The Neuromuscular System

Question 1

Type 1

Answer 1

Slow oxidative 
Red 
Low intensity - long distance running
Don’t fatigue as fast 
Aerobic 
More capillaries 
More mitochondria 
Mo farah 

High no. Of mitochondria
High level of myoglobin
High capillary density
High levels of oxidative enzymes

Question 2

Type IIa

Answer 2

Fast oxidative 
Moderate intensity- middle distance e.g. 800-1500m 
Pink 
Anaerobically 
Usain bolt

High pc stores
High glycogen stores
High myosin ATPase activity
High glycolytic enzyme activity

Question 3

Type IIx

Answer 3

Fast glycolytic
Fatigue very easily - sprinting 
Anaerobically 
Only able to use for seconds 
Bigger 
Usain bolt 

High PC stores
High glycogen stores
High myosin ATPase activity
High glycotic enzyme activity

Question 4

what does a high pc store mean (fast twitch)

Answer 4

Increased energy source for ATP production via the ATP-PC system

Question 5

High glycogen stores mean

Answer 5

Increased energy source for ATP production via the lactate anaerobic system

Question 6

High myosin ATPase activity

Answer 6

Increased enzyme activity for ATP production within the ATP-PC system

Question 7

High glycolytic enzyme activity

Answer 7

Increased enzyme activity or ATP production within the lactate anaerobic system

Question 8

High number of mitochondria

Answer 8

Increased the ability to produce large amount of ATP as mitochondria are the site of the Krebs cycle

Question 9

High level of myoglobin

Answer 9

Myoglobin stores oxygen on the cell, therefore cells have a high 02 storage capacity

Question 10

High capillary density

Answer 10

Provides a large and continuous supply of 02 and glucose

Question 11

High levels of oxidative enzymes

Answer 11

Allowing O2 to be used efficiently to produce energy aerobically

Question 12

What is a motor unit

Answer 12

A motor neurone + muscle fibre

Question 13

What is an action potential

Answer 13

An impulse big enough for a muscle to react and contract

Question 14

What are motor units

Answer 14

How a muscle contraction is produced

Question 15

What is synaptic cleft

Answer 15

The space between the neurone and receptors on muscle fibers

Question 16

What two things must happen for a contraction to occur

Answer 16

Action potential

Acetylcholine to be released and able to travel across the synaptic cleft

Question 17

What is the all or none law

Answer 17

The law is that either all muscle fibers in one motor neurone contract, or no muscle fibers in the motor neurone contract

Question 18

Wave summation

Answer 18

A way of increasing the strength of a muscle contraction
Decreasing the time between the impulses sent so that the muscles fibers do not have time to relax
Resulting in a continuous wave of contractions = wave summation
Smooth sustained contraction (tetanic contraction)

Question 19

Spatial summation

Answer 19

This is when the strength of a contraction changes by altering the number and size of the muscles motor units recruited

Occurs by the motor neurone receiving impulses as the same time but in different locations on the nerve

Add up to cause large impulse allowing the bigger motor units to be recruited

Question 20

What happens when an inhibitory response is sent

Answer 20

The muscles relax

Question 21

What are golgi tendons and where are they found

Answer 21

They’re a type of proprioceptor found between the muscle and the tendon

Question 22

How do golgi tendons work

Answer 22

They sense an increase in tension and will then send on inhibitory signal to brain and that causes muscle to relax

Question 23

What is an autogenic inhibition

Answer 23

Where there is a sudden relaxation of the muscle in response to high tension. Caused by the golgi tendon organs

Question 24

What happens when an exciting response is sent

Answer 24

The muscles contract

This causes something to start doing something

Question 25

muscle spindles

Answer 25

Sense how far a muscle is stretched
Very sensitive proprioceptors
Found between skeletal muscle fibers
Provide info to the nervous system about how far and fast a muscle is being stretched
Helps to prevent over stretching and reduce chance of injury

Question 26

What is proprioceptive neuromuscular facilitation (PNF)

Answer 26

Passive stretch to increase muscle tension and activate golgi tendons
Isometricallg contract antagonist muscle by applying resistance
Limb extended until tension felt - detected by muscle spindles
Stretch reflex to occur it too far
Repeat until gains in flexibility