Types of Reflexes

Bookmark added to your notes.
View Notes

What is a Reflex?

The types of reflexes will be discussed after we make you familiar about a reflex or reflex action. Reflex is an involuntary or instantaneous action by our body parts in response to a stimulus. It is due to the numerous neural pathways known as reflex arcs that act on an impulse before it reaches the brain. For reflex to occur, there is no requirement of any conscious thought or awareness about the automatic response.

When a specialized tissue is receiving a stimulus, it may either directly or indirectly change the relation of other tissue or also the whole individual to the environment from where that stimulus arises. A few examples of the reflex action are the pupil of the eye changing its size where light acts as a stimulus; withdrawing our hands or legs suddenly when we touch something very hot and coughing or sneezing when dust or foreign particles enter our nasal passages. Our reactions are instantaneous, quick and involuntary in these situations. It doesn’t require much of a thinking process and the action is called the reflex action. And here, the mechanism of reflex includes the roles of spinal cord and the nerve pathway, involved in this action including a sensory nerve, a synapse, and a motor nerve, which altogether is termed as reflex arc. 

Classification of Reflexes

There are several ways to classify the reflexes of the body. Following are the classification of reflexes.

  1. Based on the Type or Function

This is based on the movement of the organs or parts of the body that move due to the reflex. Some reflexes that move the skeletal muscles are extensor, flexor, locomotor and statokinetic. Reflexes that involve the function of internal organs include cardiovascular, digestive, secretory and excretory. 

  1. Based on the Degree of Complexity

Reflexes can also be classified based on the degree of complexity of the neuron or  nerve organization within the reflex arcs. Under this category, these can be monosynaptic or monosegmental reflexes that involve only one segment of the central nervous system and multisynaptic or intersegmental reflexes that involve more than one segment of the central nervous system.

  1. Based on the Development

Reflexes can be innate reflexes and acquired reflexes where the former includes genetically determined and the latter type includes learned reflexes.

  1. Based on the Response

Reflexes can be somatic reflexes that control skeletal muscle contractions and include superficial and stretch reflexes; the other one includes visceral or autonomic reflexes.

Importance of Reflexes

Different types of reflex actions are known which are involuntary responses of effectors to the stimulus. It aids us in protection from any sudden stimulus that may harm us and therefore takes care of the survival of an organism. 

The significance of reflex action is due to the fact that reflex arcs are composed of major components creating a reflex. The function of each of these components is explained below-

  1. Receptor - It receives the information and thus helps in generating impulses. 

  2. Sensory Nerve - It transmits information from the receptor to the interneurons in the spinal cord. 

  3. Interneuron - It generates effective responses by effectively processing the information.

  4. Motor Nerve - It carries the respective information from the spinal cord to the effector organ. 

  5. Effector Organ - It receives information from effector neurons and helps in generating the appropriate response (reflex). 

Some Common Types of Reflexes 

We have briefly explained some reflex action examples in humans in the following points:

  1. We close our eyes when a bright or shining light or torch hits our eyes.

  2. We suddenly withdraw hands or legs when they touch something sharp, hot or pricking objects.

  3. We cough or sneeze due to irritants, thread or foreign substances in the nasal passage.

  4. We perform batting of eyelids frequently when something irritates our eyes.

  5. We blink eyes when insects come in contact suddenly while driving.

  6. There is a rooting reflex in infants where newborn babies automatically turn the face toward the stimulus to make sucking/rooting motions with the mouth whenever we touch the lip or cheek. The rooting reflex helps in ensuring successful breastfeeding.

  7. Infants indulge in grasp reflex; it is such that when an object is kept in an infant's hand and the child’s palm is stroked, the fingers will close reflexively and the object is grasped.

  8. Muscular reflex can be seen in the abdominal region where abdominal muscles contract upon any force to the abdomen.

  9. Also known as patellar reflex, the Knee-jerk reflex makes the patellar tendon stretch and this way the contraction of quadriceps takes place.

Grasp Reflex

(Image to be added soon)

FAQ (Frequently Asked Questions)

1. What is the Meaning of Reflex? What is the Main Component of Reflex?

Reflex is the involuntary action of body parts in response to a stimuli. It occurs with the help of a reflex arc which is a nerve pathway via which varied components like receptor, interneuron, sensory neuron and effector work together to generate a reflex action. It is a five step process by which they generate a reflex action.

2. What is Multisynaptic or Polysynaptic Reflex?

A multisynaptic reflex involves more than one neuron or interneurons within the reflex arc process. It works together with more than one area of the central nervous system, mainly the brain and the spinal cord. An example of such kind of reflex is flexor reflex.

3. What is Monosynaptic or Monosegmental Reflex?

Monosynaptic or monosegmental reflex involves only one segment of the central nervous system.

4. What Are the Different Types of Reflexes?

The different types of reflexes depend upon varied factors such as type, function, degree of complexity, development and response. The different reflexes may include  extensor, flexor, locomotor and statokinetic. Two types of reflex arcs are the autonomic reflex arc that affects inner organs, and the other type is the somatic reflex arc that affects muscles.