What is the pathway of a reflex arc?

The pathway of a reflex arc involves five main steps: receptor, sensory neuron, integration centre, motor neuron, and effector.

A reflex arc is a neural pathway that controls an action reflex, an immediate response to a specific stimulus. The pathway of a reflex arc begins at the receptor, the site where the stimulus is detected. This could be a sensory organ like the skin, which detects changes in temperature, or the nose, which detects chemical changes in the air.

The stimulus is then converted into an electrical signal, or nerve impulse, by the sensory neuron. This neuron carries the impulse from the receptor to the integration centre in the central nervous system (CNS), which is usually the spinal cord or brain. The sensory neuron transmits the signal by releasing neurotransmitters, chemicals that allow the impulse to jump from one neuron to the next across a synapse, or gap.

The integration centre processes the information from the sensory neuron and determines the appropriate response. This is where the decision to react is made. The response is then sent to the motor neuron, which carries the impulse from the CNS to the effector.

The effector is the muscle or gland that carries out the response. If the stimulus was a hot surface, for example, the effector would be the muscles in your hand that contract to pull your hand away. The entire process, from detecting the stimulus to responding, happens incredibly quickly and often without conscious thought, allowing the body to react to potential threats in a timely manner.

In summary, the pathway of a reflex arc is a complex process involving multiple steps and components. It begins with the detection of a stimulus at the receptor, followed by the transmission of a nerve impulse by the sensory neuron to the integration centre. The integration centre processes the information and sends a response via the motor neuron to the effector, which carries out the action.