Histology-Eye

Question 1

3 layers of the eye

Answer 1

1) Fibrous (cornea & sclera) 2) Uvea (iris, ciliary body, choroid) 3) Retina

Question 2

Main refractive structure of they eye

Answer 2

Cornea

Question 3

White of the eye continuous with the dura matter that covers the optic nerve

Answer 3

Sclera

Question 4

Contains smooth muscle that adjusts the size of the pupil

Answer 4

Iris

Question 5

Contains smooth muscle that adjusts the size of the lens

Answer 5

Ciliary body

Question 6

Vasculature that nourishes the outer layers of the retina

Answer 6

Choroid

Question 7

3 chambers of the eye

Answer 7

1) Anterior (aqueous humor) 2) Posterior (aqueous humor) 3) Vitreous (vitreous humor)

Question 8

Identify the labeled structures of the eye:

Answer 8

1) Sclera 2) Ciliary body 3) Optic Nerve 4) Vitreous chamber 5) Lens 6) Posterior chamber 7) Iris 8) Anterior chamber 9) Cornea

Question 9

Identify the labels structures of the eye:

Answer 9

1) Cornea 2) Eyelid 3) Palpebral Conjunctiva 4) Fornix 5) Ciliary body 6) Bulbar Conjunctiva 7) Ciliary process 8) Lens 9) Iris 10) Anterior chamber 11) Vitreous space *Note how the bulbar conjunctiva makes a u-turn at the fornix to become to palpebral conjunctiva

Question 10

In what structure at the ciliary muscles contained?

Answer 10

Ciliary body

Question 11

What connects the ciliary body to the lens?

Answer 11

Zonular fibers from the suspensory ligament of the lens connect to the ciliary process.

Question 12

What are the different layers of the cornea?

Answer 12

1) Corneal epithelium 2) Corneal stroma 3) Corneal endothelium

Question 13

Corneal epithelium sensory innervation

Answer 13

V1 (opthalmic nerve)

Question 14

Part of cornea that is only collagen

Answer 14

Stroma. It is also avascular so you can see through it

Question 15

Damage to this layer of the cornea causes swelling and opacities in the cornea.

Answer 15

Corneal endothelium

Question 16

Most quickly regenerating part of the cornea.

Answer 16

Corneal epithelium

Question 17

Identify the labeled structures below:

Answer 17

1) Bulbar conjunctiva 2) Sclera 3) Ciliary Muscle 4) Ciliary Process 5) Zonular Fibers 6) Iris

Question 18

Ciliary muscle innervation

Answer 18

CN III parasympathetic (ciliary ganglion)

Question 19

What do the zonular fibers do when you are reading a text?

Answer 19

They relax to make the lens more round. This increases the refractive power of the lens for near sight.

Question 20

What is the function of the structures indicated below?

Answer 20

1) Iris. The stroma contains fibroblasts and melanocytes that determine eye color. 2) Sphincter pupillae. These are innervated by the ciliary ganglion (CN III) and contract to constrict the pupil. Note that the lens is below the iris with a protective capsule and epithelial layer.

Question 21

Identify the structures indicated below:

Answer 21

1) Canal of Schlemm 2) Trabecular Meshwork 3) Iris 4) Dilator Pupillae 5) Ciliary Processes

Question 22

What is the region called where the cornea meets the sclera?

Answer 22

Limbus

Question 23

What regions of the eye may have a pathology in patients with glaucoma?

Answer 23

Aqueous humor is secreted by the ciliary processes into the posterior chamber, it then enters the anterior chamber via the pupil, it then percolates through the trabecular meshwork and exits via the canal of Schlemm. Blockage anywhere along this pathway can cause glaucoma.

Question 24

What muscles are responsible for changing the pupil during sympathetic stimulation?

Answer 24

Dilator pupillae. They are innervated by the superior cervical ganglion.

Question 25

What are the different structures indicated below?

Answer 25

The image is that of ciliary processes. 1) Inner non-pigmented layer continuous with the neural retina. 2) Pigmented outer layer continuous with the pigmented retinal epithelium.

Question 26

Clouding of the lens

Answer 26

Cataract

Question 27

Where are the oldest cells found in the lens?

Answer 27

At the center. The outer layer is an epithelial layer. Th internal layer is differentiated fiber cells that move internally as they age.

Question 28

What is the function of each retinal layer indicated below?

Answer 28

1) Photopigment of rods & cones (light-sensitive) 2) Nuclei of rods and cones 3) Axons of rods & cones headed towards dendrites of bipolar cells 4) Bipolar cells 5) Axons of bipolar cells headed toward dendrites of ganglion cells 6) Ganglion cells 7) Axons of ganglion cells that course to the optic disc to form CN II

Question 29

In what region of the retina is this image not from?

Answer 29

Fovea. In the fovea there are only cones. In this image, there are both rods and cones.

Question 30

Where does the central artery of the retina enter the eyeball?

Answer 30

Through the optic disc. Note that there are no photoreceptors here and this is the blind spot of the eye.

Question 31

What is the function of each structure indicated below?

Answer 31

1) Skin: protects eye 2) Orbicularis Oculi Muscle: blinks eye, innervated by CN VII 3) Meibomian (tarsal) glands: lubricate sclera, when inflamed = chalazion and stye 4) Palpebral conjunctiva: glide on eye, when inflamed = conjunctivitis

Question 32

Which photoreceptor is most sensitive to light? To color?

Answer 32

Light = rods. Color = cones.