The sensory system is comprised of five senses: sight, hearing, smell, taste, and touch. Each sense has its own specialized structures. The eyes contain the retina, cornea, iris and lens for sight. The ears are made of the pinna, eardrum, ossicles and cochlea for hearing. Smell occurs via olfactory receptors in the nose. Taste buds on the tongue allow for taste. And touch is sensed by receptors in the skin.
9. Eye Trivia
Which famous screen
actress was noted for her
stunning eyes?
Many people thought
her irises were violet in
color…
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10. Structures of the eyes
Internal structures
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11. Structures of the eyes
Rods and cones
Rods
Active in dim light
Peripheral vision
Do not perceive color
Cones
Active in bright light
Perceive color
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12. Name the structures…
Eyes sclera
Ciliary
Review body choroid
conjunctiva retina
cornea
iris
pupil lens
Blood
Anterior vessels
chamber Optic
nerve
Optic disc
(blind spot)
External eye
muscle
12
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13. Ears
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14. Structures of the ears
External ear
Middle ear
Also known as
the tympanic
cavity
Inner ear
Also known as
the labyrinth
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15. Structures of the ears
External ear
Pinna or
auricle
Auditory
canal or
external
auditory
meatus
Ceruminous
glands
Tympanic
membrane
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16. Structures of the ears
Middle ear
Ossicles
malleus
incus
stapes
Eustachian
tube
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17. Structures of the ears
Inner ear
Cochlea
Perilymph
fluid
Semicircular
canals
Endolymph
fluid
Vestibule
chamber
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18. Name the structures…
Ears malleus anvil
stapes
Semicircular
pinna canal
Review cochlea
Auditory
canal
Eustachian
tube
Tympanic membrane
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19. Nose
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20. Structures of the nose
Nares
Nasal cilia
Nasal septum
Olfactory receptors
Turbinates
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21. Structures of the nose
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22. Structures of the nose
Olfactory area
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23. Tongue
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24. Structures of the tongue
Taste receptors
Also known as
gustatory buds or
taste buds
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25. Trivia Tongue
Did you know…
Taste is the weakest of the five senses
We have almost 10,000 taste buds inside our mouths;
even on the roofs of our mouths
Everyone’s tongue print is different similar to
fingerprints
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26. Skin
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27. Structures of the skin
Epidermis layer
Dermis layer
Subcutaneous layer
Touch receptors
Tactile corpuscles
located in the skin
Temperature
sensors
Pain receptors
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28. Structures of the sensory system
Did you know…..
Our eyes are always
the same size from
birth, but our nose
and ears never stop
growing!
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29. Essential questions
What are the structures of the
sensory system?
The End
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Editor's Notes
The human eye is a tender sphere about 1 inch in diameter. It is protected by the orbital socket of the skull, the eyebrows, eyelids, and eyelashes.
Orbit- the eye socketEyelids – the covering of the eyeEyelashes-the hair on our eyelidsConjunctiva- the thin membrane that lines the eyelids and covers part of the eye. It secretes mucus to help lubricate the eyeLacrimal apparatus- gland located above the lateral area of the eye. Duct- corner of the eyes and empties into the nasal cavity. Extrinsic muscles- provide movement to the eyeball
Superior- rolls eyeball upwardInferior- rolls eyeball downwardLateral- rolls eyeball laterallyMedial rectus-rolls eyeball mediallySuperior oblique-rolls eyeball on its axis, moves cornea downward and laterallyInferior oblique- rolls eyeball on its axis, moves cornea upward and laterally
Sclera- the outer layer ( the whites of the eye). Tough fibrous capsule which maintains the shape of the eye. Cornea- the very front of the eye. It is a clear area. Sometimes referred as the window of the eye. Consists of 5 layers of flat cells arranged much like sheets of plate glass. It contains pain and touch receptors. It is very sensitive to any foreign particles. Choroid – the middle layer of the eye. Contains blood vessels. Pupil- circular opening in front of the choroidIris- colored muscular layer surrounding the pupil. Lens- is located between the anterior and posterior chamber. It is a crystalline structure located behind the iris and pupil.Retina- is the innermost part of the eye. It is located between the posterior chamber and the choroid.
Iris may be blue green gray brown or black. The eye color is related to the number and size of melanin pigment cells in the iris. If there is little melanin present, the eyes will be blue because light is more scattered. With increasing quantity of melanin, eye color ranges from green to black. The total absence of melanin results in pink eye color (albino)
Macula- Yellow disk in the back of the eyeFovea centralis- where cones are located. Around the fovea is where rods are located Optic disk- located to the side of the fovea. Nerve fibers from the retina gather here to form the nerve. It has neither rods nor cones….there is no vision in this spot “blind spot”.
LOOK INTO MY EYES ACTIVITY SHEET
The ear is a special sense organ that is especially designed to pick up sound waves and send the impulses to the auditory center of the brain. The auditory center of the brain is located in the temporal area just above the ears.
The pinna is the external part of the ear and it collects sound waves and directs them into the auditory canal. Auditory canal is lined with sebaceous glands which secrete wax like substance called cerumen. Cerumen protects the ear. Auditory canal leads to the eardrum or tympanic membrane. Tympanic membrane separates the outer ear from the middle ear.
Middle ear is really a cavity in the temporal bone. It connects with the pharynx (throat) by the eustachian tube. The tube serves to equalize the air pressure in the middle ear with the outside atmosphere. There is a chain of three tiny bones (ossicles) is found in the middle ear. Malleous (hammer), incus (anvil), and Stapes (stirrups). They transmit sound waves from the ear drum to the inner ear.
The inner ear consists of several membrane lined channels which lie deep in the temporal bone. Cochlea is a spiral shaped passage which contains the cochlear duct. This duct is filled with fluid (perilymph fluid) that vibrates when the sound waves from the stirrup bone strikes against it. Located in the cochlear duct are delicate cells which make up the organ of Corti. These hair like cells pick up vibrations caused by the sound waves against the fluid, and then transmit them through the auditory nerve to the hearing center of the brain. 3 semicircular canals also lie within the inner ear. They also contain liquid (endolymph) and delicate hair like cells which bend when the liquid is sent in motion by head or body movements. These impulses are sent to the cerebellum helping us to maintain our body balance or equilibrium. They have NOTHING to do with our sense of hearing. Vestibule chamber is located between the cochlear canal and the semicircular canals that detect body position.
The human nose can detect 10,000 different smells. Smell accounts for 90% of what we think we taste.
Nares-the two opening of the noseNasal cilia- “nose hairs”Nasal septum-the cartilage which divides the nose into left and rightOlfactory receptors- located in the nose is a small area about the size of a postage stamp with specialized nerve cells to send signals to the olfactory bulb.Turbinates-bony structures in the nasal cavity
The tongue is a mass of muscle tissue which has structures called papillae
Located on the papilla are taste buds for sweet sour bitter and salty which are stimulated by the flavors of foods. The receptors in the taste buds send stimuli through 3 cranial nerves to the cerebral cortex for interpretation.
