Lab Day 1 Special Senses-Vision

Receptors

Structures that detect changes in the body's internal and external environment.

General Receptors

Receptors found throughout the body.

Special Receptors

Specific parts of the body that have sensory receptors, such as those involved in hearing.

Photoreceptors

Receptors in the eyes that detect vision.

Chemoreceptors

Receptors involved in the sense of smell and taste.

Mechanoreceptors

Receptors in the ears that detect hearing and equilibrium.

Accessory structures of the eye

Include eyebrows, eyelids, conjunctiva, lacrimal apparatus, and extrinsic eye muscles.

Function of Eyebrows

Shade eyes from sunlight.

Function of Eyelids

Protect eyes anteriorly.

Conjunctiva

Membrane covering the eye; becomes inflamed in conjunctivitis.

Lacrimal Apparatus

Produces tears, which contain mucus, antibodies, and lysozyme.

Extrinsic Eye Muscles

Muscles that move the eyes; include 4 rectus muscles and 2 oblique muscles.

Layers of the Eye

Fibrous (sclera), vascular (choroid), and inner (retina).

Vitreous Humor

Jelly-like substance inside the eye.

Aqueous Humor

Water-like substance toward the front of the eye.

Suspensory Ligaments

Structure that holds the lens in place.

Optic Disk

Blind spot of the eye where the optic nerve exits.

Rods

Photoreceptors used in dim light; do not perceive color.

Cones

Photoreceptors used in bright light; provide high resolution and color vision.

Lens of the Eye

Avascular structure that focuses light on the retina; flexible and changes shape.

Cataracts

Condition causing cloudiness in the lens, often due to age.

Myopia

Nearsightedness; objects are focused in front of the retina.

Hyperopia

Farsightedness; focal point is behind the retina; eyeball is too short.

Astigmatism

A condition where the lens curvature is irregular.

Emmetropic Eye

An eye with normal vision.