Senses!

SENSES

THE VISUAL SYSTEM

• The eye is a unique organ because its external anatomy may be easily assessed. Even the internal eye is visible through the cornea, where blood vessels and Central Nervous System tissues (the retina and optic nerve) may be visualized without the use of x-rays or invasive procedures.

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External Structures of the Eyelids (palpebrae) Eye

and eyelashes: protect the eye from foreign particles •   • Conjunctiva – Palpebral Conjunctiva: pink; lines inner surface of eyelids – Bulbar Conjunctiva: white with small blood vessels, covers anterior

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External Structures of the Eye Lacrimal apparatus (lacrimal gland and its ducts and passages): produces tears to lubricate the eye and moisten the cornea; tears drain into the nasolacrimal duct, which empties into nasal cavity. Tears- lipids, dissolve salts, glucose, urea, CHON, lysozyme Meibomian glands- oil secreting gland on upper and lower lids  Movement of the eye is controlled by six extraocular muscles.

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Internal Structures of the Eye Three Layers of the Eyeball – Outer Layer • Sclera: tough, white connective tissue (“white of the eye”); located anteriorly and posteriorly  • Cornea: transparent avascular tissue , convex in shape and 0.5 mm thick , through which light enters the eye. Powerful lens that bends and direct light to the retina. Derives O2 from the env’t.

Internal Structures of the Eye – Middle Layer /Uveal tract – middle vascular layer that furnishes blood supply to the retina • Choroid: highly vascular layer; located between retina and sclera, compose of 3 layers of vessels attached that both ciliary body and optic nerve; nourishes the retina • Ciliary body: anterior to choroids, secretes acqueous humor;

Internal Structures of the Eye – Middle Layer • Iris: pigmented membrane behind cornea; gives color to the eye; located anteriorly; color is determined by the degree of pigmentation; 2 iris muscles (sphincter and dilator) determine pupil diameter hence regular amount of light entering the eye • Pupil: a circular opening in the middle of the iris that constricts or dilates to regulate amount of

Internal Structures of the Eye • RETINA - Thin semitransparent layer

of nerve tissue that forms the innermost lining of the eye Inner Layer: Retina •  Light-sensitive layer composed of rods and cones (visual cells) •  a.1 Cones: specialized structure for fine discrimination and color vision; 6 million and concentrated at the center peak sensitive to red, green, and blue • Macula – center of the retina about 5mm in dm; yellowish spot with depressed center known as fovea (point of finest vision) •  a.2 Rods: more sensitive to light than cones; aid in peripheral vision; about 125 million distributed in the periphery of the retina; fxns best in

Internal Structures of the Eye • Lens: transparent body that focuses image on retina biconcave avascular, 4mm thick, 9 mm in dm, suspended behind the iris, consist of 65% H2O and 75% CHON • Fluids of the Eye – Aqueous Humor: clear, watery fluid in anterior and posterior chambers in anterior part of the eye; serves as refracting medium and provides nutrients to lens and cornea; contributes to the maintenance of intraocular pressure. – Vitreous Humor: clear, gelatinous material that fills posterior cavity of the eye; maintains transparency and form of the eye. Account about 2/3 of the eye fluid

Visual Pathways • Light passes through the cornea, aqueous humor, lens and vitreous humor. Retina (rods and cones) translates light waves into neural impulses that travel over the optic nerves. Optic nerves for each eye meet at the optic chiasm Optic nerves continue from optic chiasm as optic tracts and travel to the cerebrum (occipital lobe), where visual impulses are perceived and interpreted. •  

• BINOCULAR VISION – ability of the eyes to fuse 2 images into a single image • Near vision – contraction of the ciliary muscles which increases curvature of the lens and brings near objects into focus on the retina • Far vision – accomplished by relaxing ciliary muscle and flattening the lens

ASSESSMENT OF THE EYE 4 MOST COMMON PREVENTABLE CAUSES OF PERMANENT VISION LOSS IN DEVELOPED NATION: 1) 2) 3) 4)

Amblyopia Diabetic Retinopathy Age related maculopathy Glaucoma

 Biographical and Demographic data  Incidence of cataracts, dry eye, retinal detachment, glaucoma, esotropia, exotropia increases with age  Hereditary color vision deficits are more common among men (7%) than women (0.5%)  Exploration of Current Manifestations  Chief Complaint – most common is a change or loss of vision; it may also be headache or eyestrain. Chief complaint is often a vague problem as “something is

Symptom analysis

• Abnormal Vision – considerations include: • a refractive (focusing) error, such as in the presence of glare or halos in uncorrected refractive error, scratches on glasses, dilated pupils, corneal edema, or cataract • interference from lid ptosis (drooping eyelid)

