera?

A

Limbus

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

What are the 5 layers of the cornea?

A 
Epithelium 
Bowmans membrane
Stroma 
Descemet's membrane 
Endothelium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What kind of epithelium is the cornea?

A

stratified squamous

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

Where does the cornea get its nutrients from?

A

The aqueous humour and environmental oxygen

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

What is ulcerative keratitis?

A

Inflammation of the cornea from a break in the epithelium

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

Does the cornea have blood vessels?

A

No

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

What is keratoconus and what causes it?

A

Bulging of the eyeball due to weak mesenchymal collagen

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

What is the role of the sclera?

A

Insertion of the extraocular eye muscles, protection and support

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

What is the histology of the sclera?

A

Dense fibrous avascular tissue which is continuous with the dura surrounding the optic nerve

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

What conditions have a thinning of the sclera?

A

connective tissue disorders such as marfans, Ehlers danlos and osteogenesis imperfecta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What will you see histologically in thinning of the sclera?

A

Underlying choroidal pigment shows through which will result in a blue colour (normal in newborns)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the role of the iris?

A

Regulates the amount of light coming in (aperture control), esures light enters through the pupil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What innervates the iris?

A

ANS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the iris made of and what are teh surfaces composed of?

A

Pigmented stromal cells
Anterior: irregular with fibroblasts and melanocytes
Posterior: Smooth pigmented epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What determines eye colour

A

The amount of pigment in the stroma

25
Q

What are the iris muscles?

A

Dilator pupillae and Constrictor pupillae

26
Q

What orientation are the dilator and constrctor pupillae, what are the made of and what is their innervation?

A

Dilator: radially oriented made of myoepithelial cells extending from the ciliary body SYMPATHETIC

Constrictor: Circumferentially oriented, smooth muscle PARA

27
Q

What is a coloboma?

A

defect in one of teh structures of the eye

28
Q

What is CHARGE syndrome?

A 
Coloboma 
Heart defects, 
Atresia of the choanae, 
Retarded growth and development
Genital hyperplasia 
Ear abnormalaties
29
Q

What is aniridia and what causes it?

A

Absence if the iris - congenital or due to penetrating eye injury

30
Q

What is WAGR syndrome?

A

Wilms tumour
Aniridia
Genitourinary abnormalities
Retardation

31
Q

What is Mydriasis and what causes it?

A

Dilation of the pupil - darkness, autonomic neuropathy, trauma, drugs, raised ICP

32
Q

What is the ciliary body?

A

A continuous thickened ring on the inner surface of the anterior sclera that is a continuation of the choroid

33
Q

What is the function of the ciliary body?

A

Contains ciliary muscle
Permits fine focusing of images on the retina
Attaches lens via the zonules
Secrete aqueous humour

34
Q

What is the ciliary muscle and what does it do?

A

smooth muscle which inserts onto the sclera and ciliary body

controls the shape of the lens

35
Q

What is the role of the ciliary process?

A

Anchor the lens into place and form aqueous humour

36
Q

What are the two layers of epithelium of the ciliary processes?

A

Outer: non pigmented, actively transports aqueous humour

Inner: continuous with retina pigmented epithelium

37
Q

What are the zonules?

A

Fibrillin that attaches the lens to the ciliary process

38
Q

What are the layers of the lens?

A

Capsule
Subcapsular epithelium
Lens fibres

39
Q

What is the function of the lens?

A

Permits focussing on near and far objects

Accommodation in conjunction with ciliary muscles

40
Q

what happens when you focus on a near object?

A

Ciliary muscles contract causing forwards displacement of the choroid and ciliary body reliving tension on the zonules - lens will round up keeping object in focus

41
Q

What is a cataract and what does it cause?

A

Opacity of the lens causing light to be scattered and only a small amount transmitted

42
Q

What is glaucoma?

A

Raised intra-ocular pressure due to obstruction of the flow of aqueous humour

43
Q

What causes open angle glaucoma?

A

Obstruction of the drainage structures in the angle of the anterior chamber

44
Q

What causes closed angle glaucoma?

A

Narrow anterior chamber which leads to the peripheral part of the iris compressing the trabecular meshwork

45
Q

What is the function of the choroid?

A

Supplies nutrients and oxygen to all layers of the eye and absorbs light to prevent light scattering within the eye

46
Q

Where does the choroid lie?

A

Between the retina and the sclera

47
Q

Where is the vitreous and what is its function

A

Posterior compartment

Transmits light, supports the lens, holds the retina in place, contributes to intraocular pressure

48
Q

What is the function of the retina?

A

photoreception
conversion of photons into action potential
Visual processing

49
Q

What are the 3 types of cells in the retina?

A

Neurons (ganglion, bipolar, horizontal, amacrine, photoreceptors)

Pigmented epithelial cells
Neuronal support cells (Muller cells)

50
Q

How many and what are the layers of the retina?

A 
10 
Internal limiting membrane 
Nerve fibre 
Ganglion cell 
Inner plexiform 
Inner nuclear (Muller cells) 
Outer plexiform 
Outer nuclear 
External limiting membrane 
Photoreceptors 
Retinal pigmented epithelium
51
Q

Where are rods concentrated

A

outer edge of the retina

52
Q

What is the inner and outer segments of rods made of?

A

Inner: golgi and mitochondria
Outer: flattened membranous discs with rhodopsin

53
Q

What happens with rod loss?

A

Night blindness and loss of peripheral vision

54
Q

What are cones sensitive to?

A

blue red and green light

55
Q

What kind of epithelium is the retinal pigmented?

A

Columnar with basal nucleus

56
Q

What is the function of retinal pigmented epithelium?

A

Synthesis of melanin that absorbs stray light
Phagocytose shed rod discs
Support for photoreceptors

57
Q

What fibres form the optic disc?

A

non myelinated afferent fibres converge medial to the fovea

58
Q

How does the optic nerve form?

A

Non myelinated afferent fibres converge at the optic disc, penetrate the sclera through the lamina cribrosa to become the optic nerve - become myleinated fibres from the optic disc

59
Q

What is papilloedema?

A

Swollen optic nerve head secondary to raised intracranial pressure causing disc margins to be blurred but no affect on visual acuity

Block 6 (48 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions