Muscle 1

Question 1

Types of muscle

Answer 1

smooth, cardiac, and skeletal

Question 2

Agonist

Answer 2

Flexion: contracts bicep
Extension: contracts tricep

Question 3

Antagonist

Answer 3

Flexion: contracts bicep
Extension: relaxes bicep

Question 4

Synergists

Answer 4

contracts to complement flexion : deltoid anterior

Question 5

Fixator

Answer 5

contracts to steady scapula closer to body: serratus anterior

Question 6

Thin filaments

Answer 6

actin

Question 7

thick filaments

Answer 7

myosin

Question 8

Fascicle

Answer 8

Numerous muscle fibres wrapped by a thick connective tissue (Perimysium (around))

Question 9

Sliding filament Theory

Answer 9

Muscle contraction occurs due to actin sliding over myosin:
Motor nerve activates muscle fibre
Myosin head temporarily attaches to actin; cross bridge formation
Cross bridges move similar to stroking of the oars
Actin filaments move and sarcomere shortens
1% of sarcomere
25-40% of myofibril length
I band and H zone shrink, while A band remains the same

Question 10

Optimal Joint Angle

Answer 10

Sarcomeres at optimal distance
Optimal number of cross bridges
Maximal force developed

Question 11

Large Joint angle

Answer 11

Sarcomeres too far apart
Fewer cross bridges
Smaller force developed

Question 12

Small joint angle

Answer 12

Sarcomeres too close together
Cross bridges interfere
Smaller force developed

Question 13

Slow Twitch muscle fibers (type 1

Answer 13

ST or Type I
Appear red(cow)
Slow contraction
Aerobic
Fatigue resistant
Small fibres

Question 14

Fast twitch muscle fibers (type 2)

Answer 14

FT or Type II
Appear white
Fast contraction
Anaerobic
Fatigue fast
Large fibres(like chicken)

Question 15

Motor Unit

Answer 15

Group of fibres activated via the same nerve
Basic functional unit of muscular activity

• One motor unit per muscle fibre
• Each motor unit can consist of many muscle fibres but of the same type (ST or FT)

-Each muscle can be composed of different motor units
Alpha motor unit

Question 16

Isometric

Answer 16

Iso- same    metric-length 
-no visible change in muscle length 
-No work, high tension and energy
Work = force * distance
Internal and external forces are balanced
Or agonist balanced by antagonist

Question 17

Concentric action

Answer 17

• muscle overcomes a load and is shortened

ex) flexion of bicep

Question 18

Isokinetic action

Answer 18

Iso-same kinetic- motion

• Neuromuscular works at a constant speed, at each movement space it is concentric/eccentric, and hight resistance
  ex) bicep curls

Question 19

Eccentric Action

Answer 19

muscle overcomes a load, , lengthens

ex) extension of bicep

Question 20

Plyometric Action

Answer 20

A rapid eccentric loading and muscle stretching followed by a strong concentric contraction

• protects muscle overstretching
  ex) leaping, depth jumping