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clouding or interference in the cornea, lens, aqueous or vitreous space malfunction of the retina, optic nerve or intracranial visual pathway flashing or flickering light- may indicate retinal traction or migraine floating spots – may represent normal vitreous body strands or pathologic presence of blood, pigment, or inflammatory cells in the vitreous body Diplopia – double vision, may be caused by refractive correction, muscle imbalance, neurologic d/o

RETINAL DETACHMENT

NORMAL VISION

MACULAR DEGENERATION -loss of central vision

GLAUCOMA -loss of peripheral vision

CATARACT -hazy & out of focus

DIABETIC RETINOPATHY -blind spot

• Abnormal Appearance – most common is red eye. Includes growth or lesions, edema, and abnormal position Diseases causing red eye: • Conjunctivitis – bacterial, viral, allergic, and irritative • Herpes Simplex Keratitis – inflammation of the cornea • Scleritis – inflammation of the sclera • Angle- closure glaucoma – sudden occlusion of the anterior chamber angle by iris tissue • Adnexal disease – stye, dacryocystitis, blepharitis, lid lesions (carcinoma), thyroid disease and vascular lesion • Subconjunctival Hemorrhage – accumulation of blood in the potential space between the conjunctiva and sclera • Pterygium – abN growth of tse that progresses over the cornea • Keratoconjunctivitis sicca – inflammation assoc. w/ lacrimal def. • Abrasions and foreign bodies – hyperemic response

Abnormal Sensation • non-specific complaints include eyestrain, pulling, pressure, fullness or generalized headache. • Eye pain • Foreign- body sensation • Deeper internal aching • Itching

Abnormal Sensation  Dryness, burning, grittiness and mild foreign-body sensation  Tearing  Increased ocular secretions usually indicate viral or bacterial infections and may also be present in allergic and non-infectious irritations.

Past Health History •

Childhood and infectious Diseases – Ask about systemic disorders with possible ocular sequelae such as diabetes mellitus, retinoblastoma, thyroid disorders, rheumatoid arthritis exposure to STDs such as syphilis and AIDS. Inquire about vaccinations,

• RETINOBLASTOMA

Major Illnesses and Hospitalizations

Ask about hypertension, multiple sclerosis, myasthenia gravis, and adult onset of thyroid disorders, rheumatoid arthritis, and DM. Inquire also when was the last eye exam and if there is any history of head or eye trauma related to vehicular accidents, sports, injury, or other unintentional events. Ocular diseases and structural problems include

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Medications- Ask for both prescription and OTC drugs (insulin, oral hypoglycemics, and thyroid replacement hormones, OTC drops, antihistamines and decongestants) Allergies – allergies on medications and other substances such as inhalants (dusts, chemicals or pollens) and contactants (cosmetics or pollens

 Family Health History – ask about strabismus, glaucoma, myopia and hyperopia, migraine, retinoblastoma, macular degeneration, retinitis pigmentosa, sickle cell anemia and DM  Psychosocial History and Lifestyle – occupational hazards, leisure activities and hobbies, and health mgmt, driving history, exposure to irritating fumes, smoke, or airborne particle, use of safety garments, insufficient lighting, harsh or glaring light, contact sports, outdoor activities such as gardening, hiking, etc.

Review of Systems (ROS) •

inquire about manifestations such as headaches and problems with sinusitis. Ask if such manifestations occur with pain or discomfort, visual changes, swelling, redness, or drainage from the eyes.

PHYSICAL EXAMINATION • Examination of the eyes include assessment of external structures, using inspection and palpation, extracocular movements (EOMs), visual acuity, and visual fields (peripheral vision)

External eye examination • •

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Eye position – assess eye position for symmetry and alignment Eyebrows –inspect for symmetry, hair distribution, skin condition and movement – Eyelids and Eyelashes for placement and symmetry PTOSIS PTOSIS ENTROPION EXTROPION ENTROPION

 Blink response – an involuntary reflex that occurs bilaterally up to 20 times a minute  Eyeballs – palpate for symmetry and firmness.  Lacrimal Apparatus – observe the area for swelling or tenderness. Inspect the area between the lower lid and the nose. Gently palpate the area over the lower orbit rim near the inner canthus.

• Conjunctivae and Sclerae – inspect for color changes, texture, vascularity, lesions, thickness, secretions and foreign bodies. • Corneal reflex – performed to assess the function of the 5th (trigeminal) cranial nerve. • Cornea –inspect for abnormalities such as surface irregularities and cloudiness (opacity). – ARCUS SENILIS

» Anterior Chamber – inspect for clarity and transparency with no shadow cast upon the irises. » Iris and Pupil – assess or test for PERRLA, and direct and consensual response. » AbN if with photophobia, irregular or unequal pupils (anisocuria) » AbN pupil may be due

Ocular motility/ Extraocular Muscle Test • provides information about the extraocular muscles; the orbit; the oculomotor, trochlear and abducen nerves; the brain stem connection and the cerebral cortex. Note for speed, smoothness, range and symmetry of ocular movements and observe for unsteadiness of fixation.

