1 / 11

The Special Senses

The Special Senses. Vision (sight) Gustation (taste) Olfaction (smell) Hearing Equilibrium (balance). Chapter 17. Accessory Structures of the Eye. Eyebrows divert sweat and contribute to facial expressions Eyelids (palpebrae) blink to protect the eye and lubricate their surface

bussr
Download Presentation

The Special Senses

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Special Senses • Vision (sight) • Gustation (taste) • Olfaction (smell) • Hearing • Equilibrium (balance) Chapter 17

  2. Accessory Structures of the Eye • Eyebrows divert sweat and contribute to facial expressions • Eyelids (palpebrae) blink to protect the eye and lubricate their surface • Eyelashes detect and deter foreign objects

  3. Accessory Structures of the Eye Cont. • Conjunctiva - a mucous membrane lining the inside of the eyelids and the anterior surface of the eyes • Conjunctivitis (“pinkeye”) - inflammation of conjunctiva

  4. Accessory Structures of the Eye Cont. Lacrimal Apparatus: • Lacrimal gland • Lacrimal sac • Nasolacrimal duct • Keeps conjunctival surfaces moist and clean

  5. Eye Muscles • Lateral, medial, superior, and inferior rectus muscles; superior and inferior oblique muscles

  6. Internal Anatomy of the Eye • Aqueous humor - clear, watery fluid in the anterior chamber • Cornea - transparent tissue covering the front of the eye; bends light • Pupil - hole in the center where light passes through • Iris - controls the size of the pupil; gives "color" to the eye • Lens - transparent tissue that bends light passing through the eye • Retina - on the back of the eye, contains photoreceptors (center of retina = fovea)

  7. Internal Anatomy of the Eye • Rods - photoreceptors responsive in low light conditions • Cones - photoreceptors responsive to color and in bright conditions • Sclera – the “white” of the eyeball • Choroid – membrane between sclera & retina • Vitreous Humor - clear, jelly-like fluid found in the back portion of the eye, maintains shape

  8. www.uniteforsight.org/course/eyeanatomy.php http://www.youtube.com/watch?v=gvozcv8pS3c

  9. Visual Disorders Myopia (nearsightedness) – objects far away appear blurry; can be corrected with concave lenses (- diopter) Hyperopia (farsightedness) – close objects appear blurry; can be corrected with convex lenses (+ diopter)

  10. Visual Disorders Cont. • Astigmatism - uneven curvature in cornea causes out of focus image • Cataract - clouding of the lens, scatters the light rays

  11. Visual Disorders Cont. • Glaucoma - caused by a build-up of aqueous humor; the excessive amount of fluid causes pressure against the retina, affecting vision; if untreated, will result in permanent blindness • Presbyopia - form of hyperopia due to weakening of eye muscles; normal part of aging

More Related