HHP:1300- EXAM 3 UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

HHP:1300- EXAM 3 UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS

Question:
1. what two muscle types are striated?
Answer:
skeletal and cardiac

Question:
2. what is the only muscle type that is NOT striated?
Answer:
smooth muscles

Question:
3. what is the only muscle type that is voluntary?
Answer:
skeletal muscle

Question:
4. what are the two muscle types that are involuntary?
Answer:
smooth and cardiac muscle

Question:
5. what is the source of calcium in skeletal muscle?
Answer:
sarcoplasmic reticulum

Question:
6. what is the source of calcium in cardiac muscle?
Answer:
extracellular fluid and sarcoplasmic reticulum

Question:
7. what is the source of caclium in smooth muscle?
Answer:
majority from extracellular fluid

Question:
8. how are cells in skeletal muscle fibers stimulated?
Answer:
via alpha motor neurons

Question:
9. how are cells in both cardiac and smooth muslce stimulated?

,Answer:
via gap junctions

Question:
10. what is the only muscle type that does NOT have gap junctions?
Answer:
skeletal muscles

Question:
11. functions of skeletal muscle
Answer:
movement of the body posture generation of body heat movement of substances nutrient reserves support
soft tissues and organs

Question:
12. what is another name for a muscle cell?
Answer:
muscle fiber

Question:
13. connective tissue components of skeletal muscle tissue
Answer:
epimysium (outermost) perimysium endomysium (inner most)

Question:
14. how is skeletal muscle linked to bones?
Answer:
by tendons

Question:
15. main components of a muscle fiber
Answer:
sarcolemma sarcoplasm myofibrils

Question:
16. myofibrils
Answer:
contractile component of muscle fiber bundles of thick and thin myofilaments

Question:
17. what leads to the striations seen in skeletal muscle?
Answer:
arrangment of myofilaments

Question:
18. A band

,Answer:
dark area extends length of thick filaments composed of BOTH thick and thin filaments

Question:
19. I band
Answer:
light band thin filaments ONLY

Question:
20. H zone
Answer:
central region of A ban contains only THICK (not overlapped by thin) at center of sarcomere

Question:
21. M line
Answer:
line at center of thick filaments (A band) serve to anchor thick filaments to help them stay together during
a contraction

Question:
22. what composes the thick filament?
Answer:
myosin

Question:
23. role of myosin head
Answer:
form cross bridges between thick and thin filaments

Question:
24. role of actin binding site on myosin head
Answer:
where the myosin head will bind and interact with actin (thin) filament

Question:
25. role of ATP binding site on myosin head
Answer:
where ATP molecule binds in critical for the release of myosin from the actin

Question:
26. role of ATPase in myosin head
Answer:
enzyme that hydrolyzes ATP to ADP + P

Question:
27. why is ATPase critical in muscle contraction?

, Answer:
hydrolyzes the ATP molecule so that the myosin head can bind to the actin in the high energy state

Question:
28. components of thin filament
Answer:
actin tropomyosin troponin

Question:
29. what kind of protein is actin?
Answer:
contractile protein

Question:
30. what kind of proteins are tropomyosin and troponin?
Answer:
regulatory proteins

Question:
31. tropomyosin role
Answer:
blocks the myosin binding sites on actin that prevent the formation of cross bridges

Question:
32. what is the position of tropmyosin when the muscle fiber is at rest?
Answer:
covering the myosin binding sites blocking interaction

Question:
33. main role of troponin
Answer:
bind to calcium in order to move tropomysoin from myosin binding site on actin to allow for cross bridge
formation

Question:
34. what can be said about the calcium concentration and position of tropomyosin when the muscle fiber is
at rest?
Answer:
low calcium concentration calcium can't bind to troponin to move tropomyosin out of the way myosin
binding site on actin is blocked

Question:
35. what can be said about the calcium concentration and position of tropomyosin when the muscle fiber is
contracting?
Answer:
high calcium concentration calcium binds to troponin to move tropomyosin out of the way cross bridges
are being formed