NYSTAGMUS

Corneal Light Reflex Test (Hirschberg’s Test) • – determines eye alignment • STRABISMUS • TROPIA/PHORIA • • • •

ESOTROPIA EXOTROPIA HYPERTROPIA HYPOTROPIA

Cover-Uncover Test

• – assess eye muscle function and alignment for tropia and phoria.

Visual acuity •

Testing visual acuity is the standard and routine method used to determine the clarity of the ocular media (cornea, lens and vitreous) and the function of the visual pathway from the retina to the brain. Traditionally measured with the SNELLEN CHART at a distance of 20 feet.

• Test near vision w/ card or newsprint held 12 to 14 in from the client’s eyes • Correctives lenses maybe worn if needed • If client becomes familiar with the letters through repeated exam’n, have the client read the letters backward • If client can read most of the letter in a particular line but misses 1 or 2, document the visual acuity as 20/40

SNELLEN CHART

Visual acuity – A 20/20 vision is normal; the patient can read at 20 feet what a person with normal vision can read at 20 feet. – A visual acuity of 20/60 means that the patient can read at a distance of 20 feet only what a patient with a normal vision can read at 60 feet

Visual acuity – The patient with myopia has results of 20/30 or greater, signifying that the patient can read at 20 feet only what a person with normal vision can read at 30 feet. – Hyperopia results are 20/15 or less; that is the patient can read at 20 feet what a person with normal vision can read at 15 feet. – Legal blindness is defined as 20/200 or less with corrected vision (glasses or contact lenses) or less than 20 degrees of visual field in the better eye.

TEST FOR COLOR VISION • ISHIHARA PLATE • Causes: nutritional problems, optic nerve d/o and problems w/ fovea centralis • Use for screening people seeking a license to operate a motor vehicle or for employment • Scotoma – central area blindness

Visual fields -Used to evaluate peripheral vision • Two Methods – Confrontational Method – Perimetry assesses peripheral vision, visual fields PERIMETRY

Internal Eye Examination • •

Opthalmoscopic Exam Direct opthalmoscopy – hand-held direct opthalmoscope provides a magnified (x15) image of the fundus (posterior portion of the eye), and detailed view of disc and retinal vascular bed

• Indirect opthalmoscopy – provides a stereoscopic picture over a large area of the retina. The light source comes from the hand mounted light – The examiner holds a convex lens in front of the client’s eye, and through a viewing device attached to the headband, sees inverted reversed image – It provides a binocular visual perception with depth perception and permits a wider field of view compared with the direct method

Tonometry • – a method of measuring intraocular fluid pressure with the use of calibrated instruments that indent or flatten the corneal apex. • Normal intraocular pressure (IOP): 12-

2 types of tonometer • Measures the force required to flatten the corneal apex by standard amount

• Applanation tonometer

Hand-held tonometer

• Measures the amount of tension on the cornea. First, the cornea is anesthetized w/ topical anesthetic drop. While the client sits and looks straight forward, the tonopen is held perpendicular to the cornea and tapped several

Slit-Lamp Examination • Use to illuminate and examine the anterior segment of the eye under magnification an optical cross section of anterior chamber

AUDITORY SYSTEM Hearing and balance problems can reduce the ability to communicate, limit social activities, and hinder the constructive use of leisure time. The ears are a pair of complex sensory organs for both hearing and balance. Their location on either side of the head produces binaural hearing, allows the detection of sound direction, and aids in maintaining equilibrium.

STRUCTURES OF THE EAR  

External Ear Auricle (Pinna): outer projection of the ear composed of cartilage and covered by skin; collects soundwaves.

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Parts of cartilage that hold the pinna – – – –

Helix – outer rim of the pinna Lobule – inferior portion Concha – deepest part leading to the ear canal Tragus and antitragus – triangular folds of cartilage that protect over the entrance to the ear canal

STRUCTURES OF THE EAR  

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External Ear External auditory canal : lined with skin; glands secrete cerumen, providing protection; transmits sound waves to tympanic membrane. Tympanic membrane (eardrum): located at the end of the external canal; vibrates in respond to sound and transmits vibrations to middle ear. Thin, translucent, pearly gray membrane obliquely directed downward and inward

Middle Ear  

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A. Ossicles Three small bones: Malleus (Hammer) attached to tympanic membrane, Incus (Anvil), Stapes (Stirrups) Ossicles are set in motion by sound waves from tympanic membrane. Sound waves are conducted by vibration to the foot plate of the stapes in the oval window ( an opening between the middle and the inner ear.)

