Multiple Choice Questions

ATP is hydrolyzed when myosin head is attachedADP and P are bound to myosin head attaches to actinADP and P release caused head to change position and actin filament to moveBinding of ATP causes myosin head to return to resting position
  • mechanism of contraction
  • sarcomere
  • Myofilaments __________.
  • Which type of muscle fiber has no myofibrils?
A myosin head bound to actin
  • The type of attachment in which the muscle fibers seem to attach directly to a bone is
  • The region of thin filaments only that is part of two adjacent sarcomeres is the __________.
  • The property of skeletal muscle function that allows recoil after being stretched is ______.
  • The cross bridge cycle is a series of molecular events that occur after excitation of the sarcolemma. What is a cross bridge?
smooth
  • The area that contains no thin filaments is known as the
  • In striated muscle, the I band is where
  • Which type of muscle fiber has no myofibrils?
  • The type of attachment in which the muscle fibers seem to attach directly to a bone is
ability to be stretched
  • elasticity
  • contractility
  • excitability
  • extensibility
the region where calcium ions bindit also stores calcium
  • In striated muscle, the I band is where
  • In a sarcomere, the thin filaments are __________.
  • Acetylcholine binds to its receptor in the sarcolemma and triggers __________.
  • The area that contains no thin filaments is known as the
Myosin heads of thick filaments attach to thin filaments at both ends of a sarcomere and pull the thin filaments toward the center of the sarcomere.
  • Why are there fewer muscle fibers per motor unit in the fingers than in the muscles of the thighs?
  • mechanism of contraction
  • How does the myosin head obtain the energy required for activation?
  • How does the sliding filament mechanism result in concentric contraction of skeletal muscle?
• The basic unit of contraction of skeletal muscle • Z disc (Z line) • boundaries of each sarcomere• Thin (actin) filaments • extend from Z disc toward center of sarcomere• Thick (myosin) filaments • in center of sarcomere • overlap inner ends of the thin filaments • contain ATPase enzymes
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  • endomysium
  • sarcomere
  • motor unit
  • myofibrils
• contractile proteins • myosin and actin• regulatory proteins • turn contraction on & off • troponin and tropomyosin• structural proteins • provide proper alignment, elasticity and extensibility • titin
  • When does cross bridge cycling end?
  • muscle tissue
  • the proteins of muscle
  • myofibrils and sarcromeres
• Functions of muscle tissue• Body movements• Movement of substances within body • blood, lymph, urine, air, food and fluids• Stabilizing body positions• Posture• Producing heat • shivering
  • skeletal muscle
  • cardiac muscle
  • smooth muscle
  • muscle tissue
• Sarcoplasmic reticulum • Specialized smooth ER • Contains calcium ions • released when muscle is stimulated to contract • Calcium ions diffuse through cytoplasm • trigger the sliding filament mechanism
  • sarcomere
  • Myofilaments __________.
  • sarcoplasmic reticulum and T tubules
  • sarcomere structure
The lengths of the I bands and the H zone decrease.
  • During contraction, which of the following occurs in a sarcomere?
  • Acetylcholine binds to its receptor in the sarcolemma and triggers __________.
  • Calcium ions couple excitation of a skeletal muscle fiber to contraction of the fiber. Where are calcium ions stored within the fiber?
  • If you could not see the H zone in a photomicrograph of a sarcomere in skeletal muscle, ______.
Synaptic vesicles fuse to the plasma membrane of the axon terminal and release acetylcholine.
  • Sodium and potassium ions do not diffuse in equal numbers through ligand-gated cation channels. Why?
  • Calcium entry into the axon terminal triggers which of the following events?
  • The property of skeletal muscle function that allows recoil after being stretched is ______.
  • Action potentials travel the length of the axons of motor neurons to the axon terminals. These motor neurons __________.
• heart• striated• involuntary control
  • Smooth muscle
  • Skeletal muscle
  • Muscle tissue
  • Cardiac muscle
• Name comes from a Latin word for "little mouse"• The main tissue in the heart and walls of holloworgans• Makes up nearly half the body's mass
  • permysium
  • muscle tone
  • muscle
  • smooth muscle
Acetylcholine is released by axon terminals of the motor neuron.
  • the neuromuscular junction
  • The neuromuscular junction is a well-studied example of a chemical synapse. Which of the following statements describes a critical event that occurs at the neuromuscular junction?
  • Action potential propagation in a skeletal muscle fiber ceases when acetylcholine is removed from the synaptic cleft. Which of the following mechanisms ensures a rapid and efficient removal of acetylcholine?
  • The cross bridge cycle is a series of molecular events that occur after excitation of the sarcolemma. What is a cross bridge?
a fleshy attachment
  • The point at which a nerve ending and skeletal fiber meet is called a(n) ______.
  • This type of muscle makes up the walls of hollow organs, such as the stomach and uterus.
  • The type of attachment in which the muscle fibers seem to attach directly to a bone is
  • When the distance between two adjacent Z disks grows shorter, the muscle fiber is experiencing
between myofibrils but in fibers.
  • Sarcoplasmic reticulum lies
  • sarcomere structure
  • aponeurosis
  • cardiac and smooth muscle are?
a sheet of dense connective tissue.
