Block 2: Muscle

Question 1

What is the outer connective tissue covering of a muscle? a. Epimysium b. Sarcoplasm c. Perimysium d. Sarcolemma e. Endomysium

Answer 1

Answer: a The outer connective tissue covering of a muscle is the epimysium. Within the muscle, there are subdivisions called fascicles. The perimysium surrounds these muscle fascicles. The endomysium is the covering around an individual muscle fiber. The sarcolemma is the plasma membrane of a muscle cell. The sarcoplasm is the cytoplasm of a muscle cell.

Question 2

What is myosin? a. Muscle fibers b. Myofibrils c. Myocardium d. Myofilament e. Muscle cell

Answer 2

Answer: d Myofilaments are the contractile protein within a muscle cell. The myofilaments are actin and myosin. The thin filaments are actin and the thick filaments are myosin. The muscle cell is a muscle fiber. The term “muscle cell” and “muscle fiber” are synonymous. A myofibril is a longitudinal bundle of myofilaments within a muscle cell. Myocardium is the muscular layer of the heart. Thus, the myocardium is composed of cardiac muscle.

Question 3

Where is cardiac muscle found? a. Myofilaments b. Myosin c. Muscle fibers d. Myofibrils e. Myocardium

Answer 3

Answer: e Myofilaments are the contractile protein within a muscle cell. The myofilaments are actin and myosin. The thin filaments are actin and the thick filaments are myosin. The muscle cell is a muscle fiber. The term “muscle cell” and “muscle fiber” are synonymous. A myofibril is a longitudinal bundle of myofilaments within a muscle cell. Myocardium is the muscular layer of the heart. Thus, the myocardium is composed of cardiac muscle.

Question 4

What type of muscle has visible cross striations? a. Skeletal muscle b. Cardiac muscle c. Smooth muscle d. Both “a” and “b” e. “a” “b” and “c”

Answer 4

Answer: d Both skeletal muscle and cardiac muscle have visible striations. Collectively, skeletal muscle and cardiac muscle are classified as “striated muscle”.

Question 5

What type of muscle is specialized for contraction? a. Skeletal muscle b. Cardiac muscle c. Smooth muscle d. Both “a” and “b” e. “a” “b” and “c”

Answer 5

Answer: e The fundamental property of muscle tissue is that it is specialized for contraction.

Question 6

What is released at a synapse? a. Motor unit b. Motor neuron c. Motor end plate d. Neuromuscular spindle e. Neurotransmitter

Answer 6

Answer: e A single motor neuron and the aggregation of muscle fibers innervated by that single neuron is called the motor unit. A motor neuron is a neuron which innervates a muscle cell. The point of contact where a neuron contacts a muscle is the motor end plate. A neuromuscular spindle is a receptor which is sensitive to stretching of the muscle. A neurotransmitter is the chemical released by a nerve at a synapse.

Question 7

Which fiber type is more resistant to fatigue? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 7

Answer: a Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism. Red fiber and slow twitch muscle is for endurance. White fiber and fast twitch muscle is for a burst of power.

Question 8

Lance Armstrong is the seven time winner of the Tour de France. The Tour de France is a bicycle race which covers between 3500 to 4000 kilometers. What type of muscle fiber probably predominates in his legs? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 8

Answer: a Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism. Red fiber and slow twitch muscle is for endurance. White fiber and fast twitch muscle is for a burst of power.

Question 9

What region is made of thin filaments? a. A band b. I band c. Z line d. H band e. M line

Answer 9

Answer: b The A band is the darker staining band. The I band is the light band. The I band is made of thin filaments. The Z line runs through the I band. The H band bisects the A band. The M line runs through the H band. A sarcomere is the segment that runs from Z line to Z line.

Question 10

On a cross section of a muscle, how many thin filaments surround each thick filament? a. 2 b. 3 c. 4 d. 6 e. 8

Answer 10

Answer: d On a cross section of a muscle, each thick filament is surrounded by 6 thin filaments.

Question 11

What is the connective tissue covering of a muscle fascicle? a. Sarcolemma b. Endomysium c. Epimysium d. Sarcoplasm e. Perimysium

Answer 11

Answer: e The outer connective tissue covering of a muscle is the epimysium. Within the muscle, there are subdivisions called fascicles. The perimysium surrounds these muscle fascicles. The endomysium is the covering around an individual muscle fiber. The sarcolemma is the plasma membrane of a muscle cell. The sarcoplasm is the cytoplasm of a muscle cell.

