Chapter 12 A&P 207 Smart Book

Neurotransmitters are stored in ______.

synaptic vesicles

To ______ is the basic function of a neuron.

transmit nerve impulses

Some antidepressant drugs are SSRIs. SSRI stands for

Selective Serotonin Reuptake Inhibitors

What is the primary tissue of the nervous system?

nervous tissue

The thin outer layer of the neurolemmocyte is called the ______.

neurilemma

There are ______ different types of glial cells in the CNS.

4

The leak of potassium ions tends to drive the membrane potential to -90 millivolts, and yet the normal resting membrane potential (RMP) of a neuron is around -70 millivolts. What is the reason for this difference?

A small leak of sodium ions makes the RMP more positive

The brain and spinal cord are part of the ______.

Central Nervous System (CNS)

True or false: Graded potentials vary in size depending on the stimulus.

True

True or false: There are more potassium leak channels in a neuron membrane than sodium leak channels.

True

Action potentials are always propagated along an axon at the same ______ but ______ can vary depending on the strength of the stimulus.

amplitude; frequency

The perivascular feet of the ______ help create a blood-brain barrier.

astrocyte

______ are star shaped.

astrocytes

The myelin sheath covers ______.

axon

A nerve is a bundle of parallel

axons or fibers

Most synapses in the human body are ______ synapses.

chemical

A difference in the number of charged particles between two sides of the membrane forms a(n) ______.

electrical gradient

A motor neuron is a ______ classification of a neuron.

functional

Negatively charged proteins and other large organic molecules are found in ______.

greater amounts inside a neuron

functional classes of neurons

interneurons sensory neurons motor neurons

The myelin sheath is made of a high percentage of ______.

lipids

The resting membrane potential is measured in ______.

millivolts

Interneurons are ______ neurons.

multipolar

A cablelike bundle of axons in the peripheral nervous system is called a

nerve

Nervous tissue is composed of

neurons and glial cells

Chemicals that are released from synaptic knobs and bind to receptors on postsynaptic membranes are called

neurotransmitters

______ are released from neurons in response to conductive activity.

neurotransmitters

When sodium ions flow into a cell through a leak channel they make the membrane potential more

positive

Voltage represents ______ energy.

potential

A ______ transmits an impulse through its axon toward the synapse.

presynaptic neuron

The functions of astrocytes are to ______.

regulate the composition of interstitial fluid, help form the blood-brain barrier, and assist neuronal development.

The relative difference in charge across the plasma membrane of a resting neuron is known as the

resting membrane potential

The function of a neuron is dependent on ______.

resting membrane potentials changing

The removal of neurotransmitters from the synaptic cleft by transport into the synaptic knob is known as ______.

reuptake

characteristics of neurons

secretion conductivity extreme longevity excitability amitotic

In retrograde transport, substances are moved ______ the cell body.

toward

Vesicles involved in retrograde transport are moving ______ the cell body.

toward

______ are released from synaptic knobs into the synaptic cleft.

Neurotransmitters

Cytoplasm within an axon is called ______.

axoplasm

The synapse is located ______ the presynaptic neuron and postsynaptic neuron

between

A synapse is a junction ______.

between a neuron and another cell

two structural examples of sensory neurons

bipolar unipolar

The ependymal cells help produce ______.

cerebrospinal fluid

Another way for the neurotransmitter to be removed from the synaptic cleft is by ______ where there is uptake by surrounding glial cells.

diffusion

The choroid plexus is made from capillaries and ______.

ependymal cells

cells that are part of the central nervous system

ependymal cells microglia oligodendrocyte astrocyte

______ is responsiveness to a stimuli.

excitability

Neurons are ______.

excitable cells that transmit electrical signals

It usually takes ______ neurolemmocytes to myelinate one axon.

many