Muscle Contraction

Question 1

caused by minor muscle contractions in
the area, or uncontrollable twitching of a
muscle group that is served by a single
motor nerve fiber.

Answer 1

Muscle Twitch

Question 2

3 Phases of Muscle Twitch

Answer 2

1) Latent Period
2) Period of Contraction
3) Period of Relaxation

Question 3

time between the stimulus
and the initiation of contraction

Answer 3

Latent Period

Question 4

Causes of Muscle Twitch

Answer 4

• Lack of Sleep
• Exercise
• Lack of nutrients
• Stress & Anxiety
• Autoimmune disorders
• Drug Overdose

Question 5

a state of sustained contraction of a
muscle during which the muscle does
not relax to its initial length or tension,
induced by a rapid succession of stimuli.

Answer 5

Tetanus

Question 6

the process by which different
motor units are activated to
produce a given level and type
of muscle contraction.

Answer 6

Recruitment

Question 7

The occurrence of additional twitch
contractions before the previous twitch
has completely relaxed.

Answer 7

Summation

Question 8

Skeletal muscle contractions can be
grouped based on the _____ and ______.

Answer 8

length and frequency of contraction.

Question 9

Two major types of skeletal muscle fibers

Answer 9

• slow-twitch muscle fiber
• fast-twitch muscle fiber

Question 10

also known as muscle cells, are the
individual cells that make up skeletal muscles and are responsible for their contraction and relaxation. They help to control the physical forces within the body. When grouped together, they can facilitate organized movement of your limbs and tissues.

Answer 10

Muscle Fibers

Question 11

• also known as the type I fibers.

• cause the fibers to contract more
slowly and be more resistant to fatigue

• are used or adapted for endurance
activities

Answer 11

Slow-twitch

Question 12

• also known as the type II fibers

• cause the fibers to contract quickly and to fatigue quickly

Answer 12

Fast-twitch

Question 13

Two types of Fast-twitch muscle fibers

Answer 13

• Type IIa
• Type IIb

Question 14

Type IIa also called as _____

Answer 14

fast-oxidative glycolytic fibers

Question 15

Type IIb also called as ______

Answer 15

fast-glycolytic fibers

Question 16

• are characterized by their high
resistance to fatigue and their reliance
on aerobic metabolism
• have a large number of mitochondria
• rich in capillaries which allows them to
efficiently generate ATP using oxygen
and glucose

Answer 16

SLOW-TWITCH

Question 17

• contracts slowly:
better suited for activities that
require endurance, such as long-
distance running or cycling.
• are more fatigue-resistant than fast-
twitch muscle fibers
• respond relatively slowly to nervous
stimulation.

Answer 17

SLOW-TWITCH

Question 18

are characterized by their high
resistance to fatigue and their reliance
on _____________

Answer 18

aerobic metabolism

Question 19

Slow-twitch have a large number of ______

Answer 19

mitochondria

Question 20

rich in _____ which allows them to
efficiently generate ATP using oxygen
and glucose

Answer 20

capillaries

Question 21

Slow-twitch are more ______ than fast-twitch muscle fibers

Answer 21

fatigue-resistant

Question 22

The enzymes on the myosin heads
responsible for the breakdown of
ATP are called __________

Answer 22

myosin ATPase

Question 23

_______ fibers break down
ATP slowly because their myosin
heads have a slow form of myosin
ATPase which causes the muscle to
contract slowly.

Answer 23

Slow-twitch

Question 24

________ is the primary source for ATP synthesis in slow-twitch muscles. Their capacity to perform aerobic respiration is enhanced by a plentiful blood supply and the presence of numerous mitochondria. They are called oxidative muscle fibers because of their enhanced capacity to carry out aerobic respiration

Answer 24

Aerobic respiration

Question 25

Slow-twitch fibers also contain large amounts of ______ which binds oxygen and acts as an oxygen reservoir in the muscle fiber when the blood does not supply an adequate amount. Myoglobin thus enhances the capacity of the muscle fibers to perform aerobic respiration.

Answer 25

myoglobin

Question 26

have very little myoglobin and fewer and smaller mitochondria

Answer 26

Fast-twitch

Question 27

have large deposits of ______ and are well adapted to perform anaerobic
respiration.

Answer 27

glycogen

Question 28

rely on both anaerobic and
aerobic ATP production

Answer 28

Type IIa

Question 29

rely almost exclusively on
anaerobic glycolysis for ATP
production

Answer 29

Type IIb

Question 30

• Requires oxygen and breaks down glucose to produce ATP
• More efficient
• Can produce up to 36 ATP molecules
• Uses greater variety of molecules as energy sources.

Answer 30

AEROBIC RESPIRATION

Question 31

Aerobic Respiration can produce up to _____ ATP molecules

Answer 31

36 ATP molecules

Question 32

• Does not require oxygen and results in the breakdown of ATP
• Less efficient than aerobic respiration, but it is much faster, especially when insufficient is available for aerobic respiration.

Answer 32

ANAEROBIC RESPIRATION

Question 33

• Constant state of exhaustion, burnout or lack of energy.
• Decreased capacity and reduced efficiency of performance to do activities.
• Possible sites of fatigue include the nervous system, muscles and neuromuscular junction

Answer 33

Fatigue

Question 34

TYPES OF FATIGUE

Answer 34

• Psychological Fatigue
• Muscular Fatigue
• Synaptic Fatigue
• Physiological Contracture

Question 35

are essential for movement and various bodily functions. Muscle contraction is the tightening, shortening, or lengthening of muscles when you do some activity. It can happen when you hold or pick up something, or when you stretch or exercise with weights.

Answer 35

Muscle contractions

Question 36

Two types of Muscle Contractions

Answer 36

• ISOTONIC CONTRACTION

• ISOMETRIC CONTRACTION

Question 37

the tension developed in the muscle
remains almost constant while the
muscle changes its length. It has two types: concentric and eccentric

Answer 37

ISOTONIC CONTRACTION

Question 38

the tension generated is not enough to exceed the resistance of the object to be moved, and the muscle does not change its length

Answer 38

ISOMETRIC CONTRACTION

Question 39

Two types of Isotonic Contraction

Answer 39

concentric and eccentric

Question 40

• the amount of tension produced by the
muscle is constant during contraction
but the length of the muscle changes
• used for body movements and for
moving objects
• movements of the upper limbs or
fingers, as in waving or using a
computer keyboard, are predominantly
isotonic contractions.

Answer 40

Isotonic Contraction

Question 41

are isotonic contractions in which
tension in the muscle is great enough
to overcome the opposing resistance,
and the muscle shortens

Answer 41

Concentric

Question 42

result in an increasing tension as the
muscle shortens

Answer 42

Concentric

Question 43

many of the movements performed by muscles require concentric contractions

Answer 43

Concentric

Question 44

are isotonic contractions in which tension is maintained in a muscle, but the opposing resistance is great enough to cause the muscle to increase in length

Answer 44

Eccentric

Question 45

the tension exerted by the myosin cross-bridges resists movement of a load and slows the lengthening process

Answer 45

Eccentric

Question 46

are responsible for the constant length of the postural muscles of the body, such as the muscles that hold the spine erect while a person is sitting or standing

Answer 46

ISOMETRIC CONTRACTION

Question 47

important for maintaining posture and for supporting objects in a fixed position

Answer 47

ISOMETRIC CONTRACTION

Question 48

An example would be holding a dumbbell steady using an outstretched arm.

Answer 48

Isometric Contraction