Question 12

What is actin? a. Myofilament b. Myosin c. Muscle fibers d. Myofibrils e. Myocardium

Answer 12

Answer: a Myofilaments are the contractile protein within a muscle cell. The myofilaments are actin and myosin. The thin filaments are actin and the thick filaments are myosin. The muscle cell is a muscle fiber. The term “muscle cell” and “muscle fiber” are synonymous. A myofibril is a longitudinal bundle of myofilaments within a muscle cell. Myocardium is the muscular layer of the heart. Thus, the myocardium is composed of cardiac muscle.

Question 13

Which of the following is composed of smooth muscle? a. Upper esophagus b. Heart c. Tongue d. Biceps muscle e. Walls of the visceral organs

Answer 13

Answer: e There are two chief categories of muscle: striated and non striated muscle (smooth muscle).Striated muscle can be sub-categorized into cardiac muscle and skeletal muscle. The tongue, biceps muscle, and upper esophagus are made of striated muscle. The heart is composed of cardiac muscle.Non striated muscle is also called smooth muscle. Smooth muscle is involuntary muscle. It is found in viscera and blood vessels.

Question 14

What is a receptor in muscle? a. Motor unit b. Motor neuron c. Motor end plate d. Neuromuscular spindle e. Neurotransmitter

Answer 14

Answer: d A single motor neuron and the aggregation of muscle fibers innervated by that single neuron is called the motor unit. A motor neuron is a neuron which innervates a muscle cell. The point of contact where a neuron contacts a muscle is the motor end plate. A neuromuscular spindle is a receptor which is sensitive to stretching of the muscle. A neurotransmitter is the chemical released by a nerve at a synapse.

Question 15

Which fiber type is larger in diameter? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 15

Answer: b Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism.Red fiber and slow twitch muscle is for endurance.White fiber and fast twitch muscle is for a burst of power.Red fiber and slow twitch muscle is for endurance.White fiber and fast twitch muscle is for a burst of power.

Question 16

Which fiber type is make up fast-twitch muscle? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 16

Answer: b Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism.Red fiber and slow twitch muscle is for endurance.White fiber and fast twitch muscle is for a burst of power.

Question 17

Which fiber type has more myoglobin? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 17

Answer: a Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism.Red fiber and slow twitch muscle is for endurance.White fiber and fast twitch muscle is for a burst of power.

Question 18

Which fiber type gets its energy primarily from glycogen? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 18

Answer: b Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism.Red fiber and slow twitch muscle is for endurance.White fiber and fast twitch muscle is for a burst of power.

Question 19

Which fiber type is seen in skeletal muscle? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 19

Answer: d Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism.Red fiber and slow twitch muscle is for endurance.White fiber and fast twitch muscle is for a burst of power.

Question 20

What is line that bisects the dark band in muscle? a. A band b. I band c. Z line d. H band e. M line

Answer 20

Answer: d The A band is the darker staining band. The I band is the light band. The I band is made of thin filaments. The Z line runs through the I band. The H band bisects the A band. The M line runs through the H band.A sarcomere is the segment that runs from Z line to Z line.

Question 21

What is the plasma membrane of a muscle cell called? a. Endomysium b. Sarcolemma c. Sarcoplasm d. Perimysium e. Epimysium

Answer 21

Answer: b The outer connective tissue covering of a muscle is the epimysium. Within the muscle, there are subdivisions called fascicles. The perimysium surrounds these muscle fascicles. The endomysium is the covering around an individual muscle fiber. The sarcolemma is the plasma membrane of a muscle cell. The sarcoplasm is the cytoplasm of a muscle cell.

Question 22

What are the thin filaments? a. Myocardium b. Myofibrils c. Myofilaments d. Muscle fibers e. Myosin

Answer 22

Answer: c Myofilaments are the contractile protein within a muscle cell. The myofilaments are actin and myosin. The thin filaments are actin and the thick filaments are myosin. The muscle cell is a muscle fiber. The term “muscle cell” and “muscle fiber” are synonymous. A myofibril is a longitudinal bundle of myofilaments within a muscle cell. Myocardium is the muscular layer of the heart. Thus, the myocardium is composed of cardiac muscle.

Question 23

Which of the following is composed of skeletal muscle? a. Tongue b. Blood vessel c. Walls of the visceral organs d. Lower esophagus e. Heart

Answer 23

Answer: a There are two chief categories of muscle: striated and non striated muscle (smooth muscle). Striated muscle can be sub-categorized into cardiac muscle and skeletal muscle. The tongue, biceps muscle, and upper esophagus are made of striated muscle. The heart is composed of cardiac muscle. Non striated muscle is also called smooth muscle. Smooth muscle is involuntary muscle. It is found in viscera and blood vessels.

