Muscle Physiology
Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross Third event
ATP attaches to myosin head
Neurotransmitter that stimulates skeletal muscle contraction.
Acetylcholine
A type of chemically-gated ion channel located on the junctional folds of the muscle fiber.
Acetylcholine Receptor
Arrange the sequence of events at the NMJ from first to last. Rank the sequence of events at the NMJ that initiate an action potential in the muscle fiber, from first to last. Step 5:
Acetylcholine binds to its receptors on the Junctional Folds.
Arrange the sequence of events at the NMJ from first to last. Rank the sequence of events at the NMJ that initiate an action potential in the muscle fiber, from first to last. Step 4:
Acetylcholine is released into the Synaptic Cleft.
Enzyme located in the synaptic cleft that breaks down acetylcholine.
Acetylcholinesterase
Arrange the sequence of events at the NMJ from first to last. Rank the sequence of events at the NMJ that initiate an action potential in the muscle fiber, from first to last. Step 7:
Action Potential is initiated on the Sarcolemma.
Arrange the sequence of events at the NMJ from first to last. Rank the sequence of events at the NMJ that initiate an action potential in the muscle fiber, from first to last. Step 1:
Action potential arrives at the axon terminal.
The binding of the neurotransmitter to receptors on the motor end plate causes which of the following to occur?
Binding of the neurotransmitter causes chemically gated sodium channels to open in the motor end plate.
A type of voltage-gated ion channel located on the axon terminal.
Calcium Channel
Arrange the sequence of events at the NMJ from first to last. Rank the sequence of events at the NMJ that initiate an action potential in the muscle fiber, from first to last. Step 2:
Calcium Ions enter the Axon Terminal
Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross Seventh event
Calcium ion concentration decreases below the threshold for binding to troponin
Which of the following is responsible for muscle relaxation?
Calcium ions are removed from the sarcoplasm by active transport.
Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross Sixth event
Calcium ions pumped into the sarcoplasmic reticulum
Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross Fourth event
Cross bridges detach from actin
Which of the following is NOT a role of ATP in muscle contraction?
Exposing myosin binding sites on actin
Arrange the sequence of events at the NMJ from first to last. Rank the sequence of events at the NMJ that initiate an action potential in the muscle fiber, from first to last. Step 6:
Junctional Folds become Depolarized.
Which of the following processes produces 36 ATP?
Krebs cycle and oxidative phosphorylation
What structure most directly stimulates a skeletal muscle fiber to contract?
Motor Neuron
Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross Eighth event
Myosin binding sites covered
Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross bridge cycling ending. Do not overlap any events. First event
Myosin head forms cross bridge with actin
Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross Fifth event
Myosin head is re-energized
Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross bridge cycling ending. Do not overlap any events. Second event
Power stroke moves with thin filament
Inadequate calcium in the neuromuscular junction would directly affect which of the following processes?
Release of acetylcholine from the synaptic vesicles.
A type of voltage-gated ion channel located on the sarcolemma of the muscle fiber.
Sodium Channel
The space between the axon terminal and junctional folds.
Synaptic Cleft
Membranous sac located in the axon terminal that contains neurotransmitter.
Synaptic Vesicle
Arrange the sequence of events at the NMJ from first to last. Rank the sequence of events at the NMJ that initiate an action potential in the muscle fiber, from first to last. Step 3:
Synaptic Vesicles fuse to membrane of Axon Terminal.
In a neuromuscular junction, synaptic vesicles in the motor neuron contain which neurotransmitter?
acetylcholine (ACh)
What is the type of chemical reaction used to rebuild ADP into ATP?
dehydration synthesis
What means of membrane transport is used to release the neurotransmitter into the synaptic cleft?
exocytosis
Which of the following processes produces molecules of ATP and has two pyruvic acid molecules as end products?
glycolysis
The "rest and recovery" period, where the muscle restores depleted reserves, includes all of the following processes EXCEPT __________.
pyruvic acid is converted back to lactic acid
How is acetylcholine (ACh) removed from the synaptic cleft?
simple diffusion away from the synaptic cleft and acetylcholinesterase (AChE; an enzyme)
The action potential on the muscle cell leads to contraction due to the release of calcium ions. Where are calcium ions stored in the muscle cell?
terminal cisterns (cisternae) of the sarcoplasmic reticulum
When an action potential arrives at the axon terminal of a motor neuron, which ion channels open?
voltage-gated calcium channels
Which type of muscle fiber has a large quantity of glycogen and mainly uses glycolysis to synthesize ATP?
white fast twitch fibers
