Question

a single motor neuron together with all the muscle fibers it innervates is called a(n)

dermatome.

end foot.

myotome.

motor unit.

end plate.

Explanation:

🆕 New Concept Discovered: Motor Unit
The functional relationship between nerves and muscles.

Step 1: Define the core concept

In neuromuscular physiology, skeletal muscles are stimulated to contract by signals from the nervous system. The basic functional unit of this neuromuscular control is called a motor unit.

A motor unit consists of:

1. A single somatic motor neuron.
2. All of the individual muscle fibers that are stimulated (innervated) by that single neuron's axon terminals.

When the motor neuron fires an action potential, all the muscle fibers within that specific motor unit contract simultaneously.

Step 2: Evaluate the given options

• dermatome: An area of skin supplied by sensory neurons from a single spinal nerve. (Incorrect)
• end foot: Also known as an axon terminal or synaptic bouton, this is the button-like terminal of an axon branch. (Incorrect)
• myotome: A group of muscles innervated by a single spinal nerve root. (Incorrect)
• motor unit: A single motor neuron and all the muscle fibers it innervates. (Correct)
• end plate: Specifically, the motor end plate is the specialized region of the muscle fiber's plasma membrane (sarcolemma) that lies directly beneath the axon terminal at the neuromuscular junction. (Incorrect)

Answer:

motor unit.