Effects of ageing on the neuromuscular system

Question 1

What three sources does the a-motorneurons (a-MN) receive neural input from?

Answer 1

1. efferent (descending) neuron from the brain
2. afferent (sensory) neurons from tissues
   3.spinal neurons (including interneurons)

Question 2

The premotor cortex helps coordinate what?

Answer 2

Sensory cues

Question 3

The supplementary motor area helps provide?

Answer 3

programming the motor plan?

Question 4

The primary motor cortex inites and executes what function?

Answer 4

Movement

Question 5

The cerebral cortex helps with…

Answer 5

Planning and execution

Question 6

The cerebellum provides…

Answer 6

coordination, precision, timing, processing of most sensory inputs

Question 7

Basal ganglia helps…

Answer 7

intitiate and execute complex tasks

Question 8

The hypothalamus helps…

Answer 8

initiate movement associated with feeding and drinking

Question 9

The brainstem provides a minor role in…

Answer 9

coordinating movement

Question 10

Muscle volume and cross sectional area as we age does what?

Answer 10

We see reductions

Question 11

What tissue increases as we age?

Answer 11

Non-muscle tissue (fat and connective tissue)

Question 12

Which muscle fibre type reduced with age the most?

Answer 12

Type 2 (fast twitch)

Question 13

Muscle fibres see an accelerated loss after what age?

Answer 13

60

Question 14

What underlying mechanisms cause muscle fibre reduction with age?

Answer 14

INactivity and immobilisation, changes in demands for force, velocity and duration

Question 15

Loss of type 2 fibres with age can be attributed to two factors?

Answer 15

Sometimes its a reduction in area due to decreased number of fibres, and also due to a reduction in size of the fibres

Question 16

We see a loss of ____ when we reach 60?

Answer 16

Alpha motor neurons (especially fast) from the spinal cord, with subsequent degeneration of their axons

Question 17

How does nerve conduction velocity decrease with age?

Answer 17

Demyelinisation

Question 18

Muscle contractility has two factors impacted with age which are?

Answer 18

An increase in peak tension and an increase in time to relaxation

Question 19

How can force be adjusted?

Answer 19

Varying the firing rate (or stimulation frequency) of MU’s

Question 20

What does “firing” refer to?

Answer 20

depolarisation of the neuron (impulse) and firing rate is measured in 1Hz

Question 21

Which hormone increases with ageing

Answer 21

insulin

Question 22

Which hormones decrease with age

Answer 22

Insulin sensitivity, growth hormone, IGF-I and testosterone

Question 23

What diseases have an increased prevalence with ageing?

Answer 23

Parkinsons, Opthalmoplegic muscular dystrophy, essential tremor, huntingtons disease, dystonia, and myoclonus