Question 24

What type of muscle is composed of spindle shaped cells? a. Skeletal muscle b. Cardiac muscle c. Smooth muscle d. Both “a” and “b” e. “a” “b” and “c”

Answer 24

Answer: c Smooth muscle is composed of spindle shaped cells.

Question 25

What type of muscle is always multinucleated? a. Skeletal muscle b. Cardiac muscle c. Smooth muscle d. Both “a” and “b” e. “a” “b” and “c”

Answer 25

Answer: a Skeletal muscle is multinucleated. The nuclei are seen on the periphery. Occasionally, cardiac muscle is bi-nucleated.

Question 26

Which fiber type is smaller in diameter? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 26

Answer: a Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism. Red fiber and slow twitch muscle is for endurance. White fiber and fast twitch muscle is for a burst of power.

Question 27

Which fiber type fatigues more readily? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 27

Answer: b Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism. Red fiber and slow twitch muscle is for endurance. White fiber and fast twitch muscle is for a burst of power.

Question 28

What type of muscle probably predominates in Charles Atlas, the worlds most famous power weight lifter? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 28

Answer: b Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism. Red fiber and slow twitch muscle is for endurance. White fiber and fast twitch muscle is for a burst of power.

Question 29

What is line that bisects the light band in muscle? a. A band b. I band c. Z line d. H band e. M line

Answer 29

Answer: c The A band is the darker staining band. The I band is the light band. The I band is made of thin filaments. The Z line runs through the I band. The H band bisects the A band. The M line runs through the H band. A sarcomere is the segment that runs from Z line to Z line.

Question 30

What is the name of the tissue which surrounds muscle fascicles? a. Perimysium b. Periosteum c. Perichondrium d. Perineurium e. Endosteum

Answer 30

Answer: a The perimysium is the connective tissue sheath which surrounds muscle fascicles. The periosteum is the connective tissue covering of a bone. The perichondrium is the connective tissue which surrounds cartilage. The perineurium is the covering of nerve fascicles. The endosteum is the lining of the inner bone (the side which abuts the medullary cavity). Note from Sarah Bellham: The prefix “peri” means around, such as in the word “perimeter”. The prefix “endo” means within or inner, such as in “endosteum”, “endocrine”, “endoscope”.

Question 31

What is the covering of an individual muscle fiber? a. Sarcoplasm b. Perimysium c. Endomysium d. Epimysium e. Sarcolemma

Answer 31

Answer: c The outer connective tissue covering of a muscle is the epimysium. Within the muscle, there are subdivisions called fascicles. The perimysium surrounds these muscle fascicles. The endomysium is the covering around an individual muscle fiber. The sarcolemma is the plasma membrane of a muscle cell. The sarcoplasm is the cytoplasm of a muscle cell.

Question 32

What are the thick filaments composed of? a. Myofilaments b. Myosin c. Muscle fibers d. Myofibrils e. Myocardium

Answer 32

Answer: b Myofilaments are the contractile protein within a muscle cell. The myofilaments are actin and myosin. The thin filaments are actin and the thick filaments are myosin. The muscle cell is a muscle fiber. The term “muscle cell” and “muscle fiber” are synonymous. A myofibril is a longitudinal bundle of myofilaments within a muscle cell. Myocardium is the muscular layer of the heart. Thus, the myocardium is composed of cardiac muscle.

Question 33

Which of the following is composed of cardiac muscle? a. Biceps muscle b. Tongue c. Heart d. Upper esophagus e. Walls of the visceral organs

Answer 33

Answer: c There are two chief categories of muscle: striated and non striated muscle (smooth muscle). Striated muscle can be sub-categorized into cardiac muscle and skeletal muscle. The tongue, biceps muscle, and upper esophagus are made of striated muscle. The heart is composed of cardiac muscle. Non striated muscle is also called smooth muscle. Smooth muscle is involuntary muscle. It is found in viscera and blood vessels.

Question 34

What type of muscle contains centrally placed nuclei? a. Smooth muscle b. Cardiac muscle c. Skeletal muscle d. Both “a” and “b” e. “a” “b” and “c”

Answer 34

Answer: d Skeletal muscle fibers are multinucleated. The nuclei are located on the periphery of the cell. In cardiac muscle, the nucleus is located centrally. In smooth muscle, there is also a centrally placed nucleus. PEARL from Sarah Bellham: This is an important point, as both skeletal muscle and cardiac muscle are striated. The centrally placed nucleus seen in cardiac muscle is one of the things that can be used to distinguish between the two.

