Effects of Aging on Muscle and Motor Functions
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Questions and Answers

What percentage of Type I muscle fibers is typically lost with aging?

  • 20% (correct)
  • 10%
  • 30%
  • 40%

    • How is the rate of contraction in older adults affected according to research?

  • It drops by approximately 30%.
  • It increases by 50%.
  • It remains the same as younger adults.
  • It drops by approximately 50%. (correct)

    • What is the effect of aging on motor unit firing rates?

  • They fire at lower rates. (correct)
  • They increase significantly.
  • They remain unchanged.
  • They only fire during physical activity.

    • What happens to the vestibulo-ocular reflex (VOR) gain as people age?

    <p>It slightly reduces.</p> Signup and view all the answers

    What type of muscle fibers experience the greatest loss with aging?

    <p>Type II glycolytic fibers.</p> Signup and view all the answers

    How much loss of vestibular nerve fibers occurs with aging?

    <p>40%</p> Signup and view all the answers

    What is a consequence of slower twitch contractions in older adults?

    <p>Slower torque development rate.</p> Signup and view all the answers

    What is believed to enhance the remaining vestibular receptors as people age?

    <p>Central gain enhancement.</p> Signup and view all the answers

    What is the term used to describe the general reduction in muscle mass associated with aging?

    <p>Sarcopenia</p> Signup and view all the answers

    Which type of muscle fibers experiences the smallest loss with aging?

    <p>Type I (slow, oxidative)</p> Signup and view all the answers

    How does the decline in motor neuron number affect muscle innervation with age?

    <p>Muscle fibers either atrophy or shift to larger motor units</p> Signup and view all the answers

    Which muscle group typically shows a greater effect of atrophy with aging?

    <p>Lower limbs</p> Signup and view all the answers

    What phenomenon allows for a greater amplitude EMG despite a reduction in the number of motor neurons?

    <p>Remodeling of the motor pool</p> Signup and view all the answers

    What is the primary cause of lost muscle fibers in older adults?

    <p>Deprivation of innervation</p> Signup and view all the answers

    Which of the following is not a characteristic of aging in the motor system?

    <p>Increased muscle fiber size</p> Signup and view all the answers

    What factor primarily contributes to balance control issues in older adults?

    <p>Decline in sensory systems</p> Signup and view all the answers

    What is the approximate percentage loss of hair cell receptors due to aging?

    <p>40%</p> Signup and view all the answers

    Which age group showed more sensitivity to virtual rotations evoked with EVS at higher frequencies?

    <p>Older adults</p> Signup and view all the answers

    How does aging affect visual acuity?

    <p>It causes macular degeneration, reducing visual acuity</p> Signup and view all the answers

    What condition occurs during the aging of the eye that contributes to blurriness of vision?

    <p>Misshaped eyeballs</p> Signup and view all the answers

    What factor contributed to the reduced perceptual sensitivity to head rotations in older adults?

    <p>Loss of vestibular nerve fibers</p> Signup and view all the answers

    What impact does visual acuity reduction have on daily life?

    <p>Decreases contrast sensitivity</p> Signup and view all the answers

    At which frequency did young adults have a lower threshold in response to virtual rotations?

    <p>0.5 Hz</p> Signup and view all the answers

    What are 'Drusen' in the context of macular degeneration?

    <p>Build-ups of lipids and proteins</p> Signup and view all the answers

    Which reflex shows gain enhancement as determined by Stochastic Vestibular Stimulation (SVS)?

    <p>Vestibulo-spinal reflex</p> Signup and view all the answers

    What method is used to measure eye torsion when assessing vestibulo-ocular reflex gain?

    <p>Ink dots on the sclera</p> Signup and view all the answers

    How is the vestibulo-ocular reflex gain affected by aging?

    <p>It is slightly reduced due to central gain enhancement.</p> Signup and view all the answers

    Which of the following frequencies is commonly associated with daily life experiences and is important for vestibular stimulation?

    <p>1 Hz</p> Signup and view all the answers

    How much is perceptual sensitivity to head rotations reduced in older adults compared to younger adults at a frequency of 1 Hz?

    <p>Decreased from 1.3 deg/s to 2.4 deg/s</p> Signup and view all the answers

    At what frequency range do older adults exhibit greater gain to Electrical Vestibular Stimulation (EVS)?

    <p>0.5 to 5 Hz</p> Signup and view all the answers

    What type of current is applied during Stochastic Vestibular Stimulation (SVS)?

    <p>Low amplitude noisy currents</p> Signup and view all the answers

    What role does central gain enhancement play in the aging sensory systems?

    <p>It counteracts reduced perceptual sensitivity</p> Signup and view all the answers

    What is the approximate loss of vestibular nerve fibres with aging?

    <p>40%</p> Signup and view all the answers

    What is the impact of aging on vestibular nerve fibers?

    <p>Approximately 40% loss occurs.</p> Signup and view all the answers

    Why is the torsional vestibulo-ocular reflex (VOR) significant in studies of aging?

    <p>It assesses central gain enhancement.</p> Signup and view all the answers

    At what angular velocity was the threshold for young adults measured at 0.1 Hz?

    <p>3 deg/s</p> Signup and view all the answers

    What statistical significance level was observed in the effect at 1 Hz?

    <p>p = 0.08</p> Signup and view all the answers

    Which head positioning method was used to examine head rotations?

    <p>Positioning the head downward</p> Signup and view all the answers

    What does the Useful Field of Vision primarily refer to?

    <p>The area of the visual scene from which information can be processed</p> Signup and view all the answers

    How does aging affect vibration detection in older adults?

    <p>They require larger vibrations to feel them</p> Signup and view all the answers

    What is a key predictor of standing balance stability in older adults?

    <p>Sensitivity of the foot soles</p> Signup and view all the answers

    What proportion of adults aged 65 and older experiences falls each year?

    <p>1 in 3</p> Signup and view all the answers

    What does higher postural sway in older adults correlate with?

    <p>Weaker cutaneous reflexes</p> Signup and view all the answers

    What estimated annual cost do falls account for in the U.S. government by 2020?

    <p>$54.9 billion</p> Signup and view all the answers

    Which of the following is NOT a consequence of aging on balance control?

    <p>Increased sensitivity to cutaneous input</p> Signup and view all the answers

    What is the primary reason for the high incidence of falls in older adults?

    <p>Decreased Useful Field of Vision</p> Signup and view all the answers

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