VOCABULARY
What is sarcomere?
An individual muscle fiber contracts with maximal force in response to an action potential. What is this law called?
What is the all-or-none law of skeletal muscle contraction.
How does the action potential get to the sarcoplasmic reticulum?
What is ATP. If a muscle is stiff, the myosin heads will not let go of the active sites. This means there is not enough ATP in the muscle cells to bind to the myosin heads so that they will release the active sites.
Identify B. It is also known as the ____________ ___________.
The functional unit of the nervous system, a nerve cell.
What is a neuron?
What is skeletal, cardiac, and smooth
Calcium ions are diffusing across the membrane of the sacroplasmic reticulum. Is the cell beginning or ending a contraction?
What is beginning to contract. Calcium ions must bind to the troponin on an actin myofilament to start the contraction process. If calcium ions are DIFFUSING, they are moving OUT of the sarcoplasmic reticulum.
A nerve is being stimulated with a submaximal stimulus. Are there any motor units that have not been recruited?
What is yes. Submaximal means that some, but not all of the motor units have been recruited.
Identify C. The whole muscle is divided into bundles of cells called __________________.
What is fascicle.
The interface between a neuron and another cell.
What is a synapse.
A stimulus strong enough to create one action potential in a neuron.
What is threshold stimulus.
Two muscle fibers lie side by side, but contract at different times. Are they part of the same motor unit?
What is no? If they were a part of the same motor unit, they would contract at exactly the same time.
Lactic acid is building up in a muscle cell. What kind of respiration is occurring?
What is anaerobic respiration. Lactic acid is a byproduct of anaerobic respiration.
Identify A. The fascicles are wrapped in another layer of collagen called the ____________________.
What is the epimysium.
A chemical released by a neuron. This chemical travels across the synaptic cleft, allowing the neuron to communicate with another cell.
What is neurotransmitter
This muscle tissue is striated with many nuclei located peripherally per cell.
What is skeletal muscle.
What must happen after the action potential reaches the presynaptic terminal and before an action potential is established on the membrane of a muscle cell?
ACh must be released by the presynaptic terminal, and the ACh must travel across the synaptic cleft. You can also include the fact that ACh must interact with the cell membrane.
A motor unit is recruited. What happens to the muscle fibers in that motor unit?
What is they all contract (maximally).
Sarcomere. Identify a and b.
A is the thinner filament/protein.
B means muscle protein. Thicker of filaments.
What is a-actin filament and b-myosin filament.
One motor neuron and all the muscle fibers it innervates.
What is motor unit.
Without__________ to destroy____________, a muscle cell would stay contracted.
What is Acetylcholinesterase and ACh.
When a sarcomere contracts, what happens between the power stroke and the return stroke?
What is ATP binds to the myosin heads, causing them to release the active sites.
A muscle cell is using creating phosphate to convert ADP into ATP. Does this require oxygen?
What is this does not require oxygen. It is an alternative to aerobic respiration, so it does not require a wait for oxygen to be transported to the cell.
Identify C and D.
Hint for C: No actin is present in this area, only myosin.
Hint for D: Thick, dark stripes.
What is C-H zone and D-A band.