Question

1. A condition in which a muscle is unable to contract is

a. isometric    b. isotonic    c. tetanus    d. spastic paralysis   e. flaccid paralysis

f. hypertrophy    g. wave summation    h. motor unit summation (recruitment)

2. Which of the above describes an increase in the maximum force of contraction as the frequency of stimuli increase?

a. isometric    b. isotonic    c. tetanus    d. spastic paralysis   e. flaccid paralysis

f. hypertrophy    g. wave summation    h. motor unit summation (recruitment)

3. Which of the above describes a contraction unable to move a load?

a. isometric    b. isotonic    c. tetanus    d. spastic paralysis   e. flaccid paralysis

f. hypertrophy    g. wave summation    h. motor unit summation (recruitment)

4. Which of the above describes a contraction in which the length of the muscle does not change?

a. isometric    b. isotonic    c. tetanus    d. spastic paralysis   e. flaccid paralysis

f. hypertrophy    g. wave summation    h. motor unit summation (recruitment)

5. Which of the above describes a contraction in which the length of the muscle changes continuously while the force applied by the muscle remains the same?

a. isometric    b. isotonic    c. tetanus    d. spastic paralysis   e. flaccid paralysis

f. hypertrophy    g. wave summation    h. motor unit summation (recruitment)

6. Which of the above describes an increase in the number of muscle fibers participating in a contraction?

a. isometric    b. isotonic    c. tetanus    d. spastic paralysis   e. flaccid paralysis

f. hypertrophy    g. wave summation    h. motor unit summation (recruitment)

Answer 1

1. e. Flaccid paralysis

2. g.wave summation

3. a.isometric contraction

4. a.isometric contraction

5. b.isotonic contraction

6. h.motor unit recruitment

Explanation

Isometric contraction : In an isometric contraction, tension increases while muscle length remains same and also the load does not move.

Isotonic contraction : In an isotonic contraction , tension or force applied remains same and muscle length changes and also the load moves .

Flaccid paralysis : Flaccid paralysis is when the muscle is unable to contract . This results from impairment of somatic motor neurons .This is a lower motor neuron lesion . Due to injury or disease when a motor neuron is non functional then the muscles that are innervated by that nerve becomes paralyzed. The affected muscled loses the ability to contract . We can see this polio. Muscle wasting is seen.

Spastic paralysis : This is a upper motor neuron lesion. Spastic paralysis is when the muscle stays in contraction state. Muscles go into a tigthened or stiffened state.

Tetanus : This is also called lock jaw. It is a bacterial infection charecterised by muscle spasms . The bacteria produce toxins that interfere with muscle contraction. Prolonged muscular action causes sudden , powerful and painful contractions of muscle groups which is called tetany.

Hypertrophy : Muscular hypertrophy is an increase in the size of skeletal muscle through Increase in size of the cells. This is achieved by performing exercise.

Wave summation : when there is increase in the frequency of stimulus , the maximum force of contraction increases. This is called wave summation. In wave summation , second stimulus is applied before the muscle goes into contraction. Due to the combined effect , force of contraction increases.

Motor unit summation (recruitment ) : A motor units consits of motor neuron and all the muscle fibers it stimulates. Activation of additional motor units to bring an increase in contractile strength in a muscle is called motor unit summation.