Lecture 9 - Muscles As Levers

Question 1

What are the components of a rigid skeleton necessary for locomotion

Answer 1

Connective tissue, tendons, ligaments and the contractile and series-elastic components of muscle

Question 2

What does connective tissue divide within a muscle

Answer 2

Muscle fibres

Question 3

What s connective tissue extended beyond the muscle known as

Answer 3

A tendon

Question 4

What is tension in a muscle generated in

Answer 4

The sarcomere

Question 5

How is tension in a sarcomere transmitted to the bone

Answer 5

Through the tendon

Question 6

What type of elasticity does connective tissue have

Answer 6

Passive

Question 7

What is the series-elastic component composed of

Answer 7

Extracellular titin, connective tissue and tendons

Question 8

What is the series-elastic component

Answer 8

The build up of tension within the sarcomeres being passed onto the tendon and allowing movement of the bone

Question 9

What is the area in which the muscle attaches to the stationary part of the skeleton

Answer 9

Origin

Question 10

What is the area in which the muscle attaches to the active part of the skeleton

Answer 10

The insertion

Question 11

When a muscle contracts what does it affect in a joint

Answer 11

Its structure

Question 12

What is a single twitch composed of

Answer 12

A lag phase, tension phase and a relaxation phase

Question 13

Once an action potential has been fired what must happen to the membrane before another can be fired

Answer 13

It must return to rest membrane potential

Question 14

What must happen for a muscle to shorten during contractions

Answer 14

The tension developed in the muscle must exceed the forces that oppose movement of the bone to which the muscle’s insertion is attached

Question 15

What are the two types of muscle contraction

Answer 15

Isotonic and isometric

Question 16

Isotonic contraction

Answer 16

The muscle tension remains constant as the muscle length changes

Question 17

Uses of isotonic contractions

Answer 17

Body movement and lifting objects

Question 18

What type of muscle contraction moves the tongue

Answer 18

Isotonic

Question 19

What is prevented during isometric contractions

Answer 19

Shortening of the muscle

Question 20

What are the two types of isotonic muscle contraction

Answer 20

Concentric and eccentric

Question 21

What is a concentric muscle contraction

Answer 21

When the muscle shortens under a load

Question 22

What is an eccentric muscle contraction

Answer 22

When a muscle lengthens under a load

Question 23

What is happening to the muscle fibre in eccentric contractions

Answer 23

It is resisting the stretch

Question 24

Synovial joint labelled

Answer 24

Bony articular surface
Hyaline cartilage
Ligaments
Synovial membrane 
Capsule
Joint cavity

Question 25

What is the function of the synovial membrane

Answer 25

It lubricates the joint and provides nourishment for the cartilage

Question 26

What is the function of the capsule

Answer 26

It holds the joint together

Question 27

What does the synovial membrane do

Answer 27

It produces the synovial fluid

Question 28

What does the articular cartilage do

Answer 28

It protects the bone and cushions any impact

Question 29

Where are intrinsic ligaments

Answer 29

Within the capsule

Question 30

Where are extrinsic ligaments

Answer 30

Out with the capsule

Question 31

What is the function of the ligaments

Answer 31

To hold the bones together and prevent unwanted movement

Question 32

What is a lever

Answer 32

A rigid structure capable of moving around a pivot point known as a fulcrum

Question 33

In the body what functions as levers, fulcrum and providing force

Answer 33

Bones are levers, the joints are the fulcrum and the muscles provide the force

Question 34

Levers that use a small amount of force to move a large mass have

Answer 34

Mechanical advantage

Question 35

What are the four parts to a simple lever

Answer 35

A lever arm, pivot, effort and load

Question 36

How are levers classified

Answer 36

In the way in which the joint or muscles are attached to the bone and how they are arranged around the pivot

Question 37

Class one levers

Answer 37

The pivot lies between the effort and the load

Question 38

What classes of levers have mechanical advantage

Answer 38

Class one and two

Question 39

Class two levers

Answer 39

The load is between the pivot and the effort

Question 40

Class three levers

Answer 40

The load is further away from the pivot than the effort

Question 41

What do class three levers provide

Answer 41

Larger and greater speed of movement

Question 42

What can lever systems provide

Answer 42

Either strength or speed but not both

Question 43

What is the pivot arm

Answer 43

The distance from the fulcrum to the upwards force

Question 44

What is the load arm

Answer 44

The distance from the fulcrum to the load