The parasympathetic nervous system is a crucial part of the autonomic nervous system that regulates bodily functions at rest and during relaxation. Together with the sympathetic nervous system, the parasympathetic nervous system is responsible for maintaining the internal balance of the body, known as homeostasis. In this article, we will explore in detail the functions and pathway of the parasympathetic nervous system, as well as its importance for overall health and well-being.
Components of the System Parasympathetic Nervous
The parasympathetic nervous system is made up of nerves that originate in the brain stem and spinal cord. These nerves are divided into two main groups: the cranial nerves and the sacral nerves. Cranial nerves emerge from the brainstem, specifically the medulla oblongata and medulla oblongata, while sacral nerves originate from the sacral region of the spinal cord. Together, these nerves are part of the parasympathetic division of the autonomic nervous system.
Cranial Nerves
The parasympathetic cranial nerves are responsible for innervating structures of the head, such as the eyes, mouth and the salivary glands. Some of the cranial nerves involved in the parasympathetic nervous system include the oculomotor nerve (III), the facial nerve (VII), and the glossopharyngeal nerve (IX). These nerves transmit parasympathetic signals to specific organs to regulate functions such as pupillary contraction, saliva secretion, and facial expression.
Sacral Nerves
On the other hand, the sacral nerves of the system Parasympathetic nerves originate in the sacral region of the spinal cord and are part of the pelvic nerves. These nerves innervate organs located in the pelvis, such as the urinary bladder and reproductive organs. Activation of the sacral parasympathetic nervous system promotes relaxation of the bladder and facilitates sexual function, among other activities.
Functions of the Parasympathetic Nervous System
The parasympathetic nervous system plays a fundamental role in the regulation of various bodily functions that take place in situations of rest and relaxation. Some of the main functions of the parasympathetic nervous system include:
1. Restoration and Rest
One of the main functions of the parasympathetic nervous system is to promote restoration and rest of the body. When we are in a state of calm and relaxation, the parasympathetic promotes energy recovery, proper digestion and tissue repair. Activities such as sleep and relaxation are facilitated by the parasympathetic nervous system, allowing the body to recover from daily demands.
2. Digestive Stimulation
The parasympathetic nervous system also plays a crucial role in stimulating the digestive system. When we are in a state of relaxation, this system promotes the secretion of digestive enzymes, increases intestinal motility and promotes the absorption of nutrients in the gastrointestinal tract. In this way, it contributes to effective digestion and the maintenance of a healthy digestive system.
3. Heart Rate Control
Another important function of the parasympathetic nervous system is to regulate heart rate. When we are at rest, the parasympathetic slows our heart rate by decreasing the activity of the sinus node, the heart's natural pacemaker. This action helps maintain a stable heart rate suitable for conditions of rest and relaxation, preventing arrhythmias and other cardiac problems.
4. Contraction of the Urinary Bladder
The parasympathetic nervous system also controls the contraction of the urinary bladder during urination. When the bladder is full, parasympathetic signals stimulate bladder contraction and relaxation of the internal sphincter to allow urine to be expelled in a controlled and coordinated manner. This function is essential for the proper emptying of the bladder and the regulation of the urinary system.
Course of the Parasympathetic Nervous System
The circuit of the parasympathetic nervous system involves the transmission of signals from the central nervous system (brain stem and spinal cord) to the effector organs, where the corresponding responses are carried out. Broadly speaking, the journey of the parasympathetic nervous system follows the following steps:
1. Origin in the Central Nervous System
The parasympathetic fibers have their nuclei of origin in the brain stem and the sacral cord. In the brainstem, the nuclei of origin are found in structures such as the oculomotor nucleus, the superior salivary nucleus, and the dorsal vagus nucleus. These nuclei emit parasympathetic fibers that project through the cranial nerves to the target organs in the head and neck.
2. Transmission of Signals
Once the parasympathetic signals have been generated in the nuclei of origin, they are transmitted through the cranial or sacral nerves to the effector organs. In the case of the cranial nerves, parasympathetic fibers travel through structures such as the oculomotor nerve, facial nerve, and glossopharyngeal nerve to reach their destinations in the head and neck. On the other hand, sacral parasympathetic fibers travel through the pelvic nerves to the organs of the pelvis and the sacral region.
3. Action on Effector Organs
Once parasympathetic signals reach the effector organs, they trigger specific responses depending on the organ and the physiological situation. For example, in the case of digestive stimulation, parasympathetic signals cause the release of digestive enzymes and the contraction of intestinal muscles to facilitate the digestion of food. In the case of heart rate, parasympathetic signals slow down the heart rate to adapt it to resting conditions.
Importance of the Parasympathetic Nervous System
The parasympathetic nervous system is essential for health and general well-being, since it regulates vital functions at rest and in relaxation situations. Maintaining a proper balance between the sympathetic and parasympathetic nervous systems is key to optimal body and mental function. A healthy parasympathetic nervous system contributes to:
1. Stress Reduction
By promoting calm and relaxation, the parasympathetic nervous system helps reduce stress and anxiety levels in the body. Activating this system during moments of rest and meditation can counteract the effects of chronic stress, promoting a state of emotional and mental balance.
2. Improved Digestion
Proper function of the parasympathetic nervous system is essential for healthy digestion. By stimulating digestive activity and promoting the absorption of nutrients, the parasympathetic helps to maintain a gastrointestinal system in optimal condition. Problems such as constipation, heartburn and other digestive disorders can improve with an active and balanced parasympathetic nervous system.
3. Sleep Regulation
The parasympathetic nervous system plays an important role in regulating the sleep-wake cycle. During the rest phase, parasympathetic activation promotes muscle relaxation, decreased brain activity and preparation for restful sleep. A healthy parasympathetic nervous system can help improve sleep quality and prevent problems such as insomnia.
4. Cardiovascular Maintenance
The regulation of heart rate by the parasympathetic nervous system is essential for cardiovascular health. A proper balance between the sympathetic and parasympathetic systems helps prevent conditions such as high blood pressure, cardiac arrhythmias and other heart-related disorders. Strengthening the parasympathetic nervous system can have significant benefits for the health of the heart and blood vessels.
Conclusions
In conclusion, the parasympathetic nervous system plays a fundamental role in regulating functions body at rest and relaxation situations. From restoration and rest to digestive stimulation and heart rate control, this autonomic system is essential for physiological balance and overall well-being. Understanding the functioning and importance of the parasympathetic nervous system can be key to promoting comprehensive health and improving quality of life.