The Nervous System

A voltage-gated sodium ion channel opens when there is a change in the voltage of the membrane and allows sodium ions to flow across its electrochemical gradient. These voltage-gated channels are made up of amino acids and they aid in generating and moving an action potential down a membrane or axon (Brooker, Robert, 106).

The nervous system is made up of basic units called neurons. The main role of the neurons is to receive, integrate and transmit information throughout the body. There are some neuroglial cells found in nervous system aswell which provide support to the neurons by giving protection and nourishment Neurons have nerve processes that looks like finger like projections extended from the nerve cell body. They also contain axons and dendrites which enable them to transmit signals throughout the body. Normally, axon carry signals away from the cell body and dendrites carry signals toward the cell body according to Regina Bailey (2013). Neurons have three different shapes: bipolar, unipolar and multipolar where bipolar has two neuronal processes coming out of the cell body, unipolar has only one neuronal process coming out of the cell body and multipolar has many neuronal processes coming out of the cell body.

As well as these there are also the axon of the cell which is covered in myelin sheaths which carried information away from the cell body and hands the action potentials, these are small short bursts of change in the electrical charge of the axon membrane through openings of ion channels, off to the following neurons dendrites through terminal buttons at the end of the axons. Whenever an action potential is passed through these terminal buttons it releases a chemicals that pass on the action potential on to the next neuron through the terminal button and dendrite connection. The chemicals that are

To send a message, a neuron will send a ripple of electrical energy down its axon. This ripple is called "action potential." The way it works is by changing the chemical makeup of the axon's negatively charged interior. Positively charged sodium ions move into the cell and negatively charged potassium ions move out, then the ions move to their original positions. This produces a wave of positively charged

Resting potentials require ions as they play a vital role in the process. In the surface membrane of a cell there are protein carriers. These actively pump Na+ ions out of the cytoplasm to the outside of the cell. At the

Once a presynaptic neuron is passive, an electrical current is spread along the length of the axon (Schiff, 2012). This is known as action potential (Pinel, 2011). Action potential happens once an abundant amount of depolarisation reaches the limit through the entry of sodium, by means of voltage gated sodium channels

B ) (1) neurotransmitter released (2) diffused across the synaptic cleft to a receptor protein (3) binding of the transmitter opens pores in the ion channels and negative ions move in.

Neurons communicate with one another along a synapse. Neurons are excitable cells that are activated via electrical or chemical signals. Nerve cells are an integral part of the nervous system. Neurons are made up of three distinct parts. The three integral parts of the neuron are the cell body, the dendrites, and the axon. The cell body is the middle portion of the neuron and contains the nucleus. It also contains the organelles such as the endoplasmic reticulum and the mitochondria.

The nervous system operates using an electrochemical process (see Video Clip: The Electrochemical Action of the Neuron). An electrical charge moves through the neuron itself and chemicals are used to transmit information between neurons. Within the neuron, when a signal is received by the dendrites, is it transmitted to the soma in the form of an electrical signal, and, if the signal is strong enough, it may then be passed on to the axon and then to the terminal buttons. If the signal reaches the terminal buttons, they are signaled to emit chemicals known as neurotransmitters, which communicate with other neurons across the spaces between the cells, known as synapses.

Neuronal messages are transmitted by electrical impulses called the Action Potential. This is actually a net positive inward ion flux that leads to depolarization or voltage change in the neuronal membrane. The ions involved include sodium, potassium, calcium and chloride. Normally brain tissues prevent hyper excitability by several inhibitory mechanisms involving negative ions like chloride ions.

Depolarization in membrane potential triggers an action potential because nearby axonal membranes will be depolarized to values near or above threshold voltage.

An influx of sodium ions is needed to effect an action potential. Action potentials are quantized: they either occur after sufficient sodium ion influx or they don't occur

Neurotransmitters are substances that are produced by neurons and are transferred chemically. Once an axon releases these substances the action potential moves through the axon into the terminal branch where they are kept and then released. This helps neurons pass impulses to other

As soon as the electrical signal reaches the end of the axon, mechanism of chemical alteration initiates. First, calcium ion spurt into the axon terminal, leading to the release of neurotransmitters “molecules released neurons which carries information to the adjacent cell”. Next, inside the axon terminal, neurotransmitter molecules are stored inside a membrane sac called vesicle. Finally, the neurotransmitter molecule is then discharged in synapse space to be delivered to post synaptic neuron.

Nerve cells generate electrical signals to transmit information. Neurons are not necessarily intrinsically great electrical conductors, however, they have evolved specialized mechanisms for propagating signals based on the flow of ions across their membranes.