Download Biol 1151L Muscle Physiology Pre-lab Don`t forget to type your

Biol 1151L Muscle Physiology Pre-lab
Don’t forget to type your name on the assignment.
Completer the following prior to coming to lab, type your answers, and turn them in at the
beginning of lab.
Define the following terms.
1. Epimysium
2. Fascicle
3. Permysium
4. Muscle fiber
5. Endomysium
6. Sarcolemma
7. T-tubule
8. Sarcoplasmic reticulum
9. Terminal cisternae
10. Myofibril
11. Myofilament
12. Thick fimalment
13. Thin filament
14. Acitn
15. Myosin
16. Action potential
17. Crossbridge cycle
18. Excitation-contraction coupling
19. Sliding filament mechanism
20. Length-tension relationship
21. Zone of overlap
22. Troponin
23. Tropomyosin
24. Tendon
25. Ligament
26. Aponeurosis
27. Motor end plate
28. Neuromuscluar junction
29. Sarcomere
30. Origin
31. Insertion
Part II
1. Number the following events of skeletal muscle contraction in the proper order, with number
1 for the first event and number 9 for the last event.
____ Actin binds to myosin, and a power stroke occurs as ADP and Pi dissociate from myosin.
____ The terminal cisternae of the sarcoplasmic reticulum release calcium ions into the
sarcoplasm because of the action potential.
____ The energy from ATP hydrolysis “cocks” the myosin crossbridge into an upright position.
____The sarcoplasmic reticulum removes calcium ions from the sarcoplasm, and tropomyosin
returns to its original position.
____ Acetylcholinesterase degrades acetylcholine in the synaptic cleft.
____ Calcium ions bind to receptors on the motor end plate and opens cation channels.
____ Acetylcholine binds to receptors on the motor end plate and opens cation channels.
____ ATP binds and causes the actin and myosin to dissociate from one another, after which it is
hydrolyzed and myosin is recocked. The cycle repeats.
____Sodium ions flood the sarcoplasm and initate an action potential that spreads along the
sarcolemma and into the muscle fiber along the T-tubules.
2. The drug Botox is made from the toxin of the bacterium Clostridium boutlinum. It is injected
subdermally to minimize fine lines and creases in the face. The toxin prevents motor neurons
from releasing acetylcholine. How would this produce the desired cosmetic results? What
could happen if this toxin were absorbed systemically?
3. You are at the gym with a friend who complains that she cannot lift as much weight on a new
machine as she could on the old machine. You examine the machine and note that the starting
position for the exercise puts your friend’s muscles in a stretched position. How does this
explain her seeming loss of strength?