BIO 225 ch13 part 2 notes

These flashcards cover key concepts related to the structure and function of the peripheral nervous system, including nerve classifications, regeneration processes, and specific nerve functions.

What are the two types of nerves based on their direction of signal transmission?

Afferent nerves carry information towards the central nervous system, while efferent nerves carry information away from the central nervous system.

What are the two components of neurons classified by?

They are classified by cell bodies and axons.

What do we call bundles of axons in the central nervous system?

Tracts.

What are bundles of axons called in the peripheral nervous system?

Nerves.

How many pairs of cranial nerves do humans have?

12 pairs.

How many pairs of spinal nerves does the human body have?

31 pairs.

What tissue surrounds each individual axon in the peripheral nervous system?

Endoneurium.

What surrounds a bundle of nerve fascicles in the peripheral nervous system?

Epineurium.

What type of nerve primarily carries both sensory and motor information?

Mixed nerves.

What are the two types of ganglia relevant to the spinal cord?

Dorsal root ganglia and autonomic ganglia.

What is the first step in nerve fiber regeneration in the peripheral nervous system?

Mullerian degeneration.

What are the four steps involved in the regeneration of peripheral nerve fibers?

1. Mullerian degeneration, 2. Clean-up by macrophages, 3. Formation of regeneration tubes, 4. Remyelination.

What are the two main divisions of the lumbosacral plexus?

Lumbar plexus and sacral plexus.

What is the function of the phrenic nerve?

It innervates the diaphragm.

What is the largest nerve in the body?

The sciatic nerve.

According to Hilton's law, how are joints innervated?

The nerve that innervates a muscle also innervates the joint that the muscle crosses.

What is the term for the area of skin innervated by a specific spinal nerve?

Dermatome.

What structure protects the spinal cord within the vertebral column?

Vertebrae.

What are the three main branches of a spinal nerve?

Dorsal ramus, ventral ramus, and meningeal ramus.