Brainscape's Knowledge GenomeTM

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


See full index

SS Histology > Eye > Flashcards

Eye Flashcards

1
Q

Enumerate layers of wall of eye

A
  1. Outer fibrous layer (cornea & sclera)
  2. Middle vascular layer or uvea (choroid, ciliary body, iris)
  3. Inner nervous layer (retina)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Enumerate chambers of the eye and their contents

A
  1. Anterior chamber: between cornea & iris contains aqueous humour
  2. Poterior chamber between iris, lens and suspensory ligament contains aqueous humor
  3. Vitreous chamber: behind lens & zonule surrounded by retina, it is occupied by the vitreous body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Enumerate layers of the cornea

A
  1. Epithelium (stratified squamous non-keratizoned)
  2. Bowman’s membrane
  3. Substantia propria (stroma)
  4. Descemet’s membrane
  5. Corneal endothelium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Function of superficial microvilli of corneal epithelium

A

To help retaining a film of tears between them to keep the cornea wet

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

Bowman’s membarne is formed of….., its injury leads to…..

A

TypeI collagen/intercellular substance
Scar formation/corneal opacity

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

Mention contents of corneal substantia propria

A

About 60 layers of parallel collagen type I bundles aligned at right angles to each other
Flattened fibroblasts-like cells in between these lamellae called keratocytes
Ground substance reach in proteoglycans

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

Descemet’s membarne is formed by……

A

Underlying endothelium

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

Describe feature of corneal epithelium

A

Signs of active transcellular endocytosis:
Numerous mitochondria
Pinocytotic vesicles as they absorb excess fluid from stroma keeping it relatively dehydrated and maintaining transparency of cornea

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

Describe the nutritional supply of cornea

A

Nutrition from aqueous humor (for center) and limbus vessels for periphery
Oxygen from atmosphere

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

GR: The cornea is transparent

A
  1. It is avascular structure
  2. Regular arrangement of cells & collagen fibers
  3. Same refractive index of all its components
  4. Continuous withdrawal of fluids from stroma through endothelium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Enumerate layers of sclera

A

Episcleral tissue: fibroelastic CT
Sclera proper formed of dense CT
Inner suprachoroid lamina containing melanocytes and less collagen

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

Mention the histological characters of limbus

A

Corneal epithelium becomes thickened and cont with bulbar conjunctiva
Bowman’s capsule abruptly ends and is replaced by subconjuctival CT
Substantia propria becomes irregular and forms sclera proper. At this point canal of Schlemm surrounds the limbus
Descemet’s membarne forms trabecular meshwork that drains into the canal
Endothelium lines these channels and the canal of Schlemm
Stem cells are concentrated at the limbus, they are rapidly dividing cells move into corneal epithelium

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

GR; Sclera is opaque

A

Due to irregular arrangement of its fibers
Difference in refractive index of its elements

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

Mention the parts of choroid

A
  1. Choriocapillary layer: has rich microvasculature for nourishment of outer 1/3 of retina
  2. Bruch’s memrane: It is composed of collagen & elastic fibers, innermost component of choroid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In cross-section ciliary body is triangular bound by…,…..,…..

A

Sclera, vitreous body, lens & posterior chamber

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

Describe structure of ciliary body

A
  1. Loose CT containing elastic fibers, bv, melanocytes & ciliary muscle
  2. The two surfaces facing lens and vitreous body are covered with two layers of low columnar cells;
    A) outer pigmented layer, cont with pigmented epithelium of retina
    B) inner non-pigmented layer, cont with sensory layer of retina
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Function of ciliary processes and structural specialization

A

Basolateral membrane infoldings on both if its epithelium layers for aqueous humor secretion

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

The anteriormost segment of uvea is…..

