What is the function of Reticular Activating System?

Image Credit: 
Main Image: 

Each and every function which we perform consciously or even sometimes unconsciously is done by some part of the brain. Brain is one of the most complex structures of matter in the whole universe. Brain has created our mind as the entity and every thought which peeps up in our mind has its thread located in the mastermind which is the brain. Reticular activating system is one of the most important parts of our brain that has great influence over cognition. Recent neuroscience studies related to mammalian brains has unleashed that this system performs lots of cognitive functions which are related to awareness.


What is reticular activating system?

This system is considered the brain’s attention center. It is the key for switching on your brain and also considered as the main center of motivation. The Reticular activating system is connected to the spinal cord at its base from where it accepts information which comes from the ascending sensory tracts directly. It travels up to the mid brain and while going up forms a complex neuron collection that act as convergence point for signals from the interior environment as well as the external surroundings. So, reticular activating system is a place where your thoughts, internal feelings and the outside influences converge. It is very skilled in producing dynamic effects on the motor activity centers located in the brain and the cortex activity such as the frontal lobes.


What is the structure of reticular activating system?

Scientists have found out that the reticular activating system (RAS) comprise of two important parts known as the ascending reticular system and the descending reticular system. The ascending system is connected to cerebral cortex, hypothalamus, and also the thalamus. The descending system is connected to several sensory nerves and the cerebellum. The reticular system consists of those brain parts which are in charge of survival instincts. That is the reason why this system has deep connection with the various awareness brain functions. The functions of RAS are under the control of some cholinergic (acetylcholine) and adrenergic (Adrenaline) neurotransmitters. The main parts of RAS are:

  • Reticular Formation in the Midbrain
  • Mesencephalon
  • Dorsal Hypothalamus
  • Thalamic Intralaminar Nucleus
  • Tegmentum


What are its functions of Reticular activating system?

The most important function of Reticular activating system is to regulate the shift between sleep and wakefulness. The transition made by our body from deep slumber to being completely awake as well as functional and vice versa is under the control of this system. It also plays a vital role during our sleep and when we see dreams. It is also responsible for supplying integrated response to the outside stimuli. The skill to sluice out information brought out by the external sources and to pin point a particular fact with detailed thought is the controlled effect of the reticular activating system. Coordination while walking, eating or sexual functions are carried out by RAS.


What are the disorders related to RAS?

Reticular activating system damage can make the patient go to coma. Since it is placed at the back of brain, it is more vulnerable to injury or damage. The disorders in RAS are attention deficit disorders, narcolepsy, sleep disorders, Alzheimer’s disease. The psychotropic drugs or the anesthetics affect this system directly which makes the transition from unconsciousness to semi consciousness possible.


External References
Related Videos: 
See video