Lec 18 - sensory (ear)

what happens to mechanical receptors with aging? (4)

Reduced ability to sense temperature changes and extremes

Increased two-point threshold

Can’t detect light touch

Reduced pressure sensations

Aging-related tast changes? (2)

Taste buds decrease in number and size

• After age 50 for men

• After age 40 for women

• Salt and sweet most affected

Decreased sense of thirst and dry mouth

sense of smell affect with aging? (4)

Affects 50% of adults over age 60

• Reduction in sensory cells

• Reduction in neurotransmitter levels

• Olfactory membrane changes

• Reduction of hippocampus

  • Smell and memory

Reduced smell affects taste

how is taste altered? (5)

Contributing factors

Oral conditions

• Poor dentition

• Improperly fitting dentures

• Infections

Olfactory function

Medications

Diseases

Surgical interventions

What is xerostomia? potential causes? (3)

Dry Mouth

• 1 in 3 people over age 60

• Results from salivary gland dysfunction

Potential causes

• Systemic diseases

• Radiation

• Medications

What implications occur with xerostomia? (7)

Altered taste

Dysphagia (difficulty swallowing)

Periodontal disease

Speech difficulties

Dry lips and mucosa

• Increased infections

Halitosis

Sleeping problems

What is olfactory dysfunction?

reduced or complete loss of smell

• Impacts 50% of adults over age 60

• reduction of chemoreceptors

potential causes of olfactory dysfunction? (7)

Olfactory nerve damage

Upper respiratory infections

Head trauma, stroke, Alzheimers

Inflammatory conditions

Neurodegenerative diseases

Medications

Smoking

What is the structure of the ear?

Pinna and auditory canal

• tympanic membrane

Malleus, stapes, and incus bones

semicircular canals and cochlea

• hearing and equilibrium

What hearing changes occur to external ear with aging?

Auricle wrinkles and droop

Cerumen (ear wax)

• Becomes drier

• Accumulates in ear canal

What hearing changes occur to middle ear with aging?

Stiffer ear bones

• Otosclerosis

• Reduced amplification

Thicker tympanic membrane

What hearing changes occur to inner ear with aging?

Increased pruritis (itchiness)

Atrophy of organ of Corti and cochlear neurons

• Starts at age 40

Loss of sensory hair cells

• Born with 40,000

• Don’t regenerate after damage

Loss of high sound frequencies

signs and symptoms of the ear? (4) tests? (2)

Otalgia (ear pain)

Deafness

Vertigo (dizziness)

Tinnitus (ringing)

Tests

• Otoscopy

• Audiometry

Who is hearing impairment common in?

Older adults

Caucasian

Males

Rf for hearing impairments? (7)

Long-term exposure to excessive noise

Impacted cerumen

Ototoxic medications

• Some NSAIDS, antibiotics

Tumours

Smoking / alcohol

History of middle ear infections

Chemical exposure

What is conductive deadness? Causes? solution?

external or middle ear disorders

• ↓ conduction

Causes

• impacted cerumen

• Otosclerosis (stiff bones)

• ruptured eardrum

Hearing aids

What is sensorineural deadness? Causes? solution?

Cochlear or auditory nerve damage

• ↓ impulses to brain

Causes

• damaging noise levels

• ototoxic medications

• Infections

• Aging

• Tumours

• Alcohol

  • Damages hair cells

• Smoking – interferes with neurotransmitters

What is presbycusis?

Progressive sensory deafness

• related to aging

• hearing loss with aging

Hearing aids often needed

types of presbycusis? (3)

Sensory

• Loss of hair cells

Metabolic/Strial

• Loss of blood supply to cochlea

Neural

• Loss of nerve fibres and neural elements

What is tinnitus? causes? (5) solution?

Ringing in the ears

• Perception of sound without sound stimulus

Potential causes

• Medications

• Infections

• Neurological conditions

• Disorders related to hearing loss

• Inner ear changes

Staying hydrated may help

What is Meniere’s disease? Symptoms? (3) treatment? (4)

Chronic disease of inner ear

• May be due to high pressure in ear (unclear)

Symptoms:

• Tinnitus / Vertigo

• hearing loss

• Attacks last hours - days

Treatment:

• Low-salt diet

• Diuretics

• Antihistamines

• Smoking cessation