LAB 3 Chapter 9 Myelination and Nervous Tissue

This set of flashcards is designed to help students review key concepts related to myelination and nervous tissue from their BIO 121 Anatomy and Physiology II lecture.

Myelination in the PNS is performed by __, which wrap around axons multiple times.

Schwann cells

The layer of membrane formed by myelination consists largely of __.

lipid

Myelination can be thought of as analogous to __ in electrical wires.

insulation

If a wire is not insulated, electrical charge could spread to materials around it, making it less __.

efficient

The action potential is more efficiently conducted along an axon when it is __.

insulated

Not all axons in the PNS are __.

myelinated

Unmyelinated axons are encased by __, but lack a wrapped coating of myelin.

Schwann cell cytoplasm

Gaps in the myelin sheath between adjacent Schwann cells are called __.

nodes of Ranvier

Electrical activity associated with nerve impulse transmission occurs primarily at the __ in myelinated fibers.

nodes of Ranvier

Nerve fibers in the PNS are myelinated by neuroglial cells known as __.

Schwann cells

In the CNS, myelination is performed by __.

oligodendrocytes

The __ is the soma of the oligodendrocyte responsible for myelination in the CNS.

Node of Ranvier

Synapses can occur in three configurations: axoaxonic, axodendritic, and __.

axosomatic

In the CNS, the areas containing myelinated axons are known as __ matter.

white

Areas that consist primarily of neuronal cell bodies in the CNS are referred to as __ matter.

gray

The dorsal root ganglia contain the cell bodies of __ neurons.

sensory

Satellite cells are neuroglial cells that surround sensory neuron cell bodies to maintain their __.

environment

A series of Schwann cells lined up along a myelinated axon provides __.

insulation

Myelination helps prevent electrical charge from leaking to surrounding __.

materials

The efficiency of action potential propagation in myelinated fibers is due to __.

saltatory conduction

The function of satellite cells is to __ the environment around neurons in the PNS.

maintain

The electrical activity occurs specifically at the __ in unmyelinated nerve fibers.

entire length of the fiber

A teasing procedure for mammals reveals the gaps in the myelin sheath known as __.

nodes of Ranvier

Myelinated fibers conduct impulses __ compared to unmyelinated fibers.

faster

The cytoplasm of Schwann cells encasing unmyelinated axons lacks __.

myelin

The insulating layer formed by Schwann cells is called the __ sheath.

myelin

Myelination of axons is crucial for rapid __ transmission in the nervous system.

impulse

The characteristic nodes between myelinated sections of axons enhance __ conduction.

nerve

The cell body of a sensory neuron contains the __ of the neuron.

nucleus

Schwann cells play a key role in the maintenance and repair of __ in the peripheral nervous system.

nerve fibers

In the spinal cord, __ matter is located centrally and is surrounded by white matter.

gray

Differences in matter are observed in various sections of the brain and spinal cord.

gray and white

Electrical impulses only effectively propagate at the __ on myelinated neurons.

nodes of Ranvier