Special Senses

Question 1

What are the three layers of the eye

Answer 1

cornea-sclera
uvea
retina

Question 2

What are the three chambers of the eye

Answer 2

vitreous
posterior
anterior

Question 3

does vitreous body get washed away in H&e stains

Answer 3

yes

Question 4

Where does the cornea-sclera layer become one or the other

Answer 4

corna 1/6 sclera 5/6. the junction is called the cornealscleral junction

Question 5

Is the cornea vascular? innervated?

Answer 5

No… i t is transparent. it gets its nourishment from aqueous humor and tear film
it is highly innervated

Question 6

What is the epithelium of the cornea? endothelium

Answer 6

stratified squamous is the epitherlium

endothilium is large simple squamous

Question 7

What is the basement membrane of the cornea

Answer 7

There are two. The OUTER membrane is the Bowman’s membrane and the one near the anterior chamber is the Descemet’s membrane.

Question 8

What is between the epi and endothelium of the cornea

Answer 8

THe stroma. it is mostly regularly arrange collagen fibers with fibroblasts.

Question 9

Where does herpes virus target on the eye

Answer 9

the corneal epitheilum and causes keratitis

Question 10

What is the sclera composed of

Answer 10

eosinophilic collagen fibers, elastic fibers and fibroblasts (structural support)

Question 11

Is the sclera vascularized

Answer 11

poorly

Question 12

Is the retina or sclera thicker

Answer 12

Sclera is much thicker

Question 13

Where is aqueous humor made

Answer 13

Ciliary body epithelial in the cornea-sclera junction. aqueous humor is in the anterior and posterior chambers of the eye

Question 14

What is the canal of schlemm

Answer 14

drainage of the aqueous humor bc aqueous humor is continually produced. from the anterior chamber and through trabecular meshwork into the venous system of the eye

Question 15

What is a glaucoma

Answer 15

increased intra-ocular pressure because of decreased drainage of aqueous humor

Question 16

What are the two types of gluacoma

Answer 16

Open angle chronic glaucoma- progress at a slow rate

acute angle closure- emergency, sudden onset of pain, redness, increased pressure, nausea, vomiting

Question 17

The choroid, ciliary body, iris, and lens are all part of what layer of the eye?

Answer 17

Uvea

Question 18

which layer of the eye is the vascular layer

Answer 18

uvea

Question 19

What is the choroid? what kind of cells

Answer 19

Heavily pigmented melanocytes to absorb light passed through the retina
the melanocytes are a non-reflective base for the cells to sit upon

Question 20

What is the choriocapillary layer

Answer 20

the rich capillary layer with areterioles and venules

Question 21

What is the cilliary body? the cilliary processes?

Answer 21

Pigmented epithelium that covers the vitreal and posterior chamber surfaces and makes aqueous humor.
The cilliary process are fingerlike extensions that extend to the posterior chamber

Question 22

What is the cilliary muscle

Answer 22

muscle for lens accomidation

Question 23

What are the zonule fibers

Answer 23

they attach the cilliary process to the lens

Question 24

What happens to the zonule fibers when the cilliary muscle is relaxed? What is the effect?

Answer 24

There is increased tension on the zonule fibers so the lens stretches and flattens allowing the eye to focus at a distance

Question 25

What happens to the zonule fibers when the cilliary muscle is contracted? What is the effect?

Answer 25

Less tension so the lens is round and focus on near objects

Question 26

What is the pars ciliaris of retina

Answer 26

A dual layer of epithelial cells that covers the cilliary process (one pigmented one not pigemented layer)

Question 27

What is the iris? What kind of tissue is it?

Answer 27

Extension of ciliary body that divides the anterior and porteior chambers a loose vascular tissue with melanocytes and fibroblasts

Question 28

What causes pupil dilation? Sympathetic or parasympathetic?

Answer 28

Radially oriented myoepithilal cells by sympathetic dilation

Question 29

What causes pupil contraction? Sympathetic or parasympathetic?

Answer 29

Circumfrential (sphincter) smooth muscle. Of parasympathetic control.

