ANATOMY AND PHYSIOLOGY EXAM 3
QUESTIONS & ACTUAL CORRECT
ANSWERS PASSED
Sarcolemma - Correct Answer ✔✔ muscle plasma membrane
Sarcoplasm - Correct Answer ✔✔ cytoplasm of a muscle cell
Muscle cells respond to neural, stretch, or other signals by changing their _______. -
Correct Answer ✔✔ sarcolemma electrical potential (voltage)
The electrical potential change is coupled to intracellular changes that result in ______.
- Correct Answer ✔✔ force generation (contraction)
Contractility - Correct Answer ✔✔ active shortening of muscle cell and generation of
tension (force)
Extensibility - Correct Answer ✔✔ passive stretching of muscle cells
Elasticity - Correct Answer ✔✔ return of muscle cells to original resting length after
being stretched
Which muscle tissue(s) has cells w/ obvious stripes called striations - Correct Answer
✔✔ skeletal, cardiac
Which muscle tissue is voluntary and which is involuntary? - Correct Answer ✔✔
voluntary-skeletal......involuntary-cardiac,smooth
What muscle tissue contracts rapidly but tires easily? - Correct Answer ✔✔ skeletal
Cardiac muscle contracts at a rate set by the heart's ________. - Correct Answer ✔✔
pacemaker
Which muscle tissue is primarily found in the walls of hollow visceral organs? - Correct
Answer ✔✔ smooth
Which muscle tissue forces food and other substances through internal body cavities? -
Correct Answer ✔✔ smooth
What are the three connective tissue sheaths? - Correct Answer ✔✔ endomysium,
perimysium, epimysium
,What is a fine sheath of connective tissue composed of reticular fibers surrounding each
muscle fiber? - Correct Answer ✔✔ endomysium
What is fibrous connective tissue that surrounds groups of muscle fibers called
fascicles? - Correct Answer ✔✔ perimysium
What is an overcoat of dense regular connective tissue that surrounds the entire
muscle? - Correct Answer ✔✔ epimysium
each muscle is served by ________. - Correct Answer ✔✔ one nerve(bundle of nerve
fibers), an atery, and one or more veins
when muscles contract... - Correct Answer ✔✔ the movable bone (insertion) moves
toward the immovable bone (origin)
How does a muscle attach to a bone directly? - Correct Answer ✔✔ epimysium of the
muscle is fused to the periosteum of a bone (less common)
How does a muscle attach to a bone indirectly? - Correct Answer ✔✔ connective tissue
wrappings extend beyond the muscle as a tendon or aponeurosis that attaches to a
bone (more common)
What is a single muscle cell called? - Correct Answer ✔✔ a myocyte or muscle fiber
Myocyte size - Correct Answer ✔✔ 10 to 100 micrometers in diamter and many 10s of
cm long
Each mature myocyte is created by fusion of multiple precursor cells called _________.
- Correct Answer ✔✔ myoblasts
Sarcoplasm has numerous ________ and an oxygen-binding protein called _________.
- Correct Answer ✔✔ glycosomes, myoglobin
Myocytes contain the usual organelles, as well as.... - Correct Answer ✔✔ myofibrils,
sarcoplasmic reticulum, T-tubules
Densly packed rodlike contractile elements are called ________. - Correct Answer ✔✔
myofibrils
What is the smallest contractile unit of a muscle called? - Correct Answer ✔✔ a
sarcomere
What is the region of a myofibril b/w two succesive Z-discs? - Correct Answer ✔✔ a
sarcomere
, What is a sarcomere composed of? - Correct Answer ✔✔ thick and thin myofilaments
made up of contractile proteins
How long does a thick filament of a myofilament extend? A thin filament? - Correct
Answer ✔✔ thick: the entire length of an A-band
thin:across the I band and part way into the A band
What is a coin-shaped sheet of proteins (connectins) that anchors the thin filaments and
connects myofibrils? - Correct Answer ✔✔ Z-disc
Where do elastic filaments stretch and what are they made of? - Correct Answer ✔✔
from Z-disc through the thick filament to the M-line.
a huge protein called titin.
What are thick filaments composed of? - Correct Answer ✔✔ 200-500 myosin protein
molecules
What protein has a rod-like tail and two golbular heads? - Correct Answer ✔✔ myosin
What is the primary contractice protein in thin filaments and what is it made out of? -
Correct Answer ✔✔ F-actin
each F-actin strand is a double helical polymer of individual globular subunits called G-
actin
Each G-actin subunit contains an active site to which _______ attaches to during
contraction. - Correct Answer ✔✔ a myosin head
What is a filamentous protein bound in the grooves of the F-actin helix that blocks the
myosin binding site inrelaxed muscle? - Correct Answer ✔✔ tropmyosin
What is troponin and what does it do? - Correct Answer ✔✔ a regulatory protein
complex bound to F-actin and tropomyosin, and binds calcium ions
Sarcolplasmic reticulum is a type of ________ that mostly runs ________ and
surrounds each ________. - Correct Answer ✔✔ elaborate, smooth ER
longitudinally
myofibril
_________ of SR form perpendicular cross channgels. - Correct Answer ✔✔ paired
terminal cisternae
The sarcoplasmic reticulum functions to regulate intracellular _________ levels. -
Correct Answer ✔✔ calcium
Elongated tubes of sarcolemma called ________ penetrate into the cell's interior at
each A band-I band junction - Correct Answer ✔✔ T-tubules
QUESTIONS & ACTUAL CORRECT
ANSWERS PASSED
Sarcolemma - Correct Answer ✔✔ muscle plasma membrane
Sarcoplasm - Correct Answer ✔✔ cytoplasm of a muscle cell
Muscle cells respond to neural, stretch, or other signals by changing their _______. -
Correct Answer ✔✔ sarcolemma electrical potential (voltage)
The electrical potential change is coupled to intracellular changes that result in ______.
