Download Muscles and Muscle Tissue

C H A P T E R ^
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Muscles and
Muscle Tissue
Overview o f Muscle Tissues
1 . Nine characteristics of muscle tissue are listed below. Identify each muscle
type by choosing the correct key choices and writing the letters in the
answer blanks.
Key Choices
A. Cardiac
•
B. Smooth
C. Skeletal
1. Involuntary
2. Banded appearance
3. Longitudinally and circularly arranged layers
4. Dense connective tissue packaging
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5. Gap junctions
6. Coordinated activity allows it to act as a pump
7. Moves bones and the facial skin
8. Referred to as the muscular system
9. Voluntary
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10. Best at regenerating when injured
Chapter 9 Muscles ind'Muscle Tissue
191
Skeletal Muscle
1 . Identify the structures described in Column A by matching them with the
terms in Column B. Enter the correct letters (and terms if desired) in the
answer blanks. Then, select a different color for each of the terms in Column
B that has a color-coding circle and color the structures in Figure 9-2.
Column A
Column B
1. Connective tissue surrounding a fascicle
2. Just deep to the deep fascia
3. Contractile unit of muscle
4. A muscle cell
H". Epimysium
/
Fascicle
J^. Fiber
.
_
5. Thin connective tissue investing each
muscle cell
Vf. Myofilament
6. Plasma-membrane of the muscle cell .
Myofibril
7. A long filamentous organelle found
within muscle cells that has a banded
appearance
8. Actin-, myosin-, or titin-containing structure
C
Endomysi
Slum
9- Cordlike extension of connective tissue
beyond the muscle, serving to attach it
to the bone
- .
@
j?. Perimysium (~)
j ^ . • Sarcolemma
Sarcomere
yt. Tendon
Q
10. A discrete bundle of muscle cells
Figure 9.2
Q
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Chapter 9 Muscles and Muscle Tissue
2. Figure 9-3 is a diagrammatic representation of a small portion of a relaxed
muscle cell (the bracket indicates the portion that has been enlarged). First,
select a different color for each of the structures with a coding circle. Color
the coding circles and the corresponding structures 0 9 Figure 9.3- When you
have finished, bracket and label an A band/ an I banci, and a sarcomere/"
Then, match the numbered lines (1, 2, and 3) in part B to the cross sections
in part C.
^
Thin myofilaments
Q
Thick myofilaments
^
Z discs
B
0.0.0
•o*o*o
•
•
•
0 0 0 0 0
0 0 0 0
0 0 0
2
Figure 9.3
0:6:6:6:0
0:0:0:0
o'o'o
Chapter 9 Muscles and Muscle Tissue
193
3. After referring to Figure 9-3 showing the configuration of a relaxed sarcomere, at the right,
draw a contracted sarcomere. Label the thin
myofilaments,"the thick myofilaments, and
the Z lines. Draw an arrow beside one
myosin head on each end of the A band to
indicate the direction of the working stroke.
4. Fill in the blanks at the right below, giving the location of calcium during the
stated phases of muscle contraction. Use the key choices provided at the left.
Key
Choices
A. Becoming bound to calsequestrin
1. Unstimulated fiber
B. Attached to troponin
2. Contracting fiber
C. In terminal cisternae
3- Recovering fiber
5. Figure 9-4 shows the intimate relationship between the sarcolemma and two
important muscle cell organelles—the sarcoplasmic reticulum (SR) and the
myofibrils—in a small segment of a muscle cell. Identify each structure below
by coloring the coding circles and the corresponding structures on the
diagram. Then bracket and label the composite structure called the triad.
Myofibrils
Mitochondrion
SR
Q
T tubule
i
-..yV;
t.-
Figure 9.4
Sarcolernma
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Chapter 9 Muscles and Muscle Tissue
:
6. Correctly relate the story of contraction events in a muscle fiber by numbering each event below. The first step is indicated (number 1).
1. Myosin heads bind to active sites on actin molecules.
t
2. ATP is hydrolyzed.
3. Myosin heads return to their high-energy shape (cocked), ready for the next
working stroke.