A

Iris

19
Q

Mention components of iris

A
  1. Anterior surface: consists of irregular discontinuous layers of fibroblasts & melanocytes
  2. Stroma: consists of loose CT with melanocytes and sparse microvasculature
  3. Epithelium: posterior surface of the iris covered by 2 layers of pigmented cubical epithelium, cells of outer anterior layer of this pigmented epithelium become less pigmented and transformed into myoepithelial cells of dilator pupillae (thus it’s not a true muscle
20
Q

Functions of iris

A

Control amount of light that enters the eye & gives colour of eye

21
Q

Enumerate layers of the retina

A

Layer of pigmented epithelium
Layer of rods & cones
Outer limiting membrane
Outer nucleus layer
Outer plexiform layer
Inner nuclear layer
Inner plexiform layer
Ganglion cell layer
Optic nerve fibers layer
Inner limiting membrane

22
Q

Mention junctions between pigmented epithelium cells

A

Junctional complex + gap junctions

23
Q

Enumerate functions of pigmented epithelium

A
  1. Absorb extralight by pigment granules to prevent blurring of vision
  2. Isomerization of vitamin A
  3. Phagocytosis of old discs of photoreceptors and digest them by lysosomes
  4. Formation of the outer blood-retinal barrier
24
Q

The discs of rods are filled with……

A

Photosensitive pigment “rhodopsin”

25
Q

The inner segment is connected to outer segment of rod by……

A

Modified cilium

26
Q

The rod synapses with….

A

One or more dendrites of bipolar cells
Axons of horizontal cells

27
Q

Mention differences in structure between rods & cones

A

Same ex cones have:
Outer segment conical shaped
Membranous discs are continuous with cell membrane
Contain iodopsin
Nucleus is larger, less dense & lies just near the outer limiting membrane
Terminates as cone pedicle with short processes
They are of 3 types with specific pigment for green, blue & red light

28
Q

Horizontal cells synapse at……while amacrine cells synapse at……

A

Outer pelxiform layer
Inner plexiform layer

29
Q

Enumerate cells in the inner nuclear layer

A

Bipolar cells, Muller cells, hirizontal & amacrine cells

30
Q

Describe the amacrine cells

A

Pear-shaped cells with no axons but dendrites only that extensively synapse with axons of bipolar cells & dendrites of ganglion cells

31
Q

Ouer ends of Muller cells joint to……, while inner ends……..

A

Photoreceptors by tight & adherent junctions forming outer limiting membrane
Join with their basement membrane forming inner limiting membrane

32
Q

Descrie the optic disc

A

The site where the ganglion cell axons converge and exit from the eye. It has no photoreceptors and is insensitive to light, in addition retinal blood vessels enter & exit through it.

33
Q

Describe special histological features of fovea centralis

A

Layers from fourth diverge to the sides
Photoreceptors are cones only (specialized accurate diurnal vision)
No blood vessels

34
Q

Describe the blood-retinal barriers

A

Outer b-r barrier: formed of tight junctions between lateral borders of pigmented epithelium of the retina
Inner b-r barrier formed of tight junctions between endothelial cells of retinal bv

35
Q

Describe retinal detachment

A

The nervous tissue of retina becomes separated from layer of pigmented epithelium which remains closely attached to Bruch’s membrane & choroid.

36
Q

Describe structure of blood aqueous barrier

A

Tight junctions between inner non pigmented cells

37
Q

Describe blood and nerve supply of lens

A

No blood or nerve supply, it is nourishef by aqueous humor.

38
Q

Lens capsule is formed from…..and formed by……

A

Collagen type IV and proteoglycans
Underlying subcapsular epithelium

39
Q

Lens fibers develop by……., as they grow they become filled with…..

A

Division of subcapsular epithelium at the level of equator
Crystallins

40
Q

Lens fibers are connected by…….

A

Gap junctions, tight junctions and desmosomes to prevent sliding of fibers

41
Q

Describe functions of vitreous body

A
  1. Transmits light
  2. Supports the lens anteriorly and keep it in place
  3. Support the retina posteriorly and prevent retinal detachment
  4. Helps in retinal metabolism, it allows transfer of material from and to retina
42
Q

Type of conjunctival epithelium

A

Stratified columnar epithelium with goblet cells

43
Q

Mention special features of skin of eyelids

A

Eyelashes at lid margin with no arrector pilli muscle
Modified sebaceous glands (glands of Zeis) and modified sweat glands (glands of Moll)

44
Q

Tarsal plate contains ……..

A

Meibomian glands

SS Histology (2 decks)

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