A&P Lab Special Senses: Vision

What is a rounded opening through which light passes?

What is formed by axons that leave the retina in a tight bundle of fibers, where the ganglion cells are stimulated e.g. Light stimulates photoreceptors spreading to the bipolar neurons that stimulate the ganglion cells to generate an action potential. This potential from the nerves carries visual information to the brain.

The Optic Nerve is formed by axons that leave the ____ in a tight bundle of fibers, where the ganglion cells are stimulated e.g. Light stimulates photoreceptors spreading to the bipolar neurons that stimulate the ganglion cells to generate an action potential. This potential from the nerves carries ____ information to the brain.

What is attached to the ciliary body and are fibers that hold the lens in its upright position in the eye?

What is defined as the ability of the eye to focus differentially for objects of near vision?

Emmetropic (normal) eye has the ability to ______ properly.

Myopia; known as _______: the image normally focuses in the front of the retina; difficulty seeing objects from a distance.

_____; known as nearsightedness: the image normally focuses in the front of the retina; difficulty seeing objects from a distance.

Hyperopia; known as _______: the image focuses behind the retina; difficulty seeing _____ objects.

_____; known as farsightedness: the image focuses behind the retina; difficulty seeing close objects.

What is presbyopia?

What is defined as irregularities in the curvatures of the lens and/or cornea lead to a blurred vision?

What is "two-eyed" provides three-dimensional vision and an accurate mean of locating objects in space?

_____ is generally tested with a Snellen Eye Chart, which consists of letters of various sizes printed on a white card. This test is based on certain letter sizes that can be seen clearly by eyes with normal vision at a specific distance.

Visual Acuity is generally tested with a _________, which consists of letters of various sizes printed on a white card. This test is based on certain ____ that can be seen clearly by eyes with normal vision at a specific distance.

Term: Lens becoming increasingly hard and opaque causes vision to become hazy or entirely obstructed, which is common in the elderly.

What is glaucoma?

What is conjunctivitis?

Your eye is about 2.5 cm or 1 inch in diameter but only about 1/6th is seen.

The rest sits in the orbital of the skull and is protected by the ____ and cushioned by the ____ that surrounds it. Tears also protect the eye by providing lubrication and an_____ compound called lysozyme.

Lacrimal apparatus consist of the following:

Lacrimal gland-releases tears which are diluted salt solution with lysozyme
-__________
-lacrimal sac
-__________
-nasal cavity

eyelids (palpebrae)

-protect the eye
-medial commissure and lateral commissure are where the upper and lower eyelid meet

______ is a fleshy elevation at the medial commissure that produces a whitish oily secretion

conjunctiva-a mucous membrane that lines the ____ surface of the eyelids; secretes mucus that aids in _____ the eyeball

_____-row of short hairs that project from the border of each eyelid

____ glands-modified sweat gland; lie between eyelash hair follicle & help lubricate eyeball

____- is an inflammation of one of the ciliary glands or a small oil gland

Six extrinsic eye muscles are attached to exterior surface of each eyeball. They control eye movement and allow the eye to follow a moving object.

The six muscles are the lateral rectus, medial rectus, superior rectus, inferior rectus, inferior oblique, and superior oblique. Based on what you know about haow muscles are named can you label the following diagram?

The six muscles are the lateral rectus, medial rectus, superior rectus, inferior rectus, inferior oblique, and superior oblique. Based on what you know about haow muscles are named can you label the following diagram?

The wall of the eye is composed of three layers.


1. fibrous (outermost)2 regions: sclera & cornea-the sclera is opaque and white and covers most, it is the "white of the eye"-the cornea is the anterior portion of the fibrous layer and is transparent, the cornea allows light to enter the eye

The wall of the eye is composed of three layers.


2. uvea-middle layer-is the vascular tunic-contains the choroid to the posterior-nutritive layer with pigment that prevents light from scattering on the surface of the retina-contains the ciliary body-made oc ciliary muscles that control the shape of the lens-ciliary processes-that secrete aqueous humor-iris-to the anterior, has an opening in the center, is composed of smooth muscle that controls how much light enters the eye, the colored part of the eye-pupil-to the anterior, center of the iris

The wall of the eye is composed of three layers.


3. retina-sensory, innermost layer-consist of two layers which contain-photoreceptors -rods-light, -cones-color-optic disc-"blind spot", where the optic nerve leaves the eyeball, does not have photoreceptors-macula lutea (yellow spot)- directly behind the lens, high cone density-fovea centralis- center of the macula lutea, has a very high concentration of cones and is the area of highest visual acuity

3 major neuronal populations1-photoreceptors (rods & cones)2-bipolar cells3-ganglion cells  ▪light must pass thru the ganglion cell layer & the bipolar layer to reach & excite the rods & cones

The ____ are the specialized receptors for dim light. Visual interpretation of their activity is in gray tones.

The ____ are color receptors that permit high levels of visual acuity, but they function only under conditions of high light intensity.

Retina: 

Other name for eyelids?