A and P of the EYE

Which 3 cranial nerves innervate the eye?

(3) Occularmotor (4) Trochlear (6) Abducin

Stimulation of which receptors can cause the formation of tears (A) M3 (B) B2 (C) M2 (D) a-1

(A), (C), & (D).

Which of the following is a correct association? (A) Macula lutea: only cones (B) Fovea centralis: only cones (C) Macula lutea: mostly cones (D) fovea centralis: mostly cones

(B) & (C)

Which of the following is not a characteristic of aqueous humor (A) Carries away metabolic wastes (B) slow production (C) maintains intraocular pressure (D) supplies nutrients and oxygen.

(B) Aqueous humor is continuously produced and drained.

___ clouding of the lens by clumping of crystallins that cause lens opaqueness. (A) glaucoma (B) cataracts (C) color blindness (D) myopic degeneration

(B) cataracts. Can be unilateral(age related) or bilateral (congenital).

Which of the following is a association. (A) Stye: tarsal gland (B) conjunctivitis: conjunctiva (C) collasia: ciliary gland (D) none of the above

(B) conjunctivitis; conjunctiva

Which of the following is a cause of conjunctivitis (A) Bacteria (B) Allergy (C) Virus (D) All of the above

(D) all of the above

The interior portion of the eye is divided into what sections.

Anterior and Posterior Segments.

T/F. The inner segment of rods directly connect to the cell body.

False. This is cones. The inner segment of rods to the cell body by the outer fiber.

T/F. Diplopia is wandering eye that can go laterally or medially.

False. This is strabismus. Diplopia is double vision caused by uncoordinated movenebt due to weak or paralyzed eye muscles.

T/F. Aqueous humor is a viscous liquid.

False. Vitreous humor is a viscous liquid with a very slow turnover in production.

T/F. Rods have low sensitivity and respond to bright light.

False. these are cones. Rods have high sensitivity and respond to dim light.

How is aqueous humor drained.

From the anterior chamber via trabecular meshwork and the scleral venous sinus or canal of schlemm.

___ is blockage or inflammation of the cilliary glands in the hair follicle.

Sty (hordeolum)

What is opsin

a protein that determines the wavelengths that retinal will absorb

The pigmented layer of the retina ___ light.

absorbs. Prevents the scattering of light in the eye and provides local storage of vitamin A.

Cilliary processes are responsible for making

aqueous humor

The anterior segment is responsible for the creation of ____ humor. Posterior segment makes _____ humor.

aqueous; vitreous

Conjunctivitis with associated thick, yellow, discharge in 1 eye is usually caused by what?

bacteria. Virus affects both eyes and produces watery secretions.

Amacrine cells synapse with __ and ___ cells.

bipolar and ganglion cells.

Light first enters the eye at the ____

cornea. Most anterior portion of the eye. Avascular/ transparent w/ less collagen fibers.

In the retinal periphery, cone density ____ and rod density ____

decreases; increases.

Sclera is white in color with ____ collagen fibers

dense. Anchoring site for extrinsic eye muscles. Protects and shapes.

Lens ____ are cuboidal cells on the anterior portion of the lens.

epithelium. They differentiate into lens fibers.

lens___ make up the bulk of the lens.

fibers. (no nuclei, few organelles) made up of crystallins.

The axons of ____ cells in the neural layer of the retina give rise to the optic nerve.

ganglion

Rod photopigment is ____. Cones photopigment is __ of 3.

gray; 1 of 3 vivid colors (blue, red, green).

Two types of interneurons,

horizontal and amacrine cells.

Horizontal cells synapse with ____ and ____ cells.

photoreceptors and bipolar cells.

The neural later of the retina primarily functions in what?

phototransduction

Ciliary bodies that produce aqueous humor are located in the ____ chamber of the anterior segment.

posterior. Anterior chamber just allows for movement of aqueous humor.

___ small opening in the iris that allows light entry.

pupil

What is the most common type of X-linked color blindness

red-green.

The anterior segment is divided into what sections

the anterior and posterior chamber.

The inner layer (Retina) main function is what

the perception of vision.

Bipolar cells do what

transfer signal from photoreceptors to ganglion cells via depolarizations or hyperpolarizations.

T/F. Action potentials only occur in the ganglion cells.

true.

T/F. Warm/cold compress and keeping the area clean with baby shampoo typically helps to relieve stys or chalazions.

true.

T/F. The iris is pigmented

true. The less pigment the lighter the eyes.

Blockage of aqueous humor drain causes intraocular pressure to rise which can cause compression of the retina and optic nerve. T/F

true. This is characteristic of glaucoma which can lead to blindness.

the cilliary ____ holds lens in place

zonule/ suspensory

___ red irritated eyes caused by the inflammation of the conjunctiva

Conjunctivitis.

Explain why at night a person may notice a movement "out of the corner of the eye" but, when the person tries to focus on the area of movement, it appears as though nothing is there.

Rods are working for peripheral vision. When you focus directly on it, you are using your cones. You may not see the object.

What are the two layers of the fibrous layer

Sclera Cornea

____ are transparent, folded proteins that form body of lens.

Crystallins.

What are the 3 layers of the eye?

-Fibrous -Vascular (uvea) -Inner Layer (retina)

___ rectus & ___ obliques help move the eye

4:2

The vascular layer (Uvea) consists of what parts

Choroid (dark brown) Ciliary body Iris

Describe the pathway of phototransduction.

Light is received and converts 11-Cis retinal to all-trans retinal. This activates the G protein, transducin. Transducin activates the PDE which converts cGMP toGMP. This causes the ion channels to close and cause a hyperpolarization.

Rhodopsin is made up of what two components

Opsin and Retinal.

The iris contains what components?

Pupil, Circular and Radial smooth muscles.

____ is the light absorbing molecule.

Retinal. Made using Vitamin A

___ is blockage or inflammation of the tarsal glands of the eyelid

chalazion

Accommodation is the contraction of ___ muscles which curves the lens and allows for focusing on close objects.

ciliary.

Circular muscles ___ pupil. Radial muscles ___ pupil.

constrict pupils (M3/ Miosis/ Parasympathetic); dilate (A1/ Mydriasis/Sympathetic).

Double of blurry vision is caused by the buldging of the __

lens.

Vitreous humor is a jelly-like substance that _____ of the eye.

maintains the shape. It also holds neural layer against pigmented layer of the retina (keeps it in place).

Why is it possible to "taste" medications, such as eyedrops, that have been placed into the eyes?

medications in the eye can drain into the oral cavity through the nasal lacrimal duct.

The cillary ___ control the shape of the lenses and is responsible for accommodation.

muscle (smooth muscle). Pushes aqueous humor through the eye.

The "optic disc" is located in ___ layer of the retina. This is where the optic nerve leaves the eye and is considered the blind spot.

neural layer. There are no photoreceptors in this area.

Components of a photoreceptor

outer segment (receives light) inner segment cell body inner fiber