1. Introduction to Health Science Special Senses

2. Vocabulary- combining forms Acous/o hearing Audit/o hearing Blephar/o eyelid Conjunctiv/o conjunctiva Dacry/o tear Dipl/o double Gloss/o tongue Kerat/o horny tissue/ cornea Lacrim/o tear Ocul/o eye Ophthalm/o eye Opt/o eye/ vision Ot/o ear Scler/o sclera/ white of the eye Retin/o retina Tympan/o ear drum / tympanic membrane

3. Vocabulary- prefixes & suffixes Intra- within -ar pertaining to -ic pertaining to -ory pertaining to -tic pertaining to -al pertaining to -algia pain -dynia pain -itis inflammation - -logist specialist -logy study of -scope instrument to view -scopy visual examination -pathy disease -plasty surgical repair -spasm involuntary contraction -rrhea flow or discharge -opia vision -tomy incision

4. Vocabulary ENT ear, nose, throat Olfactory pertaining to smell Auditory pertaining to hearing Gustatory pertaining to taste Lacrimal pertaining to tears Ossicles bones of the middle ear

5. Types of Receptors The special senses work with specialized neurons or receptors. There are three different types that respond to different things. Chemoreceptors respond to chemicals Photoreceptors respond to light Mechanoreceptors respond to movement

6. Smell Smell occurs when specialized cells in the nose (chemoreceptors) detect chemicals resulting in nerve impulses which are sent to the brain for interpretation.

7. Nose In the upper part of the nasal cavity are specialized nerve cells called olfactory receptor cells. The olfactory receptor cells contain hair called cilia to which the dissolved chemicals attach. In the upper part of the nasal cavity are specialized nerve cells called olfactory receptor cells. The olfactory receptor cells contain hair called cilia to which the dissolved chemicals attach. Nerve impulses are transmitted from the olfactory receptors cells to the olfactory bulb, to the olfactory nerve, to the brain where the sense of smell is interpreted. Nerve impulses are transmitted from the olfactory receptors cells to the olfactory bulb, to the olfactory nerve, to the brain where the sense of smell is interpreted. Basic smells include: Basic smells include: putrid (rotting food) putrid (rotting food) pungent (spicy) pungent (spicy) floral (flowers) floral (flowers) ethereal (medicine smell) ethereal (medicine smell) mint mint

9. Taste Taste occurs when specialized cells on the tongue (chemoreceptors) detect chemicals resulting in nerve impulses which are sent to the brain for interpretation.

10. Mouth and Tongue The sense organs that detect dissolved chemicals for the sense of taste are the taste buds. Taste buds are located in the tongue and throughout the mouth. When the taste buds are stimulated by chemicals, they generate nerve impulses which are sent to the brain for interpretation. There are five basic tastes, although they are not limited to specific parts of the tongue: – – sweet (sugars and carbohydrates) – – sour (acids) – – salt – – bitter – – umami (protein and amino acids)

13. Hearing Hearing involves the movement of sound vibrations through the ear until they reach a specialized region in the inner ear where nerve impulses are generated by cells that detect movement (mechanoreceptors). These nerve impulses travel to the brain where they are interpreted as sound.

14. Parts of the Ear The Ear has three sections – – The outer ear Auricle or pinna External auditory canal – – The middle ear Tympanic membrane Eustachian tube Ossicles Oval window – – The inner ear Cochlea Vestibule

16. Outer Ear Auricle (or Pinna) – – The visible portion of the ear on the side of the head. – – Composed of cartilage – – Captures the sound waves from the environment and directs them toward the auditory canal. Auditory Canal – – Tube lined with hair and wax. – – Assists in the passage of sound waves to the middle ear. – – Provides protection for the ear as particles, debris and dust are trapped by the hair and wax.

18. Middle Ear Tympanic Membrane – – Known as the eardrum, it is the first structure of the middle ear. – – It vibrates with the sound waves and passes the vibrations to the middle ear bones. Eustachian Tube (auditory tube) – – Small tube extending from the middle ear into the throat. – – Helps to equalize pressure inside the ear.

19. Middle Ear Auditory Ossicles – – Three tiny bones in the middle ear that continue the passage of sound vibrations. Malleus (hammer) Incus (anvil) Stapes (stirrup) – – They amplify the vibrations twenty times. – – Transfer force through the oval window to the cochlea

21. Inner Ear Cochlea Snail shaped structure composed of a series of membrane-lined fluid-filled canals that continue to pass along the sound vibrations. Organ of Corti The sound vibrations eventually reach a specialized structure of the inner ear called mechanoreceptors where nerve impulses are generated. The impulses are transmitted to the brain where they are interpreted.

23. Inner Ear- balance dynamic equilibrium - interprets balance when one is moving – – Semicircular Canals static equilibrium - interprets the position of the head to maintain stability and posture when the head and body are not moving – – Vestibule

24. Inner Ear-balance Semicircular Canals: – – A series of membrane-lined fluid-filled canals – – Are the body's balance organs, detecting motion in the three perpendicular planes. Vestibule: – – Contains the saccule and utricle – – Work with the eyes to maintain postural balance

25. Touch Touch is the detection of various amounts of pressure by the skin. Nerve impulses are generated by cells that are sensitive to movement (mechanoreceptors) and sent to the brain for interpretation.

