Biology 50B Lab Manual - Microscopic Anatomy and Structure of a Nerve

Vocabulary flashcards covering the microscopic anatomy, structure, classification, and cranial nerve designations from Biology 50B Lab Manual pages 1-3.

Nerve

A bundle of myelinated nerve fibers (processes) wrapped in layers of connective tissue, or a bundle of axons in the peripheral nervous system.

Axon

Long, thin part of neuron that carries signal away from cell body and sends impulses to other neurons, muscles, or glands.

Myelin

Fatty insulation wrapped around axons that makes nerve signals travel faster.

Fascicle

A bundle of nerve fibers wrapped together by connective tissue.

Endoneurium

Thin connective tissue that wraps each individual nerve fiber (axon).

Perineurium

The connective tissue that surrounds each fascicle of nerve fibers.

Epineurium

The outermost connective tissue layer that surrounds the entire nerve.

Node of Ranvier

Small gap between myelin segments where the action potential is boosted.

Vasa nervorum

Tiny blood vessels that supply nutrients and oxygen to nerves.

Neurilemma

The outermost layer of a Schwann cell that helps repair damaged axons in the PNS.

Schwann cell nucleus

The nucleus of the Schwann cell that sits on the outside of the myelin sheath.

Functional types of nerves

Sensory, motor, and mixed nerves.

Origin of Nerves

All nerves arise from Central Nervous System (CNS) structures, specifically the brain and spinal cord.

Cranial nerves

Nerves that arise directly from the brain.

Spinal nerves

Nerves that arise from the spinal cord, formed by dorsal and ventral roots, and classified functionally as mixed nerves.

Spinal nerve soma locations

The structures where soma associated with axons of spinal nerves are found, specifically the dorsal root ganglion and the grey matter of the spinal cord.

Intervertebral foramina

Openings through which spinal nerves exit the vertebral column.

Cranial Nerve I

Olfactory nerve

Cranial Nerve II

Optic nerve

Cranial Nerve III

Oculomotor nerve

Cranial Nerve IV

Trochlear nerve

Cranial Nerve V

Trigeminal nerve

Cranial Nerve VI

Abducens nerve

Cranial Nerve VII

Facial nerves

Cranial Nerve VIII

Vestibulocochlear nerve

Cranial Nerve IX

Glossopharyngeal nerve

Cranial Nerve X

Vagus nerve

Cranial Nerve XI

Accessory nerve

Cranial Nerve XII

Hypoglossal nerve