Nerves Are Bundles of Fibers That Transmit Signals Across the Body
- These fibers are the long extensions of neurons, the cells responsible for communication in the nervous system.
Definition
Nerve
A bundle of axons that transmits electrical signals between the CNS and the body.
Remember: Epineurium is the outermost layer, like the epidermis of your skin.
Myelinated vs. Unmyelinated Nerve Fibers
- Myelinated Fibers
- Wrapped in a myelin sheath, which acts as an insulator.
- Enables rapid signal transmission through saltatory conduction.
- Unmyelinated Fibers
- Lack a myelin sheath.
- Transmit signals more slowly.
Think of myelinated fibers as high-speed trains that skip stations, while unmyelinated fibers are local trains stopping at every station.
Key components of a nerve (from inner to outer layers)
- Axons (nerve fibers) – Conduct electrical impulses.
- Myelin sheath – Insulates some axons to speed up signal transmission.
- Endoneurium – Surrounds individual axons.
- Perineurium – Groups multiple axons into fascicles.
- Epineurium – The outermost layer, enclosing the entire nerve.
How might the study of nerve structure and function influence advancements in medical technology, such as prosthetics or neural interfaces?
Common Mistake- Don’t confuse nerves with neurons.
- Nerves are bundles of fibers, while neurons are individual cells.
- How do sensory and motor fibers work together in a mixed nerve?
- What is the difference between myelinated and unmyelinated fibers?
