Bài giảng Medical Assisting - Chapter 33: The Special Senses System

ChapterPowerPoint® to accompany Second EditionRamutkowski  Booth  Pugh  Thompson  WhickerCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.Medical AssistingChapter 331Objectives (cont.)33-1 Spell, define, and correctly use the Key Terms in this chapter.33-2 Describe the anatomy of the nose and the function of each part.33-3 Describe how smell sensations are created and interpreted.33-4 Describe the anatomy of the tongue and the function of each part.The Special Senses System233-5 Describe how taste sensations are created and interpreted. 33-6 Name the four primary taste sensations.33-7 Describe the anatomy of the eye and the function of each part.33-8 Describe various disorders of the eye.33-9 Trace the path of a visual image through the eye and to the brain for interpretationObjectives (cont.)The Special Senses System333-10 Describe the anatomy of the ear and the function of each part.33-11 Describe various disorders of the ear. 33-12 Explain how sounds travel through the ear and are interpreted in the brain.33-13 Explain the role of the ear in equilibrium.Objectives (cont.)The Special Senses System4Introduction Special senses that have sensory receptors located within relatively large, sensory organs in the head; Nose – smell Tongue – taste Eyes – vision Ears – hearing and equilibrium 5 Nose Smell receptors Olfactory receptorsChemoreceptorsRespond to changes in chemical concentrationsChemicals must be dissolved in the mucus of the nose to activate smell receptors 6Smell Sensationsend the information along olfactory bulbs and tracts different areas of the cerebrum cerebrum interprets the information as a particular type of smell Smell receptors are activated, they send their information to the olfactory nerves7Smell undergoes sensory adaptationSame chemical can only stimulate smell receptors for a limited amount of time Smell receptors no longer respond to the chemical and you can no longer smell You smell perfume when you first encounter it but in a few minutes, you no longer smell it. Smell Sensation (cont.)8Apply Your KnowledgeYou notice an odor coming from a patient when you enter the exam room. Why would the patient not be able to smell it?9Apply Your Knowledge -AnswerAfter a few minutes, smell receptors no longer respond to the chemical and the patient can no longer smell the odor. You notice an odor coming from a patient when you enter the exam room. Why would the patient not be able to smell it?10TongueTaste or gustatory receptors –taste budsFound on "the bumps" of the tongue (papillae)Taste buds are microscopic Also on roof of your mouth and walls of your throat Click for Larger View11Tongue (cont.)12Taste SensationFour types of taste cells - activated by a particular group of chemicals Sweet - tip of the tongue.Sour - sides of the tongue.Salty - tip and sides of the tongue.Bitter - back of the tongue 13Outer layerScleraCorneaMiddle layerChoroidIrisCiliary bodyInner layerRetina – contains rods and conesEye 14Outer layer:Sclera is the “white of the eye” and does not allow light to enter the eye Cornea - anterior to the sclera Allows light to enter the eye (“window of the eye”) Contains sensory receptors can detect even the smallest of particles Eye (cont.)15Middle layer:Also called vascular and pigmented layerRichly supplied with blood vessels and pigmentsChoroid lines the sclera and absorb extra lightCiliary body functions to hold and move the lens to focus the eye.Cloudy areas on the lens are called “cataracts.”Hole in iris is called the pupil.Eye (cont.)16Inner layer:Also called the retinaRichly supplied with blood vessels and pigmentsContains visual receptors called rods and conesRods allow us to detect black, white, and gray shades and images in dim light.Cones allow us to see images in bright lightCones allow us to see color.Eye (cont.)17Eyelid - skin, muscle, and dense connective tissue. Orbicularis oculi muscle and is responsible for blinking Conjunctivas - mucous membranes Line the inner surfaces of the eyelids Fold back onto the anterior surface of each eyeball Eye (cont.)18Vitreous humorLensChoroidScleraRetinaPupilIrisCorneaConjunctivaEye (cont.)Draw a line to each part of the eye.19Lacrimal apparatus consists of lacrimal glands and nasolacrimal ducts. Mostly water but also contain enzymes that can destroy bacteria and viruses Lacrimal glands are on the lateral edge of each eyeball and they produce tears. Outer oily layer that prevents them from evaporating When a person