  • sarcomere
  • aponeurosis
  • myofibrils
  • endomysium
Involuntary contraction• small number of motor units • asynchronous activation• goal is not to produce movement• Maintains • posture • head upright • blood pressure • smooth muscles in walls of blood vessels
  • elasticity
  • motor unit
  • muscle tone
  • skeletal muscle
a single motor neuron and all muscle fibers it innervatesMotor unit =• one somatic motor neuron &• all the skeletal muscle fibers the motor neuron innervates• approximately 10 cells to 2,000 cells
  • myofibrils
  • sarcomere
  • motor unit
  • endomysium
The energy comes from the hydrolysis of ATP.
  • In a sarcomere, the thin filaments are __________.
  • How does the myosin head obtain the energy required for activation?
  • Endomysium, perimysium, and epimysium __________.
  • Acetylcholine binds to its receptor in the sarcolemma and triggers __________.
the boundaries of two adjacent sarcomeres
  • Acetylcholine binds to its receptor in the sarcolemma and triggers __________.
  • How does the myosin head obtain the energy required for activation?
  • Z discs (Z lines) are ______.
  • cardiac and smooth muscle are?
Nerve impulse stimulates the release of the neurotransmitter acetylcholine (ACh) into the synaptic cleft.2.ACh stimulates changes in the sarcolemma that excite the muscle fiber. This stimulus is carried down the T tubules to initiate fiber contraction.3.Enzymes in the synaptic cleft break down ACh and thus limit its action to a single muscle twitch.
  • The neuromuscular junction is a well-studied example of a chemical synapse. Which of the following statements describes a critical event that occurs at the neuromuscular junction?
  • the neuromuscular junction
  • sarcoplasmic reticulum and T tubules
  • skeletal muscle
The inside surface of the sarcolemma is negatively charged compared to the outside surface. Sodium ions diffuse inward along favorable chemical and electrical gradients.
  • Sodium and potassium ions do not diffuse in equal numbers through ligand-gated cation channels. Why?
  • Why are there fewer muscle fibers per motor unit in the fingers than in the muscles of the thighs?
  • motor unit
  • If you could not see the H zone in a photomicrograph of a sarcomere in skeletal muscle, ______.
I band
  • The region of thin filaments only that is part of two adjacent sarcomeres is the __________.
  • This type of muscle attaches to bone, but may also attach to skin, cartilage, fascia or a raphe.
  • This type of muscle is found in large vessels leading to and from the heart.
  • The type of attachment in which the muscle fibers seem to attach directly to a bone is
• in walls of hollow organs • blood vessels • digestive tract• nonstriated• involuntary
  • cardiac muscle
  • muscle tissue
  • smooth muscle
  • skeletal muscle
Acetylcholine
  • __________ is the neurotransmitter that signals a single contraction of a muscle cell.
  • This type of muscle attaches to bone, but may also attach to skin, cartilage, fascia or a raphe.
  • The type of attachment in which the muscle fibers seem to attach directly to a bone is
  • A cell of this type of muscle is striated and can be uninucleated or binucleated.
H zone
  • How does the myosin head obtain the energy required for activation?
  • The area that contains no thin filaments is known as the
  • What structure is the functional unit of contraction in a skeletal muscle fiber?
  • This type of muscle is found in large vessels leading to and from the heart.
ability to return to original shape after stretch
  • excitability
  • extensibility
  • contractility
  • elasticity
the opening of ligand-gated cation channels
  • If you could not see the H zone in a photomicrograph of a sarcomere in skeletal muscle, ______.
  • During contraction, which of the following occurs in a sarcomere?
  • Excitability is the special functional feature of muscle tissue that __________.
  • Acetylcholine binds to its receptor in the sarcolemma and triggers __________.
allows electrical impulses to travel along the cells' sarcolemma, leading to contraction
  • Excitability is the special functional feature of muscle tissue that __________.
  • Action potentials travel the length of the axons of motor neurons to the axon terminals. These motor neurons __________.
  • Calcium entry into the axon terminal triggers which of the following events?
  • Endomysium, perimysium, and epimysium __________.
the sarcomere is fully contracted
  • What structure is the functional unit of contraction in a skeletal muscle fiber?
  • After a power stroke, the myosin head must detach from actin before another power stroke can occur. What causes cross bridge detachment?
  • During contraction, which of the following occurs in a sarcomere?
  • If you could not see the H zone in a photomicrograph of a sarcomere in skeletal muscle, ______.
neuromuscular junction
  • The cross bridge cycle is a series of molecular events that occur after excitation of the sarcolemma. What is a cross bridge?
  • The point at which a nerve ending and skeletal fiber meet is called a(n) ______.
  • This type of muscle makes up the walls of hollow organs, such as the stomach and uterus.
  • If you could not see the H zone in a photomicrograph of a sarcomere in skeletal muscle, ______.
respond to chemicals
  • extensibility
  • elasticity
  • excitability
  • contractility
involuntary
  • In striated muscle, the I band is where
  • Titin is a protein that __________.
  • cardiac and smooth muscle are?
  • Brachialis
• Striations result from internal structure of myofibrils• Myofibrils • Long rods within cytoplasm • Make up 80% of the cytoplasm • Specialized contractile organelle found in muscletissue • A long row of repeating segments called sarcomeres
  • myofibrils and sarcromeres
  • muscle tissue
  • Myofilaments __________.
  • motor unit
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Multiple Choice Questions
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