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Image # 16 – Sodium potassium gate – depolarization action potential to produce electrical current – shows sodium entering the cell


Image # 17 – The energy transformation cycle

Energy Production Automobile vs the Human Body
• CategoriesAutomobileHuman Body
• Energy SourceGasolineGlucose, Proteins and Fats
• Fuel Intake SystemGasoline TankGI Track or Intravenous
• Oxygen for CombustionCarburetor/air filterRespiratory System
• Combustion SystemEngineCell Body – Mitochondria
• Energy ProductionElectricity/CurrentElectricity/Current
• Energy StorageBatteryAdenosine Triphosphate (ATP)
• Energy UtilizationTurn on ignitionTurn on Ion Pump System (cell membrane)
• ResultStarts AutomobileOpen Ion Gates (sodium, calcium, chloride, etc.)
• First MessageElectrical/CurrentElectrical/current
• Energy TransformationConvert to MechanicalElectrical to Chemical to Mechanical
• Mechanical end pointMovement of GearsMovement of a body or perform body function

This electrical gradient is then propagated down along the second part of the nerve cell called the axon.

I know this is getting challenging, but stay with me…

The Axon

The second major part of the nerve cell is the axon, which extends from the cell body (like electrical wires) and end in branches called nerve terminals. The axon has 360-degree insulation along its length like in electrical wires. The insulation system around nerve cells is called the myelin sheath. In the brain, the myelin sheath is created by a supporting cell called the oligodendrocyte. The myelin sheath is divided into small regions, and the junction between each region is known as the node of Ranvier.

In the spinal cord, the myelin sheath is produced by a cell called the Schwann cell, and each Schwann cell serves one region of individual axon insulation. Electrical currents created by the process of depolarization jump or travel the axon from one node of Ranvier to another. This form of jumping electrical currents (messenger) along the axon is called “salutatory conduction” and allows nerves to conduct currents at a faster rate than if the current had flown directly through the axon. Current flowing directly through the axon will experience more resistance, causing the current or electrical messages to decay and slow down. In conditions such as multiple sclerosis, the myelin sheath is damaged, and this causes a slowing of electrical conduction.


Image # 18 – Saltatory Conduction with node of Ranvier and Schwann cell

So, let us summarize this first messenger system that the cell utilizes to send messages.

It all starts in the cell body with the utilization of an energy source.

Table # 12 – Energy and the Messenger System

Cell BodyCreation and propagation of the first messengerDescription
Chemical energy sourceGlucose, protein, fatsFrom nutritional intake (GI and IV) to bloodstream
Oxygen sourceRespiratory systemLungs and bloodstream
Combustion systemMitochondriaEnergy source and oxygen combust to create energy.
Chemical energy storageAdenosine triphosphate (ATP)Supply of energy to the cell membrane and pump system
Pump systemOpen ion gates – sodium-potassium, calcium, chloride, or other systemsUtilize ATP as a chemical energy source
Create electrical energyIons move in and out of cell membrane, causing an electrical gradient in the internal and external environment of the Cell.Depolarization of the membrane begins – this is the propagation of electrical impulse or energy from the cell body to the axon.
Axon – second part of the cellPropagation of electrical impulse – the myelin sheath with its node of Ranvier allows for rapid saltatory conduction.To the axon terminal
Electrical current createdThe gradient between two regions of the cell membraneCauses the current to start moving from one part of the cell along the Axon
Saltatory electrical currentFlow of current along the axon, jumping from one node of Ranvier to the nextElectrical messenger flowing outside the cell down the axon to the axon terminal-- Axon terminal – third part of the cell

A Second Messenger System of the Cell

Another messenger system that exists in the nerve cell is the neurochemical messenger system, which gets its order from the core of the cell (the nucleus), also located in the cell body. This system starts with an instruction system referred to as DNA. DNA contains all the instructions for the productions of many neurochemicals in the nervous system. Like electric currents, neurochemicals are classified as messengers. Neurotransmitters are created in the cell body based on instructions from DNA. These chemical messengers or neurochemicals are also called neurotransmitter substances, as they truly transmit messages.

They are produced in a precursor state in the cell body. Precursor neurotransmitters are neurotransmitters in their non-active state. By the time they get out of the cell body and are transmitted to the axon terminals (endpoint) through the axon, they transform from the precursor neurotransmitters to full-fledged neurotransmitters.

Concussion

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