The Peripheral Nervous System’s Duo: A Guide to Its Two Parts

Peripheral Nervous System’s Duo: A Guide to its Two Parts

The nervous system plays a crucial role in the body’s functioning, and it is essential to understand its various parts. One of the main parts of the nervous system is the peripheral nervous system. The peripheral nervous system comprises two parts, the somatic nervous system, and the autonomic nervous system.

What is the Peripheral Nervous System?

The Peripheral Nervous System (PNS) comprises all the nerves that are located outside the brain and spinal cord. It controls the external senses, such as touch, smell, sound, taste, and sight, and regulates the communication between the body’s internal organs and the central nervous system. The PNS has two primary divisions – the somatic and the autonomic nervous systems.

The Two Parts of the Peripheral Nervous System

The Somatic Nervous System

The somatic nervous system (SNS) is responsible for the voluntary movements that we undertake every day, such as walking, talking, and writing. The nerves in this division of the PNS are responsible for transmitting sensory information received from sense organs throughout the body to the CNS. The SNS also coordinates the communication between the brain and the muscles that are responsible for performing the voluntary movements that we take part in.

The Autonomic Nervous System

The Autonomic Nervous System (ANS) controls involuntary bodily functions of our internal organs, including respiration, digestion, heartbeat, and glandular function. The autonomic nervous system has three main subdivisions: the sympathetic, parasympathetic, and enteric nervous systems.

The Sympathetic Nervous System

The sympathetic nervous system (SNS) is responsible for the body’s “fight or flight” response. SNS prepares the body to react to emergency situations, causing the heart rate to increase, breathing rate to quicken, the eyes to dilate, and perspiration to occur. It helps us respond quickly to stressful situations, and it is responsible for releasing the adrenaline hormone.

The Role of Sympathetic Nervous System in Stress Response

The sympathetic nervous system’s activation during a stressful situation causes the body to release the hormone adrenaline and cortisol. These hormones increase alertness, change how the body utilizes energy, and affect various body systems. They increase blood glucose levels, which provide a quick source of energy to help us react in the situation that causes stress. The response of the sympathetic nervous system prepares the body to act quickly and respond to potential danger.

The Parasympathetic Nervous System

The parasympathetic nervous system (PNS) acts to decrease the body’s physiological effects that the SNS has. The PNS helps the body to calm down and relax, which helps to conserve energy. It influences the digestive system, lungs, and heartbeat, among other bodily functions.

The Role of Parasympathetic Nervous System in Relaxation

The parasympathetic nervous system typically operates when the body is relaxed, and not under stress. It works to reduce the effects of the sympathetic nervous system on bodily functions by lowering the heart rate, respiration rate, and blood pressure. It also promotes digestion and nutrient absorption by stimulating glandular secretions and contraction of intestinal muscles.

The Enteric Nervous System

The Enteric Nervous System (ENS) is often referred to as the second brain, and it is because it can operate independently of the CNS. It is comprised of many nerve cells located in the digestive tract, which helps regulate gastrointestinal function. The ENS receives signals from the CNS and processes them to control digestive processes, including the release of enzymes and contractions of the stomach and intestine.

How Does the Enteric Nervous System Control Our Digestive Function?

The ENS controls a wide variety of digestive processes, including the process of absorption, digestion, and elimination. The system controls the secretion of digestive enzymes, as well as the contraction of the digestive system’s muscles. It also controls the opening of the gastroesophageal sphincter to permit food to enter the stomach and regulate the expulsion of fecal matter from the body.

The Relationship Between Somatic and Autonomic Nervous System

The SNS and ANS work together most of the time to keep our bodies functioning as efficiently as possible. The somatic system makes movements, and the autonomic system regulates the functionality of organs and organ systems needed to execute those movements. The ANS controls involuntary functions, whereas the SNS controls voluntary functions.

How Do the Somatic and Autonomic Nervous Systems Work Together?

When a voluntary movement is initiated, impulses from the CNS activate the appropriate muscle group. It activates the somatic nervous system, which causes a coordinated contraction of muscles required for the movement. After movement, the PNS helps to adjust particular functions that were affected during the movement. These functions include breathing, digestion, heart rate, and blood pressure regulation.

Conclusion

The Peripheral Nervous System’s (PNS) two primary branches are the somatic and autonomic nervous systems. The SNS orchestrates the voluntary movements of the body while the ANS manages involuntary functions such as breathing, circulation, and digestion. The autonomic system has three main subdivisions: the sympathetic, parasympathetic, and enteric nervous systems. These branches work in tandem to keep the body healthy and functioning as needed. Understanding the PNS’s central role in our well-being helps us appreciate how it works and how we can maintain healthy nervous system function.

Frequently Asked Questions:

  • What is the peripheral nervous system?
  • The peripheral nervous system (PNS) comprises all the nerves that are located outside the brain and spinal cord.

  • What are the two parts of the peripheral nervous system?
  • The two parts of the peripheral nervous system are the somatic nervous system (SNS) and the autonomic nervous system (ANS).

  • What does the somatic nervous system do?
  • The somatic nervous system is responsible for voluntary movements that we make in our daily life, such as walking, running, and writing.

  • What is the autonomic nervous system?
  • The autonomic nervous system (ANS) regulates involuntary bodily functions of the internal organs, including respiration, digestion, circulation, heartbeat, and glandular function.

  • What are the three subdivisions of the autonomic nervous system?
  • The three subdivisions of the autonomic nervous system are the sympathetic, parasympathetic, and enteric nervous systems.

References:

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