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Chapter 11: Nervous Tissue Review | BIOL - Anatomy & Physiology, Quizzes of Physiology

Class: BIOL - Anatomy & Physiology; Subject: Biology / Biological Sciences; University: Sinclair Community College; Term: Forever 1989;

Typology: Quizzes

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TERM 1
What does the acronym CNS stand
for?
DEFINITION 1
Central Nervous System
TERM 2
What does the acronym ANS stand
for?
DEFINITION 2
Autonomic Nervous System
TERM 3
What does the acronym PNS stand
for?
DEFINITION 3
Peripheral Nervous System
TERM 4
Which of the systems (CNS, ANS or PNS) are
voluntary?
DEFINITION 4
The central nervous system (CNS) a nd peripheral nervous system
(PNS) are under voluntary control.*T he book states that the
somatic nervous system (composed of somatic nerve fibers that
conduct impulses from the CNS to sk eletal muscles) is known as
the voluntary nervous system, beca use the system allows
conscious control of skeletal muscles . The book states that the
somatic nervous system is a part of th e motor (efferent) division of
the PNS.
TERM 5
What system (CNS, ANS or PNS) is
involuntary?
DEFINITION 5
The autonomic nervous system (ANS) is under involuntary
control.
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Download Chapter 11: Nervous Tissue Review | BIOL - Anatomy & Physiology and more Quizzes Physiology in PDF only on Docsity!

What does the acronym CNS stand

for?

Central Nervous System

TERM 2

What does the acronym ANS stand

for?

DEFINITION 2

Autonomic Nervous System

TERM 3

What does the acronym PNS stand

for?

DEFINITION 3

Peripheral Nervous System

TERM 4

Which of the systems (CNS, ANS or PNS) are

voluntary?

DEFINITION 4

The central nervous system (CNS) and peripheral nervous system

(PNS) are under voluntary control.*The book states that the

somatic nervous system (composed of somatic nerve fibers that

conduct impulses from the CNS to skeletal muscles) is known as

the voluntary nervous system, because the system allows

conscious control of skeletal muscles. The book states that the

somatic nervous system is a part of the motor (efferent) division of

the PNS.

TERM 5

What system (CNS, ANS or PNS) is

involuntary?

DEFINITION 5

The autonomic nervous system (ANS) is under involuntary

control.

Explain afferent neurons

The afferent (sensory) nerves move information towards the

spinal cord and brain; all afferent (sensory) nerves are

directed towards the spinal cord and brain.

TERM 7

Explain efferent neurons

DEFINITION 7

The efferent (motor) neurons move information towards

effector organs; efferent (motor) nerves are a way to effect

or work all of the different motor responses.

TERM 8

How do spinal nerves differ from cranial

nerves?

DEFINITION 8

The spinal nerves send information to and from the spinal

cord. The cranial nerves send information to and from the

brain (12 cranial nerves).

TERM 9

What are the two sub-divisions of the

autonomic nervous system (ANS)? Explain the

function of the two sub-divisions.

DEFINITION 9

The two sub-divisions of the autonomic nervous system

(ANS) are the sympathetic and parasympathetic divisions.

The sympathetic division stimulates, while the

parasympathetic division inhibits.*The roles of the two sub-

divisions can reverse for certain organs.

TERM 10

What role do glial cells provide?

DEFINITION 10

The glial cells function as support cells; supporting and

maintaining the health of a neuron through various activities

(confirming the neuron fires properly, helping to maintain a

consistent pH level and maintaining a proper amount of fluid

in the space between cells).

What is the function of satellite cells? How do

satellite cells differ from neurolemmocytes

(Schwann Cells)?

The satellite cells surround the neuronal cell body in ganglia;

ganglia are intersections for nerves (a traffic jam). The

function of a satellite cell is to regulate and stabilize the

environment around ganglion cell bodies. The satellite cells

only differ from neurolemmocytes (Schwann Cells) in terms

of location.

TERM 17

What are the two types of neuroglia present

in the autonomic nervous system (ANS)?

DEFINITION 17

The two types of neuroglia present in the autonomic nervous

system are satellite cells and neurolemmocytes (Schwann

Cells).

TERM 18

How many types of neuroglia are found in the

human body? How many types of neuroglia

are in the central nervous system (CNS) and

the autonomic nervous system (ANS)?

