Lecture 20 - Ear and Eye

Question 1

3 layers of the eye

Answer 1

tunica fibrosa, Uvea, and Retina

Question 2

components of the tunica fibrosa

Answer 2

sclera and cornea

Question 3

components of the uvea

Answer 3

choroid (vascular layer that provides nutrients to the retina), ciliary body, and iris

Question 4

components of the retina

Answer 4

neural (rods and cones) and non-neural (lines the ciliary body and iris)

Question 5

Anterior chamber vs the posterior chamber

Answer 5

Anterior - in front of the iris

Posterior - behind the iris in the vitreous chamber

Question 6

Macula (fovea)

Answer 6

only cones in the back of the eyeball region. responsible for visual acuity and central focus.

Question 7

Where is the blind spot in the eye?

Answer 7

where they are no rods or cones where the optic nerve and blood vessels leave.

Question 8

What did the lens develop from?

Answer 8

tunica albuginea.

Question 9

Where are the sclera and cornea located?

Answer 9

Make up the tunica fibrosa (outer most layer). Sclera in the back of the eye and the cornea in the front that is in contact with air and fluid.

Question 10

Sclera make up and function

Answer 10

CT layer with fibroblasts, fibrous and amorphous tissue. Holds the eye in place

Question 11

Cornea’s 5 layers

Answer 11

corneal epithelium, bowman’s membrane (non-cellular, thick extracellular material), stroma (thickest), descemet’s membrane, and endothelium (squamous)

Question 12

Canal of Schlemm location and function

Answer 12

junction of sclera and cornea. facilitates equilibrium of pressure in the eye.

Question 13

What surrounds the canal of schlemm?

Answer 13

trabecular networks

Question 14

Choroid

Answer 14

vascular layer. provides nutrients to the sclera and the retina. contains the choriocapillary layer which is closest to the rods and cones of the retina. also contains melanocytes

Question 15

Ciliary body

Answer 15

containing muscle that can contract the shape of the lens for visual accommodation.

Question 16

Ciliary processes function

Answer 16

folds of epithelium on the surface of the muscle. Zonula fibers are attached to the lens, allowing for contraction or relaxation of the lens.

Question 17

Ciliary processes make up

Answer 17

double layer of low columnar to cuboidal. Non-pigment on the outer layer and pigmented on the inner layer.

Question 18

Iris

Answer 18

double layer of epithelium continues to the posterior iris. eye color is determined by amount of pigment in the epithelium.

Question 19

Eye color

Answer 19

determined by amount of pigment in the epithelium. Less pigment (blue), intermediate (green), more pigment (brown)

Question 20

Zonula fibers

Answer 20

oxytalin fibers (elastic fibers) that connect the ciliary proccesses to the lens.

Question 21

Ora serrata

Answer 21

transition from the neural to non-neural retina

Question 22

3 layers of photosensitive cells

Answer 22

outer layer - rods and cones embedded in the pigmented epithelium
middle layer - bipolar neurons
inner layer - ganglion cells

Question 23

Mullet cells

Answer 23

support cells in the neural retina

Question 24

Rod cells

Answer 24

black to shades of grey and white (rhodopsin)

Question 25

Cone cells

Answer 25

color (variants of iodopsin)

Question 26

Dry vs wet macula degeneration

Answer 26

dry - cellular debris between retina and choroid | wet - blood vessels grow from choroid and leak

Question 27

4 accessory structures of the eye

Answer 27

lens, eyelid and conjunctiva, and lacrimal apparatus

Question 28

Layers of the lens

Answer 28

Lens capulse (proteoglycans, type IV collagen), Lens epithelium (simple cuboidal to columnar), differentiating lens fibers, and mature lens fibers

Question 29

Conjuctiva of eyelid

Answer 29

inner most layer and is in contact with the eyeball. Stratified columnar or stratified squamous.

Question 30

Tarsal fibroelastic plate of the eyelid

Answer 30

provides rigidity, helps in movement

Question 31

Meibomian gland of eyelid

Answer 31

secretes sebaceous type materials

Question 32

Orbicular muscle of eyelid

Answer 32

contracts to help you move your eyes

Question 33

Lacrimal apparatus

Answer 33

produces tears. tubuloalveoli acini and serous

Question 34

Structures of the outer ear

Answer 34

pinna (lobe), auditory canal and ceruminous glands, and tympanic membrane (ear drum)

Question 35

Pinna components

Answer 35

elastic cartilage and connective tissue

Question 36

3 components of the tympanic membrane

Answer 36

external epidermis, middle fibrous CT, and inner simple cuboidal and or squamous epithelium

Question 37

3 articulating bones

Answer 37

Malleus (hammer), incus (anvil), and stapes (stirrup)

Question 38

purpose of the middle ear

Answer 38

to amplify the sound and to cause vibration of the oval window of the inner ear

Question 39

2 nerves connected to the inner ear

Answer 39

vestibular and cochlear nerve

Question 40

Vestibule

Answer 40

contains the utricle and saccule (which is responsible for motion - and has the macula).

Question 41

Semicircular canals

Answer 41

in 3 different orientations to help with balance. contain the cristae ampullares (help with orientation and motion)

Question 42

Cochlear duct

Answer 42

organ of corti (responsible for hearing via sensory hairs)

Question 43

3 inner ear sensory regions

Answer 43

vestibule, semicircular canals, and cochlear duct

Question 44

Most important chamber of the cochlear

Answer 44

scala media. endolymph filled (via stria vascularis layer of cells) to help maintain the viability of the organ of corti

Question 45

How the organ of corti works

Answer 45

fluid within the canal is pushed by a pressure wave and causes the tectorial membrane to rub against the hair cells. This vibration is then transmitted to the cochlear/auditory nerve

Question 46

Macula components

Answer 46

sensory cells that contain stereocilia and one true long cilia in a gelatinous layer. Otoliths on top of the layer. Movement will cause the gelatin layer to move. This causes an opening of ion channels in the hair cells.

Question 47

Cristae ampullares

Answer 47

the copula (gelatinous layer) rubs against the other side of the canal.