Question 30

WHat is responsible for accommodation/docus

Answer 30

lens

Question 31

What is the shape of the lens

Answer 31

a biconcave epithelial body

Question 32

How many layers does the lens have?

Answer 32

3, the capsule (thick basement membrane), epithelium (homeostatic fxns)` and fibers

Question 33

What is a cataract

Answer 33

visual impairment and blindness causes by lens clouding

Question 34

What is prebyopia

Answer 34

Impaired vision because of decreased elasticity of the lens associated with aging

Question 35

Where is the focal point when the lens of relaxed? when stretched?

Answer 35

relaxed: stretched: distance

Question 36

Where is the retina proper?

Answer 36

it is the photosensitive neural retina found on the posterior part of the eye

Question 37

What is the transition of the retina from the retina proper to the bi layer part of the retina

Answer 37

Ora Serrata

Question 38

Where do you find the pigmented epithelium of the retina? is it photosensitive?

Answer 38

No it is not photosensitive it is the layer just outside of the neurosensory retina that nourishes retinal visual cells and is attached to the underlying choroid.

Question 39

what is the site of most acute vision

Answer 39

Fovea

Question 40

embryonic retinal development - retina comes from what structure?

Answer 40

The optic vessicle which grows from the diencephalon of the brain. Once it reaches the anterior surface it invaginates itnto a double walled cup.

Question 41

When the double walled cup forms during retinal development what does the inner layer become? the outer layer?

Answer 41

Inner- photosensitive retina | Outer- pigmented epithelium

Question 42

What is the blind spot?

Answer 42

the optic disc (papilla) leaving as the optic nerve

Question 43

Is the pigmented layer exterior of the photosensitive retina

Answer 43

True.

Question 44

Where do you find the greatest number of rods?

Answer 44

20 degrees of central foveal discs

Question 45

What do rods do? are there more or less rods than cones

Answer 45

Mediate vision in dim light. | There are more rods

Question 46

What do cones do

Answer 46

Mediate daylight vision and sense color (different wavelengths)

Question 47

What is the photosensitive pigment within photoreceptors

Answer 47

Rhodopsin

Question 48

Which is the apical region of the photoreceptors?

Answer 48

Outersegment- it has foldings of plasmalemma that contain photosensitive proteins.

Question 49

Which cells do photoreceptors synapse with?

Answer 49

Bipolar cells (which synapse with ganglion cells)

Question 50

What is the layer next to the pigmented layer? the layer after that?

Answer 50

Receptor layer with rods and cones, then the external limiting membrane

Question 51

What is in the external limiting membrane?

Answer 51

Junctional Complexes

Question 52

In what layer is the synaptic zone between receptors, bipolar and horizontal cells

Answer 52

Outer plexiform layer

Question 53

What layer of the retina do you find Mullers cells

Answer 53

Inner nuclear layer is where the nuclei are and the end process are in the internal limiting membrane

Question 54

Where is the synaptic zone for the bipolar and ganglion cells

Answer 54

Inner plexiform layer

Question 55

What layer of the retina does the optic nerve form?

Answer 55

Optic Nerve Fiber Layer

Question 56

which photoreceptor is responsible for detecting motion

Answer 56

Rods

Question 57

Where do you find the most cones

Answer 57

Fovea

Question 58

What is the site of most acute vision

Answer 58

Fovea

Question 59

What does the fovea look like

Answer 59

depression on the posterior surface of the retina just lateral to the optic disk. retina is thin (other layers pushed aside) so there is more direct access to receptors for light

Question 60

What is the optic disk

Answer 60

where the ganglion cells collect to form the optic nerve.

Question 61

What is retinal detachment

Answer 61

something causes fluid under the neural retina between the pigmented epithelium

Question 62

What causes diabetic retinopathy? How common is it? Is it easily detectable?

Answer 62

hyperglycemia from diabetes that kills pericytes around capillaries; weakens the capillary walls and thus their permeability. 20-40% of diabetics have it. yes it is easily detectable

Question 63

What causes hypertensive retinopathy

Answer 63

adaptice changes to arteriolar circulation in the eye. eventually cna lead to hemorrahages in the retinal nerve fiber alyer caused by high blood pressure. -readily detected, easy to confuse with other things.