The neuromuscular system

Question 1

neuromuscular system

Answer 1

the nerves and the muscles working together in order to produce different movements

Question 2

Type 1 slow oxidative

Answer 2

a slow twitch muscle fibre used during endurance events

Question 3

Type 11a fast oxidative glycolytic

Answer 3

a fast twitch muscle fibre with some resistance to fatigue

Question 4

Type 11x fast glycolytic

Answer 4

a fast twitch muscle fibre capable of producing a powerful contraction

Question 5

motor unit

Answer 5

made up of a motor neurone and skeletal muscle fibres

Question 6

motor neurone

Answer 6

nerve cells located in the motor unit, recieve impulses sent from the brain

Question 7

wave summation

Answer 7

where a greater frequency in nerve impulses results in a more powerful contraction, the next impulse will begin before the last has finished so that there is no time for the muscle to relax and the sizoe of contraction will increase
- repated nerve impulses resulting in a stronger contraction

Question 8

tetanic contraction

Answer 8

a number of motor units recieving impulses at the same time, resulting in a more powerful contraction
- if the impulses are fast enough then a substained contraction will occur (tetanic contraction)

Question 9

spatial summation

Answer 9

a number of motor units reciving impulses at the same time, resulting in a more powerful contraction

Question 10

PNF

Answer 10

Proprioceptive Neuromuscular facilitation, an advanced stretching technique

1. stretch is preformed with help of partner, until tension is felt in muscle
2. preformer will then immediately isometrically contract the muscle by pushing back against the partner for 8 seconds
3. the muscle then breifly relaxes before the partner pushed aginst it once again, going pasy the normal range of movement for 20 seconds
4. preformer rests for 30 secds before repeating

Question 11

Proprioceptors

Answer 11

receptors found in the muscles tendons and joints, relay message to the brain regarding muscle movement

Question 12

muscle spindles

Answer 12

a proprioceptor the detects tension and signals for a muscle to relax

Question 13

isometric contraction

Answer 13

when a muscle contracts without any movement at a joint

Question 14

features of slow oxidative (type 1)

Answer 14

• small motor
• large myoglobin content
• high oxidative capacity
• slow contraction time
• suited for aeorobic exercise
• high resistance to fatigue
• low force production
• low glycolytic capacity
• high capillary density

Question 15

features of fast oxidative (type 11a)

Answer 15

• large motor beuron size
• intermediate myoglobin content
• high oxidative capacity
• fast contraction time
• suited for lengthy anaerobic exercise
• medium reisitance to fatigue
• high force production
• high glycolytic capacity
• medium capillary density

Question 16

features of fast glycolyctic (11b)

Answer 16

• large motor neuron size
• small myoglobin content
• low oxidative capacity
• fastest contraction time
• suited for short anaerobic exercise
• low resistance to fatigue
• highest force production
• high glycolytic capacity
• low capillary density

Question 17

what is myelin sheath

Answer 17

acts as an electrical insulator around the axons

Question 18

what is axons

Answer 18

extentions of a nerve cell that carry an impulse

Question 19

all or none law

Answer 19

after a motor neurone has stimulates the muscle fibres within a motor unit, they will either all contract or none will contract
- impossble for only some of the muscle fibres to contract
- intensity of the stimulation must be high enough to result in a contraction

Question 20

increasing the strength of a contraction

Answer 20

there are two different ways when a greater strength of contraction is equired from the muscles for example
- wave summation
- tetanic contraction

Question 21

step by step process of how muscle spindles prevent injury

Answer 21

1. stretch receptors provide information to the central nervous system, muscle being stretched
2. the central nervous system then sends an impulse back to muscle telling it to contract
3. this triggers stretch reflex, the reflex action that causes the muscle to contract to prevent other stretching reduces risk of injury

Question 22

step by step process of how golgi tendon organs prevent injury

Answer 22

1. detects level of tension ina muscle, when the muscle is contracted isometrically
2. sense the increase in muscle tension and sends inhibitory signals to the brain which allows the antagonist muscle to relax and lengthen
3. known as autogenic inhibititon