Exam 3 : Ch. 9 & 10 Muscles & Muscular System

Question 1

Functions of the Muscular System

Answer 1

MMGPS:

• Maintain Posture
• Move Bones
• Generate heat
• Produce movement
• Stabilize joints

NOT functions:

• protect the brain
• act as levers
• absorb heat

Question 2

Continue this pattern from larger units to smaller units

Answer 2

Muscle 
Fascicle 
Muscle Fiber
Myofibril 
Filaments

Question 3

epimysium

Answer 3

fibrous connective tissue that surrounds the entire muscle

Question 4

perimysium

Answer 4

surrounds a fascicle (bundle of muscle fibers)

Question 5

endomysium

Answer 5

surrounds each muscle fiber (around each cell)

Question 6

Muscle contraction involves the shortening of:

Answer 6

Muscle Fiber

Question 7

Muscle Type Characteristics:

cells in branching, interwoven network; intercalated discs; involuntary action

Answer 7

Cardiac

Question 8

Muscle Type Characteristics:

cells are fibers, usually cylindrical & multinucleate; voluntary action

Answer 8

Skeletal

Question 9

Muscle Type Characteristics:

cells spindle-shaped, uninucleate; no distinct sarcomeres, involuntary action

Answer 9

Smooth

Question 10

Describe mature smooth muscle cells

Answer 10

• not striated
• involuntary,
• found in walls of hollow organs (visceral)
• uninucleate

Question 11

Describe Skeletal muscle cells

Answer 11

• striated
• voluntary; usually attached to the skeleton (except sphinters),
• multinucleated.

Question 12

What neurotransmitter plays a key role in generating an action potential in the sarcolemma?

Answer 12

Acetylcholine (ACh)

Question 13

Between neurons and muscle is a synapse with the special name of

Answer 13

neuromuscular junction.

Question 14

One “unit” of a myofibril is

Answer 14

Sarcomere

Question 15

Polarized

Answer 15

The resting sarcolemma of the muscle cell can best be described as

Question 16

Depolarized

Answer 16

An action potential or impulse causes the sarcolemma to become:

Question 17

For muscle contraction to occur, which energy source must be readily available?

Answer 17

Adenosine triphosphate (ATP)

Question 18

Under the high power lens of the microscope, the “I bands” of skeletal muscle show as light strips, reflecting the fact that the “I bands” are in an area of:

Answer 18

Actin only (thin)

Question 19

The “A bands” appear darker because of the presence of

Answer 19

c. both myosin and actin

Question 20

Which is “rope like”

which is “sheet like”

Answer 20

rope (tendon)

sheet (aponeuroses)

Question 21

Which attaches to “more movable part of bone”

which attaches to “less movable part of bone”

Answer 21

More Moveable = insertion

Less Movable = origin

Question 22

What is meant by a “direct” connection of muscle to bone?

Answer 22

epimysium is fused to the periosteum (bone) or to the perichondrium (cartilage)

Question 23

Steps in the contraction of a muscle

Answer 23

1. nerve impulse
2. acetylcholine release (ACH)
3. action potential through sarcolemma & T-tubules
4. Ca2+ release
5. troponin changes shape
6. tropomysosin moved from active site
7. Contraction

Question 24

What energy molecule is needed to power the cycle of attachment and detachment of the myosin-actin cross-bridges and the removal of Ca2+ by active transport into the sarcoplasmic reticulum?

Answer 24

ATP

Question 25

All or None Law

Answer 25

A single muscle fiber either contract with threshold stimulation or does not contract

Question 26

Threshold stimulus:

Answer 26

minimal stimulus to cause 1st contraction

Question 27

put the following sources of energy in correct order during short duration, high intensity exercise:

a. glucose
b. stored ATP
c. creatine phosphate
d. glycogen

Answer 27

Stored ATP
Creatine phosphate
glycogen
glucose

Question 28

Which organelle is actively involved in aerobic respiration?

Answer 28

Mitochondria

Question 29

What two processes take place when there is oxygen debt?

Answer 29

reconverting: reconverts lactic acid to pyruvic acid (which is then oxidized aerobically)
replenishing: replenishes ATP and glycogen stores

Question 30

Resistance training using weights primarily affects ________________ respiration. Which muscle fiber types are more commonly used?

Answer 30

• anaerobic

- Fast Glycoltic muscle fibers

Question 31

Prolonged running uses - which pathway? ___________________;

- which fibers? ______________________; - may use this energy source: ________________;

Answer 31

• Aerobic (glucose+oxygen-> CO2+ H20+ 36 ATP)
• Slow oxidatove muscle fibers
• lipids

Question 32

The number of muscle fibers stimulated, the bulk of the muscle, and the size of the muscle fibers affects the _____________ of muscle contraction.

Answer 32

__Force__

Question 33

Which type of contraction actually shortens the muscle?

-does not change muscle length?

Answer 33

Isotonic contraction: muscle tension maintained as muscle shortens or lengthens

• Isometric contraction: muscle tension maintained does not shorten or lengthens muscle

Question 34

Wave summation and treppe occur because of the build up of:

Answer 34

_Calcium Ca2+

Question 35

give the net number of ATPs produced by the breakdown of one glucose molecule
aerobically: __? ATP_________; anaerobically __? ATP___

Answer 35

aerobically: __32 ATP_________; anaerobically __2 ATP___