The General Sensory Receptor
The general sensory receptor, which is found in the skin, is the receptor neuron in charge of relaying information from Amy's finger to her peripheral nervous system. It is in charge of identifying environmental changes that the body is exposed to, such as temperature, touch, and pain, according to Mai & Paxinos (2011).
Afferent Receptor Neuron
An afferent receptor neuron is one that transmits data to the central nervous system. The neurotransmitters in the central nervous system, specifically the brain, carry the information from the general sensory receptor cell (Mai & Paxinos, 2011).
Involuntary Response
The result of Amy having to move her finger away from the stove is because the brain sends back a response to the peripheral nervous system telling the hand muscles to pull away. This is an involuntary response that occurs within seconds to Amy touching the burner. For this kind of a response to occur, there have to be two different kinds of neurons involved, that is the afferent that sends signals to the brain and the afferent which carries the response back from the brain. Evolutionarily, the human body has this system in place to act as a survival mechanism against environments or circumstances that are registered as harmful. If we did not have this response, we would get hurt easily and worse, not be able to react appropriately when faced with danger. This potentially means that our mortality rate would be a lot higher than it is.
Early Onset Parkinson's Disease
Early Onset Parkinson’s disease is the term used for a diagnosis made to a person between the ages of 21-50 years. Usually, Parkinson’s is known to affect persons over the age of 50 years. The specific cell type affected by Parkinson’s disease is the nerve cells. The disease affects the cells by affecting and stopping the production of dopamine (Klein & Westenberger, 2012). It is a neurotransmitter that plays the important role in ensuring movement and relevant motor skills are achieved. With Parkinson's, the nerve cells are thus destroyed, meaning dopamine is not produced, thus the symptoms of the disease.
The Structure of a Synapse
To explain the structure of a synapse, Mai & Paxinos (2011) observe that cells have axons that are part of the cell's nucleus. At the very end of these axons are dendrites which house the synapses. The latter is usually responsible for relaying the signals they receive to respective other synapses that are attached to various nerve cells. Therefore, the process allows for the brain to be able to determine which part of the body the information is coming from, thus the appropriate response. Glen's neurologists would prescribe a dopamine agonist to combat the effects of the disease. They achieve this by acting as dopamine which the brain can interpret and use to carry out the needed motor skills.
Genetic Testing and Parkinson's Disease
From the genetic testing performed on Gen, I would recommend that the same be carried out on his children. Genetically, the disorder through the LRRK2 or SNCA gene can be inherited but in an autosomal dominant pattern (Klein & Westenberger, 2012). Since Glen is affected, chances are that his children would also be or be carriers of the disease.
Multiple Sclerosis
Multiple sclerosis, also known as MS, is a disease that disables the central nervous system by simply disrupting the manner in which it can be able to receive and give responses. This means that it is a disease of the central nervous system since it is the only one that is affected. The main cell structure that is affected by MS is myelin, a fatty layer of the neurons cells that usually carry electrical signals between the brain and the body (Scolding & Wilkins, 2012). MS destroys this cell by attacking and causing destruction in patches through a process known as demyelination. It is the latter that results in scarring of the myelin sheath, thus the presentation of symptoms.
Action Potential of Neurons in MS
In MS, the action potential of a neuron is affected by decreasing its speed. Scolding & Wilkins (2012) explain that myelin is responsible for increasing the action potential of a neuron. Therefore, when affected or removed, the same speed is gradually affected. As the origins of MS remain unclear, scientists hypothesize the cause to be immunologic. It is where the immune system tends to malfunction and result in attacking the central nervous system. What triggers the attack is also unknown.
References
Klein, C & Westenberger, A. (2012). “Genetics of Parkinson’s Disease.” Cold Spring Harbor Perspectives in Medicine 2(1). Retrieved from doi: 10.1101/cshperspect.a008888
Mai, J. & Paxinos, G. (2011). The Human Nervous System. Cambridge: Academic Press
Scolding, N. & Wilkins, A. (2012). Multiple Sclerosis. New York: OUP Oxford
