chapter 12 smartbook

What is the approximate ratio of glial cells to neurons?

10:1

List the fundamental physiological properties of neurons.

Excitability, conductivity, secretion

Which correctly describe axonal transport?

It involves transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma). It is bidirectional (retrograde and anterograde transport)

Which are properties of action potentials?

Nondecremental (signal maintains amplitude) All or none Self-propagating

Which are usually found inside the cell body (or soma) of a mature neuron?

Nucleus Rough endoplasmic reticulum Mitochondria

Which factors influence the speed of nerve signal conduction?

Presence of myelin Diameter of axon

What is the primary function of the myelin sheath?

To increase the speed of signal conduction in the axon

Which best describes an electrical potential?

a form of potential energy that can produce current

Which term refers to the passage of proteins, organelles and other materials along an axon?

axonal transport

Which term refers to a synapse that releases acetylcholine from the presynaptic axon terminal?

cholinergic

Which fundamental physiological property of neurons allows them to send signals quickly over long distances?

conductivity

In electrical synapses, electrical signals move quickly from cell to cell through which of the following?

gap junctions

______ cells protect the neurons and help them function.

glial

Which are characteristics of local potentials?

graded decremental

The myelin sheath is composed mostly of which of the following?

lipids

At a synapse, the neuron that responds to the neurotransmitter is the ______ neuron

postsynaptic

Which ion has the greatest influence on the resting membrane potential of most neurons?

potassium

An electrical potential is a form of what type of energy?

potential energy

At a synapse, the neuron that releases neurotransmitter is the ______ neuron.

presynaptic

The refractory period in which it is possible to trigger a new action potential, but only with an unusually strong stimulus is the ______ refractory period.

relative

Which neuroglial cell is found in the peripheral nervous system?

satellite cell

Which type of glial cell aids in regeneration of damaged peripheral nerve fibers by forming a regeneration tube to help reestablish the former connection?

schwaan cells

The release of a neurotransmitter is an example of which physiological property exhibited by a neuron?

secretion

afferent neurons are _______ neurons

sensory

Which are names for the cell body of a neuron?

soma neurosoma

Which term refers to the microscopic physical gap between the presynaptic and postsynaptic neurons at a chemical synapse?

synaptic cleft