Muscular System Review Packet Answers
Worksheet Page 1
Vocabulary Review
1. B
2. E
3. K
4. A
5. F
6. A & L
7. I
8. N
9. J
10. D
Test Your Knowledge Group A
1. A – muscle fiber
2. C – actin
3. C – acetylcholine
4. C – epimysium
5. B – tetanus
6. C – ATP
7. A – sarcomere
8. B – irritability
9. A – latent period
10. D – heat
Test Your Knowledge Group B
1. Skeletal muscle
2. Myosin; Actin
3. Sliding Filament
4. ATP
5. Oxygen debt
Chapter 6 Text Review pg. 198 – 200
Multiple Choice:
1. a, b, c
2. c
3. c
4. b
Short Answer:
1. To contract or shorten = movement
4. They protect, reinforce, strengthen, & insulate delicate muscle tissue.
Endomysium, Perimysium, Epimysium.
7. Acetylcholine is released & diffuses through synaptic cleft & attaches to
receptors on the sarcolemma; the sarcolemma’s permeability to sodium ions
increases briefly & sodium ions rush into the muscle cell, changing the
electrical conditions of the resting sarcolemma; an action potential is initiated
& sweeps over the entire sarcolemma; calcium ions are released from storage
areas in the muscle cell; attachment of calcium ions to the myofilament
triggers the sliding of myofilaments; contraction occurs.
8. Isotonic contractions: muscle tension remains the same & muscle shortens
Isometric contractions: muscle tension increases & the muscle does not
Shorten
9. Muscle tone is a state of continuous, partial contraction of muscles resulting
from discontinuous but systematic stimulation by the nervous system. ( a
muscle without tone is paralyzed – unable to contract- and becomes flaccid).
At the Clinic:
4. Eric’s oxygen intake has not been adequate to keep his muscles supplied with
the oxygen they needed to support prolonged aerobic activity. His heavy
breathing will supply oxygen to repay the oxygen debt. His muscle cells were
relying on aerobic metabolism and their oxygen consumption led to
breathlessness. When the oxygen ran out, anaerobic metabolism took place
leading to lactic acid accumulation, muscle fatigue, & muscle soreness.
Muscular System Review Guide Answers
1. List several functions of the muscular system
Movement (finding food, shelter, escaping danger, communication),
breathing, digestion, pumping blood, eliminating waste, maintaining
body temperature, posture, childbearing, stabilizing joints, etc.
2. List the three types of muscle tissue, their location in the body, major
function, and whether they are under voluntary or involuntary control
cardiac – in heart; pumps blood; involuntary
smooth – internal organs; moves organs; involuntary
skeletal – over bones; movement of body; voluntary
3. A muscle fiber is the same as a muscle __cell_____.
4. How can you tell actin apart from myosin?
Actin = thin filament
Myosin = thick filament
5. Define the term sarcomere.
Functional unit of contraction in skeletal muscle cells; a repeating
unit bordered by Z-lines
6. Why do muscle cells have so many mitochondria?
To produce enough energy for movement
7. What are striations and what causes them?
Striping appearance – produced by the repeating pattern of
actin/myosin filaments (special arrangement of myofilaments)
8. What characteristic of muscle tissue allows it to shorten?
contractility
9. The gap between a motor neuron and a skeletal muscle it stimulates is
called the Neuromuscular junction (synaptic cleft is acceptable here)
10. Explain the sliding filament theory in your own words.
Nerve impulse = release of calcium = cross bridge formation &
power stroke = actin filaments slide toward each other
11. Why are there different sources of energy for muscle contraction? List
the three pathways used to generate ATP.
Each source(pathway) has different speed & efficiency
Creatine Phosphate (CP), anaerobic glycolysis (fermentation), &
aerobic (cellular) respiration.
12. Which phase of a muscle twitch takes the longest? What is the first
phase of a muscle twitch? Which phase occurs immediately following
contraction?
Recovery phase takes the longest; Latent phase = 1st phase;
Relaxation phase occurs after contraction
13. Compare and contrast white fast twitch fibers with red slow twitch fibers.
White: anaerobic, fatigues rapidly, high glycogen stores,
hypertrophy with high intensity exercise
Red: aerobic, fatigue resistant, myoglobin stored, endurance
exercise
14. What is muscle fatigue? What causes it? How does it end?
Burning, sore, tired muscles that eventually will be unable to
contract when stimulated; Caused by oxygen debt, reduced ATP
levels, and a build up of lactic acid (as occurs with prolonged or
intense exercise); muscle fatigue ends when the exercise stops &
deep, rapid breathing repays the oxygen debt & allows waste
products to be metabolized
15. Why does the nervous system cause some muscles to remain in a state
of partial contraction?
Muscle tone - posture
16. Define the all-or-none law.
A muscle fiber cannot partially contract – it contracts all the way or
not at all
17. What would happen if a nerve stimulus is below threshold?
Nothing – the muscle would not respond (contract)
18. What term is used to describe the shrinking/wasting of a muscle due to
lack of use? atrophy
19. Know the main characteristics of the muscle system disorders presented
in class. (See Notes Chart)