Nodes of Ranvier
The single long axon is surrounded by myelin sheath, which is a fatty substance produced by Schwann cells in the peripheral nervous system. The gaps along the axon are called nodes of Ranvier, where the axon is exposed and allows for faster nerve impulse transmission known as saltatory conduction.
No, internodes are not the gaps in myelin along the axon; they refer to the segments of the axon that are covered by myelin sheaths. The gaps between these myelinated segments are called nodes of Ranvier. These nodes play a crucial role in the conduction of nerve impulses, allowing for faster transmission through a process called saltatory conduction.
As you may know nerve cells (Neurones) have a layer of fatty Insulation surrounding them called a Myelin Sheath. These a long flat structures projecting from various cells wrap around the Axon. This forms a Discontinuous sheeth meaning it has section that are covered but with gaps in the middle. Ions cannot pass through the membrane of the neurone at parts that are sheethed but only at the gaps. The gaps are what are known as Node Of Ranvier, called node because "electrical" conduction takes place here.
Myelinated neurons are those with an axon covered by a sheath but with gaps exposed, kind of like marshmallows on a stick. The marshmallows are the sheaths, and the stick is the axon. The gaps between the sheaths are called the nodes of Ranvier. When an action potential arrives, it jumps over the areas covered with the sheath, landing and springing off the nodes of Ranvier. This is called saltatory conduction. It allows the electric signal (action potential) to travel more quickly along the axon. When an axon is not covered, the whole axon is exposed, meaning that the action potential has nothing to jump over. This results in a slower signal because it needs to travel the full length of the axon without skipping over any segments.
In myelinated axons, the voltage gated sodium ions are located along the nodes of Ranvier, the exposed places between the myelin segments. The gates here, however, are not particularly more concentrated than on other un-myelinated axons. TRUE
Between myelin segments surrounding the axon The axon of a neuron is the single long fibre which caries impulses away from the cell body. It is surrounded by a fatty layer, the myelin sheath, produced by Schwann cells arranged along the length of the axon. The gaps between the myelin sheath cells are called nodes of Ranvier. See http://en.wikipedia.org/wiki/Axon for more information and a diagram. easy answer between the myelin segments surrounding the axon b. between myelin segments surrounding the axon
nodes (:I do not disagree with that answer, but I just want to point out that the nodes have a special name. They are called Nodes of Ranvier, named after the man that discovered them (so Ranvier is capitalized). C:
Node of Ranvier
The axon is not insulated with myelin at the nodes of Ranvier. These are small gaps along the axon where the myelin sheath is absent and allow for faster propagation of action potentials by saltatory conduction.
The gaps in the myelin sheath are called Nodes of Ranvier. These nodes are crucial for a process known as saltatory conduction, where nerve impulses jump from one node to the next, significantly increasing the speed of transmission along the axon. This jumping occurs because the myelin sheath insulates the axon, allowing the electrical signal to travel more efficiently. As a result, the presence of these nodes enhances the overall speed and efficiency of neural communication.
In a myelinated neuron, an impulse travels via a process called saltatory conduction. The myelin sheath, which insulates the axon, allows the action potential to jump between the nodes of Ranvier—gaps in the myelin. This jumping significantly increases the speed of impulse transmission compared to unmyelinated neurons, as it minimizes the depolarization of the membrane and reduces the time needed for the entire length of the axon to depolarize. Consequently, myelinated neurons conduct impulses more efficiently and rapidly.
Axons are coated in a fatty substance called myelin - a "myelin sheath". It insulates and protects the cell body of neurones. The myelin doesn't completely coat the axon: there are small gaps between the myelin, called the nodes of Ranvier.