Staying upright and age

Question 1

What systems maintain balance

Answer 1

Sense: Vision, proprioception, tactile sense, , vestibular system

CNS processing, effector mechanisms of muscle and joint

Question 2

What is proprioception

Answer 2

Sense of position, movement and force

Question 3

What is tactile sense:

Answer 3

Pressure sense on bottom of foot

Question 4

What do the otolith organs of the vestibular system do?

Answer 4

Detects linear acceleration of the head (ie walking forward)

Question 5

What do the semicircular canals of the vestibular system do?

Answer 5

Detects angular acceleration (ie nodding)

Question 6

WHat is the vestibulo-ocular reflex

Answer 6

A head reflex that stablises gaze during movement

Question 7

WHat is the vestibulo-spinal reflex?

Answer 7

Keeps the head level

Question 8

where do the stretch reflex and crossed extensor reflexes occur?

Answer 8

Spinal cord

Question 9

What is the stretch reflex

Answer 9

A notable example is the knee jerk reflex. Stretch a muscle and it contracts, maintains muscle strength and tone

Question 10

What is a crossed extensor reflex

Answer 10

Standing on a pin increases tone in standing leg for example

Question 11

What maintains postural muscle tone and rights reflexes

Answer 11

The brain stem maintains postural muscle tone and rights reflexes

Question 12

What area of the cerebral cortex controls direct control and voluntary movement

Answer 12

The primary motor cortex (M1)

Question 13

What area of the cerebral cortex performs motor acts linked to external stimuli?

Answer 13

The premotor cortex

Think catching a ball, turning to meet a sound, etc

Question 14

What does the supplementary area of the prefrontal cortex do?

Answer 14

Learned internally cued motor acts needing retrieval of memory (walking, riding a bike, playing piano)

Question 15

What does the parietal lobe do?

Answer 15

Cortical map of position in space

Question 16

What does the occipital lobe do?

Answer 16

Visual perception

Question 17

What does the basal ganglia do (oh god)

Answer 17

links to SMA/M1, timing cues for automatic movement, postural reflexes and muscle tone

Question 18

What does the cerebellum do?

Answer 18

Fine tunes postural adjustments
Makes ‘course adjustments’ for slow voluntary movement
Coordinates rapid, ballistic movements

Question 19

What are compensatory reflexes?

Answer 19

Responses to perturbation

Question 20

What are anticipatory reflexes?

Answer 20

Start before volitional movement

Question 21

how does ageing affect vision?

Answer 21

Reduced acuity, contrast sensitivity dark adaptation and depth perception

Question 22

How does ageing affect sensation?

Answer 22

Reduced proprioception and touch sensitivity in feet

Question 23

How does ageing affect the vestibular system?

Answer 23

Reduced hair cells and nerve fibres, vestibular reflexes slower and less accurate

Question 24

How does ageing affect the brain

Answer 24

Fewer neurones, fewer active fibres, leading to slower reaction times, impaired integration of sensory information

Question 25

How does ageing affect muscle

Answer 25

Disuse:

Reduced muscle mass and strength, slower contraction,

Question 26

What four broad categories cause falls

Answer 26

Accident, disease, poisons (medicines/alcohol) and environmental factors

Question 27

What diseases cause balance

Answer 27

Cataracts, macular degenration. Bifocal lenses and macular degeneration can also be a risk

Question 28

What vestibular disease can affect balance

Answer 28

Benign paroxysmal positional vertgo, where dislodged calcium carbonate crystals in posterior semi-circular canals falsely stimulate cupula. Looking up/down/turning head stimulates vertigo

Question 29

What medicines increase risk of falls

Answer 29

Pyschotropics like diazepam, as well as BP lowering agents (hypertension, heart failure, angina), also polypharmacy (4+ medications)