27. Vision The sense organs that respond to light are the eyes. The light waves travel through the eyes until they reach the back of the eye called the retina where nerve impulses are generated by specialized cells that are sensitive to light (photoreceptors). The impulses travel to the brain where they are interpreted as visual images and provide much information about the external world.

29. Eye Eyelid – – Structures composed of skin, muscles, and lashes – – Protect the eye from foreign objects by the blink reflex. – – Moves tears along the surface of the eyeball to keep the eyeball moist. Conjunctiva – – Membrane lining the insides of the eyelids and eyeball. – – Reduces friction during blinking

32. Eye Sclera – – The white part of the eye. – – Provides protection and shape to the eye. Cornea – – The clear window in the front part of the eye. – – Allows light waves to enter the eye. – – Helps to bend the light waves on to the back of the eye (retina)

33. Eye Iris – – The colored portion of the eye which contains two sets of muscles. – – Regulates the size of the pupil to control the amount of light entering the eye. Pupil – – An opening in the center of the iris. – – Passage for light. Lens – – Transparent disc shaped structure located behind the iris and pupil. – – Focuses light waves onto the retina.

34. Eye Retina – – Most inner layer of the eyeball. Located under the sclera. – – Contains the photoreceptors that when stimulated by light generate nerve impulses which are then sent to the brain for interpretation. – – Rods see black and white (most active in low light) – – Cones see color (blue, green, red) (most active in bright light) * Macula Lutea is an area in the very back of the eye which has a depression called the Fovea Centralis that contains only cones and allows for high visual acuity

35. Optic Nerve This is the cranial nerve that takes information from the eye to the occipital lobe of the cerebrum to be processed Where the optic nerve attaches to the eye, the retina has no rods or cones

36. Conjunctivitis – – Conjunctivitis is the inflammation of the conjunctiva. – – Can be caused by viruses, bacteria, fungi, and allergies. The most common cause is viral. – – ”Pinkeye” is the common term for conjunctivitis. – – Treatment usually includes topical or oral medication

37. Tinnitus Tinnitus is the term used for any ear noise when there is not outside source for the sounds. Tinnitus is the term used for any ear noise when there is not outside source for the sounds. Is common. Most people have experienced it – and it only lasts for a few minutes. Is common. Most people have experienced it – and it only lasts for a few minutes. Causes are unknown but may be associated with an ear infection, ear injury, and as a reaction to various drugs including alcohol, caffeine, antibiotics and aspirin. Causes are unknown but may be associated with an ear infection, ear injury, and as a reaction to various drugs including alcohol, caffeine, antibiotics and aspirin. Also known as ringing in the ears. Also known as ringing in the ears. Treatment depends on the cause Treatment depends on the cause

38. Vertigo Also known as dizziness, light headedness, or a feeling that the room is spinning or moving. Occurs when: – – there is not enough blood to the brain – – changing the position of the head – – a viral infection of the inner ear – – or Meniere’s disease (an inner ear disease). Treatment can be physical therapy or medications

39. Middle Ear Infection (Otitis Media) Causes of otitis media include anything that causes the Eustachian (auditory) tubes to become blocked, inflamed or irritated. – – Examples include colds, sinus infections, allergies, tobacco smoke or other irritants, babies who spend a lot of time drinking on his or her back. Most common symptom is earache Treatment includes antibiotics for bacterial infections, use of warm cloths and analgesics to relieve pain and possible surgery if ear infections recur frequently.

40. Deafness Deafness is the complete or partial loss of hearing in one or both ears. May be caused by a blockage of the sound waves through the middle ear by wax build up, foreign objects, tumors or other matter. – – This type of deafness generally improves once the blockage is removed. Deafness may also result from damage to the nerves or to the Organ of Corti. – – This type of deafness is usually irreversible and may progressively get worse. Treatment may include removal of the blockage, hearing aids, or cochlear implants. www.kidshealth.org

41. Myopia Nearsightedness; when a person sees near objects clearly and distant objects are blurred. Occurs when the physical length of the eye is greater than the optical length. Symptoms include blurred vision of distant objects, squinting, eyestrain, and sometimes headaches. Treated with concave lenses or LASIK surgery

42. Hyperopia Farsightedness; when a person sees far objects clearly and near objects are blurred. Occurs when the physical length of the eyeball is too small or the focusing power of the lens is too weak. Symptoms include blurred vision of close objects, eye strain, aching eyes, and headaches while reading. Treated with convex lenses. Surgical options also available.

43. Presbyopia The normal loss of accommodation power of the eye which occurs as a consequence of aging. It occurs because the lens becomes less flexible and less able to bulge or accommodate for near vision. Symptoms are similar to those of farsightedness and include: – – blurring of close objects – – eye strain – – holding objects further from the face to focus – – headaches or fatigue from focusing on close objects. Treatments may include the use of reading glasses or bifocals.