A&P 1 Ch 9a
Calcium ions are moved from the sarcoplasm into the sarcoplasmic reticulum because of the action of: a. ion diffusion channels in the sarcolemma b. active transport Ca+2 pumps in the sarcoplasmic reticulum membrane c. myosin binding sites in the sarcoplasmic reticulum membrane d. acetylcholine receptors on the cell surface
b
Elasticity refers to the ability of a muscle fiber to: a. shorten b. stretch c. return to original shape after contracting or stretching d. respond to a stimulus
c
In the sliding filament mechanism, actin myofilaments are being pulled toward: a. the Z disc b. sarcolemma c. M line d. A band e. I band
c
myofiber (fiber)
3 (items smallest to largest)
fasciculi
4 (items smallest to largest)
muscle
5 (items smallest to largest)
Change of shape of troponin shifts tropomyosin off myosin binding sites on actin
A
In the diagram above, which "disc" moves toward the center of the sarcomere (closer together) when the fiber contracts?
A
Tissue is able to stretch without damage
A (Extensibility)
In the diagram above, where the Z disc?
A (ends of sarcomere)
In the diagram above, what letter is located at the ends of a sarcomere?
A (represents Z-disk)
In the diagram above, where is the H zone?
D (middle of A-band, only thick filaments)
High concentrations of Ca+2 cause troponin to displace this molecule
D (tropomyosin)
Which of the following functions as a motor protein in all three types of muscle tissue? a. actin b. myosin c. troponin d. titin e. tropomyosin
b
A muscle fascicle is surrounded by: a. endomysium b. epimysium c. perimysium d. sarcomysium
c
According the sliding filament theory: a. both myosin and actin move past each other b. myosin moves past actin c. actin moves past myosin d. the Z-lines repel one another e. none of the preceding are correct
c
Muscles produce body movements, stabilize the body positions and: a. line organs that open to the outside b. produce heat c. coordinate homeostatic functions for the body d. protect the body from invading organisms
c
The binding of Ca+2 to ________ starts the contraction cycle. a. tropomyosin b. ATP c. troponin d. sarcoplasmic reticulum
c
The oxygen-binding protein found in skeletal muscle fibers is: a. hemoglobin b. creatine phosphate c. myoglobin d. adenosine triphosphate
c
Ca+2 ion concentration increases in the sarcoplasm after release from the sarcoplasmic reticulum
D
In the diagram above, where is the M line?
D
On the diagram above, which letter represents the tendon?
A (look up "muscle diagram with tendon" on google images)
Binding of myosin head strengthens and the power stroke begins as myosin heads shift actin toward the M line
C
In the diagram above, which are motor proteins?
C
arrival of an action potential at triad opens Ca+2 channels in the adjacent terminal cisternae
C
diffusion of ACh across the synaptic cleft
C
On the above diagram, what letter represents the perimysium?
C (look up "muscle diagram with tendon" on google images)
Attachment of this molecule to the myosin head is required to break cross bridges
C (ATP)
Chemical energy molecule needed to activate myosin heads
C (ATP)
High concentrations of these in sarcoplasm needed for muscle contraction to continue.
C (ATP) or B (Ca+2)
Able to return to resting length after stretching
C (Elasticity)
action potential is propagated along sarcolemma
D
Membrane has a high voltage potential able to transmit an action potential
D (Irritability/Excitability)
Excitability refers to the ability of a cell to: a. return to its original length after stretching b. respond to a stimulus by producing an electrical signal c. shorten d. assume a desired shape regardless of how much it has been stretched
b
The connective tissue sheaths surrounding muscle fibers, muscle fascicles, and the whole muscle combine together at the ends to form a dense regular connective tissues called: a. a tendon or aponeurosis b. a ligament c. a fibrous sheath d. an epithelial band
b
What regulatory proteins can be found on an actin molecule? a. troponin and titin b. myosin and titin c. tropomyosin and troponin d. titin and tropomyosin e. titin and actin
c
When calcium ion concentration in the sarcoplasm is low the: a. myosin stretches and the muscle relaxes b. actin detaches from the Z discs c. troponin-tropomyosin complex slides back over the myosin binding sites on actin d. muscle cell membrane releases acetylcholine
c
How much of the total body weight of the average adult is muscle tissue? a. 10-20% b. 20-30% c. 30-40% d. 40- 50% e. 50-60%
d
Muscle contraction is triggered by nerve impulses carried delivered by: a. sensory neurons b. afferent neurons c. myofibrils d. motor neurons
d
Myofibrils are composed primarily of: a. troponin b. ATP c. tropomyosin d. actin and myosin
d
Myofibrils contain: a. contractile proteins b. regulatory proteins c. structural proteins d. all of the preceding e. none of the preceding
d
The mitochondria in muscle fiber are arranged: a. randomly b. in circles c. around the nuclei d. in rows close to the myofibrils throughout the muscle fiber e. closest to the sarcolemma
d
The sarcoplasmic reticulum: a. is the cell membrane around each muscle fiber b. opens to the outside through the sarcolemma c. produces ATP for muscle contraction d. releases Ca+2 to initiate the contraction of a muscle fiber
d
This is (These are) responsible for the striations of striated muscle. a. troponin-tropomyosin interaction b. hydrolysis of ATP c. position of H zones d. alternating of A bands and I bands
d
This is the sheath of fibrous connective tissue that surrounds a fascicule: a. tendon b. ligament c. endomysium d. perimysium e. epimysium
d
This part of the skeletal muscle fibert releases calcium when stimulated by the T tubules: a. myofibrils b. sarcoplasm c.sarcomeres d. terminal cisterna of sarcoplasmic reticulum e. none of the preceding
