Category: Uncategorized
Neuron Communication Summary
Neuron Structure
Motor Neuron
Interneuron
Sensory Neuron
The cell body, dendrites, and axon are the basic components of a neuron.
Cell body: Contains genetic information, maintains the structure of the neuron, and provides energy for the neuron to function effiently
Dendrites: Receives signals from other neuron
Axon: Passes messages away from the cell body to other neurons
Other components of a neuron:
Nucleus: Provides the energy to the neuron
Myelin sheath: Covers the axon of some neurons and helps speed neural impulses
Nucleus of Schwann cell: Surrounds neurons, keeping them alive and sometimes covering them with a myelin sheath
Axon terminal: Forms connections with other cells
Node of Ranvier: Allow the axon to produce a fast electrical impulse
Synaptic knobs: Connections that develop between two different neurons (dendrites and terminals)
Neuron Function
- How an action potential moves along the neuron fibre
The neuron is a nerve cell that transmits all over the body also known as information messengers and an action potential occurs when it transmits information like energy through an axon, away from the cell body. Action potential is caused by movement of the positive ions into and out of the axon, the amount of negatively charged ions inside an axon is equal to the amount of positively charged ions outside the axon. Since the charged ions are balanced, the axon is polarized meaning it’s at its resting state. The action potential then flows down the axon and the channels in the neuron cell’s cell membrane open when the signal reaches the axon, allowing Na+ ions to enter; this is caused by depolarization due to the imbalance ions in the axon membrane. Repolarization comes last, during which channels open to let sodium ions leave the axon. The following segment of the axon depolarizes as the charge returns to normal. The action potential continues to move on to the following segment until it reaches the axon terminal and a synapse.
Synapse Structure
Synapse Function:
- How a signal is sent from axon of sending neuron to dendrite of receiving neuron
- How the receiving neuron “determines” whether or not to send its own action potential
When a signal reaches the end of an axon, it forms a synapse. The synapse occurs at the axon terminal where the action potential from synaptic vesicles releases neurotransmitters into the synaptic gap. The neurotransmitters will diffuse and bind to the receiving neuron’s receptors. The receiving neuron determines whether or not to send its own action potential depending on whether the neurotransmitter is received as excitatory or inhibitory. If a neurotransmitter is excitatory, the message will be transmitted and an action potential will be produced by the receiving neuron. If inhibitory is determined the chemical message will be prevented for further transmission.