Which of the following muscles is an example of a large motor unit?

The gastrocnemius muscle serves as an example of a large motor unit due to its role in producing powerful movements, specifically during activities like running and jumping. Large motor units are characterized by a higher number of muscle fibers innervated by a single motor neuron, which enables the generation of greater force. The gastrocnemius, being one of the primary muscles in the calf, is associated with activities that require significant force and strength, thus it comprises larger motor units to effectively support these demanding movements.

In contrast, muscles such as the eye muscles and hand muscles consist of small motor units. These small motor units allow for fine motor control and precision movements, which are essential for tasks like tracking visual stimuli and manipulating small objects. Facial muscles also typically contain smaller motor units, enabling subtle and intricate facial expressions. The distinction between large and small motor units is critical in understanding how different muscles perform their respective functions based on the demands of the activity.