Question

The sequence of a reflex arc is
A) Receptor $\to$ Sensory neuron $\to$ Motor neuron $\to$ Effector$\to$ Response
B) Effector $\to$ Sensory neuron $\to$ Motor neuron $\to$ Receptor$\to$ Response
C) Effector $\to$ Motor neuron $\to$ Interneuron $\to$ Receptor$\to$ Response
D) Receptor $\to$ Motor neuron $\to$ Sensory neuron $\to$ Effector$\to$ Response

Answer 1

Hint: Our nervous system has a group of neurons .they work as a circuit to send out and receive information. Reflex is the simpler circus in the nervous system. It is an automatic reaction to a stimulus. Reflexes don't require thinking it is sudden.

Complete step by step answer:
- Every reflex whether it is simple or complex consists of five parts that take place in a specific order.
- The five-part of a reflex arc is a sensor, sensory neuron, control center, motor neuron, and muscle.

These work as a team to receive information from the sensor to the spinal cord and back to the muscles.
1) Sensor: the reflection starts from a structure known as a sensor. It detects touch, stretch, heat, light, smell, and vibration. Some of the sensors are neurons and give nerve impulses when stimulated but other cells are not neurons and can signal only nearby sensory neurons. Whenever stimuli are detected by them all the information has to be changed into nerve impulse before the information used by the circuits of a nervous system.
2) Sensory neuron: Every reflex has a sensory neuron. The nerve impulse is started by the Sensory neurons and travels to the spinal cord or the brain. Sensors are present in the eyes, ears, muscles, skin, and other body parts.
3) Control center: The Sensory neurons divided into 3 branches. Each branch forms a synapse. One branch connects to an interneuron. It sends information to the spinal cord. Another branch goes to the motor neuron and the third branch goes to the other interneuron.
The cerebral cortex is an important control center. Information comes from eyes, ears, skin, muscles, and travel along sensory neurons to go to the cortex. Then the cerebral cortex processes this information and decides how to respond.
4) Motor neuron: It is called the output phase. It sends an impulse to either muscle or glands. In short, it carries the message from the central nervous system to the effector.
5) Effector: It produces a response. Ex when we touch hot things, muscles contract to move the hand away.
So, the correct answer is, "Receptor $\to$ Sensory neuron $\to$ Motor neuron $\to$ Effector$\to$ Response".

Note:
- in the many of the reflex arc system sensory neurons connect to a motor neuron by the association with the neurons that are called interneurons in the central nervous system.
- carry information from the receptor to the sensory neuron and carry a message from the motor neuron to the effector. This is done by interneurons of the central nervous system and the making of the right connections is called integration.