Exam 21: Movement and Muscle at Work: Plasticity in Response to Use and Disuse

Suppose you take a muscle biopsy from an elite athlete and perform a histological analysis on the sample. You find that the muscle cells are relatively small in diameter, contain high numbers of mitochondria, and have an unusually large proportion of Type IIa myosin. The athlete is most likely a

There currently is great scientific interest in identifying genetic polymorphisms that underlie different individual responses to exercise training. The muscle size and bulk of a champion bodybuilder, for example, might be due in part to a missense mutation in the

Studies of bears indicate that their adaptations for a lifestyle that involves hibernation include

Resistance training increases muscle mass primarily by increasing the

Resistance training of skeletal muscle would normally result in an increase in the

Refer to the figure shown. An elite distance runner would display a curve that is closest to

Describe the effects of exercise training on cardiac muscle and identify how they are similar to the effects of either endurance or resistance training on skeletal muscle.

In skeletal muscle, endurance exercise

Describe the effects of wearing a cast for a broken foot on whole-muscle performance in a person's calf muscles.

Endurance training produces the greatest percentage increase in expression of genes encoding

To identify the cellular signals responsible for exercise effects in human muscle, scientists can examine

Compare and contrast the effects of resistance and endurance exercise on skeletal muscle tissue. What changes in protein expression occur in each mode of training? How do the overall effects on the muscle cells and the whole muscle differ between the two modes?

Fast glycolytic fibers can generate more power than slow oxidative fibers of similar diameter because they

A training program that increased the proportion of slow oxidative fibers in a muscle would _______ the muscle's maximum _______.

List two experimental techniques used to study muscle atrophy in animal or human models.

Binding of IGF-1 (insulin-like growth factor-1) to its receptor on a skeletal muscle cell membrane leads to _______ protein synthesis and _______ protein degradation.

Endurance exercise involves

Burmese pythons are a uniquely useful model for studies of cardiac hypertrophy because their heart(s)

Bob has been sedentary for several years. As a New Year's resolution, he starts an intense exercise program, but after three months he stops exercising completely. What was the likely effect of the program on his heart mass while he was exercising, and what is the most likely outcome a year later?

Increases in mitochondrial number and capillary number