Over the past several weeks, we focused on the extremities of the human body, discussing each joint, muscle, and different conditions affecting each region. We did not go into great detail about the neurology and how a network of nerves innervates (connect) different muscles and organs so they can function at optimal levels. In this week’s blog, we are going to briefly reintroduce the three parts of the nervous system, briefly discuss the nerve plexus system, and reiterate what we can do to help.
The Central Nervous System (CNS)
The CNS is the powerhouse of the nervous system. It consists of both the brain and the spinal cord. The brain sends and receives signals to and from the spinal cord allowing human movement, sensation, reflexes, and entire body function. Once signals leave the spinal cord and go out to the body, we are now in the Peripheral Nervous System.
The Peripheral Nervous System (PNS)
The PNS begins once we exit the spinal cord and messages are sent out to the arms and legs for full functioning. The PNS consists of spinal nerves and cranial nerves. We have 12 cranial nerves that have various functions such as sight, smell, hearing, touch and movement of the neck and face. Spinal nerves consist of two different nerves: motor and sensory. Motor nerves allow for human movement while sensory nerves allow for human sensation.
The Autonomic Nervous System (ANS)
The ANS controls our internal organs such as the lungs and heart to allow for functions such as breathing, blood circulation, digestion, urination, etc. The ANS has two different responses: Sympathetic and Parasympathetic. These two responses work as a team to regulate organ function and do the opposite. For example: when the heart rate increases, that is a sympathetic response. When the heart decreases, that is a parasympathetic response.
The Nerve Plexus System
A nerve plexus is a network of nerves that intersect and interconnect with one another. The human body has two different nerve plexuses: Spinal plexus and autonomic plexus. The autonomic nerve plexus runs the entire length of the thoracic region and controls internal organs. The spinal plexus is divided into 5 sections: cervical plexus, brachial plexus, lumbar plexus, sacral plexus, coccygeal plexus. Each plexus has a network of nerves that branch out to innervate muscles for motor function and different receptors for sensory function. Each plexus has several nerves with different functions. Due to the many nerves in each region and the complexity of each spinal plexus, we will provide a brief overview of each plexus, and then will explain what we can do to help. In future blogs, we can further discuss each plexus and nerves separately.
The cervical plexus, as shown below, is a network of nerves located in the neck region and is formed by the anterior branches of the first four cervical spinal nerves (C1-C4). The cervical plexus is responsible for supplying sensory and motor innervation to different regions of the head, neck, and shoulders. There are five major nerves associated with the cervical plexus.
In addition to sensory and motor functions, the cervical plexus also contributes innervation to the thyroid gland and the muscles attached to it.
The brachial plexus is the largest and most complex of the spinal plexuses. The brachial plexus is a complex network of nerves located in the shoulder region and is formed by the lower four cervical nerves (C5-T8) and the first thoracic nerve (T1). These nerves come together and form various branches that supply sensory and motor innervation to the upper limb, including the shoulder, arm, forearm, and hand.
What makes the brachial plexus more complex than the other plexuses is that the brachial plexus is divided into roots, trunks, divisions, cords, and branches opposed to the other plexuses only having branches. We are not going to discuss each division, but if you look at the image below, you can see how much larger and more complex the brachial plexus is compared to the other plexuses.
The lumbar plexus, as shown below, is a network of nerves located in the lumbar region and is formed by the anterior branches of the first four lumbar nerves (L1-L4). The lumbar plexus is responsible for supplying sensory and motor innervation to the lower abdomen, pelvis, and parts of the lower limbs. There are five major nerves associated with the lumbar plexus.
The sacral plexus, as shown below, is a network of nerves located in the pelvic region and is formed by the anterior branches of the fourth and fifth lumbar nerves (L4-L5), and the first four sacral nerves (S1-S4). The sacral plexus is responsible for supplying sensory and motor innervation to the buttocks, pelvic region, and the lower limbs. There are five major nerves associated with the sacral plexus.
The sacral plexus is also responsible for sensory and motor innervation to the internal/external genitalia, and the muscles involved in urinary and anal sphincter control.
The coccygeal plexus, as shown below, is a network of nerves located in the region of the coccyx, the final segment of the vertebral column, and is formed by the anterior branches of the coccygeal nerve (Co1). The coccygeal plexus is responsible for supplying sensory innervation to the skin over the coccyx and the surrounding area. It also contributes motor innervation to the pelvic floor muscles and the anus.
What Can We Do to Help?
Over the past several weeks, we discussed the extremities and common conditions affecting each region. One condition affecting every region is nerve interference. Every nerve associated with one of the five spinal plexuses can be affected by nerve interference. No matter which plexus is affected, it can be treated the same way. The only difference in distinguishing which plexus is affected is based on clinical presentation; meaning is weakness and sensation present in the upper body or lower body.
A chiropractor’s main focus is to remove any nerve interference so that the body can function at optimal levels. Nerve interference happens when a nerve is impinged between one or more vertebra causing nervous system disruption. Nerve interference symptoms include pain, weakness, numbness/tingling, and organ malfunction.
Performing a neurological exam and conducting a set of x-rays in the region of complaint is necessary to know exactly what is creating the nerve interference and to determine the correct course of action.
Whether that course of action includes spinal manipulation, non-surgical spinal decompression, and/or neuropathy management, we provide high-quality care and spend a significant amount of time with each patient so that we can achieve positive results.
For more information or questions about the spinal plexuses, please call us at (724) 547-3377 and checkout our website at www.drlarrywilkinsspinalcare.com for more content.
Yours In Health,
Larry E. Wilkins, DC
Brian M. Steinert, DC