VEM 015: Eyes and Ears

Third eyelid

Nictitating membrane

Causes dogs eyes to glow

Tapetum lucidum

Enhances an animals ability to see in the dark

Tapetum lucidum

Complex phenomenon in which light emanating from objects in the environment is caputred by the eye and focused onto the retinal photoreceptors

Vision

Retinal photoreceptors

Site where light is focused

Average field of vision for dogs

240-250 degrees

Colors that are mostly seen by dogs

Yellow
Blue

White, opaque outer layer of the eye that provides protection and structural support

Sclera

Responsible for the shape of the eye

Fibrous outer tunic

Junction of the cornea and the sclera

Limbus corneae

Forms the anterior segment of the fibrous tunic

Cornea

Transparent, dome-shaped front part of the eye that covers the iris, pupil, and anterior chamber

Cornea

Focuses light onto the retina

Cornea

Colored part of the eye that surrounds the pupil

Iris

Plays a crucial role in regulating the amount of light that enters the eye by controlling the size of the pupil

Iris

Black circular opening in the center of the iris that regulates the amount of light that enters

Pupil

Controls how much light reaches the retina

Pupil

Protects the eye from foreign particles

Cilia

Junction between the cornea and the sclera

Limbus

Thin, transparent membrane that covers the front surface of the eye and lines the inside of the eyelids

Conjunctiva

Corner angle of the eye

Canthus

Small openings located on the inner corner of the upper and lower eyelids that are responsible for draining excess tears

Punctum

Fluid-filled space in the eye located between teh cornea and the iris

Anterior chamber

Maintains the eye's pressure and nourishes the eye structures

Anterior chamber

Transparent, flexible, biconvex structure located behind the iris

Lens

Large space within the eye filled with the vitreous body

Vitreous chamber

A series of fine, thread-like fibers that connect the cillary body to the lens of the eye

Zonule

Spiral-shaped fluid-filled structure resembling a snail shell

Cochlea

Converts sound vibrations into electrical signals

Cochlea

Responsible for maintaining balance and spatial orientation

Vestibular system

Bony structure in the skeleton that houses the middle ear

Tympanic bulla

Parts of the auditory ossicles

Malleus
Incus
Stapes

Hammer

Malleus

Anvil

Incus

Stirrup

Stapes

Thin, cone-shaped membrane that separates the external ear from the middle ear

Tympanic membrane

Converts sound waves into mechanical vibrations

Tympanic membrane

Small, rounded prominence located at the front of the ear in the external ear region; protrudes over the opening of the external auditory canal

Tragus

Prominent structure of the outer ear; formed by a fold of cartilage that curves inward, creating a Y-shaped configuration

Antihelix

Outer rim of the ear; forms a prominent circular fold

Helix

Small prominent structure located opposite of the tragus

Antitragus

Junction of the helix and antihelix

Cutaneous marginal pouch

Shape of a dog's auditory canal

L-shaped