Neuromuscular System

Question 1

Golgi tendons

Answer 1

Detect levels of tension in a muscle when the muscle contracts isometrically in PNF and snd inhibitory signals to the brain al;lowing the antagonistic muscle to relax and lengthen (autogenic inhibition)

Question 2

Isometric contraction

Answer 2

Where there is tension in a muscle but no visible movement

Question 3

Muscle spindles

Answer 3

These detects how far and how fast a muscle is being stretched and produce the stretch reflex to stop over stretching and stop muscles from tearing

Question 4

The motor unit

Answer 4

A motor unit consists of one motor neurone and all the fibres it stimulates. This figure shows three motor units.

Question 5

all or none law

Answer 5

When an impulse is sent via motor neuron, all muscle fibres in the motor unit will contract, if the impulse is not high enough contraction will not occur.

Question 6

Spatial summation

Answer 6

The change in contraction strength due to change in number of motor units

Question 7

Titanic contraction

Answer 7

Continuous muscle contraction caused by many quick impulses. No rest periods and is maximal effort example - Tennis first serve

Question 8

Wave summation

Answer 8

Repeated nerve impulses with motor unit no time to relax

Question 9

Type 1 muscle fibre characteristics

Answer 9

Slow twitch
High numbers of mitochondria 
High levels of myoglobin 
Slow to fatigue 
Low levels of force production

Question 10

Type 2a muscle fibre characteristics

Answer 10

Fast speed of contraction 
Speed endurance events 
Quick to fatigue 
High PC stores 
High force levels

Question 11

Type 2b muscle fibre characteristics

Answer 11

Very fast speeds of contraction 
Very high force production 
White in colour 
Very high PC stores 
Very quick to fatigue

Question 12

Sympathetic nervous system

Answer 12

Increases heart rate and breathing rate in preparation for a sporting activity, such as a rugby player getting ready to start a match. This is done by a release of adrenaline into the bloodstream.

Question 13

Parasympathetic system

Answer 13

Inhibits messages sent to the nervous system, to slow down bodily functions; for example an archer being able to slow down their breathing and heart rates to help them concentrate, relax muscle and steady their aim. This is controlled by a release of acetylcholine.