cries, the abundance of tears entering the nose produces the “runny nose” associated with crying. Tears20Extrinsic eye muscles are skeletal muscles that move the eyeball Each eyeball has 6 extrinsic eye muscles attached to them that move the eyeball Superiorly Inferiorly Laterally MediallyEye Muscles21Eye works like a cameralight passes through the cornea, pupil, lens and fluids of the eye, which focuses the light onto the retinaThe image is projected upside down on the retinaRetina converts the light into nerve impulses that are sent to the brain The brain interprets these impulses, turns the image right-side up and develop a picture of the object.Process of Seeing22Parts of the EyeChoroidAbsorbs extra light in eyeCiliary BodyHolds lens, moves lens for focusingIrisControls amount of light entering eyeLensFocuses light onto retina23RetinaContains visual receptorsRodsAllow vision in dim light, detect black-and-white images, detect broad outlines of imagesConesAllow vision in bright light, detect colors, detect detailsOptic NerveCarries visual information from rods and cones toward the brainParts of the Eye (cont.)24Aqueous Humor -nourishes structures in anterior eye cavityVitreous Humor -holds retina in place; maintains shape of eyeballParts of the Eye (cont.)25Common eye problems Conjunctivitis - inflammation of the conjunctivaBlepharitis - inflammation of the eyelidCorneal abrasions - scratching of the corneaEye Disorders (cont.)26Astigmatism - cornea has an abnormal shape which causes blurred images during distant or near vision. Amblyopia - commonly called “lazy eye” Cataracts - structures in the lens that prevent light from going through the lens Dry Eye Syndrome - one of the most common eye problems treated by physicians Glaucoma - condition in which too much pressure is created in the eye by excessive aqueous humor Eye Disorders (cont.)27Hyperopia - called farsightednessMyopia - called nearsightedness Presbyopia - a common eye disorder that develops with age -difficulty seeing objects close up Eye Disorders (cont.)28Macular Degeneration -a progressive disease that usually affects people over 50. It occurs when the retina no longer receives an adequate blood supply.Retinal Detachment -occurs when the layers of the retina separate. Considered a medical emergency and if not treated right away, leads to permanent vision loss. Eye Disorders (cont.)29Eye Safety and Protection WorksCommon eye injuries that occur whileplaying a sport include: Scratched corneas Inflamed iris Bleeding in the anterior eye chamber Traumatic cataracts Inflamed retinas Eye socket fractures30The EarExternal earAuricleTympanic membraneMiddle earMalleusStapesIncusInner ear - labyrinthCochleaSemicircular canals31The Ear (cont.)AuricleTympanic membraneEar canalEustachian tubeAuditory nerveCochleaSemicircular canalsDraw a line to each part of the ear.32Hearing ProcessSound enters the external ear which makes the eardrum vibrateThe middle ear amplifies the vibrations and the waves cause the tiny hairs in the cochlea to bend.Movement of the hairs triggers nerve impulses.The impulses are transmitted via auditory nerve to the brain.The brain perceives the sound.33Ear and Balance Brain constantly monitors the position of one’s body on the information received from the semicircular canals, eyes and muscles.Change in position is detected by the canal and passed to the brainThe brain uses this information to maintain balance34Disorders of the Ear Conductive deafness -produced when sound waves cannot be conducted through the ear Sensorineural deafness - produced when neural structures associated with the ear are damaged Tinnitus - ringing in the ear35Apply Your KnowledgeWhat would happen if a patient had damage to the middle ear?36Apply Your Knowledge -AnswerThe middle ear amplifies the vibrations and the waves cause the tiny hairs in the cochlea to bend so if there was damage to this part of the ear, the patient may have impaired hearing.What would happen if a patient had damage to the middle ear?37How to Recognize Hearing Problems in ChildrenHearing problems in babies and toddlers are not easy to recognizeBy 4 months the infant should:Startle by loud noises (barking dog, hand-clap, etc.)Wake up at the sound of voices.Turn head or move eyes to follow a soundRecognize the mother’s voice better than other voices 38Summary Medical AssistantKnowledge of the Special Senses will assist you in providing care for the patient with diseases and disorders of the special senses.39End of ChapterEnd of Chapter40