Animal Anatomy: Sense Organs

Portion of the middle vascular layer of the eye; consists mainly of pigment and blood vessels and located between the sclera and the retina

Choroid

: Portion of the middle vascular layer of the eye located immediately behind the iris; contains ciliary muscles that adjust the shape of the lens

Ciliary body

Snail shell-shaped cavity in the temporal bone of the skull that contains the hearing portion of the inner ear

Cochlea

Photoreceptors in the retina of the eye that perceive color and detail

Cones

Space between the bulbar and palpebral portions of the conjunctiva; space between the eyelid and the eyeball

Conjunctival sac

Clear "window" on the front of the eye that admits light to the interior of the eye; part of the outer fi brous layer of the eyeball

Cornea

Muscles that move the eyeball.

Extraocular muscles

Process of experiencing pain

Nociception

What structure of the eye contains the rods and cones?

retina

Stapes =

stirrup

What causes the green reflection from the eyes of an animal in photographs or at night?

tapetum lucidem

What is the tiny membrane of connective tissue at the end of the external ear canal that vibrates in response to sound waves?

tympanic membrane

Area behind the ciliary body and lens

vitreous compartment

Clear soft gelatin like fluid that fills part of the eyeball behind the lens and ciliary body

vitreous humor

Portion of the aqueous compartment of the eye in front of the iris

Anterior chamber

Compartment of the eye in front of the lens and ciliary body; divided by the iris into the anterior chamber and the posterior chamber

Aqueous compartment

Watery fluid that fi lls the aqueous compartment of the eye

Aqueous humor

Transparent membrane that covers the front portion of the eyeball

Bulbar conjunctiva

Junction of the upper and lower eyelids

Canthus

Tube that connects the middle ear cavity with the pharynx

Eustachian tube

Tube that carries sound waves from the pinna to the tympanic membrane

External auditory canal

Externally visible part of the ear made up of the pinna and external auditory canal

External ear

Sense of taste

Gustatory sense

One of three ossicles that help transmit sound waves across the middle ear; also known as the anvil; middle of the three ossicles

Incus

Fluid-fi lled compartments within the temporal bone of the skull that are involved with hearing and balance; made up of the cochlea, vestibule, and semicircular canals

Internal ear

Colored portion of the eye; pigmented, muscular diaphragm that controls the amount of light that enters the posterior part of the eyeball

Iris

Glands that are the primary source of tears

Lacrimal glands

Openings to the nasolacrimal ducts that help carry tears away from the surface of each eye; located near the medial canthus on both the upper and lower eyelid margins

Lacrimal puncta

lateral corner of the eye where the upper and lower eyelids come together

Lateral canthus

soft, transparent structure in the eye made up of layers of microscopic fibers that are arranged like layers of an onion; mainly functions to help focus a clear image on the retina

Lens

Junction of the cornea and sclera of the eye

Limbus

Tube that carries tears from the lacrimal sac to the nasal cavity

Nasolacrimal duct

One of the three ossicles; also known as the hammer; helps transmit sound waves across the middle ear from the tympanic membrane; attached to the tympanic membrane

Malleus

Medial corner of the eye where the upper and lower eyelids come together

Medial canthus

Air-filled compartment within the temporal bone of the skull that transmits vibrations of the tympanic membrane to the cochlea; includes the tympanic membrane and the ossicles

Middle ear

Amplifi cation or suppression of pain impulses that occurs in the spinal cord

Modulation

Sense of smel

Olfactory sense

Area where half the fi bers of each optic nerve cross to the other side

Optic chiasma

Area of the retina where nerve fi bers on its surface converge to form the beginning of the optic nerve; blind spot of the eye

Optic disc

Formed from retinal nerve fi bers; carries visual nerve impulses to the optic chiasma and on to the brain

Optic nerve

Skull bones that are the bones of the ear; located in the middle ear; transmit sound wave vibrations from the tympanic membrane to the inner ear

Ossicles

Tiny crystals in the gelatinous mass of the vestibule that help it sense the position and linear motion of the head

Otoliths

Transparent membrane that lines the inner portion of the eyelid

Palpebral conjunctiva

Part of the pain sensation that involves the brain consciously recognizing pain

Perception

Sensory receptors that convert photons of light energy to nerve impulses that are interpreted by the brain as vision; rods and cones of the retina

Photoreceptors

Externally visible part of the ear that collects sound waves and funnels them down into the external ear canal; ear fl ap

Pinna

Portion of the aqueous compartment of the eye behind the iris

Posterior chamber

Opening in the center of the iris

Pupil

Inner nervous layer of the eye where the photoreceptors are located

Retina

Photoreceptors in the retina of the eye that perceive dim light images in shades of gray

Rods

White portion of the eye; part of the outer fibrous layer of the eyeball

Sclera

Portion of the inner ear that senses rotary motion of the head

Semicircular canals

Ossicle in the middle ear shaped like a stirrup

Stapes

Highly refl ective area of the choroid in the back of the eye of most domestic animals; also called tapetum lucidum

Tapetum

Glands on the eyelid margins that produce a waxy substance that helps prevent tears from overfl owing onto the face; also called meibomian glands

Tarsal glands

Structures found mainly on certain papillae of the tongue that contain the receptor cells for taste

Taste buds

Soft gelatinous fluid that fills the vitreous compartment of the eye

Vitreous humor

T-shaped plate of cartilage covered by conjunctiva; has lymph nodules and a gland that contributes to the tear fi lm on its ocular surface; also called nictitating membrane

Third eyelid

Part of the pain sensation that involves conversion of the painful stimulus to a nerve impulse

Transduction

Part of pain sensation that involves sending the impulse up nerve fi bers to the spinal cord

Transmission

Paper-thin connective tissue membrane that is tightly stretched across the opening of the external ear canal into the middle ear; also called eardrum

Tympanic membrane

Middle vascular layer of the eye

Uvea

Portion of the inner ear that senses position and linear motion of the head

Vestibule

Compartment of the eye behind the lens and ciliary body

Vitreous compartment

Space in front of the iris

anterior chamber

Incus =

anvil

Area in frony of the ciliary body and lens

aqueous compartment

Clear water fluid that fills the anterior and posterior chambers

aqueous humor

The ____ ____ is the musclular ring of tissue that surrounds the lends and adjusts its shape

ciliary body

In what structure are the sensory receptors for hearing located?

cochlea

What is the third eyelid covered with?

conjuctiva

What is the "clear window" that admits light to the interior of the eye?

cornea

Rods are used for detail color or dim light vision?

dim light

What ___ ____ connects the middle ear with the pharynx

eustacian tube

Funnels sound waves

external ear

Malleus =

hammer

Sensory receptors

inner ear

The ____ is the "colored" part of the eye that is visible externally

iris

The ____ ____ is the tiny hole in the medial canthus of the eyelid that allows tears to drain from the eyes.

lacrimal punctum

What adjustable eye structure helps focus a clear image on the retina?

lens

What is the name for the junction between the cornea and the sclera of the eye?

limbus

Amplifies and transmits vibrations

middle ear

Do domestic animals have more rods or cones in their retinas?

more rods

What is the "blind spot" of the eye?

optic disc

What is the external flap of the ear called?

pinna

Space behind the iris but behind the lens

posterior chamebr