16. What is the synaptic cleft? The space at the neuromuscular junction where the terminal end of the neuron synapses (meets) the muscle cell.17. What is the junction between the nerve axon and the muscle fiber called? Neuromuscular junction18. What is the role of ATP during muscle contraction? ATP is needed to detach the cross-bridges between myosin heads and the myosin-bonding sites on the actin in order for another cross-bridge and power stroke to happen.19. What is Rigor Mortis? Muscle contraction requires ATP to detach the myosin heads from the myosin-binding sites on the actin (breaking the cross-bridge) in order for another cross-bridge to form and a power stroke to happen and muscle contraction-relaxation to continue. In the absence of ATP (dead tissue) once a contraction occurs, the cross-bridge can’t detach, thus the muscle tissue stays contracted and becomes rigid.20. What is Extensibility? What does it allow muscles to do? The ability to stretch. It allows a muscle to be stretched and get lengthened.
21. What is Excitability? What ion connects muscle excitation to muscle contraction? The same as responsiveness or irritability. The ability to receive & respond to stimuli. In muscles the respond to nerve impulse by contracting.22. Name 3 types of muscle tissue? Which is striated? Which is involuntary?A. smooth muscle- not striated and are involuntaryb. Cardiac muscle-striated and involuntary.C. Skeletal muscle- striated and voluntary23. How does weight bearing increase the size/volume of muscles? By increasing the size and volume of existing muscle cells24. Write the correct sequence of muscle contraction:Action potential reached the end of the nerve axon that synapses with the muscle cell at the neuromuscular junctionAcetylcholine is released into the synaptic cleft at the neuromuscular junctionAch binds to the muscle cell sarcolemma and causes an Action potential to occur at the muscle cellthe action potential of the muscle cell travels through the Sarcolemma and deep into the cell via the T-tubulesAt the end of the T-tubules where they meet the Sarcoplasmic Reticulum, the action potential causes the release of Ca+ that has been stored in the Sarcoplasmic ReticulumCa+ binds to Troponin (on the Actin) causing it to change shape which then causes the