Human anatomy Exam questions and
answers graded A+
Sarcolemma - ANS✅✅muscle plasma membrane
Sarcoplasm - ANS✅✅cytoplasm of a muscle cell
Muscle cells respond to neural, stretch, or other signals by changing their _______. -
ANS✅✅sarcolemma electrical potential (voltage)
The electrical potential change is coupled to intracellular changes that result in ______. -
ANS✅✅force generation (contraction)
Contractility - ANS✅✅active shortening of muscle cell and generation of tension (force)
Extensibility - ANS✅✅passive stretching of muscle cells
Elasticity - ANS✅✅return of muscle cells to original resting length after being stretched
Which muscle tissue(s) has cells w/ obvious stripes called striations - ANS✅✅skeletal, cardiac
Which muscle tissue is voluntary and which is involuntary? - ANS✅✅voluntary-
skeletal......involuntary-cardiac,smooth
What muscle tissue contracts rapidly but tires easily? - ANS✅✅skeletal
Cardiac muscle contracts at a rate set by the heart's ________. - ANS✅✅pacemaker
Which muscle tissue is primarily found in the walls of hollow visceral organs? - ANS✅✅smooth
Which muscle tissue forces food and other substances through internal body cavities? -
ANS✅✅smooth
,What are the three connective tissue sheaths? - ANS✅✅endomysium, perimysium, epimysium
What is a fine sheath of connective tissue composed of reticular fibers surrounding each muscle
fiber? - ANS✅✅endomysium
What is fibrous connective tissue that surrounds groups of muscle fibers called fascicles? -
ANS✅✅perimysium
What is an overcoat of dense regular connective tissue that surrounds the entire muscle? -
ANS✅✅epimysium
each muscle is served by ________. - ANS✅✅one nerve(bundle of nerve fibers), an atery, and one
or more veins
when muscles contract... - ANS✅✅the movable bone (insertion) moves toward the immovable
bone (origin)
How does a muscle attach to a bone directly? - ANS✅✅epimysium of the muscle is fused to the
periosteum of a bone (less common)
How does a muscle attach to a bone indirectly? - ANS✅✅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? - ANS✅✅a myocyte or muscle fiber
Myocyte size - ANS✅✅10 to 100 micrometers in diamter and many 10s of cm long
Each mature myocyte is created by fusion of multiple precursor cells called _________. -
ANS✅✅myoblasts
Sarcoplasm has numerous ________ and an oxygen-binding protein called _________. -
ANS✅✅glycosomes, myoglobin
, Myocytes contain the usual organelles, as well as.... - ANS✅✅myofibrils, sarcoplasmic reticulum, T-
tubules
Densly packed rodlike contractile elements are called ________. - ANS✅✅myofibrils
What is the smallest contractile unit of a muscle called? - ANS✅✅a sarcomere
What is the region of a myofibril b/w two succesive Z-discs? - ANS✅✅a sarcomere
What is a sarcomere composed of? - ANS✅✅thick and thin myofilaments made up of contractile
proteins
How long does a thick filament of a myofilament extend? A thin filament? - ANS✅✅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? - ANS✅✅Z-disc
Where do elastic filaments stretch and what are they made of? - ANS✅✅from Z-disc through the
thick filament to the M-line.
a huge protein called titin.
What are thick filaments composed of? - ANS✅✅200-500 myosin protein molecules
What protein has a rod-like tail and two golbular heads? - ANS✅✅myosin
What is the primary contractice protein in thin filaments and what is it made out of? - ANS✅✅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. -
ANS✅✅a myosin head
answers graded A+
Sarcolemma - ANS✅✅muscle plasma membrane
Sarcoplasm - ANS✅✅cytoplasm of a muscle cell
Muscle cells respond to neural, stretch, or other signals by changing their _______. -
ANS✅✅sarcolemma electrical potential (voltage)
The electrical potential change is coupled to intracellular changes that result in ______. -
ANS✅✅force generation (contraction)
Contractility - ANS✅✅active shortening of muscle cell and generation of tension (force)
Extensibility - ANS✅✅passive stretching of muscle cells
Elasticity - ANS✅✅return of muscle cells to original resting length after being stretched
Which muscle tissue(s) has cells w/ obvious stripes called striations - ANS✅✅skeletal, cardiac
Which muscle tissue is voluntary and which is involuntary? - ANS✅✅voluntary-
skeletal......involuntary-cardiac,smooth
What muscle tissue contracts rapidly but tires easily? - ANS✅✅skeletal
Cardiac muscle contracts at a rate set by the heart's ________. - ANS✅✅pacemaker
Which muscle tissue is primarily found in the walls of hollow visceral organs? - ANS✅✅smooth
Which muscle tissue forces food and other substances through internal body cavities? -
ANS✅✅smooth
,What are the three connective tissue sheaths? - ANS✅✅endomysium, perimysium, epimysium
What is a fine sheath of connective tissue composed of reticular fibers surrounding each muscle
fiber? - ANS✅✅endomysium
What is fibrous connective tissue that surrounds groups of muscle fibers called fascicles? -
ANS✅✅perimysium
What is an overcoat of dense regular connective tissue that surrounds the entire muscle? -
ANS✅✅epimysium
each muscle is served by ________. - ANS✅✅one nerve(bundle of nerve fibers), an atery, and one
or more veins
when muscles contract... - ANS✅✅the movable bone (insertion) moves toward the immovable
bone (origin)
How does a muscle attach to a bone directly? - ANS✅✅epimysium of the muscle is fused to the
periosteum of a bone (less common)
How does a muscle attach to a bone indirectly? - ANS✅✅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? - ANS✅✅a myocyte or muscle fiber
Myocyte size - ANS✅✅10 to 100 micrometers in diamter and many 10s of cm long
Each mature myocyte is created by fusion of multiple precursor cells called _________. -
ANS✅✅myoblasts
Sarcoplasm has numerous ________ and an oxygen-binding protein called _________. -
ANS✅✅glycosomes, myoglobin
, Myocytes contain the usual organelles, as well as.... - ANS✅✅myofibrils, sarcoplasmic reticulum, T-
tubules
Densly packed rodlike contractile elements are called ________. - ANS✅✅myofibrils
What is the smallest contractile unit of a muscle called? - ANS✅✅a sarcomere
What is the region of a myofibril b/w two succesive Z-discs? - ANS✅✅a sarcomere
What is a sarcomere composed of? - ANS✅✅thick and thin myofilaments made up of contractile
proteins
How long does a thick filament of a myofilament extend? A thin filament? - ANS✅✅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? - ANS✅✅Z-disc
Where do elastic filaments stretch and what are they made of? - ANS✅✅from Z-disc through the
thick filament to the M-line.
a huge protein called titin.
What are thick filaments composed of? - ANS✅✅200-500 myosin protein molecules
What protein has a rod-like tail and two golbular heads? - ANS✅✅myosin
What is the primary contractice protein in thin filaments and what is it made out of? - ANS✅✅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. -
ANS✅✅a myosin head
