Unit: 7- Special Senses

1. Unit: 7- Special Senses

2. 1. The eye Characteristics of the eye: ________________ sphere Diameter is about ______ cm ______ of the _____________side shows

3. Accessory structures of the eye ________________ short course hairs that overlie the supraorbital margins of the skull Function- shade from ____, prevent ________________ from entering eye.

4. Accessory structures of the eye 2. Eyelids (aka ________________ ) ________________ the eye ________________ - protect from ______and _____ from entering the eye. _____________ ____________ -separates the eyelids

5. Accessory structures of the eye 2. Eyelids (continued) Corners of the eye: _____________ _____________ and _____________ _____________ _____________ contains _____________ and sweat glands; secretion looks whitish, sometime collects in the medial canthus (during sleep).

6. Accessory structures of the eye 2. Eyelids (continued) _________ _______- connective tissue that attaches to _____________ that allow the eye to blink.

7. Accessory structures of the eye 2. Eyelids (continued) Glands _____________ / _____________ embedded in tarsal plate that is a modified sebaceous gland that produces an oily secretion that lubricates the eyelid and prevents the eyelids from sticking together ___________/ _____________ glands- modified sweat gland that is located between the lashes

8. Accessory structures of the eye 3. _____________ - a transparent mucus membrane. Produces a _____________ __________that prevents the eyes from __________ out. _____________ _____________ - part of the conjunctiva that coats the inside of the eyelids. _____________ / _________ _____________ - covers only the white part of the eye

9. Accessory structures of the eye 4. _____________ _____________ Drains excess secretions into the nasal cavity _____________ __________ - lies above the orbit above the lateral end of the eye that releases a dilute saline solution called lacrimal secretion (tears) _____________ _____- medial to the eye, where tears drain.

10. Accessory structures of the eye 4. Lacrimal Apparatus (continued) _____________ _______- located below the lacrimal sac and empties tears into the nasal cavity. _____________ - an _____________ found in the lacrimal fluid and helps destroy bacteria.

11. Accessory structures of the eye 5. _____________ Eye Muscles Originate at the ____ orbit Allows the eye to follow _______objects _____________ _______ - located on the lateral side of the eye and moves the eye laterally. _____________ _______ located on the medial side of the eye and moves the eye medially

12. Accessory structures of the eye 5. Extrinsic Eye Muscles (continued) _____________ _______ - located on the top of the eye and elevates the eye _____________ _______ - located on the bottom of the eye and depresses the eye _____________ _______ - located below the eye and elevates the eye and turns it laterally. _____________ _______ - located above the eye and depresses the eye and turns it laterally

13. Structure of the Eyeball Shape- irregular _______ sphere ____________ _______- the outermost coating of the eye that is composed of dense ____________ connective tissue. ___________ - _____ of the eye; protects and shapes the eye; provides a site for muscle attachment ___________ - bulges anteriorly from its junction with the sclera and allows light to enter the eye

14. Structure of the Eyeball 3. Vascular Tunic (AKA uvea) Located in the middle layer of the eye ___________ ___________ - highly vascular bark brown membrane that helps absorb _________ and provides ___________ to all tunics through blood vessels.

15. Structure of the Eyeball 3. Vascular Tunic (continued) _____________ _______ - ring of tissue that encircles the lens and consists of ciliary muscles that shape the lens. _____________ _______ - located near the lens and secretes aqueous humor that fills the cavity of the anterior segment of the eyeball

16. Structure of the Eyeball 3. Vascular Tunic (continued) _____________ _______- extends from the ciliary processes to the lens in order to hold the _____ in its upright position. _____ -the colored part of the eye that is located between the cornea and lens ______ -the center of the iris that allows light to enter the eye

17. Structure of the Eyeball 4. Sensory Tunic (AKA retina) (continued) The innermost coat of the eye 2 layers: _____________ _______ - absorbs light and prevents it from scattering in the eye; stores vitamin A _____________ _______ - plays a direct role in vision _____________ _______ - / _____________ _______ - where the optic nerve exits the eye __________ - the weak spot of the optic disk because it is not reinforced by the scelera.

18. Structure of the Eyeball 4. Sensory Tunic (AKA retina) (continued) _______ - assists in ______ light and _____________ vision; they are sensitive to light and do not provide sharp images or color vision. ____________ - operate in bright _________ and provide color _____________.

19. Structure of the Eyeball 5. Lens ____________, ____________ and flexible Can change shape to allow precise focusing of ______ on the retina. Regions:

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