1. The Eye
Accessory Structures

2. 70% of sensory receptors in the body are in the eyes.

3. Accessory Structures of the Eye

4. Eyebrow
Shades
Limits sweat trickling into eye

5. Eyelids
Protects
Distributes tears

6. Eyelashes
Protects and shades

7. Sebaceous Glands
Lubricates
Prevents sticking of lids
Sty

8. Conjunctiva
produces lubricating mucous

9. Pinkeye = Conjunctivitis

10. Accessory Structures and Functions:
eyebrows
shade and limit sweat trickling into eye
eyelids
protection and distribution of tears
eyelashes
follicles rich with nerve endings to stimulate blink reflex
protect and shade
sebaceous glands at base of lashes keep lashes and lids
lubricated and prevent sticking of lids
sty - infected gland

11. Conjunctiva
mucous membrane that lines lids and covers surface of eye
produces lubricating mucous
Pinkeye - viral or bacterial infection

12. Canals

13. Lacrimal Apparatus Lacrimal gland releases tears - lacrimal secretions
spread with blinking
Lacrimal Canals
Nasolacrimal Duct
Nasal Cavity

14. Pathway Lacrimal Gland ↓ Across Surface of Eye Lacrimal Canals
Lacrimal Sac
Nasolacrimal Duct
Nasal Cavity

15. Lacrimal Secretions = Tears
tears contain water, mucous, antibodies, and antibacterial enzymes
decrease with age
tears produced in response to drying, irritation, and emotion

17. Extrinsic Eye Muscles move eyeballs and support eyeballs
most precisely and rapidly controlled skeletal muscles