Sense Organs

Eye

Organ of sight and vision

Ear

Organ of hearing

Nose

Olfactory, organ of smell

Taste buds

Gustatory, organ of taste

Eage

Eyeball, bulb of eye in Anglo-Saxon

Oculus

Eyeball, bulb of eye in latin

Eye

It is spherical in

shape except

anteriorly where it

bulges forward. It

measures about 1

inch in diameter

- Fibrous or outer layer

- Vascular or middle layer

- Nervous or internal layer

Coverings of eyeball (Tunics)

- Sclera

- Cornea with conjunctiva

Eyeball, Fibrous or outer layer:

Fibrous or Outer Layer

Provides protection and helps maintain shape of the eye

- choroid

- ciliary body

- iris and pupil

Eyeball, Vascular or middle layer:

Vascular or middle layer

Responsible for blood supply and plays a role in controlling light entering the eye

- Retina

Eyeball, Nervous or internal layer

- Aqueous humor

- Lens, capsule and suspensory ligament

- Vitreous humor (body)

- Cornea

Refracting media of the eyeball:

Constrictor of pupil, dilator of pupil

Muscle of Iris: regulates the amount of light entering the eye

Ciliary circular radiating

Muscle of lens: help adjust the shape of the lens for focusing

Refracting media

fill the cavity of the

eyeball. They are transparent so that

light may pass through them to reach

the retina

Refracting media

Their function is to change

the direction of the light waves so as

to focus the image on the inner

surface of the retina

Retina

contains

receptors that detect light and convert it into nerve impulses.

Sclera

white of the eye

Cornea

Clear front window

Lens

positioned behind the pupil

to focus light

aqueous humor

The internal chambers, the anterior and posterior chambers, are

filled with ...

Vitreous body

a large cavity filled with jelly-like

vitreous humor

vitreous humor

jellylike substance found behind the lens in the posterior cavity of the eye that maintains its shape

Fovea centralis

a depression in the macula lutea responsible for the

sharpest vision

Optic disc

blind spot where the optic

nerve and vessels exit toward the brain

lateral and medial rectus muscles

control side-to-side movement of the eye

Optic pathway

Responsible for transmitting visual information of the eye to the brain

Optic chiasma

is the point of

crossing of the medial nerve

fibers

Chiasma

It resembles the letter "X" a

letter in the Greek alphabet called

chi, so ...

Optic tracts

are two bundles of

nerve fibers that emerge from the

optic chiasma and pass obliquely

across the cerebral peduncles to

enter the brain

Optic nerve or second cranial nerve

Carries visual impulses from the retina toward the brain

optic chiasma, optic tracts

Ensures that visual information is properly transmitted & processed for interpretation

Extrinsic muscles of the eye

Work together in a coordinated manner to allow precise & smooth eye movement which are essential for proper vision and focus

- Superior rectus

- Inferior rectus

- Medial rectus

- Lateral rectus

- Superior oblique muscle

- Inferior oblique muscle

Extrinsic muscles of the eye:

Eyelids

upper and

lower protect the eyes

and cover them during

sleep.

Eyelids

Serve to protect the eye from foreign particles such as dust and debris

Superior Rectus and Inferior Rectus

Moves the eye upward and downward

Medial Rectus

Moves the eye toward the midline

Lateral Rectus

Moves the eye away from the midline

Superior and Inferior Oblique Muscle

Allows complex movements, such as rotation and diagonal

motion of the eye

Levator palpebrae superioris

Muscle responsible for elevating the upper eyelid.

Frontal bone (roof) and maxilla (floor)

The bony orbit is formed by the ... and ...

Medial canthus

The inner corner of the eye and is located near

the nose

Lateral canthus

The outer corner of the eye and is located

away from the nose

Strabismus

squint or crossed eyes is

a condition in which both eyes do not

move in the same direction at the

same time.