- Correct Answer ✔✔ force generation (contraction)
Contractility - Correct Answer ✔✔ active shortening of muscle cell and generation of
tension (force)
Extensibility - Correct Answer ✔✔ passive stretching of muscle cells
Elasticity - Correct Answer ✔✔ return of muscle cells to original resting length after
being stretched
Which muscle tissue(s) has cells w/ obvious stripes called striations - Correct Answer
✔✔ skeletal, cardiac
Which muscle tissue is voluntary and which is involuntary? - Correct Answer ✔✔
voluntary-skeletal......involuntary-cardiac,smooth
What muscle tissue contracts rapidly but tires easily? - Correct Answer ✔✔ skeletal
Cardiac muscle contracts at a rate set by the heart's ________. - Correct Answer ✔✔
pacemaker
Which muscle tissue is primarily found in the walls of hollow visceral organs? - Correct
Answer ✔✔ smooth
Which muscle tissue forces food and other substances through internal body cavities? -
Correct Answer ✔✔ smooth
What are the three connective tissue sheaths? - Correct Answer ✔✔ endomysium,
perimysium, epimysium
,What is a fine sheath of connective tissue composed of reticular fibers surrounding each
muscle fiber? - Correct Answer ✔✔ endomysium
What is fibrous connective tissue that surrounds groups of muscle fibers called
fascicles? - Correct Answer ✔✔ perimysium
What is an overcoat of dense regular connective tissue that surrounds the entire
muscle? - Correct Answer ✔✔ epimysium
each muscle is served by ________. - Correct Answer ✔✔ one nerve(bundle of nerve
fibers), an atery, and one or more veins
when muscles contract... - Correct Answer ✔✔ the movable bone (insertion) moves
toward the immovable bone (origin)
How does a muscle attach to a bone directly? - Correct Answer ✔✔ epimysium of the
muscle is fused to the periosteum of a bone (less common)
How does a muscle attach to a bone indirectly? - Correct Answer ✔✔ connective tissue
wrappings extend beyond the muscle as a tendon or aponeurosis that attaches to a
bone (more common)
What is a single muscle cell called? - Correct Answer ✔✔ a myocyte or muscle fiber
Myocyte size - Correct Answer ✔✔ 10 to 100 micrometers in diamter and many 10s of
cm long
Each mature myocyte is created by fusion of multiple precursor cells called _________.
- Correct Answer ✔✔ myoblasts
Sarcoplasm has numerous ________ and an oxygen-binding protein called _________.
- Correct Answer ✔✔ glycosomes, myoglobin
Myocytes contain the usual organelles, as well as.... - Correct Answer ✔✔ myofibrils,
sarcoplasmic reticulum, T-tubules
Densly packed rodlike contractile elements are called ________. - Correct Answer ✔✔
myofibrils
What is the smallest contractile unit of a muscle called? - Correct Answer ✔✔ a
sarcomere
What is the region of a myofibril b/w two succesive Z-discs? - Correct Answer ✔✔ a
sarcomere
, What is a sarcomere composed of? - Correct Answer ✔✔ thick and thin myofilaments
made up of contractile proteins
How long does a thick filament of a myofilament extend? A thin filament? - Correct
Answer ✔✔ thick: the entire length of an A-band
thin:across the I band and part way into the A band
What is a coin-shaped sheet of proteins (connectins) that anchors the thin filaments and
connects myofibrils? - Correct Answer ✔✔ Z-disc
Where do elastic filaments stretch and what are they made of? - Correct Answer ✔✔
from Z-disc through the thick filament to the M-line.
a huge protein called titin.
What are thick filaments composed of? - Correct Answer ✔✔ 200-500 myosin protein
molecules
What protein has a rod-like tail and two golbular heads? - Correct Answer ✔✔ myosin
What is the primary contractice protein in thin filaments and what is it made out of? -
Correct Answer ✔✔ F-actin
each F-actin strand is a double helical polymer of individual globular subunits called G-
actin
Each G-actin subunit contains an active site to which _______ attaches to during
contraction. - Correct Answer ✔✔ a myosin head
What is a filamentous protein bound in the grooves of the F-actin helix that blocks the
myosin binding site inrelaxed muscle? - Correct Answer ✔✔ tropmyosin
What is troponin and what does it do? - Correct Answer ✔✔ a regulatory protein
complex bound to F-actin and tropomyosin, and binds calcium ions
Sarcolplasmic reticulum is a type of ________ that mostly runs ________ and
surrounds each ________. - Correct Answer ✔✔ elaborate, smooth ER
longitudinally
myofibril
_________ of SR form perpendicular cross channgels. - Correct Answer ✔✔ paired
terminal cisternae
The sarcoplasmic reticulum functions to regulate intracellular _________ levels. -
Correct Answer ✔✔ calcium
Elongated tubes of sarcolemma called ________ penetrate into the cell's interior at
each A band-I band junction - Correct Answer ✔✔ T-tubules
