The Eye Accessory Structures

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

Accessory Structures of the Eye

Eyebrow Shades Limits sweat trickling into eye

Eyelids Protects Distributes tears

Eyelashes Protects and shades

Sebaceous Glands Lubricates Prevents sticking of lids Sty

Conjunctiva produces lubricating mucous

Pinkeye = Conjunctivitis

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

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

Canals

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

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

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

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