Question 35

What is the point that a neuron contacts a muscle called? a. Motor unit b. Motor neuron c. Motor end plate d. Neuromuscular spindle e. Neurotransmitter

Answer 35

A single motor neuron and the aggregation of muscle fibers innervated by that single neuron is called the motor unit. A motor neuron is a neuron which innervates a muscle cell. The point of contact where a neuron contacts a muscle is the motor end plate. A neuromuscular spindle is a receptor which is sensitive to stretching of the muscle. A neurotransmitter is the chemical released by a nerve at a synapse.

Question 36

Which fiber type makes up slow-twitch muscle? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 36

Answer: a Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism. Red fiber and slow twitch muscle is for endurance. White fiber and fast twitch muscle is for a burst of power.

Question 37

Which fiber type uses more anaerobic metabolism? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 37

Answer: b Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism. Red fiber and slow twitch muscle is for endurance. White fiber and fast twitch muscle is for a burst of power.

Question 38

What is the dark band in muscle? a. A band b. I band c. Z line d. H band e. M line

Answer 38

Answer: a The A band is the darker staining band. The I band is the light band. The I band is made of thin filaments. The Z line runs through the I band. The H band bisects the A band. The M line runs through the H band. A sarcomere is the segment that runs from Z line to Z line.

Question 39

What bisects the H band a. A band b. I band c. Z line d. E band e. M line

Answer 39

Answer: e The A band is the darker staining band. The I band is the light band. The I band is made of thin filaments. The Z line runs through the I band. The H band bisects the A band. The M line runs through the H band. A sarcomere is the segment that runs from Z line to Z line.

Question 40

What type of muscle has intercalated discs? a. Skeletal muscle b. Cardiac muscle c. Smooth muscle d. Both “a” and “b” e. “a” “b” and “c”

Answer 40

Answer: b Intercalated discs are seen in cardiac muscle. Intercalated discs are specialized junctions between cardiac cells.

Question 41

What is the cytoplasm of a muscle cell? a. Epimysium b. Sarcolemma c. Endomysium d. Sarcoplasm e. Perimysium

Answer 41

Answer: d The outer connective tissue covering of a muscle is the epimysium. Within the muscle, there are subdivisions called fascicles. The perimysium surrounds these muscle fascicles. The endomysium is the covering around an individual muscle fiber. The sarcolemma is the plasma membrane of a muscle cell. The sarcoplasm is the cytoplasm of a muscle cell.

Question 42

What is another term for muscle cells? a. Myofilaments b. Myosin c. Muscle fibers d. Myofibrils e. Myocardium

Answer 42

Answer: c Myofilaments are the contractile protein within a muscle cell. The myofilaments are actin and myosin. The thin filaments are actin and the thick filaments are myosin. The muscle cell is a muscle fiber. The term “muscle cell” and “muscle fiber” are synonymous. A myofibril is a longitudinal bundle of myofilaments within a muscle cell. Myocardium is the muscular layer of the heart. Thus, the myocardium is composed of cardiac muscle.

Question 43

Which of the following contains a substantial amount of smooth muscle? a. Upper esophagus b. Blood vessels c. Heart d. Biceps muscle e. Tongue

Answer 43

Answer: b There are two chief categories of muscle: striated and non striated muscle (smooth muscle). Striated muscle can be sub-categorized into cardiac muscle and skeletal muscle. The tongue, biceps muscle, and upper esophagus are made of striated muscle. The heart is composed of cardiac muscle. Non striated muscle is also called smooth muscle. Smooth muscle is involuntary muscle. It is found in viscera and blood vessels.

Question 44

What type of muscle contains actin and myosin? a. Skeletal muscle b. Cardiac muscle c. Smooth muscle d. Both “a” and “b” e. “a” “b” and “c”

Answer 44

Answer: e All types of muscle contain actin and myosin.

Question 45

What is a single neuron and the aggregation of muscle fibers innervated by that single neuron called? a. Motor unit b. Motor neuron c. Motor end plate d. Neuromuscular spindle e. Neurotransmitter

Answer 45

Answer: a A single motor neuron and the aggregation of muscle fibers innervated by that single neuron is called the motor unit. A motor neuron is a neuron which innervates a muscle cell. The point of contact where a neuron contacts a muscle is the motor end plate. A neuromuscular spindle is a receptor which is sensitive to stretching of the muscle. A neurotransmitter is the chemical released by a nerve at a synapse.

