Introduction
The nervous system is the body’s primary system for communicating and controlling all functions. Every idea, deed, and feeling are reflection of its activity. Electrical impulses are the primary mode of communication of the brain with the body’s cells because they are quick, precise, and virtually instantaneous in their effects. The nervous system has three overlapping roles to perform its regular role: monitoring changes, sensory input interpretation, influencing reactions, managing mental activity, and homeostasis.
We only have one nervous system, but it is not easy to examine all its components simultaneously due to its complexity. To make learning straightforward, we categorize the nervous system according to its structures (structural classification) or according to its functions (functional classification) (Belleza, 2021). Despite its complexity, neurons and supporting cells comprise most of the nervous tissue cells. The brain’s four main regions are the cerebral hemispheres, diencephalon, brain stem, and cerebellum. The parasympathetic division enables us to release and preserve energy, which is an intriguing thing I learned from the material.
Spinal Cord Injury Physiology
A person with a spinal cord injury at the L2 or L3 vertebrae can have a knee-jerk reflex but no motor control of the knee or feeling on the knee. The brain is divided into four different lobes: frontal, parietal, occipital, and temporal lobes (Siebert Science, 2015). It also includes the cerebellum and the spinal cord that transmit nerves to the rest of the body. The frontal lobe is where most motor functions start whenever the brain signals to any body part. The parietal lobe contains the sensory section, which receives pain or feeling signals (Siebert Science, 2015). In this scenario, the person got injured in the lumber nerve region of the spinal cord.
Whenever an object strikes the knee, the l4 nerve sends the signal up to the lumbar region of the spinal cord. The reflex arc sends the signal up to the sensory part of the brain and travels back through the inner sensory and then to a motor neuron out of the spinal cord. The signal travels back to the l4 nerve to the muscle, which makes the leg move. The person can not have motor control of the knee or feel because a signal sent from the frontal lobe stops at the spinal cord injury (lumber region) (Siebert Science, 2015). Similarly, the sensory signal never gets past the injury to the brain; therefore, no pain can be felt.
Spinal Cord Syndromes
A cross-sectional view of the spinal cord shows that the inside is the grey matter, and the outside is the white matter. Human sensation nerves are located at the posterior of the spinal cord because most activities happen from the front. The most common cervical injury is central cord syndrome, which damages the center portion of the spinal cord (Schreyer, 2016). If it is damaged, a person will lose upper extremity activities and aperture MIDI sensation (Schreyer, 2016). However, the lower extremity around the perimeter of the spinal cord is preserved, a condition known as walking paraplegia. An accident that affects the posterior cord or dossal column will cause loss of sensation, but not motor. Therefore, a person with anterior cord syndrome can function in the upper and lower extremities, but the level below the injury will lose the ability to move. With Brown Sequard Syndrome, one side from the middle of the spinal cord is damaged, making one side of the body lose pain, sensation, and temperature. The individual will lose motor on the upper side of the body.
Neurogenic Shock vs. Spinal Shock
Neurogenic shock and spinal shock occur in patients with spinal cord injuries. A neurogenic shock means the entire nervous system is in a sock, while it is only the spinal that is in shock for spinal shock (ACLS Certification Association, 2018). The neurogenic shock disrupts the sympathetic nervous system outflow since it affects messages sent from T-12 down to L2. With the loss of sympathetic nerves, the individual loses fight-or-flight hormones (epinephrine and norepinephrine) (ACLS Certification Association, 2018). Since the patients will undergo massive vasodilation due to loss of norepinephrine, giving them fluids to maintain acceptable MAP should be a high priority. Spinal shock, like any other traumatic injury, causes bleeding and inflammation at the injury site. The damaged tissues release chemical vasoconstrictors, which results in spinal cord ischemia and hypoxia. Therefore, it results in paralysis and loss of sensation below the injury level due to a lack of oxygenated blood. I now understand the patient gains sensation, but that depends on the level of injury.
Autonomic Dysreflexia
The brain typically receives signals from the body if it has pain or discomfort before a spinal cord injury. During Autonomic Dysreflexia (AD), the discomfort or pain below the injury turns on autonomic nerves that trigger the blood vessels to squeeze tight (Craig Hospital, 2020). The constriction causes the blood pressure to rise to an abnormal level, causing the person to experience Autonomic Dysreflexia. The brain senses the rise in blood pressure and sends signals throughout the body to try to lower it and the brain to slow down. Since the injury blocks the messages, there will be no response from the blood vessels, which can lead to seizure, stroke, or even death if not stopped (Craig Hospital, 2020). Therefore, common AD symptoms are high blood pressure, severe headache, sweating above the level of spinal cord injury, slow heart rate, blotchy skin, and worry or anxiety. Anything that can cause discomfort below the spinal cord injury, such as skin irritations, bed sores, bruises, and scrapes, can cause AD (Craig Hospital, 2020). I have learned that managing blood pressure is essential to preventing or controlling Autonomic Dysreflexia if you have a spinal cord injury.
SCI Nursing
Damage to the spinal cord is referred to as a spinal cord injury (SCI). An SCI affects sensory, motor, and autonomic nervous system functions. The SCI manifests as either paraplegia or tetraplegia, which occurs due to the cervical and complete loss of the motor, respectively (elearnSCI, n.d.). The nurse’s role in spinal injury care includes accepting and demonstrating accountability, consulting with other practitioners, and helping people with SCI cope through therapy coordination.
Conclusion
Minimizing the risk of further spinal or neurologic injury includes immobilizing the spine during movement, checking medical status, and evaluating personnel and equipment required before movement. Skincare, pressure ulcers, mechanical loading, level of mobility, and neurovascular are key metrics to monitor when caring for SCI patients (elearnSCI, n.d.). Notably, SCI compromises sensory and motor functions that control breathing. A high level of SCI exposes the patient to risks of respiratory deterioration. Similarly, I learned that respiratory complications are the primary cause of death following spinal cord injury. Initially, spinal shock results in a flaccid paralysis of the muscles of inspiration. Therefore, hyperventilation is an essential step in caring for SCI patients.
References
Belleza, M. (2021). Nervous system snatomy and physiology. Nurselabs. Web.
CLS Certification Association. (2018). Neurogenic shock vs. spinal shock [Video]. YouTube. Web.
Craig Hospital. (2020). What is autonomic dysreflexia? [Video]. YouTube. Web.
elearnSCI. (n.d.). Learn about SCI nursing. Web.
Schreyer, R. (2016). Spinal cord syndrome [Video]. YouTube. Web.
Siebert Science. (2015). Spinal cord injury physchology [Video]. Youtube. Web.