MSK Muscle composition

Question 1

Give an example of a convergent skeletal muscle

Answer 1

Pectoralis major

Question 2

Give an examples of a mulitpennate skeletal muscle

Answer 2

Deltoid muscle

Question 3

What are the 4 muscle groups?

Answer 3

Agonists, Antagonists, Synergists and Fixators

Question 4

What is the roles of agonists?

Answer 4

They are prime movers (main muscles responsible for a particular movement

Question 5

What is the role of antagonists?

Answer 5

They oppose prime movers (agonists)

Question 6

What is the role of synergists?

Answer 6

They assist prime movers (agonists)

Question 7

What is the role of fixators?

Answer 7

Stabilises action of prime mover e.g fixes non mover when the prime mover is acting over 2 joints.

Question 8

Give the analogies for each of the different types of levers within the body

Answer 8

1st class; A see saw
2nd class: wheel barrow
3rd class: Fishing rod

Question 9

What is the most efficient type of lever?

Answer 9

1st class

Question 10

What is the name given to the support around where a lever picots?

Answer 10

A fulcrum

Question 11

What are a very large proportion of levers? Example?

Answer 11

3rd class. E.g the arm

Question 12

What are the 2 different types of muscle contraction?

Answer 12

Isotonic and isometric

Question 13

What is isotonic contraction? Subtypes?

Answer 13

Constant tension and variable muscle length.
Concentric - Muscle shortens
Eccentric - Muscle exerts force whilst being extended e.g walking down a hill.

Question 14

What is isometric contraction/ Example?

Answer 14

Muscle stays the same length but exerts a force e.g hand grip (forearm muscle)

Question 15

What are the two types of fibres in skeletal muscle? When are they used?

Answer 15

Fast/slow twitch muscle.
Fast = sprinting or jumping
Slow = postural muscle

Question 16

What is the awareness of self within fibres called? What are these specialised units?

Answer 16

proprioception. Called muscle spindles

Question 17

What is eectromyography? How is it carried out?

Answer 17

It is a medicine technique for evaluating and recording the electrical activity produced by skeletal muscles.
Electrodes are placed on the skin

Question 18

What is electromyography? How is it carried out?

Answer 18

It is a medicine technique for evaluating and recording the electrical activity produced by skeletal muscles.
Electrodes are placed on the skin

Question 19

Give on example of why electromyography may be a good diagnostic tool

Answer 19

For neurological diseases

Question 20

How does the relaxation of muscles take place?

Answer 20

Calcium ions are pumped back into the sarcoplasmic reticulum OR calcium ions bind to calmodulin

Question 21

What is muscle tone?

Answer 21

The force of contaction of a muscle

Question 22

What is baseline tone and what is it due to?

Answer 22

It is present in muscles at rest. It is due to motor neurone activity and muscle elasticity

Question 23

What is additional tone due to?

Answer 23

Via moon control centres in the brain and feedback from muscle signals

Question 24

What is the difference between spatial and temporal summation?

Answer 24

Spatial - lots of pre synaptic neurones and one post synaptic neurone.
Temporal - one pre synaptic neurone but send signals may times in succession

Question 25

What is serum creatine kinase a marker for?

Answer 25

Muscle damage (creatine kinase is a source of ATP)

Question 26

Why does contraction occur?

Answer 26

Because ATP sources are depleted so myosin bridges are unable to detach from actin filaments

Question 27

What is delayed muscle soreness an example of? Give examples of when this might occur

Answer 27

Example of eccentric isotonic contraction | Hill walking or ski-ing

Question 28

What is hypotonia?

Answer 28

Low level of muscle tone

Question 29

What may cause hypotonia?

Answer 29

Damage to brain or spinal cord | Damage to cerebellum (involved in feedback control)

Question 30

Why are muscle relaxants used in surgery?

Answer 30

Because they make the surgeon's job easier and less tissue damage is done is the muscle is relaxed.

Question 31

What is tetanus? What is it caused by?

Answer 31

It is caused by bacterium-clostridium tetani in the soil. | It cases muscles to remain contracted because feedback control is interfered with.

Question 32

What is the pain caused by in muscle cramp?

Answer 32

An increase in acidity (lactate) which acts on nerve endings

Question 33

What may be the causes of muscle fatigue?

Answer 33

Depletion of muscle glycogen stores | Interrupted blood flow

Question 34

How do muscle relaxants work?

Answer 34

They interfere with acetylcholinesterase