Matching 8. Ca++ low in sarcomere a) muscle relaxing 9. Ca++ high in the sarcome
ID: 3522524 • Letter: M
Question
Matching
8. Ca++ low in sarcomere a) muscle relaxing
9. Ca++ high in the sarcomere b) muscle contracting
10. How many action potentials per second are needed to stimulate a muscle to generate a smoother, stronger, full contraction as seen in fused muscular tetanus?
A) one per second is enough to do it, muscles are very efficient
b) ten per second because forces first start summating here
c) around 60-120 per second, here all evidence of relaxation in the twitches summated ends, and a smooth full contraction is produced
11. How many action potentials per second are needed to stimulate a muscle to generate a muscular twitch?
A) one per second is enough to do it
b) ten per second because forces first start summating here
c) around 60-120 per second, here all evidence of relaxation in the twitches summated ends, and a smooth full contraction is produced
12. What type of muscle fiber would be found in large amounts in an endurance muscle like the soleus in the calf. These fibers are slow in contracting, have high amount of capillaries, store large amounts of myoglobin, specialize in aerobic metabolism, have large and many mitochondria and are red in color?
a) Red, slow twitch, Type I
b) White, fast twitch, Type IIb
13. What type of muscle fiber would be found in large amounts in a fast contracting muscle like those of the eyeball controlling muscles, or finge/hand muscles. These fibers are fast in contracting, have high amount of glucose stored as glycogen, specialize in anaerobic metabolism so they can metabolize glucose quickly, have few mitochondria and are white in color?
A) Red, slow twitch, Type I
b) White, fast twitch, Type IIb
Explanation / Answer
8. b; The sarcomere act as a repository for Ca++. During contraction it releases out of sarcomere among myofilaments. Hence, during contraction low Ca++ ion occurs in sarcomere.
9. a; During relaxation Ca++ available in myofilaments returned back to the sarcomere.
10. c; 60 - 120 action potential per second are required. Action potentials per twitches summeted and results in a full contraction.
11. One action potential per second is enough to produce a twitch in the muscle.
12. a
13. b