Functional Anatomy

Question 1

Insertion

Answer 1

Is attached to the bone which moves more when the muscle contracts.
The insertion of a muscle is the point which is usually at the distal end

Question 2

Motor neuron

Answer 2

Refers to neurons located in the central nervous system that project their axon outside the CNS and directly or indirectly control muscles
- responsible for carrying impulses away from the spinal cord and brain to the muscle or glands.

Question 3

Motor unit

Answer 3

Refers to the single motor neuron and all the corresponding muscle fibres it innervates.

Question 4

All or nothing principal

Answer 4

Determined whether the signal from the brain is above or below the threshold required for contraction. Muscle fibres in a motor unit will contract with 100% force or none at all. To increase the strength of contraction the brain simply sends more signals resulting in the recruitment of more motor units

Question 5

Characteristics of type 2 A fast twitch muscle fibres

Answer 5

Fast contraction speed used for speed endurance activities 
Moderate force of contraction
Fatigue resistance 
Large motor neuron 
Moderate oxidative density 
High glycoltic capacity 
Fuel source: CP and glycogen 
Intermediate capillary density

Question 6

Characteristics of type 2 B fast twitch

Answer 6

Very fast contraction 
Very large motor neuron 
Low resistance to fatigue 
Very high force production 
Low capillary density 
Low oxidative destiny 
High glycoltic capacity 
Fuel source cp and glycogen

Question 7

Characteristics of slow twitch

Answer 7

Slow contraction speed 
Small motor neuron 
High resistance to fatigue 
Low force production 
High capillary density 
High oxidative density 
Fuel source: trigylcerides and glycogen

Question 8

Force velocity

Answer 8

Muscle can create an increase amount of force with decreased velocity with concentric action
Muscle can create a increase amount of force with increased force and a increased amount of velocity with eccentric contraction

Question 9

Isotonic forces

Answer 9

Isotonic forces- is one which results in a change in the length of a muscle performed against a constant lead
Eccentric contraction
Concentric contraction

Question 10

Concentric muscle contraction

Answer 10

Results in the shortening of the muscles length. It occurs when you apply a force against the direction of gravity

Question 11

Eccentric muscle contraction

Answer 11

A muscle contraction that results in an increased length of the muscle. A muscle lengthens when resisting the force of gravity

Question 12

Isokinetic force

Answer 12

Is one which results in a change in the length of a muscle, however is performed against a varying load. This requires expensive specialised equipment to ensure the speed of muscular contraction remains constant

Question 13

Isometric contractions

Answer 13

If the muscle length does not change then a isometric contraction is being applied

Question 14

Force length

Answer 14

The length of a muscle affects how well it creates tension

Max tension created in the muscle fibre occurs at slightly greater than resting length

Question 15

Force time

Answer 15

Also referred to as electromechanical delay (EMD)
It’s is not possible for muscle to produce maximal forces instantaneously and there is a time lapse before maximum force can be produced
White fibres have lower EMD than red and can produce peak force faster than red fibres

Question 16

Origin

Answer 16

The origin of a muscle is the attachment onto the bone that does not move when the muscle contracts. The origin is usually at the proximal end