Final answer:
Sensory neurons send a message to the muscles in LaKeisha's foot, resulting in her pulling her foot away from the glass. This reflex response does not require conscious thought.
Step-by-step explanation:
The **sensory neurons** are responsible for sending a message to the muscles in LaKeisha's foot, resulting in her pulling her foot away from the piece of glass. Sensory neurons transmit signals from the sensory receptors (in this case, the foot) to the central nervous system (CNS).
The CNS then processes the information and sends a message to the **motor neurons**, which control the muscles in LaKeisha's foot. The motor neurons receive the message from the CNS and activate the appropriate muscles, causing LaKeisha to pull her foot away.
In this situation, the response is a **reflex**, which is an involuntary and automatic response to a stimulus. Reflexes are mediated by the spinal cord without the need for conscious thought.