Conjunctiva

is a thin

transparent membrane

that covers the inner

surface of each eyelid,

and is reflected over the

anterior surface of each

eyeball.

palpebral conjunctiva

is the portion of the membrane that lines the inner surface of the upper and lower eyelids

bulbar conjunctiva

covers the anterior part

of the sclera, the white of the eye. It stops at the edge of the cornea,

the clear protective outer lay

Iris

Pigmented muscular structure that controls the amount of light entering the eye

Lacrimal apparatus

Responsible for the formation,

circulation, disposal of tears

Lacrimal apparatus

Keeps the eyes protected and lubricated

- lacrimal gland with its excretory ducts

- 2 lacrimal ducts

- lacrimal sac

- nasolacrimal duct

5 key components of the eye:

Lacrima (L), Dakryon (G)

Tear in L and G

Lacrimal gland

Located at the outer orner of the orbit, this is the primary

factor for tears

Excretory ducts

Are tiny channels that lead the tears from the glands onto the

surface of the conjunctiva

Lacrimal ducts

Are canaliculae, One tear washes across the eye, they collect in the inner corner and enters these two small ducts

Lacrimal Sac

This is the dilated upper portion of the drainage system that

sits in the lacrimal groove of the skull

nasolacrimal duct

Carries the tears from the sac down into the nasal cavity

Dacryocystogram

A specialized radiologic examination of the lacrimal

apparatus

Cryocystography

The radiographic study of the tear drainage system using a

contrast medium

Ear

The ... is the organ of hearing and

equilibrium. It is contained within

the petrous part of the temporal

bone. In sound waves are

transformed into nerve impulses.

External ear

Designated to capture and funnel sound

Auricle or pinna

Visible part of the ear primarily composed of cartilages

- Auricle or pinna

- Opening (porus) of external acoustic meatus

- External acoustic (auditory) meatus

External ear:

opening of external acoustic meatus

Actual opening or entrance of ear canal

external acoustic meatus

Canal that leads inwards toward the eardrum

Middle ear

Encounter structures responsible for mechanical conduction

- tympanic membrane of eardrum

- Auditory Ossicles

Middle ear:

- Malleus or hammer

- Incus or anvil

- Stapes or stirrup

Auditory ossicles, 3 pairs:

Tympanic membrane of eardrum

Marks the boundary between external & middle ear

Auditory ossicles

Amplify sound vibrations

Malleus or hammer

attached to tympanic membrane

Stapes or stirrup

Smalles bone which connects to the inner ear

- to external acoustic meatus

- tympanic opening of auditory tube or eustachian tube

- to mastoid antrum (tympanic antrum) and mastoid cells

- to cochlea

- to vestibule

Openings from middle ear:

Eustachian tube

Connects middle ear to nasopharynx to equalize pressure

Cochlea

spiral-shaped structure involved in hearing

Vestibule

An oval opening where the footplate of

the stapes sits, transmitting vibrations into the inner ear

- Osseous labyrinth

- Membranous labyrinth

Internal ear or labyrinth

- Vestibule with Round and Oval Openings

- Semicircular Canals - 3 Ampullae

- Cochlea

Osseous labyrinth, 3 parts:

- Utricle and Saccule in Vestibule

- Semicircular Ducts in the Semicircular

Canal

Membranous labyrinth, 3 parts:

Osseous labyrinth

outer bony shell of the internal ear

Membranous labyrinth

delicate fluid-filled tubes of the internal ear

Endolymph

The membranous labyrinth is suspended within the bony labyrinth and filled with ...

Otitis media

infection of the middle ear

Mastoiditis

An infection of mastoid cells

Olfactus

Smell

Receptors

are tufts of hair in the lining membrane

of the upper part of each nasal cavity

Endorgans

Receptors or ...

Olfactory bulbs

are the expanded anterior ends of the two olfactory

tracts, two club-shaped structures that lie on the

inferior surface of the frontal lobes of the cerebrum

Gustatio (L)

to taste

Papillae

are minute elevations on the tongue that are

the cause of roughness of this organ

Papilla

Nipple or nipplelike

Taste buds

Functional units of taste

Taste buds

are oval shaped

bodies located on the sides of

the papillae.

Taste buds

They have

elongated central cells with hair

at their surfaces