4. Calcium ions bind to troponin.
5. Cycling continues until calcium ions are sequestered by the SR.
6. Myosin cross bridges detach from actin.
7. Troponin changes shape.
8. ADP and Pj (inorganic phosphate) are released from the thick filament.
9. Myosin heads pull on the thin filaments (working stroke) and slide them toward
the center of the sarcomere.
10. ATP binds to the thick filament.
11. Tropomyosin is moved into the groove between the F-actin strands exposing
active sites on actin.
10. Which of these bands or lines narrows when a skeletal muscle contracts?
Check ( / ) the appropriate answer.
J
1. H band
2. A band
3. I band
4. M line
Chapter 9 Muscles:an'd Muscle Tissue
8.
195
Figure 9-6 shows the components of a neuromuscular junction. Identify the
parts by coloring the coding circles and the corresponding structures in the
diagram. Add small arrows to indicate the location of the ACh receptors and
label appropriately.
Mitochondrion
Q)
Synaptic vesicles
(7)
T tubule
of
Junctional folds
Synaptic cleft
(3^ Sarcomere
h
Figure 9.6
12. Number the following statements in their proper sequence to describe excitation-contraction coupling in a skeletal muscle cell. The first step has already
been identified as number 1.
1. Acetylcholine is released by the axonal ending, diffuses to the muscle cell, and
attaches to ACh receptors on the sarcolemma.
2. The action potential, carried deep into the cell via the T tubules, causes the SR to
release calcium ions.
3. AChE breaks down ACh, which separates from its receptors.
4. The muscle cell relaxes and lengthens.
5. The calcium ion concentration at the myofilaments increases; the myofilaments
slide past one another, and the cell shortens.
6. Depolarization'occurs, and the action potential is generated along the sarcolemma.
G?
7. Within 30 ms after the action potential ends, Ca2+ concentration at the
myofilaments decreases.
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Chapter 9 Muscles and Muscle Tissue
1 1 . Figure 9.7 diagrams the elements involved in excitation-contraction coupling.
Color the coding circles and the corresponding structures.
Axonal ending
Q
Tropomyosin
Q
^
Actin
(3
Myosin
^
Sarcolemma
@
Troponin
©
SR
Q
Mitochondria
(3
Synaptic vesicles containing acetylcholine
Figure 9.7
T tubule
Calcium ions
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Chapter 9 Muscles and Muscle Tissue
•;
15. In the appropriate graph spaces below, draw the indicated myograrrts.
Be sure to include arrows at the bottom to indicate each stimulus. For the
twitch myogram, label the latent, contraction, and relaxation periods.
Figure 9.8
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Chapter 9 Muscles'ran'cl Muscle Tissue
201
19. Check the appropriate column in the chart to characterize each type
of skeletal muscle fiber.
Fast g l y c o l y t i c
fibers
Slow o x i d a t i v e
fibers
Characteristics
Rapid twitch rate
Fast o x i d a t i v e
fibers
J
/
Fast myosin ATPases
Use mostly aerobic metabolism
•J
Large myoglobin stores
Large glycogen stores
Fatigue slowly
/
-
J
Fibers are white
Fibers are small
J
Fibers contain many
capillaries and mitochondria
21. Which of the following occur within a muscle cell during oxygen debt?
Place a check mark ( / ) by the correct choices.
y
Decreased AllATP
1. i^ecreasea
5. Increased oxygen
2. Increased ATP
6. Decreased carbon dioxide
y
3. Increased lactic acid
4. Decreased oxygen
C H A L L E N G I N G
At t h e Clinic
Y
7. Increased carbon dioxide
8. Increased glucose
R S E L F
/
2. Gregor, who works at a pesticide factory, comes to the clinic complaining of
muscle spasms that interfere with his movement and breathing. A blood test
shows that he has become contaminated with organophosphate pesticide.
The doctor states that this type of pesticide is an acetylcholinesterase
inhibitor. H o w would you explain to Gregor what this means? - ,
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Stop a n d T h i n k
5. Which is a cross bridge attachment more similar to: a precision rowing team
or a person pulling a rope and bucket out of a well?
3. chickens are capable of only brief bursts of flight, and their flying muscles
consist of white fibers, The breast muscles of ducks, by contrast, consist of
red and intermediate fibers. What can you deduce about the flying abilities
of ducks?