What is the Role of the Brain in Reflex Action?

January 11, 2024

What is the Role of the Brain in Reflex Action?
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High Heart Rate

The average heart beats between 60 and 100 times per minute. A heart rate of more than 100 beats per minute is regarded as high (medically termed tachycardia). Heart palpitations are not always dangerous. 


To better understand reflex action, let’s use the example of unintentionally touching a hot pan. Your hands will quickly instinctively withdraw away from the heat to avoid injury.However, how does this come about? 

An automatic reaction to a stimulus that happens almost instantly is called a reflex. Reflexes are involuntary reactions to stimuli that happen through a reflex arc and do not require conscious awareness. Prior to an impulse reaching the brain, reflex arcs respond to it.

Reflex Action

A reflex action is a quick, spontaneous movement brought on by outside stimuli. These are, to put it simply, instinctive reactions to action without any thought involved. Without conscious awareness, these quick, reflexive motions take place in a split second. Although they may appear straightforward, reflex action needs intricate brain and body part synchronisation.

Reflex Arcs and its Types

To understand how and what controls the reflex actions, one must grasp the reflex arc and all of its constituent parts. It is the nervous system route that governs reflexes that allows sensory data to be transmitted impulsively from the brain to the spinal cord and then back to the muscles or glands responsible for the reaction. 

There are two kinds of reflex arcs:

Monosynaptic Reflex Arc – A sensory neuron and a motor neuron are the only two neurons that make up a monosynaptic system. Human examples of monosynaptic reflex arcs are the Achilles and patellar reflexes.

Polysynaptic Reflex Arc – In this arc, numerous interneurons, which are also referred to as relay neurons, serve as an interface between the motor and sensory neurons in the reflex pathway.

Primary Elements of Reflex Arc

Reflex Arc further consists of the following main elements:

Sensory Receptors and Stimuli: Specific stimuli trigger the activation of specialised sensory receptors, which in turn trigger reflex action. Sensory receptors recognize a range of sensory stimuli, including pressure, pain, and heat.

Sensory Neurons and Spinal Cord: This reflex arc starts in the spinal cord, which receives sensory neuron transmissions. It sends electrical signals across sensory neurons when it receives stimuli.

Interneurons: Interneurons are also called relay neurons.They process sensory information. 

Motor Neurons: When sensory information reaches the spinal cord, motor neurons fire, causing a muscular response. Instructions from the spinal cord are transmitted to the muscles or glands responsible for the reflex action through its assistance.


The brain is an intricate organ that governs all bodily functions, including thought, memory, emotion, touch, motor skills, vision, breathing, temperature, and hunger. The brain and the spinal cord that emanates from it constitute the central nervous system, sometimes known as the CNS.60% of an adult’s weight, or three pounds, is made up of fat in the brain. Salts, carbs, protein, and water make up the remaining 40% of the composition. It is not a muscle, the brain itself is. Neural tissue, comprising neurons and glial cells, as well as blood arteries are present.The brain sends and receives chemical and electrical signals throughout the body. Different signals control different processes, and your brain interprets each. Some make you feel tired, for example, while others make you feel pain.

Some messages are kept within the brain, while others are relayed through the spine and across the body’s vast network of nerves to distant extremities. 

Role of the Brain in Reflex Action

Since a reflex action is involuntary and requires an instantaneous response to avoid negative consequences, the brain plays no direct involvement in it. Your spinal cord is responsible for managing and controlling the reflex action. Since reflex action is instantaneous and doesn’t involve thought, the spinal cord controls it.The connections known as reflex arcs, which occur between the input and output nerves, come together in a bundle within the spinal cord. The spinal cord forms reflex arcs, which allow information to enter the brain. The signal and the resulting response are all that the brain is aware of. Nevertheless, the brain is not involved in the formation of the response.The signal and the resulting response are all that the brain is aware of. 

Benefits of Reflex Action

Reflex motions play an important function in life in addition to being natural and spontaneous. Here are a few of its main advantages:

  • One important advantage of reflex action is the capacity to respond to possible threats rapidly and subconsciously, preventing harm or other undesirable results.
  • Reflex actions serve as an injury-prevention mechanism by promoting quick reactions to potentially dangerous situations.
  • Our bodies are able to react quickly to certain movements through reflex actions. 


The brain, which has a complex and varied role in reflex reaction, communicates primarily with the spinal cord. In addition to being instinctive responses, reflexes rely on an intricate network of neurological connections that span the brain, spinal cord, motor neurons, and sensory receptors. 

Frequently Asked Questions

1. Is reflex action important?

Reflex actions are not only automatic and spontaneous, but they are also quite important. By inducing quick reactions to potentially dangerous circumstances, reflex actions serve as a protective mechanism that helps prevent injury.

2. What will happen if reflex actions stop functioning?

When reflex activity is absent, there may be a problem with the nervous system, which should be taken seriously. Reflex action is essential because it enables our bodies to react to possible dangers. Their malfunctioning can impair our capacity to defend against possible dangers.

3. When should I consult a doctor?

You should speak with a healthcare provider if you believe that your reflex actions are missing or not working properly. Depending on the particular circumstances, they could assess your symptoms, recommend the tests that are required for an appropriate diagnosis, and provide treatments and preventive actions.

Disclaimer: We recommend consulting a Doctor before taking any action based on the above shared information.


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