Somatic Nervous System is also called the “Voluntary Nervous System” and is part of the Peripheral Nervous System. The human body’s nervous system consists of two parts. Central Nervous System (CNS-which contains the brain and spinal cord) and Peripheral Nervous System (PNS- it is present outside of the brain and spinal cord, consisting of all the nerves branching out from the CNS). Reflexes generated from the somatic nervous system are referred to as “Somatic Reflexes.” SNS consists of Afferent (Sensory) and Efferent (Motor) neurons.
Afferent Neurons: These carry information from sensory receptors of the skin and other organs and send it to the CNS.
Efferent Neurons: These neurons carry motor information from the CNS to different muscles and glands of the body.
An involuntary response to a stimulus is called a “Somatic Reflex.” It is a motor response to sensory stimulation.
What are Somatic Reflexes?
What are somatic reflexes?
Somatic reflexes are involuntary responses to a stimulus, such as a touch or sound, that originate in the peripheral nervous system and are transmitted to the spinal cord. These are usually triggered by physical stimuli such as pressure, heat, or cold. For example, when a person touches a hot fry pan, his peripheral nerves send a signal to the brain, which results in quickly removing his hand from the hot object.
What is the physiology of Somatic Reflexes?
There are specialized sensory receptors present in the SNS known as Proprioceptors. These are responsible for monitoring the following:
- Limb movements.
- Limb Positions.
- Other body movements.
- Amount of strain on the musculoskeletal system.
Other functions of Proprioceptors
It includes the following:
- Maintain the balance of the body.
- Orientation of the head and body according to gravity.
What is Somatic Reflex Arc?
Somatic Reflex Arc
A neural pathway that controls a reflex is known as a “Reflex Arc.” The somatic reflex arc is a three-neuron circuit that is responsible for the majority of somatic reflexes. It consists of a sensory, interneuron, and motor neuron.
Sensory Neuron
- It is also known as an afferent sensory neuron.
- It receives sensory information and stimulus.
- Sensory information is then transmitted to the integration center.
Inter Neuron
- Inter-neurons are responsible for integrating the signal.
- After integration, these signals are sent to efferent motor neurons by inter-neuron.
Motor Neuron
- These neurons are also known as efferent motor neurons.
- Efferent motor neurons stimulate the muscle or any other target of the effector.
- It then conducts the reflex action.
Categories of Somatic Reflexes
Several somatic reflexes are present; some examples are lifelong reflexes, primary infant motor reflexes, and lifelong reflexes schemes. However, a few significant categories of somatic reflexes are as follows:
- Stretch Reflex
- Inverse Stretch Reflex- Golgi Tendon Organ
- Withdrawal Reflex
- Crossed Extensor Reflex
What is the difference between normal neural pathways and reflexes?
The significant difference between normal neural pathways and reflexes is that the input or stimulus goes to the brain for processing in normal neural pathways. However, the input or stimulus is processed in the interneurons in reflexes. Other difference includes the following:
- Reflex generates a faster response.
- In reflexes, the integration occurs in the spinal cord instead of the brain.
Multiple neurons are present in some reflexes, but simple reflexes only have one neuron. In simple reflexes, only one neuron is responsible for afferent and efferent actions.