Introduction
A stroke is a medical condition which is characterized by rapid loss of brain function which is caused by interruption in the blood supply to the various parts of the brain. It can be due to a blockage and it’s known as thrombosis or lack of blood flow known as ischemia or a leakage of blood that is hemorrhage (Feigin, 2005). It results in the person’s inability to move certain parts of the body.
The brain is designed in such a way that the right hemisphere always controls the left side of the body while the left hemisphere controls the right side of the body. This explains why Joseph’s left part of the body got paralyzed even if not entirely. This also depends on the part of the right side of the brain that has restricted blood flow.
Joseph's left face and hand has been paralyzed, but not the rest of his arm or his leg because of the restricted blood flow to a portion of his right precentral gyrus which is known to control moments of the muscles in the left face and hand and it is the right side that controls the left side.
What is preventing Joseph from moving his left hand is because of lack of communication between neurons that is between the central nervous system and motor neurons.
Motor neurons are neurons that transmit signals from the brain to the effector cells which include muscle cells. Motor neurons form synapses with effector cells. When an action potential reaches a synapse pore which are present in the cell membrane opens which in turn allows positively charged calcium ions into the pre synaptic terminal. This causes neural transmitters which are chemical in nature to be released in a gap between the two cells and this is known as the synaptic cleft. The neural transmitter is able to diffuse across the synaptic cleft and proceeds to interact with proteins called receptors which are usually embedded in the post synaptic membrane (Sherwood, 2001). The receptors serve as ion channels which allow charged atoms to pass through pores within their structure and this is propagated along the dendrite towards the soma.
The destruction of a neuron that communicates with the motor neuron prevents Joseph from moving his hand by disruption of the transmission process. The motor neuron is not able to receive signal from the central nervous system neuron and thus it is not able to propagate the signal to the effector muscle that is the hand (Garrett, 2011).
In an adult human being the brain takes longer time to redevelop damaged neurons because the neurons are fully developed and this is because why Joseph’s brain cannot simply replace the damaged neurons immediately (Altman, 1963). Compensation might allow Joseph to regain some of the lost movements. This occurs through the neurons that were not damaged and serve extra role of transmitting signals for the damaged neurons but this takes time and it is achievable through therapy. Experimental treatment that might improve Joseph’s movement of his left hand is by slowly exercising the hand through aided extension and constriction of the hand muscles. The exercises can be done from time to time and it impacts on his nervous system by using the existing motor neurons to transmit signals to the hand. His nervous system will slowly undergo rearrangement so that it can utilize the existing neurons to control the left hand.
Conclusion
It is possible for the nervous system to recover from damage through natural processes for example compensation and reorganization. These processes enable the recovery of impaired functions for example of limbs and hands or any other impaired part. There are also experimental treatments that facilitate the growth of new neurons in a mature nervous system. Through proper treatment and therapy patients who suffer stroke do not suffer permanent disability especially because of these processes. This has greatly aided patients who have suffered strokes to be able to regain function of the affected parts through therapy.
References
Altman, J. (1963). Autoradiographic investigation of cell proliferation in the brains of rats and cats. Chicago: The Anatomical record.
Feigin VL. (2005). Stroke epidemiology in the developing world. USA: Lancet.
Garrett, B. (2011). Brain and Behavior: An Introduction to Biological Psychology (3rd ed.). Los Angeles: Sage.
Sherwood, L. (2001). Human Physiology: From Cells to Systems (4th ed.). Pacific Grove, CA: Brooks-Cole.
