BIO 201 CHAPTER 9
• Troponin and tropomyosin are part of the filaments within muscle
myofibrils.: thin or actin
• In a skeletal muscle fiber, each myofibril is surrounded by a network of membranous
channels that runs parallel to the myofibril and is called the
: sarcoplasmicreticulum
• Within myofibrils, the area between two successive Z lines is called a(n)
: Sarcomere
• The T tubules of a muscle fiber are extensions of the and
containextracellular fluid.: sarcolemma
• Each thick filament is composed of many molecules of , each of
which is consists of two twisted protein strands with globular parts called
: myosinheads
• What structures are positioned between adjacent cisternae of the sar-coplasmic
reticulum?: transverse tubules
• Within a muscle fiber, troponin and tropomyosin are associated with
: actin
• The membranous organelle within muscle fibers, called the
reticulum,corresponds to the smooth endoplasmic reticulum of other cells.: sarcoplas-
mic
• Match the arrow with the organelle/structure in a skeletal muscle fiber.: A
- sarcoplasmic reticulumB - transverse tubule
C - nucleus
D - mitochondrion
• The process of a neuron, its axon, conducts electrical impulses called
towards the end of the axon that innervates a target cell.: actionpotential
• What is the name of the invaginations of the sarcolemma that extendthrough the muscle
fiber?: transverse (T) tubules
• During excitation of a muscle fiber, which one of the following events comes
immediately after the release of acetylcholine from the motor neuron?-
: acetylcholine diffuses across the synaptic cleft
• True or false:The transverse tubules are located between structures calledcisternae.: true
, • The chemical called is the neurotransmitter for skeletal muscle con-
traction.: Acetylcholine
• During excitation-contraction coupling, calcium binds to .:
troponin
• On this diagram of a skeletal muscle fiber, the sarcolemma is indicated bythe arrow
labeled , and the sarcoplasm is indicated by the arrow labeled
: AC
• What is the name of the process on a neuron that carries electrical impuls-es toward the cell
to be stimulated?: axon
• True or false: Myofilaments shorten during contraction.: false
• List in order the events leading to excitation of a muscle fiber.: 1. Nerveimpulse arrives at
distal end of axon.
2. Acetylcholine is released.
3. Acetylcholine diffuses across synaptic cleft.
4. Acetylcholine binds to its receptors on the muscle fiber sarcolemma.
5. The permeability of sarcolemma to sodium ions increases.
• What is the function of acetylcholine?: neurotransmitter that stimulates themuscle to
contract
• Place the following steps of excitation-contraction coupling in order.: 1)Calcium is
released from the sarcoplasmic reticulum
2) Calcium binds to troponin
3) Troponin changes shape and alters the position of tropomyosin
4) Binding sites on actin filaments are exposed
5) Myosin heads bind to actin
• Which statements correctly describe changes in a skeletal muscle cellduring muscle
contraction?: Muscles shorten during contraction. Myofilaments overlap during contraction.
Sarcomeres shorten during contraction.
• In a muscle contraction, the force that shortens the sarcomeres comesfrom the myosin
cross-bridges pulling on the filaments.: thin or actin
• During which phase are calcium ions actively transported into the sar-coplasmic
reticulum?: relaxation
• What is the role of creatine phosphate during skeletal muscle contrac-tion?: It is used to
quickly regenerate ATP from ADP.
• Troponin and tropomyosin are part of the filaments within muscle
myofibrils.: thin or actin
• In a skeletal muscle fiber, each myofibril is surrounded by a network of membranous
channels that runs parallel to the myofibril and is called the
: sarcoplasmicreticulum
• Within myofibrils, the area between two successive Z lines is called a(n)
: Sarcomere
• The T tubules of a muscle fiber are extensions of the and
containextracellular fluid.: sarcolemma
• Each thick filament is composed of many molecules of , each of
which is consists of two twisted protein strands with globular parts called
: myosinheads
• What structures are positioned between adjacent cisternae of the sar-coplasmic
reticulum?: transverse tubules
• Within a muscle fiber, troponin and tropomyosin are associated with
: actin
• The membranous organelle within muscle fibers, called the
reticulum,corresponds to the smooth endoplasmic reticulum of other cells.: sarcoplas-
mic
• Match the arrow with the organelle/structure in a skeletal muscle fiber.: A
- sarcoplasmic reticulumB - transverse tubule
C - nucleus
D - mitochondrion
• The process of a neuron, its axon, conducts electrical impulses called
towards the end of the axon that innervates a target cell.: actionpotential
• What is the name of the invaginations of the sarcolemma that extendthrough the muscle
fiber?: transverse (T) tubules
• During excitation of a muscle fiber, which one of the following events comes
immediately after the release of acetylcholine from the motor neuron?-
: acetylcholine diffuses across the synaptic cleft
• True or false:The transverse tubules are located between structures calledcisternae.: true
, • The chemical called is the neurotransmitter for skeletal muscle con-
traction.: Acetylcholine
• During excitation-contraction coupling, calcium binds to .:
troponin
• On this diagram of a skeletal muscle fiber, the sarcolemma is indicated bythe arrow
labeled , and the sarcoplasm is indicated by the arrow labeled
: AC
• What is the name of the process on a neuron that carries electrical impuls-es toward the cell
to be stimulated?: axon
• True or false: Myofilaments shorten during contraction.: false
• List in order the events leading to excitation of a muscle fiber.: 1. Nerveimpulse arrives at
distal end of axon.
2. Acetylcholine is released.
3. Acetylcholine diffuses across synaptic cleft.
4. Acetylcholine binds to its receptors on the muscle fiber sarcolemma.
5. The permeability of sarcolemma to sodium ions increases.
• What is the function of acetylcholine?: neurotransmitter that stimulates themuscle to
contract
• Place the following steps of excitation-contraction coupling in order.: 1)Calcium is
released from the sarcoplasmic reticulum
2) Calcium binds to troponin
3) Troponin changes shape and alters the position of tropomyosin
4) Binding sites on actin filaments are exposed
5) Myosin heads bind to actin
• Which statements correctly describe changes in a skeletal muscle cellduring muscle
contraction?: Muscles shorten during contraction. Myofilaments overlap during contraction.
Sarcomeres shorten during contraction.
• In a muscle contraction, the force that shortens the sarcomeres comesfrom the myosin
cross-bridges pulling on the filaments.: thin or actin
• During which phase are calcium ions actively transported into the sar-coplasmic
reticulum?: relaxation
• What is the role of creatine phosphate during skeletal muscle contrac-tion?: It is used to
quickly regenerate ATP from ADP.
