The Neuromuscular System - Applied Anatomy and Physiology (Paper 1)

Question 1

What is the neuromuscular system

Answer 1

Where the muscles and nervous system work together to allow movement

Question 2

When do changes in the neuromuscular system take place

Answer 2

Before,during and after the exercise

Question 3

What are the types of muscle fibres

Answer 3

Slow oxidative (type 1 or slow twitch fibres)
Fast oxidative glycolytic (type 2a)
Fast glycolytic (type 2b)

Question 4

What are slow twitch fibres

Answer 4

-slower contraction speed than fast twitch fibres
-better adapted to lower intensity exercise
-Produce most of their energy aerobically

Question 5

What are fast twitch fibres

Answer 5

-faster contraction speed than slow twitch fibres
-generate much greater force of contraction
-fatigue very quickly
-produce most energy anaerobically
-two types 2a 2b

Question 6

What are type 2a fibres

Answer 6

-fast oxidative glycolytic
-fibres more resistant to fatigue than 2b
-used for 1500m in athletics where a longer burst of energy is needed

Question 7

What are type 2b fibres

Answer 7

-Fast glycolytic
-fibres fatigue much quicker than type 2a
-used for highly explosive event e.g. 100m

Question 8

What is the contraction speed of each of the muscle fibres

Answer 8

Type 1: Slow
Type 2a: Fast
Type 2b: Fast

Question 9

What is the motor neurone size in each of the muscle fibres

Answer 9

Type 1: Small
Type 2a: Large
Type 2b: Large

Question 10

What is the motor neurone conduction capacity in each fibre

Answer 10

Type 1: Slow
Type 2a: Fast
Type 2b: Fast

Question 11

What is the force produced in each of the muscle fibres

Answer 11

Type 1: low
Type 2a: High
Type 2b: High

Question 12

What is the fatigability on each if the muscle fibres

Answer 12

Type 1:low
Type 2a:medium
Type 2b:High

Question 13

What is the mitochondrial density in each if the muscle fibres

Answer 13

Type 1: high
Type 2a: medium
Type 2b: low

Question 14

What is the myoglobin content on each if the muscle fibres

Answer 14

Type 1: High
Type 2a: medium
Type 2b: low

Question 15

What is the capillary density in each muscle fibre

Answer 15

Type 1:high
Type 2a:medium
Type 2b:low

Question 16

What is the aerobic capacity on each muscle fibre

Answer 16

Type 1:very high
Type 2a:medium
Type 2b:low

Question 17

What is the anaerobic capacity of each muscle fibre

Answer 17

Type 1: low
Type 2a: high
Type 2b: very high

Question 18

What is the glycolytic enzyme activity of each muscle fibre

Answer 18

Type 1: low
Type 2a: high
Type 2b: very high

Question 19

What is the fibre type determined by

Answer 19

Genetics, however it is possible to increase the size of muscle fibres through training (hypertrophy)

Question 20

What are muscle fibres grouped into

Answer 20

Motor units

Question 21

What does a motor unit consist of

Answer 21

-Motor neurone
- and it’s muscle fibre

Question 22

How many types of muscle fibres can be found in a motor unit

Answer 22

Only one muscle fibre can be found in one particular motor unit

Question 23

What is a neuromuscular junction

Answer 23

Where the motor neurone and the muscle fibre meet

Question 24

What is the all or none law

Answer 24

Once the motor unit stimulates the muscle fibres either all of them contract or none of them contract

Question 25

Is it possible for a motor unit to partially contract

Answer 25

No, because the threshold has not been met

Question 26

What is the minimum amount of stimulation to start a contraction called

Answer 26

A threshold

Question 27

What happens if the sequence of impulses is equal to or more than the threshold

Answer 27

All the muscle fibres in a motor unit will contract

Question 28

What happens if the sequence of impulses is less than the threshold

Answer 28

Then no muscle action will occur

Question 29

What is wave summation

Answer 29

Repeated nerve impulses stimulating the muscle with no time to relax Results in a greater force of contraction

Question 30

What happens if calcium builds up in a muscle cell

Answer 30

This produces a forceful, sustained, smooth contraction also known as a tetanic contraction

Question 31

Define tetanic contraction

Answer 31

A sustained muscle contraction caused by a series of fast repeating impulses.

Question 32

What is spatial summation

Answer 32

- the recruitment of additional and bigger motor units within a muscle to develop more force. - occurs when impulses are received at the same time at different places on the neurone.

Question 33

Define spatial summation

Answer 33

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

Question 34

What does PNF stand for

Answer 34

Proprioceptors neuromuscular facilitation

Question 35

What is PNF

Answer 35

An advanced stretching technique considered to be one of the most effective forms of flexibility training for increasing range of motion

Question 36

What are the proprioceptors that make PNF possible

Answer 36

Muscle spindles Golgi tendon organs

Question 37

Define muscle spindles

Answer 37

Proprioceptors that detect how far and how fast a muscle is being stretched and produce the stretch reflex

Question 38

Define Golgi tendon organs

Answer 38

Proprioceptors that are activated when there is tension in a muscle

Question 39

Define isometric contraction

Answer 39

Where there is tension in a muscle but no visible movement

Question 40

Define autogenic inhibition

Answer 40

Where there is a sudden relaxation of the muscle in response to high tension. The receptors involved in this process are Golgi tendon organs

Question 41

What is the first step to PNF

Answer 41

- Individual performs passive stretch. They extends the leg until tension is felt. This is done by the help of a partner - If the muscle is being stretched too far then a reflex should happen

Question 42

What is the second step of PNF

Answer 42

Isometric contraction - Leg is held still

Question 43

What is the third step of PNF

Answer 43

- leg is lifted again and the golgi tendon organs are responsible for the antagonist muscle relaxing which means the leg stretches further - process is repeated until no more gains are possible

Question 44

What is the role of the Golgi tendon organs in PNF

Answer 44

send inhibitory signals which allows the antagonist muscle to relax and lengthen and delay the stretch reflex. This is known as autogenic inhibition.