Peripheral nerves

This tutorial by Nicole from Kenhub covers the histology of peripheral nerves, explaining their structure and function. It includes a detailed examination of nerve fibers, myelin, and Schwann cells through longitudinal and cross-sectional views. The video also discusses the blood supply and innervation of nerves, focusing on the vasa nervorum and nervi nervorum. A clinical scenario on peripheral neuropathy is presented, highlighting its symptoms and diagnosis. The tutorial concludes with a recap of the main points.

What is the primary function of peripheral nerves?

• To process information within the brain

• To transmit information between the CNS and the body

• To store memories

• To regulate emotions

In a longitudinal section of a nerve, what does the myelin sheath do?

• Stores nutrients for the nerve

• Produces neurotransmitters

• Increases the speed of impulse conduction

• Protects the nerve from infections

What is the role of Schwann cells in the peripheral nervous system?

• They form the myelin sheath around axons

• They produce neurotransmitters

• They connect neurons to blood vessels

• They store calcium ions

How can you identify myelinated fibers in a cross-section of a nerve?

• They appear as thick, densely packed fibers

• They have a deep purple stain and are surrounded by unstained myelin

• They are always larger than unmyelinated fibers

• They are located on the outermost layer of the nerve

What is the primary component of the epineurium?

• Elastin fibers

• Type III collagen

• Type II collagen

• Type I collagen

Which connective tissue layer surrounds individual nerve fibers?

• Endoneurium

• Epineurium

• Myelin sheath

• Perineurium

What is the function of the vasa nervorum?

• To connect nerves to muscles

• To insulate nerve fibers

• To supply blood to nerve fibers

• To transmit nerve impulses

What is peripheral neuropathy?

• A condition where the brain loses its ability to process information

• A disease affecting the central nervous system

• Damage to peripheral nerve fibers leading to decreased signal conduction

• An infection of the spinal cord

Which of the following is a symptom of peripheral neuropathy?

• Improved coordination

• Increased muscle tone

• Enhanced reflexes

• Numbness and tingling sensations

How is peripheral neuropathy typically diagnosed?

• Using an MRI scan

• By a combination of patient history and physical examination

• Through a blood test

• With a genetic test