Tension Production Energy Use and Muscular Activity Flashcards Preview

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Flashcards in Tension Production Energy Use and Muscular Activity Deck (36)
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1
Q

For sustained contractions you need

A

Asynchronous motor unit summation

2
Q

Describe small motor units

A

precise control

One motor neuron innervates a small number of muscle fibers

3
Q

Describe large motor units

A

Gross movement control

One motor neuron innervates a large number of muscle fibers

4
Q

If you want precise control over a specific part of your body you don’t want to be contracting tons of cells at the same time. What type of motor unit will produce precise control?

A

Small motor units

Found in hands eyes and speech muscles

5
Q

Define muscle tone

A

Resting tension in a skeletal muscle

6
Q

True or false, in any muscle some motor units are always active

A

True

7
Q

Greater resting muscle tone causes

A

higher resting rate of metabolism

8
Q

Why is it difficult to contract a muscle that has been overstretched?

A

Few, if any, myosin-actin cross bridges can form when sarcomeres are overextended

9
Q

Define isotonic contractions

A

Tension rises, length of muscle changes

10
Q

Define concentric

A

muscle tension exceeds resistance and muscle shortens

11
Q

Define eccentric

A

Peak tension developed is less than the resistance, muscle elongates

12
Q

Define isometric

A

tension rises, length of muscle remains

13
Q

In isometric contractions

A

Tension produced never exceeds resistance
Indiidual muscle fibers shorten until internal connective tissues are taut
Cannot shorten further

14
Q

True or false: there is an active mechanism for muscle fiber elongation

A

False

15
Q

Why does a muscle return to resting length?

A

recoil in elastic components in connective tissue
contraction of opposing muscle groups
gravity

16
Q

Muscle contraction requires large amounts of

A

ATP

17
Q

Muscle cells store only enough high energy molecules to sustain contraction until

A

additional ATP can be generated

18
Q

How long do ATP and Creatine phosphate reserves last during a contraction?

A

15 seconds

19
Q

Muscle cells must generate ATP at approximately the same rate as its

A

used for remainder of contraction

20
Q

CP reserves release stored energy in order to

A

Convert ADP to ATP when ATP is needed at start of contraction

21
Q

______ pathway provides most ATP needed for resting muscle and moderate levels of muscle activity

A

Aerobic cellular respiration

22
Q

At peak activity you need ______ pathway to generate additional ATP

A

Anaerobic glycolysis

23
Q

Describe aerobic metabolism

A

Used at rest to moderate activity
Uses O2
Releases CO2
Occurs in mitochondria

24
Q

CO2 is produced in the

A

Citric acid cycle

25
Q

What occurs during the Electron Transport Chain?

A

ATP synthesis

O2 is used

26
Q

Resting muscle fibers rely on aerobic metabolism of ___ to generate ATP

A

fatty acids

27
Q

Contracting muscle fibers rely on what type of metabolism of glucose?

A

BOTH aerobic and anaerobic

28
Q

Pyruvate metabolism is

A

Anaerobic

29
Q

Why do you use pyruvate metabolism?

A

If oxygen levels are insufficient to allow all of pyruvate to be metabolized aerobically, the rest of pyruvate is converted to lactic acid and recycles cofactors needed by glycolysis enzymes

30
Q

What are the advantages of anaerobic metabolism?

A

Produces ATP rapidly

31
Q

What are the disadvantages of anaerobic metabolism?

A

Insufficient use of glucose

Lactic acid lowers intracellular pH

32
Q

When does the recovery period begin?

A

Immediately after activity ends

33
Q

What is oxygen debt?

A

Amount of oxygen required during resting period to make enough ATP to restore muscle to normal conditions

34
Q

During the recovery period, what happens?

A

Rebuild ATP and CP levels
Recycle lactic acid to make pyruvate
Rebuild glycogen reserves

35
Q

Define fatigued muscle

A

muscle that can no longer perform at required level of activity

36
Q

What are the causes of muscle fatigue?

A

Exhaustion of energy resources
Build up of lactic acid and lower of pH
Psychological fatigue