Middle Ear B. Eustachian Tube: 

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B. Eustachian Tube: connects nasopharynx and middle ear; brings air into middle ear, thus equalizing pressure on both sides of the eardrum (maintains ventilation and pressure). C. Mastoid Process: bony protruberance behind the lower portion of the pinna. Close to several impt cranial structures and internal carotid artery

Inner Ear (Labyrinth) A. Cochlea

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Contains Organ of Corti, the receptor end-organ for hearing Transmits sound waves from the oval window and initiates nerve impulses carried by CN VIII (acoustic nerve) to the brain (temporal lobe of cerebrum.)

B. Vestibule (utricle and saccule) C. Semicircular Canal

ASSESSMENT OF THE EAR • OTOLOGIC HISTORY  Biographical and Demographic Data  Current Health  • Chief complaint – common chief complaints are as follows: hearing loss, pain, tinnitus, ear drainage, loss of balance, vertigo, dizziness, nausea or vomiting. 

Symptom analysis 

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Hearing loss – may occur suddenly or gradually and can accompany the normal aging process. The loss may be conductive, sensorineural or r/t CNS d/o The patient may report inability to hear certain words or sounds or that sounds are muffled. Pain may be perceived as a feeling of fullness in the ear.

Symptom analysis Ear drainage can be bloody (sanguineous), clear (serous), mixed (serosanguineous), or contain pus (purulent). Drainage may also be accompanied by an odor.  Tinnitus  Loss of balance may be accompanied by vertigo. 

VERTIGO 

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a sensation of motion while the person is not moving DIZZINESS – feeling of unsteadiness and a feeling of mov’t within the head or light headedness

Past Health History Childhood and Infectious Diseases Common childhood diseases involving the ears include the following:  acute middle ear infections (Otitis media)  eardrum perforations resulting from Otitis media  complications of ear infections such as chronic Otitis media, frequent upper respiratory tract infections  acute and chronic sinus infections  A pneumococcal conjugate vaccine shoes good promise in preventing initial ear infection and reducing subsequent episodes of acute otitis media in infants and children  Utero exposure to maternal influenza and rubella may result in congenital hearing loss in the child  Premature birth may cause hearing problems

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Infectious diseases with ear sequelae include mumps, measles, and meningitis. Inquire if the patient has been immunized for mumps, measles, and haemophilus influenza type b (Hib).

Major Illnesses and Hospitalizations –

inquire about a history of upper respiratory tract infection, tonsillectomy or adenoidectomy, ear surgery, trauma to the head or ear such as severe blow or sustained loud noise exposure or concussion from sudden changes in air pressure.

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Medications – use of drugs like aspirin, aminoglycosides, analgesics, salicylates, quinine, chemotherapeutic agents and protozoal agents • Allergies – allergies to medications and to other substances, allergies resulting to stuffiness and congestion (obstructs flow of air b/w the middle ear and nose so that air pressure cannot be equalized).

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• Psychosocial History – occupational hazards, environmental exposure and leisure activities and hobbies. 50 dB – ordinary speech 70 dB – heavy traffic 80 dB – uncomfortable to the human ear 85-90 dB – exposure to these for month or years could cause cochlear damage • Review of Systems (ROS) – ask about the problems with the nose, sinuses, mouth, pharynx and throat. Has the patient experienced head trauma, loss of balance, dizziness or vertigo

PHYSICAL EXAMINATION 

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Examination of the ear includes assessment of hearing acuity, balance and equilibrium. – Note size, configuration, and angle of attachment to the head. Note whether ears protrude if so the degree of protrusion, the color of the skin of the ears . Note any lumps, lesions, cysts. Palpate and manipulate the pinna to detect, tenderness, nodules or tophi Inspection and palpation of auricle, periauricular area, and mastoid area

Examination of the ear canal 

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2 Methods: – Direct observation – Otoscopic examination Otoscope – a device that consist of a handle, a light source, magnifying lens, and an attachment for visualizing the earcanal and ear drum Pneumatic device – bulb to instill air to the eardrum to test its mobility and integrity

C. Tests for Auditory Acuity –

assessment of the middle and inner ear for hearing.

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Whispered voice or ticking watch test

C. Tests for Auditory Acuity •

Weber test

C. Tests for Auditory Acuity •

Rinne Test

Tests for Vestibular Acuity  

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Romberg test Test for Nystagmus Caloric test / Oculovestibular reflex test

LABORATORY TESTS  Blood

test  Cultures  Tests for Presence of Cerebrospinal Fluid  Tissue Specimens

SENSES