Running head: BRONCHURE
Bronchure
Name
Institution
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Anatomy of the neuron
A neuron consists of a cell body, dendrite and an axon. The dendrites arise from the cell
body as thin structures branching many times to give the rise to the complex “dendrite tree”. The
axon is an extension that arise from the cell body at the axon hillock. The terminal buttons are
endings that terminate the axon branches (Ferrari et al., 2014).
Neural impulse
The central nervous system functions in a three step process which involves sensory
input, motor input and neural processing. The stage where the neurons of a sensory organ are
electrically excited is referred to as the sensory input. The brain processes information and then
neural impulses are send from the brain to the spinal cord. From the spinal cord the impulses are
then conducted to the muscles and glands which is termed as the motor output. A neuron can
affect other neurons through the release of neurotransmitters which bind to chemical receptors.
To release a neurotransmitter from one neuro to another, a presynaptic neuron must attain an
action potential (Simidjievski et al., 20140.
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Stages of neural conduction
The neurons normally transmit signals in the form of electric neural impulses from the
base of the axon to the terminal buttons. The neurons have a resting membrane potential of about
-70 to -90Mv. If this resting potential is reduced to a threshold value of -50mV, a chain of events
start at the base of the axon. Charged sodium ions (positively charged) rapidly enter the cell
causing the local charge at the base of the axon to change (depolarization). Positively charged
potassium ions rush out of the axon bringing the charge back to negative (repolarization). These
ions are then pumped back to their stating positions (refractory phase). The sodium gated
channels cannot be opened again until the membrane is repolarized to its resting state (resting
potential). The sodium-potassium pump ensures the return of the sodium ions to the outside of
the cell and potassium ions to the inside of the cell. The action potential is dependent on the
current that is produced hence referred to as all-or-none signals (Dumont et al., 2014).
Functions of Neurotransmitters
Neurotransmitters allow the transmission of signals from one neuron to another across
synapses. They are mainly found in axon endings of neurons, especially motor neurons. They
stimulate the muscle fibers. Neurotransmitters have a variety of structures and functions. The
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two main neurotransmitters are norepinephrine and acetylcholine. Other common
neurotransmitters include dopamine, epinephrine, serotonin, glutamate and GABA.
Acetylcholine affects memory, movement and sleep. Norepinephrine has been shown to affect
weakfullness, alertness and also eating. Epinephrine plays a vital role in glucose metabolism and
release of energy during exercise. Dopamine is involved in learning, attention, pleasure and
movement. GABA functions as a neural inhibitor in the central nervous system. Glutamate is
involved in areas of the brain responsible for emotion, thought and learning (Krizancic et al.,
2014).
Pain complicated with addictive disorder, particularly in patients on opiates present a
complex challenge to healthcare providers. They generate a lot of frustration and suffering to the
patient. Such pain must be taken seriously as it can impair quality of life of the patient (Dumont
et al., 2014).
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References
Dumont, Grégory, Henry, Jacques, & Tarniceriu, Carmen. (2014). A Density Model for a
Population of Theta Neurons. (BioMed Central Ltd.) BioMed Central Ltd.
In Ferrari, P. F., & In Rizzolatti, G. (January 01, 2014). Mirror neurons: Fundamental
discoveries, theoretical perspectives and clinical implications. Philosophical
Transactions of the Royal Society of London, 1644.)
Križančić, B. L. (January 01, 2014). Vid: sinaptično povezovanje med nevroni mrežnice in
obdelava signalov =: Vision: synaptic connections between retinal neurons and signal
processing. Medicinski Razgledi, 53, 101-114.
Simidjievski, N., Todorovski, L., & Džeroski, S. (2014). Constructing a library of domain
knowledge for process - based modeling of neurons using the Hodgkin-Huxley formalism.
(Human brain project.)