Question 46

Which fiber type has a lot of mitochondria? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 46

Answer: a Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism.

Question 47

Which fiber type uses more aerobic metabolism? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 47

Answer: a Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism. Red fiber and slow twitch muscle is for endurance. White fiber and fast twitch muscle is for a burst of power.

Question 48

What is the light band in muscle? a. A band b. I band c. Z line d. H band e. M line

Answer 48

Answer: b The A band is the darker staining band. The I band is the light band. The I band is made of thin filaments. The Z line runs through the I band. The H band bisects the A band. The M line runs through the H band. A sarcomere is the segment that runs from Z line to Z line.

Question 49

What type of muscle contains sarcomeres? a. Skeletal muscle b. Cardiac muscle c. Smooth muscle d. Both “a” and “b” e. “a” “b” and “c”

Answer 49

Answer: d Both skeletal muscle and cardiac muscle have sarcomeres. Smooth muscle has no sarcomeres.

Question 50

What type of muscle has branching cells? a. Skeletal muscle b. Cardiac muscle c. Smooth muscle d. Both “a” and “b” e. “a” “b” and “c”

Answer 50

Answer: b Branching cells are seen in cardiac muscle. Histology hint from Sarah Bellham: This is an important point, as both skeletal muscle and cardiac muscle are striated. The branching seen with cardiac muscle is one of the things that can be used to distinguish between the two.

Question 51

Which fiber type is seen in smooth muscle? a. Red fibers b. White fibers c. Intermediate fibers d. All of the above e. None of the above

Answer 51

Answer: e Skeletal muscle fibers can be classified as red fibers, white fibers or intermediate fibers. Red fibers are smaller in diameter; white fibers are larger in diameter. Red fibers have more mitochondria than white fibers. Red fibers make up slow-twitch muscle; white fibers make up fast-twitch muscle. Red fibers are more resistant to fatigue than are white fibers. Red fibers have more myoglobin (oxygen binding pigment) than white fibers. White fibers store glycogen and use anaerobic metabolism. Red fiber and slow twitch muscle is for endurance. White fiber and fast twitch muscle is for a burst of power.

Question 52

A sarcomere is defined as the segment from _____ to ____? a. A band b. I band c. Z line d. H band e. M line

Answer 52

Answer: c The A band is the darker staining band. The I band is the light band. The I band is made of thin filaments. The Z line runs through the I band. The H band bisects the A band. The M line runs through the H band. A sarcomere is the segment that runs from Z line to Z line.

Question 53

What are the bundle of longitudinal contractile elements within a muscle cell called? a. Myofilaments b. Myosin c. Muscle fibers d. Myofibrils e. Myocardium

Answer 53

Answer: d Myofilaments are the contractile protein within a muscle cell. The myofilaments are actin and myosin. The thin filaments are actin and the thick filaments are myosin. The muscle cell is a muscle fiber. The term “muscle cell” and “muscle fiber” are synonymous. A myofibril is a longitudinal bundle of myofilaments within a muscle cell. Myocardium is the muscular layer of the heart. Thus, the myocardium is composed of cardiac muscle.

Question 54

Identify the structure at the pointer:

A. I band
B. Z line
C. A band
D. M line
E. H band

Answer 54

B. Z Line

Question 55

Identify the type of this muscle:

A. Skeletal
B. Smooth
C. Cardiac

Answer 55

B. Smooth

Question 56

Identify the type of this muscle:

A. Skeletal
B. Smooth
C. Cardiac

Answer 56

C. Cardiac

Question 57

Identify the structure at the pointer:

A. Motor end plate
B. Muscle fiber
C. Muscle fascicle
D. Myofilament
E. Myofibril

Answer 57

A. Motor End Plate

Question 58

Identify the structure at the pointer:

A. Myofilament
B. Sarcomere
C. Muscle fiber
D. Muscle fascicle
E. Myofibril

Answer 58

C. Muscle Fiber

Question 59

Identify the type of this muscle:

A. Smooth
B. Skeletal
C. Cardiac

Answer 59

A. Smooth

Question 60

Identify the type of this muscle:

A.Smooth
B. Skeletal
C. Cardiac

Answer 60

B. Skeletal

Question 61

Identify the structure at the pointer:.

A. I band
B. H band
C. A band
D. Z line
E. M line

Answer 61

A. I band