Even when the blood supply is inadequate, the muscle is able to sustain contraction due to:

1.	the presence of hemoglobin	2.	glycogen storage
3.	myoglobin	4.	citric acid cycle

The minimum stimulus needed to cause a contraction is called the:
1. chronaxie
2. threshold
3. rheobase
4. reversal potential

A sustained muscle contraction evoked when the motor nerve that innervates a skeletal muscle emits action potentials at a very high rate is called as:
1. a sustained contraction
2. fatigue
3. tetanic contraction
4. treppe

The continuous and passive partial contraction of the muscles is called as:
1. tetany
2. tonus
3. sustained contraction
4. summation

Stimulation by a nerve impulse is always required for the contraction of:
1. multi-unit smooth muscle
2. skeletal muscle
3. visceral smooth muscle
4. cardiac muscle

A decrease in the mass of the muscle most commonly experienced when persons suffer temporary disabling circumstances is called as:

1. hypertrophy

2. atrophy

3. dystrophy

4. peristalsis

A neuromuscular disorder that causes weakness in the skeletal muscles is:

Immediately after the motor neuron passes an impulse to a muscle fiber:
1. the impulse travels over the sarcolemma in all directions.
2. calcium is released from the sarcoplasmic reticulum.
3. cross bridge forms between the actin and myosin.
4. troponin undergoes a conformational change.

Identify the incorrect statement:
1. A muscle fiber contracts in an all-or-none fashion.
2. A slight delay occurs between the reaching of impulse at the neuromuscular junction and muscle contraction.
3. Using more motor units will increase the overall force of contraction.
4. When a person is fully at rest, none of her muscles are contracting.

Identify the incorrect statement regarding a skeletal muscle fiber:
1. They continue to divide throughout childhood as skeletal muscles grow
2. Theyare formed by fusion of myoblasts during fetal development
3. They are true syncytium.
4. They are striated.