Question

Diagrammatically show the difference between the three types of muscle fibers.

Answer 1

Hint: The muscular system in an organism is responsible for the movement of the body. These muscles are attached to the bones of the skeletal system. There are more than 600 muscles in the human body, each muscle is made up of elastic tissue which consists of thousands or tens of thousands of small muscle fibers. Each fiber in the muscle comprises many tiny strands called fibrils.

Complete answer:
The three main types of muscle in the body include skeletal, smooth, and cardiac muscles.

1. Skeletal Muscle:
The skeletal muscles attached to bones are responsible for skeletal movements. These muscles are under conscious, or voluntary, control because they are connected with the peripheral portion of the central nervous system. The muscle fibers of skeletal muscles are striated and multinucleated and each works independently with the neighboring fibers.

2. Smooth Muscle
Smooth muscles are found in the walls of the hollow internal organs of the body such as blood vessels, the gastrointestinal tract, urinary bladder, and uterus, and are under the control of the autonomic nervous system. Smooth muscle cannot be controlled consciously by our will and thus acts involuntarily. The non-striated or smooth muscle cell is spindle-shaped and has only one central nucleus. These muscles contract slowly and rhythmically.

3. Cardiac Muscle:
Cardiac muscle is found in the walls of the heart; it is under the control of the autonomic nervous system. The cardiac muscle cell has one central nucleus, like smooth muscle, but has striations, like skeletal muscle. The cardiac muscle cell is rectangular in shape. The contraction of cardiac muscle is involuntary ie not in our conscious control, strong, and rhythmical.

Note:
Muscle contraction begins when the nervous system generates a signal, this signal is called an action potential which travels through nerve cells called motor neurons. A neuromuscular junction is a place where the motor neuron reaches a muscle cell. Skeletal muscle tissue is composed of cells called muscle fibers, when the nervous system sends signals it reaches the neuromuscular junction then a chemical message is released by the motor neuron. This chemical message is a neurotransmitter e.g. acetylcholine, this neurotransmitter binds to receptors on the outside of the muscle fiber and starts a chemical reaction within the muscle.