EXPH 4145-100 Lab Nine
Twitch time for Type I
120ms
Twitch time for Type IIA and IIX
64ms
________ is a strategy the nervous system employs to reduce the likelihood of fatigue by alternating which motor units are being used.
Asynchronous motor unit recruitment
Wide Z-line diameter
I
Ryanodine receptor density
I to II
SERCA density
I to II
ATPase activity
I to IIA to IIX
Diameter-men
I to IIA to IIX
Glycogen content
I to IIA to IIX
LDH, glycolytic enzymes
I to IIA to IIX
Threshold for recruitment
I to IIA to IIX
Intermediate Z-line diameter
IIA
Narrow Z-line diameter
IIX
Resistance to fatigue
IIX to IIA and I
Capillary density
IIX to IIA to I
Diameter-women
IIX to IIA to I
Lipid content
IIX to IIA to I
Mitochondria
IIX to IIA to I
Myoglobin
IIX to IIA to I
SDH, oxidative enzymes
IIX to IIA to I
________ is when more motor units are recruited in order to produce more force.
Multiple motor unit summation (MMUS)
Potentiation for Type I
No
Appearance of Type I and IIA
Red
________ is related to the orderly recruitment of motor units from smallest to largest.
Size principle
Appearance of Type IIX
White
Potentiation for Type II
Yes
Which of the following would produce the least force? a. Concentric bicep curl 30deg/sec b. They would all be about the same c. Eccentric bicep curl 30deg/sec d. Isometric bicep curl 0deg/sec
a. Concentric bicep curl 30deg/sec
Which of the following would produce the least torque? a. Concentric knee extension 300deg/sec b. Concentric knee extension 30deg/sec c. They would all be about the same d. Concentric knee extension 180deg/sec
a. Concentric knee extension 300deg/sec
Which of the following would produce the greatest torque? a. Concentric knee extension 30deg/sec b. Concentric knee extension 180deg/sec c. Concentric knee extension 300deg/sec d. They would all be about the same
a. Concentric knee extension 30deg/sec
Which of the following would require the least number of motor units to be recruited when using a 15lb weight? a. Isometric action with high force arm: resistance arm ratio b. They would all be about the same c. Isometric action with low force arm: resistance arm ratio d. Concentric action with low force arm: resistance arm ratio
a. Isometric action with high force arm: resistance arm ratio
Which of the following would have the highest EMG activity? a. Isometric bicep curl with forearm supinated with a 20lb weight b. They would all be about the same c. Isometric bicep curl with forearm pronate with a 20lb weight d. Isometric bicep curl with forearm pronated with a 15lb weight
a. Isometric bicep curl with forearm supinated with a 20lb weight
If we were using fine wire EMG and observed an increase in EMG frequency when our subject produced more force, this would be evidence of what type of summation? a. Twitch summation b. Temporal summation c. Spatial summation d. Asynchronous motor unit recruitment e. Multiple motor unit summation
a. Twitch summation
Which of the following would produce the least torque? a. Eccentric knee extension 90deg/sec b. Eccentric knee extension 30deg/sec c. They would all be about the same d. Eccentric knee extension 60 deg/sec
b. Eccentric knee extension 30 deg/sec
Considering pennate muscles and parallel muscles, which of the following is/are NOT true? a. Pennate arrangements allow for greater force production/strength compared to parallel arrangements b. Longer fibers are associated with better potential for producing force c. Parallel arrangements are generally associated with longer muscle fibers than pennate arrangements d. Pennate arrangements would increase the physiological cross sectional area compared to parallel muscles e. Three of the answers are NOT true
b. Longer fibers are associated with better potential for producing force
Which of the following would have the lowest iEMG integral when using a 15lb weight? a. They would all be about the same b. Concentric bicep curl with forearm pronated moving at 30deg/sec c. Eccentric bicep curl with forearm supinated moving at 10deg/sec d. Eccentric bicep curl with forearm supinated moving at 10deg/sec
c. Eccentric bicep curl with forearm pronated moving at 60deg/sec
Which of the following would have the lowest EMG integral when using a 15lb weight? a. Concentric action with low force arm: resistance arm ratio b. They would all be about the same c. Isometric action with high force arm: resistance arm ratio d. Isometric action with low force arm: resistance arm ratio
c. Isometric action with high force arm: resistance arm ratio
Which of the following would produce the least force? a. Knee extensors slow speed b. They would all be about the same c. Knee flexors medium speed d. Knee flexors slow speed
c. Knee flexors medium speed
Which of the following would have the lowest EMG integral with a 15lb weight? a. Concentric bicep curl 30deg/sec b. They would all be about the same c. Isometric bicep curl 0deg/sec d. Eccentric bicep curl 30deg/sec
d. Eccentric bicep curl 30deg/sec
Which of the following isokinetic actions would have the lowest EMG integral? a. Knee extensors 180deg/sec b. Knee extensors 300deg/sec c. Knee extensors 30deg/sec d. They would all be about the same
d. They would all be about the same
