L4;C6

Question 1

What are muscles comprised of?

Answer 1

• muscle fibres

Question 2

Wha do muscle fibres consist of?

Answer 2

Myofibrils

Question 3

What are myofibrils?

Answer 3

These are the contractile elements and consist of myosin and actin that are arranged in sarcomeres

Question 4

What are the three types of connective tissue?

Answer 4

Epimysium- surrounds entire muscle
Perimysium- surrounds fascicles (msuclar fibre)
Endomysium- surrounds entire muscle fibre

Question 5

Muscles develop ____ and _____ when they contract

Answer 5

Force, stiffness

Question 6

Stiffness is resistance to ______ ______

Answer 6

Changed length

Question 7

Stiffness and force are ______ and ______ functions to controlling body segmental position and motion.

Answer 7

Direct, indirect

Question 8

Bones ______ and ______

While joints _______ and ______

Answer 8

Bend, deform

Compress, shear

Question 9

It takes longer for what kind of fibre to reach peaks tension? Fastest?

Answer 9

Slow twitch, fast twitch

Question 10

What are motor units?

Answer 10

These are single motor neurons and all the fibres it innervates

Question 11

When would you have fewer muscle fibres?

Answer 11

For more precise movements, such as extra ocular muscles

Question 12

What are the five factors affecting muscle force production in the Muscle Tendon Complex?

Answer 12

Motor unit recruitment
Motor unit discharge rate 
Motor unit discharge pattern 
Mechanical structural factors 
Temporal factors

Question 13

Describe the motor unit recruitment factor

Answer 13

This is the size principle (Henneman). MUs are usually activated in orderly fashion (smallest to largest)

Question 14

Describe the motor unit discharge rate factor

Answer 14

As MU stimulation frequency increases, muscle force increases. More activation means more force, we can vary with discharge.

Question 15

Describe the five mechanical structural factors

Answer 15

Muscle length, 
muscle shortening/length velocity, 
muscle fibre arrangement 
physiological cross sectional area
Properties of fibres (FT vs ST)

Question 16

Describe the temporal factors

Answer 16

This is a time factor:

• force enhancement after stretching (SS cycle)
• stretching and force prior to movement produces most force

Question 17

What is active insufficiency?

Answer 17

This is when force production is limited when multi articular muscles are shortened. you are are unable to produce full RoM at all joints crossed simultaneously.

Question 18

What is passive insufficiency?

Answer 18

RoM at all joints crossed is simultaneously limited when multi articular muscles are fully stretched

Question 19

What are two rate limiting factors with regards to force velocity relations?

Answer 19

• Cross bridges form, its harder for them to break

- rate of length of the actual muscle will determine force

Question 20

For concentric, as velocity _______ force _______

For eccentric, as velocity __________ force _________

Answer 20

Increases, decreases

Increases, increases to a plateau

Question 21

What is power defined as? When is peak power usually hit with regards to force? Does high force mean lots of power?

Answer 21

Power is defined as High rates of force
Peak power is usually hit around 30% force
High force does not equal high rates of power

Question 22

Name the two fibre arrangements and their descriptions?

Answer 22

Parallel- every time they shorten the entire muscle shortens (biceps)
Pennate- more pennate muscles together is a stronger muscle, we can pack more of these in a space.

Question 23

Name the four behavioural properties of muscles

Answer 23

Extensibility-muscles have the ability to be stretched

Elasticity- muscles recoil and return to normal length after being stretched

Irritability- muscles respond to mechanical and electrical stimuli

Contractibility- muscles have the ability to develop tension

Question 24

What is the net muscle torque?

Answer 24

the force produced by muscles to move the object

Question 25

What does muscle visoelasticity allow?

Answer 25

This enables it to progressively lengthen over time when stretched.

Question 26

Pennate fibres produce more ______ parallel fibres ________ muscle shortening

Answer 26

Force, facilitate