Question

A reflex in skeletal muscle occurs in response to sensory input and does not depend on the activation of upper motor neurons.

A. True
B. False

Answer 1

A reflex in skeletal muscle does indeed happen in response to sensory input and does not require the activation of upper motor neurons, as it involves a reflex arc within the CNS. Examples include the withdrawal and stretch reflexes. Option A. True

Step-by-step explanation:

The statement that a reflex in skeletal muscle occurs in response to sensory input and does not depend on the activation of upper motor neurons is true. Reflexes in the skeletal system, such as the withdrawal reflex or the stretch reflex, utilize a reflex arc that incorporates sensory input directly causing a motor response without the need for conscious input from the brain. For example, a typical reflex action is when you touch a hot surface and instinctively withdraw your hand; this is a somatic reflex involving the central nervous system (CNS) in that the sensory neuron directly activates the motor neuron in the spinal cord or brain stem. However, this does not involve the upper motor neurons that are part of the conscious control of movement.

Answer 2

The correct answer is **B. False**. A reflex in skeletal muscle occurs in response to sensory input and **does** depend on the activation of upper motor neurons. Upper motor neurons are the neurons that originate in the brain and spinal cord and control the lower motor neurons that innervate the skeletal muscles. Upper motor neurons are involved in the regulation of the reflex arc, which is the pathway that mediates the reflex response.