The muscular system

Question 1

What are the three main muscle groups?

Answer 1

o Skeletal muscle- common (often striated)
o Cardiac muscle-only found in heart, very meaty coloured because of a high myoglobin content
o Smooth muscle- pale in colour hard to recognise, blood vessels lungs, all sorts of places

Question 2

What is meant by the term skeletal (striated muscle)?

Answer 2

• Fascicle- bundle of muscle fibres
• Myofibril come together to create the muscle action
• “Yellow stuff”- t-tubules- to get the electrical signal in
• Lot’s of mitochondria very energetic tissue with a high energy requirement
• Filled with myoglobin- for oxygen within the cell (myoglobin is an oxygen carrying protein)

Question 3

State the largest muscular unit to the smallest muscular unit.

Answer 3

tendon -> Muscle -> Muscle fasicle -> muscle fiber -> myofibril (contained of repeating chains/units called sarcomeres)

Question 4

What is the difference between origin and insertion?

Answer 4

Origin- proximal/fixed

Insertion- distal/mobile

Question 5

What is the difference between synergistic and antagonistic? Provide an example of both

Answer 5

Synergistic- two muscles work together- biceps/brachialis

Antagonistic- muscles oppose each other- biceps/triceps

Question 6

What is the difference between intrinsic and extrinsic? Provide an example of both.

Answer 6

Intrinsic- originates within the limb- biceps

Extrinsic- doesn’t originate within the limb- for example latissimus dorsi

Question 7

What is the difference between isotonic and isometric? Provide an example of both.

Answer 7

Isotonic- “movers”- for example biceps

Isometric- “stabilisers”- for example infraspinatus

Question 8

Explain how levers can be adjusted to modify the mechanical advantage of muscular input.

Answer 8

To increase output force move, move pivot closer to output (low gear). To increase output speed, move pivot closer to input (high gear).