NPB 101 Project: Muscular System

1. Thick filament that uses ATP to cause muscle contractions
3. If the amount of ATP available and level of Ca2+ is high then muscle _________ continues
8. Thin filament that contains troponin and tropomyosin to regulate muscle contraction
13. When muscle fiber is stimulated so rapidly that the muscle has no chance to relax
15. Motor neurons and skeletal muscle fibers are chemically linked at ____________ junctions
17. Binding of this neurotransmitter causes for Na2+ channels to open during neuromuscular junction
18. Most common type of muscle in humans
19. During muscle contraction the sarcomere length becomes _______
20. Type of muscle that is unstriated and involved in involuntary movement
23. Light area within the middle of the A band where actin does not reach
24. Enzyme that breaks down the neurotransmitter ACh at the synaptic cleft
25. Location of where myosin attaches

2. Functional and smallest unit of skeletal muscle that is needed for contraction
4. During the ________ phase of the cross-bridge cycle myosin attaches to actin
5. Caused when the muscle is no longer able to maintain tension and leads to feelings of exhaustion
6. Ion that triggers ACh to be released by exocytosis
7. When the muscle _______ it uses myosin ATPase more than the Ca2+ pump
9. How many different muscle types are there?
10. If the amount of motor units ________ then the muscle will contract
11. Type of muscle that is striated and involved in involuntary movement
12. Elongated muscle fibers held together by connective tissue
14. When the muscle _________ it uses the Ca2+ pump of the sarcoplasmic reticulum more than myosin
16. Purpose is to allow for muscle contraction and allow muscle to be stretchy so it does not tear
21. Binding to ______ causes the beginning of muscle contraction
22. Type of muscle that is striated and involved in voluntary movement