Fill in the blanks: The myelinated segment of an axon that is covered by a glial cell is called a/an_______ ; the gaps between glial cells where _____the axolemma is exposed are called          .

Verified step by step guidance

1. Identify the type of glial cell that forms the myelin sheath in the peripheral nervous system, which is the Schwann cell.
2. Recognize that the myelinated segment of an axon covered by a Schwann cell is called an internode.
3. Understand that the gaps between these myelinated segments, where the axolemma is exposed, are known as nodes of Ranvier.
4. Recall that the myelin sheath is crucial for the rapid conduction of nerve impulses along the axon.
5. Consider how the nodes of Ranvier facilitate saltatory conduction, allowing the action potential to jump from node to node, increasing the speed of transmission.

Key Concepts

Myelination

Myelination refers to the process by which glial cells, specifically oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system, wrap around the axon of a neuron. This wrapping creates a myelin sheath that insulates the axon, allowing for faster transmission of electrical signals through saltatory conduction.

Nodes of Ranvier

Nodes of Ranvier are the small gaps that occur between adjacent segments of myelin along a myelinated axon. These nodes expose the axolemma, or the neuronal membrane, allowing for the regeneration of action potentials. This arrangement enhances the speed and efficiency of nerve impulse conduction.

Axolemma

The axolemma is the specialized membrane that surrounds the axon of a neuron. It plays a crucial role in maintaining the electrical properties of the neuron and is involved in the propagation of action potentials. The axolemma is particularly important at the Nodes of Ranvier, where it is exposed and facilitates rapid signal transmission.