Nervous System 7

The Schwann cell forms a myelin sheath around the ____.

axon

The part of the neuron that typically conducts nerve impulses away from the cell body is the ____.

axon

The term central nervous system refers to the ____.

brain and spinal cord

Which ion causes neurotransmitter vesicles to fuse with the axon's membrane during the conduction of a nerve impulse from one neuron to the next?

calcium

Ganglia are collections of ____.

cell bodies

The nervous system is structurally subdivided into two systems: ____ nervous system and ____ nervous system.

central; peripheral

What canal connects the third ventricle of the diencephalon to the fourth ventricle?

cerebral aqueduct

The major role of the interneuron (association neuron) is to ____.

connect motor and sensory neurons in their pathways

What connects the cerebral hemispheres

corpus callosum

The neuron processes that normally receive incoming stimuli are called ____.

dendrites

A stroke in the primary motor area has caused Don to lose control over his skeletal muscles on the right side of his body. What lobe of his brain was damaged?

frontal lobe

The two major functional properties of neurons are ____.

irritability and conductivity

Neurons with several processes branching off the cell body, such as motor neurons and interneurons (association neurons), are structurally classified as ____.

multipolar

Impulse conduction is fastest in neurons that are ____.

myelinated

Support cells in the central nervous system are collectively called ____.

neuroglia

The substance that is released at axonal endings to propagate a nervous impulse is called ____.

neurotransmitter

The gaps between Schwann cells found at regular intervals in peripheral system neurons are called ____.

nodes of ranvier

Which of these neuroglial cells forms the myelin sheath in the central nervous system?

oligodendrocytes

During the resting state, a neuron is ____.

polarized with more sodium ions outside the cell and more potassium ions inside the cell

Immediately after an action potential is propagated, which one of the following ions rapidly diffuses out of the cell into the tissue fluid ____.

potassium

Sensory receptors located in muscles and tendons are termed ____.

proprioceptors

Nerve impulse transmissions occurring along myelinated neurons are called ____.

saltatory conduction

An action potential is caused by an influx of these ions into the cell ____.

sodium

During repolarization, ____ ions are pumped out of the cell.

sodium

Fibers that carry information from the skin, joints, and skeletal muscles to the central nervous system are ____.

somatic sensory

The gap between two communicating neurons is termed ____.

synaptic cleft

What is the relay station for sensory impulses passing upward to the sensory cortex?

thalamus

Neurons either conduct action potentials along the length of their axons, or they remain at rest. This statement best describes ____.

the all-or-none response

Bundles of nerve fibers (neuron processes) running through the CNS are called ____, whereas in the PNS they are called ____.

tracts; nerves

Ependymal cells beat their cilia to help circulate cerebrospinal fluid (CSF). T/F

true

Gray matter contains collections of unmyelinated fibers and cell bodies in the central nervous system. T/F

true

Sally has a brain injury; she knows what she wants to say but can't vocalize the words. The part of her brain that deals with the ability to speak is the ____.

Broca's area

____ connect sensory and motor neurons in neural pathways and their cell bodies are typically located in the central nervous system.

Interneurons (association neurons)

____ disease results from a degeneration of the dopamine-releasing neurons of the substantia nigra.

Parkinson's

____ cells form the myelin sheaths around nerve fibers in the PNS.

Schwann