Ex phys Lab exam2
Which of the following best describes the hold relax with agonist contraction PNF procedure if the goal is to improve stretch of the gastrocnemius muscle?
-We stretched the subject's gastrocnemius passively until we reached the limits of its ROM. -Then we had the subject contract their gastrocnemius submaximally and then maximally while we held their foot in place then had them relax while we pushed their foot further while the subject contracts their dorsiflexor muscles
In one of our lab VII experiments we looked at the effects of intensity on fuel substrate use. Which of the following statements regarding exercise intensity and fuel substrate use is/are NOT true?
-high intensity exercise decreases insulin secretion, which tends to decrease muscle glycogen breakdown. - at higher intensities the percentage of calories coming from circulating fatty acids increases - high intensity exercise is associated with greater recruitment of slow twitch fibers, which tends to increase carbohydrate use
When we perform a drop jump to try to jump higher, one issue that might reduce jump height is that motor unit recruitment might be inhibited by which of the following reflexes?
Inverse stretch reflex
During our "jumping" experiment we had our subject jump with or without a counter-movement, and we also had our subject perform some "drop jumps". We recorded EMG activity from the vastus lateralis and jump height during each. Here are some sample results from these experiments. What is a likely explanation for the increase in jump height between the counter movement jump and the 0.25m drop jump?
activation of muscle spindles, which may have increased motor unit recruitment initiation of the stretch reflex
The following figure depicts EMG and iEMG activity during dynamic bicep curls until the subject could not lift the weight anymore. They lifted the weight 17 times before they fatigued. Which of the following mechanism(s) are LEAST likely to be contributing this fatigue, given this set of data?
an increase in Pi inside the muscle fibers
Which of the following would produce the greatest force?
concentric bicep curl 30deg/sec
Which of the following would have the lowest iEMG integral when using a 15 lb weight?
eccentric bicep curl with forearm pronated moving at 60 degrees per second
which of the following would tend to increase circulating fatty acids?
hormone sensitive lipase
Which of the following fiber types would tend to have the lowest mitochondrial volume?
iix
Which of the following hormones would be unlikely to increase blood glucose? select all that apply
insulin
Which of the following hormones would increase glycogen storage in the muscle? select all that apply
insulin
which of the following is/are hormones that would tend to increase muscle glycogen storage?
insulin
which of the following hormones would inhibit muscle protein breakdown? select all
insulin and growth hormone
If the weather report (or your sling psychrometer) say that the wet bulb temperature was 45F and the dry bulb temperature was 67F, and your subject's core temperature was 37.1C, and their skin temperature was 33.2. Which of the following are true about the humidity under these circumstances?
there is a low humidity
which of the following hormones would increase gluconeogenesis in adipose tissue? select all
this process doesn't occur in this tissue
Which of the following changes would cause the smallest increase in Torque?
knee flexors going from 300 deg/sec to 30 deg/sec
If we observed an increase in EMG amplitude when our subject lifted a heavier weight, this would be evidence of what type of summation?
multiple motor unit summation
Which of the following is an enzyme that promotes breakdown of gluucose to pyruvate?
phosphofructokinase
which of the following is an enzyme that promotes breakdown of glycogen?
phosphorylase
Which of the following fiber types would tend to store the most intramuscular triglycerides (lipids)?
type I
Which of the following would produce the least torque?
. eccentric knee extension 30deg/sec
