A&p Lab- Test 3- Senses Cont. 4

Front 1

Eyebrows

Back 1

Located superior to the eye, they partially shade the yes, and protect them from sweat.

Front 2

Eyelids

Back 2

Located over the eye. The eyelids blink to moisten the eye and sweep foreign substances from the eye's surface

Front 3

Eyelashes

Back 3

Located on the margin of the eyelids. Prevent foreign substances from entering the eye,

Front 4

Lacrimal Apparatus

Back 4

Composed of the lacrimal (or tear) gland and lacrimal ducts. Secretions or tears form the gland moisten the eye and washes away foreign substances.

Front 5

Conjunctiva

Back 5

An epithelial covering in the inside of the eyelid and the anterior surface of the eye. Helps keep the cornea moist and clean.

Front 6

Oblique Eye Muscles

Back 6

The supers oblique rotates the eye downward and medially. The inferior oblique rotates the eye upward and medially.

Front 7

Rectus Eye Muscles

Back 7

The 4 muscles are the superior, inferior, medial, and lateral rectus muscles. These muscles move the eye up, down, medially, and laterally.

Front 8

Aqueous and Vitreous Humours

Back 8

These are jelly-like fluids that fill the interior of the eye.

Front 9

Sclera

Back 9

Commonly called the "white" of the eye. A tough, tendon-like layer continuous with the dura mater of the brain around the optic nerve. It shapes the eye and is the insertion point for the six muscles which control eye movements.

Front 10

Cornea

Back 10

The most anterior layer of the eye that is continuous with the sclera. Transparent to allow light into the eye. Well supplied with nerve endings for pain, reflex blinking, and to stimulate lacrimal secretions. It also lacks blood vessels.

Front 11

Choroid

Back 11

Separates the fibrous and sensory tunics. Contains a dense capillary bed that provides oxygen and nourishment to the eye. Also contains many melanocytes which give the choroid its dark appearance.

Front 12

Iris

Back 12

Lies just beneath the cornea. The layer to which we attribute eye color. Composed of two layers of pupillary muscles that control the diameter of the pupil, and thus the amount of light entering the eye.

Front 13

Pupil

Back 13

This is the round central opening in the center of the eye.

Front 14

Ciliary Body

Back 14

A thick ting of tissue attached tom and lies just beneath the iris. Anchored at its margins by the choroid. Holds the lens in place beneath the iris and centered in the pupil. Contains the ciliary muscle, a smooth muscle that attaches to the lens. Changes the lens shape to focus light onto the retina.

Front 15

Lens

Back 15

Located beneath the iris and held in the center of the pupil by suspending ligaments extending from the ciliary body. Transparent and convex on its outer and inner surfaces. Focuses an image on the retina by changing shape under the influence of the ciliary muscles.

Front 16

Retina

Back 16

The delicate, two innermost layers of the eye. The neural layer contains photoreceptor and neurons that react to light and transmit and integrate visual signals. Beneath the neural layer lies the pigmented layer. It absorbs light that has passed through the neural layer to prevent the light from bouncing back and causing "visual echos".

Front 17

Rods

Back 17

Photoreceptor cells very sensitive to light. They enable us to see shades of gray in dim light.

Front 18

Cones

Back 18

Photoreceptor cells responsible for high acuity color vision. They only operate in bright light. There are 3 types of cones: sensitive to red, green, and blue light.

Front 19

Bipolar Neurons

Back 19

Synapse with the dendrites of the rods and cones. They transmit nerve impulses to the ganglion cells.

Front 20

Ganglion Cells

Back 20

Synapse with the axons of the bipolar neurons. The axons combine to form the optic nerve, which sends nerve impulses to the brain.

Front 21

Optic Disc

Back 21

Where the optic nerve leaves the eye, Not covered by the retina. A blind spot in the eye.

Front 22

Optic Nerve

Back 22

Cranial nerve II: it transmits visual information from the eye to the brain.

Front 23

Fovea Centralis

Back 23

The portion of the retina that is responsible for sharp central vision. Humans use this region for any activity that requires detailed vision, such as driving.