Question

carefully read the introductory material and examine the entire lab. be familiar with skeletal muscle tissue and muscle structure and function from lecture or the textbook. answer the pre - lab questions.
pre - lab questions: select the correct answer for each of the following questions:

1. the outermost layer of connective tissue of a muscle is the

a. fascicle. b. endomysium.
c. epimysium. d. perimysium.

1. the thick myofibril filament of a sarcomere is composed of a proteina. myosin. b. actin.

c. titin. d. sarcolemma.

1. the muscle primarily responsible for a movement is the

a. synergist. b. prime mover (agonist).
c. antagonist. d. origin.

1. the neuron and the collection of muscle fibers it innervates is called the

a. neural impulse. b. muscle fiber.
c. motor neuron. d. motor unit.

1. the functional contractile unit of a muscle fiber (cell) is aa. sarcoplasm. b. sarcolemma.

c. sarcomere. d. sarcoplasmic reticulum.

1. the role of a particular muscle is always the same.true____ false____
2. a synergistic muscle contraction assists the prime mover.true____ false____
3. the plasma membrane of a muscle fiber (cell) is called the sarcolemma.true____ false____

Explanation:

1. The epimysium is the outermost connective - tissue layer of a muscle.
2. The thick myofibril filament in a sarcomere is composed of myosin. Actin is the thin filament. Titin is an elastic protein, and sarcolemma is the muscle - fiber membrane.
3. The prime mover (agonist) is the muscle primarily responsible for a movement. A synergist assists, an antagonist opposes, and the origin is a point of attachment.
4. A motor unit is a neuron and the collection of muscle fibers it innervates. A neural impulse is an electrical signal, a muscle fiber is a single muscle cell, and a motor neuron is just the neuron part.
5. The sarcomere is the functional contractile unit of a muscle fiber. Sarcoplasm is the cytoplasm, sarcolemma is the membrane, and sarcoplasmic reticulum stores calcium.
6. The role of a muscle can change depending on the movement. For example, the biceps brachii can be a prime mover in elbow flexion but may have a different role in other complex movements.
7. Synergistic muscle contractions assist the prime mover.
8. The plasma membrane of a muscle fiber is called the sarcolemma.

Answer:

1. c. epimysium
2. a. myosin
3. b. prime mover (agonist)
4. d. motor unit
5. c. sarcomere
6. False
7. True
8. True