Histology of the Eye and Ear

Question 1

Tunics of the eyes

-briefly highlight structures within

Answer 1

Question 2

Outer tunic:

• what is sclera, what does it transition to?
• transition zone called

Answer 2

Question 3

what is this structure

• how does corneal epithelium anchor to next layer? which is?
• what is descemets’s membrane?
• characteristics or corneal endothelium

Answer 3

Question 4

Cornea:

• where are myelinated nerves fround?
• when do they become unmyelinated?
• what does the stroma consist of?
• is the stroma vascular?
• what is the cornea permeable to?

Answer 4

Question 5

• tarsal glands do what? blockage leads to?
• sebaceous glands (zeis)
• lacrimal gland: made up of?
• palpebral/bulbar conjuctiva: epithelium type, what space do they line

Answer 5

Question 6

Embryology of the eye:

• where does optic vesicle form from?
• optic cup inner layer vs outer layer formations
• where does detached retina occur
• outer mesenchyme forms?

Answer 6

Question 7

Chambers of the eye

Answer 7

Question 8

Vascular coat:

• consists of?
• what is ciliary body?
• what muscle drives accomodation
• ciliary process function
• where does iris arise from?
• pupil contains what muscles

Answer 8

Question 9

Aqueous humor and iridocorneal angle:

• how is aqueous humor secreted into posterior chamber
• how does it get into and out of the anterior chamber?
• glaucoma risk

Answer 9

Question 10

Lens structure:

• suspended by what fibers?
• three components of lens?
• tension from ciliary body transmitted via?
• presbyopia?
• Cataracts?

distant vs close vision

Answer 10

Question 11

Answer 11

both bowman’s membrane

Answer 12

Question 13

what are the layers of the retina

Answer 13

Question 14

What are the retinal layers?

Answer 14

Question 15

Retinal layer:

• RPE type of epithelium rests on which membrane of the choroid?
• blood-neural retinal barrier?
• isomerization?

Answer 15

Question 16

Answer 16

Question 17

Rods and Cones:

• which are more sensitive
• classes of cone cells
• molecules in rods vs cones
• General structure: outer, inner, connections

Answer 17

Question 18

Answer 18

Question 19

Answer 19

Question 20

Accomodation

Answer 20

Three components contribute to the accommodation process:

1.

The ciliary muscle.

2.

The ciliary body.

3.

The suspensory ligaments, inserted at the equatorial region of the lens capsule.

When the ciliary muscle contracts, the ciliary body moves toward the lens. Consequently, the tension of the suspensory ligaments is reduced, and the elastic capsule of the lens enables the lens to acquire a spherical shape. A rounded lens facilitates close vision.

When the ciliary muscle relaxes, the ciliary body keeps the tension of the suspensory ligaments that pull at the circumference of the lens. Thus, the lens remains flat to enable distant vision. This condition is known asemmetropia (Greek emmetros , in proper measure; opia , pertaining to the eye), or normal vision.

If the eyeball is too deep or the curvature of the lens is not flat enough, the image of a distant object forms in a plane in front of the retina. Distant objects are blurry because they are out of focus, but vision at close range is normal. This condition is called myopia (Greek myein, to shut), or nearsightedness.

If the eyeball is too shallow and the curvature of the lens is too flat, the distant image is formed at a planebehind the retina. Distant objects are well resolved but objects at a closer range are not. This condition is called hyperopia (Greek hyper, above), or farsightedness.

Older people become farsighted as the lens loses elasticity. This form of hyperopia is known as presbyopia(Greek presbys , old man).

Accommodation difficulties can be improved by the use of lenses. A diverging lens corrects myopia; a converging lens corrects hyperopia.

Question 21

Clinical significance of detached retina

Answer 21

The clinical significance of the detachment of the nonsensory retinal pigmented epithelium from the sensory retina is highlighted by the following functions of the pigmented epithelium:

1.

The transport of nutrients from the choroidal blood vessels to the outer layers of the sensory retina.

2.

The removal of metabolic waste products from the sensory retina.

3.

Active phagocytosis and recycling of photoreceptor disks shed from the outer segment of the cones and rods.

4.

The synthesis of basal lamina components of Bruch’s membrane to which the retinal pigmented epithelium is firmly attached.

5.

It is essential for the formation of the photopigment rhodopsin because it regenerates the bleached photopigment by converting all -trans retinol into retinal, which is returned to the photoreceptor byinterstitial retinoid-binding protein (IRBP) , a major protein in the interphotoreceptor matrix

Question 22

Retinoblastoma:

• inheritance pattern what gene/chromosome
• what is gene supposed to do
• clinical features

Answer 22

Question 23

Answer 23

Question 24

Parts of ear overview

-outer, middle, inner

Answer 24

Question 25

Inner ear:

• auditory portion, vestibular portion
• bony labyrinth
• membranous labrynth

Answer 25

Question 26

Answer 26

Question 27

Answer 27

Question 28

Cochlea:

• Canal vs duct
• divisions of cochlear duct
• where is organ of corti

Answer 28

Question 29

Organ of corti:

• composed of what type of cells?
• how many rows of hair cells
• what is tectorial membrane
• basilar membrane does what?

Answer 29

Question 30

Answer 30

Question 31

Path of sound waves

Answer 31

Question 32

Semicircular canals and ampulla:

• filled with what?
• what is cupulla
• what is attached to cupulla
• sensors of what type of velocity

Answer 32

Question 33

Utricle and saccule

• what does macula do?
• what produces otoconia?
• sensors for what

Answer 33

Question 34

Threes in Audio-Vestibular system

Answer 34