1.3 Neromuscular System

Question 1

What is the autonomic nervous system

Answer 1

Involuntary, subconscious body responses

Question 2

What are the two nervous systems the autonomic nervous system breaks into

Answer 2

Sympathetic nervous system- prepares body for exercise (fight or flight)

Parasympathetic nervous system- relaxes body eg slows HR and breathing rate

Question 3

What are the three muscle fibres

Answer 3

Type 1- Slow oxidative (slow twitch fibres)
Type 2a- fast oxidative glycolytic (fast oxidative glycolytic)
Type 2b- fast glycolytic (fast glycolytic)

Question 4

Characteristics of type a- slow oxidative (slow twitch fibres)
And what sports they are used in

Answer 4

• small Dark red
  -low force and speed produced
  -aerobic capacity- very high

-high fatigue resistance
-high mitochondria density
-high myoglobin
-high capillary density

Question 5

Characteristics of type 2a fast oxidative glycolytic muscle fibres

Answer 5

-moderate size red
-anaerobic capacity -high
-Force and speed produced - high

-moderate fatigue resistance
-moderate mitochondria density
-moderate capillary density
-moderate myoglobin density

Question 6

Characteristics of type 2b fast glycolytic muscle fibres

Answer 6

Large size white
-very high force and speed produced
-aerobic capacity - very high

-low fatigue resistance
-low capillary density
-low myoglobin density
-low mitochondria density

Question 7

Exercise muscle fibres are used for

Answer 7

Type 1- Slow oxidative- marathons, jogging, walking (aerobic system)

Type2 a- fast oxidative glycolytic cycling, swimming, 1500m (anaerobic system)

Type2 b- fast glycolytic 100m sprint, weigh lifting (anaerobic system)

Question 8

Recovery time

Answer 8

Type 2b- Fast glycolytic slowest recovery rate as muscle fibres have a lot of damage

Type 1- slow oxidative - fast recovery rate as muscle fibres are not that damaged

Question 9

What is a motor unit

Answer 9

A motor neurone and its muscle fibres

Question 10

What is a motor neurone

Answer 10

Nerve cells that transmit the brains instructions to the muscles as electrical impulses.

Question 11

What is the all or non rule

Answer 11

Either all the muscle fibres contract or non do and they need a certain amount of stimulation to contract (threshold)

Question 12

Two ways a strength of a contraction can be changed

Answer 12

Spatial summation
Wave summation

Question 13

What is spatial summation

Answer 13

Strength of contraction altered by changing the number or size of the motor units being recruited.

Question 14

What is wave summation

Answer 14

Repeated nerve impulse with no rest break resulting in a smooth, sustained contraction rather than twitches.
Results in a stronger contraction called a tetanic contraction (sustained muscle contraction)

Question 15

Different activities need different size and amount of motor units depending on how much strength they have to generate (spatial summation):
Gross movements and example
Fine movement and example

Answer 15

Gross movement - rugby tackle need bigger and more motor units as need to generate a lot of strength.

Fine movement- darts smaller and less motor units needed as needs less strength.

Question 16

What is PNF

Answer 16

A stretching technique- used as flexibility training to increase range of motion

Question 17

What are the proprioceptors that facilitate PNF

Answer 17

Muscle spindle fibres
Golgi tendons

Question 18

What do muscle spindles do

Answer 18

Detect how fast and far the muscle is being stretched
-then send signal to CNS which tells muscle to contract triggering the stretch reflex, to prevent over stretching reducing injury.

Question 19

What do golgi tendon organs do

Answer 19

Detect tension in the muscles
When muscle is contracted isometrically they sense the increase in muscle tension and send inhibitory signal to the brain allowing antagonist muscle to relax and lengthen (this is called autogenic inhibition- sudden relaxation of the muscle)