Neuromuscular system

Question 1

What does the autonomic nervous system do

Answer 1

Regulates the function of our internal organs and controls skeletal muscles.

Question 2

What are the sympathetic and parasympathetic systems part of and what do they do

Answer 2

Peripheral nervous system and they transmit information from the rain to the parts of the body that need adjusting in preparation for excersise.

Question 3

What does the sympathetic nervous system

Answer 3

Prepares the body for excersise and is refered to as ‘flight or fight response’

Question 4

What does the parasympathetic nervous system do

Answer 4

Relaxes the body and slows down high energy functions

Question 5

What are the three types of muscle fibres

Answer 5

• Slow oxidative (type I) (slow twitch
• Fast oxidative glycolytic (type IIa)
• Fast glycolytic (type IIb)

Question 6

Fast twitch IIa have…

Answer 6

Fast contraction speed, produce energy anaerobically, large motor units, medium mitochondrial density, medium fatigability

Question 6

Slow twitch have….

Answer 6

Slower contraction speed, produce energy aerobically, small motor units, high mitochondrial density, low fatigability

Question 7

Fast twitch IIb have…

Answer 7

Fast contraction speed, produce energy anaerobically, large motor units, low mitochondrial density, high fatigability

Question 8

What does a motor unit consist of

Answer 8

Motor neurone and its muscle fibres

Question 9

What do muscle fibres do

Answer 9

Work with the nervous system so that a contraction can occur

Question 10

What does the motor neurone do

Answer 10

Transmits the nerve impulse to the muscle fibre

Question 11

What does each motor neurone have at the end

Answer 11

End of their branches there is a neuromuscular junction on the muscle fibre.

Question 12

What is the all or none law

Answer 12

Once the motor neurone stimulates the muscle fibres, either all of them contract or none of them contract. It is not possible for a motor unit to partially contract.

Question 13

How are slow/fast twitch motor units chosen

Answer 13

The brain will recruit the correct motor unit based on the excersise. Such as if a greater force of contraction is needed fast twitch units are chosen.

Question 14

How to increase the strength of contraction

Answer 14

Frequency (Wave summation + Spatial summation)
Amount of motor units
Recruting differenet types of motor units (slow+fast)

Question 15

What is wave summation

Answer 15

Where there is a repeated nerve impulse with no time to relax so a smooth, sustained contraction occurs, rather than twitches.

Question 16

How does the frequency of stimuli affect wave summation

Answer 16

The greater the frequency the greater tension is developed. Each time the nerve impulse reaches the muscle cell calcium is released which is required for a muscle contraction

Question 17

What is a tetanic contraction

Answer 17

A sustained muscle contraction caused by a series of fast repeating stimuli

Question 18

What is spatial summation

Answer 18

When the strength of a contraction changes by altering the number and size of the muscles motor units.

Question 19

When does spatial summation occur

Answer 19

When impulses are received at the same time at different places on the neurone which add up to fire the neurone

Question 20

What does PNF stand for

Answer 20

Proprioceptive neuromuscular facilitation

Question 21

What is PNF

Answer 21

An advanced stretching technique including the CRAC technique - contract, relax, antagonist, contract.

Question 22

What are the regulatory mechanisms in PNF

Answer 22

Proprioceptors such as muscle spindles, golgi tendon organs

Question 23

What do proprioceptors do

Answer 23

Inform the body of the extent of movement that has taken place

Question 24

What are muscle spindles

Answer 24

Sensitive proprioceptors that lie between skeletal muscle fibres.

Question 25

Why are muscle spindles often called stretch receptors and what is the process in the stretch reflex

Answer 25

Often called stretch receptors as they provide information to CNS about the muscle. This is then sends an impulse back telling the muscle to contract triggering the stretch reflex

Question 26

What does the stretch reflex prevent

Answer 26

Causes the muscle to contract preventing overstretching and injury

Question 27

What are golgi tendon organs

Answer 27

Found between muscle fibre and tendon detecting tension in the muscle.

Question 28

What is the autogenic inhibition

Answer 28

When contracting isometrically Golgi tndon organs sense the increase in muscle tension and send inhibitory signals to the brain allowing the antagonist to relax and lengthen