d
What energizes the myosin head? a. the actin filaments b. calcium ions c. potassium ions d. ATP hydrolysis reaction e. ADP synthesis
d
When dense connective tissue extends as a broad flat layer in its attachment to bone, it is called a(n): a. perimysium b. deep fascia c. fascicle d. aponeurosis e. endomysium
d
Which of the following is used to reinforce the sarcolemma? a. tropomyosin b. myosin c. actin d. dystrophin e. troponin
d
A "triad" involves: a. the T-tubules b. the cisternae of the sarcoplasmic reticulum c. the nuclear envelope d. the nucleus e. both a and b
e
ATP is necessary for: a. muscle contraction b. muscle relaxation c. calcium re-uptake by the sarcoplasmic reticulum d. return Na+ to the cell exterior and K+ to the cell interior e. all of the preceding
e
The different types of muscle tissue differ from each other by ___________. a. microscopic anatomy b. location c. type of control d. both a and b e. all a, b, and c
e
This is the property of muscle that gives it the ability to stretch without damage. a. electrical excitability b. contractility c. elasticity d. thermogenesis e. extensibility
e
Titin is found in a sarcomere a. in the A band only b. in the H zone only c. from Z disc to Z disc d. in the I band only e. from M line to Z disc
e
Which of the following contains thick filaments? a. zone of overlap b. darker portion of A band c. H zone d. both b and c e. all of the preceding
e
myofilament
1 (items smallest to largest)
myofibril
2 (items smallest to largest)
Released at the end of the power stroke
A (ADP)
the cross bridge cycle is initiated
E
These are the contractile organelles of the muscle fiber. a. myofibrils b. myoglobin c. mitochondria d. Z disc e. M line
a
"I bands" shorten during contraction
T
On the above diagram, what letter represents the epimysium
B (look up "muscle diagram with tendon" on google images)
High concentrations of these in sarcoplasm needed for muscle contraction to continue
B (Ca+2) or C (ATP)
Able to contract by shortening and thickening
B (Contractility)
Low concentrations of this cause tropomyosin to cover myosin binding sites on thin filaments
B (calcium ion)
Released from the sarcoplasmic reticulum to initiate muscle contraction
B (calcium ion)
High concentrations of this cause troponin to change shape
B (calcium ions)
In the diagram above, where is the M line?
B (direct middle of A-band, can see a line)
In the diagram above, which is the titin structural protein?
E
In the diagram above, where are myosin proteins found?
E (represents A-band)
In the diagram above, where are the thick filaments found?
E (represents A-band)
Actin (thin myofilaments) and myosin (thick myofilaments) shorten during contraction.
F
Due to the presence of superficial and deep fascia, the most-used tools in animal dissection are scalpels and scissors.
F
In the diagram above, what is the basic functional unit of a myofibril?
F
Lower Ca+2 causes troponin/tropomyocin complex to block myosin head binding sites
F
an action potential travels to the T-tubules
F
Bundle of several hundred myosin molecules form this myofilament
F (thick myosin myofilament)
In the diagram above, where is the I band?
G
opening Ca+2 ion channels allowing Ca+2 to enter the axon terminal
G
onsists of two actin myofilaments along with troponin and tropomyosin
G (thin actin myofilament)
In the diagram above, what letter represents the "zone of overlap"?
H
opening of Na+/K+voltage sensitive channels that lower the voltage potential of the sarcolemma membrane
H
A bundle of thick and thin myofilaments in a muscle fiber (i.e. the contractile organelle)
H (myofibril)
ATP hydrolysis activates the myosin head bringing it to its cocked position
I
On the above diagram, what letter represents a myofibril within a muscle fiber
I (look up "muscle diagram with tendon" on google images)
Specific sites on actin where cross bridges can form
I (myosin binding site)
In the diagram above, where is the A band?
J
Decreases Ca+2 concentrations in the sarcoplasm
J (active transport calcium ion pumps)
Molecule shaped like a golf club with two heads
K (myosin molecule)
Spherical molecule that forms a long filament like a string of pearls
L (actin molecule)
Arrival of action potentials cause these to open in the membrane of the sarcoplasmic reticulum
M (calcium ion channels)
The arrival of an action potential in a T-tubule causes the opening of Ca+2 channels in the adjacent sarcoplasmic reticulum and the release of Ca+2 into the sarcoplasm.
T
The inside region of a T tubule is continuous with the extracellular space.
T
Triads are paired terminal cisternae of sarcoplasmic reticulum on either side of a T tubule
T
The sarcoplasmic reticulum releases calcium ions into the cytosol: a. at the beginning of a contraction b. throughout the entire contraction c. during the midpoint only of the contraction d. after the contraction ends e. all of the preceding
a
Various connective tissue wrappings surround various parts of muscle tissue. From an individual fiber to the entire muscle, these are: a. endomysium, perimysium, epimysium b. epimysium, perimysium, endomysium c. perimysium, endomysium, epimysium d. endomysium, epimysium, perimysium
a
When ATP attaches to the myosin head: a. the head detaches from the binding site on actin b. the head attaches to troponin c. Ca2+ reacts with the ATP d. actin and myosin both shorten
a
Which of the following contain most of the thin filaments in a relaxed sarcomere? a. I band b. A band c. H zone d. both a and b e. all of the preceding
a
Which of the following properties of muscle tissue is its ability to generate tension to do work? a. contractility b. extensibility c. elasticity d. excitability
a