DEFINITION 18

The amounts of the various types of neuroglia present in the

human body are as follows:

6 types of neuroglia are present in the human body

4 types of neuroglia are found in the central nervous

system (CNS)

2 types of neuroglia are found in the autonomic nervous

system (ANS)

TERM 19

What are the four types of neuroglia present

in the central nervous system (CNS)?

DEFINITION 19

The four types of neuroglia present in the central nervous

system are:

Astrocytes

Microglia

Ependymal Cells

Oligodendrocytes (Few Processes)

TERM 20

What is the structural unit of the nervous

system?

DEFINITION 20

A Neuron

What does amitotic refer

to?

The term amitotic refers to the inability to divide; nerve cells

are amitotic (once a nerve cell dies, it is lost forever).

TERM 22

What is the longevity of a neuron?

DEFINITION 22

The longevity of a neuron is a lifetime, with the proper

nutrition.

TERM 23

Explain the cell body of a neuron

DEFINITION 23

The cell body of a neuron (also called the soma or perikaryon)

is the major bio-synthetic center of a neuron (the center of

metabolic activity in a neuron) (contains the usual organelles

needed to synthesize proteins); the cell body is typically 5-

140 micrometers long.

TERM 24

Are centrioles present in a

neuron?

DEFINITION 24

No, centrioles are not present in a neuron because centrioles

are necessary for division; nerve cells don't divide. The

centrioles are the only cell component absent in nerve cells;

all other organelles are present in neurons.

TERM 25

Explain the endoplasmic reticulum of a

neuron

DEFINITION 25

A neuron contains both rough and smooth endoplasmic

reticulum's; the rough endoplasmic reticulum of a neuron

contains Nissl Bodies (chromatophilic substances which are

the sites for protein synthesis). The reticulum's are a system

of tubes associated with the transportation of materials

within the cytoplasm.

What typical organelles are lacking in the

axon? Why is the axon lacking these specific

organelles?

The axon is lacking:

Nissl Bodies

Golgi Apparatus

The axon is lacking these specific organelles because the

axon lacks the ability for protein synthesis (the inability to

repair itself). The axon is dependent on the soma (cell body)

for repair.

TERM 32

Explain the Nodes of Ranvier, pertaining to a

myelinated neuron

DEFINITION 32

The Nodes of Ranvier are myelin sheath gaps that occur at

regular intervals along a myelinated axon (approximately 1

millimeter apart). The Nodes of Ranvier participate in the

exchange of ions necessary required to generate an action

potential. The neurolemma is exposed where there is no

myelination, located at the Nodes of Ranvier.

TERM 33

Explain the Golgi Apparatus of a neuron

(absent in the organelles of a axon)

DEFINITION 33

The Golgi Apparatus of a neuron is well developed and forms

an arc (or a complete circle) around the nucleus of a neuron.

The Golgi Apparatus plays a role in packaging peptides and

proteins into vesicles.

TERM 34

Explain the nucleus and nucleolus of a neuron

DEFINITION 34

The nucleus of a neuron contains the cell's history and all of the

basic information necessary to manufacture all of the proteins,

that are characteristic of the specific neuron; synthesizes RNA and

DNA for shipment to the cytoplasm.The nucleolus is an organelle

within the nucleus that is involved in ribosome synthesis and the

transfer of RNA to the cytosol.

TERM 35

Explain the cytosol of a neuron

DEFINITION 35

The cytosol of a neuron is watery, salty fluid with a

potassium-rich solution inside the cell containing enzymes

responsible for metabolism.

Explain the mitochondria of a neuron

The mitochondria of a neuron is responsible for the supply of

energy in the form of ATP (adenosine triphosphate); neurons

require an enormous amount of energy (the brain is one of

the most metabolically active tissues in the body). The

chemical energy stored in ATP is used to fuel most of the

biochemical reactions within the neuron

TERM 37

Explain the polyribosomes of a neuron

DEFINITION 37

The polyribosomes of a neuron are several free ribosomes

attached by a thread; the thread is a single strand of mRNA

(messenger RNA), which is a molecule involved in the

synthesis of proteins outside of the nucleus. The associated

polyribosomes work to make multiple copies of the same

protein.

TERM 38

Explain the neuronal membrane of a neuron

DEFINITION 38

The neuronal membrane of a neuron is made up of lipids and proteins (fats and

chains of amino acids); a bi-layer (or sandwich) of phospholipids arranged with

the polar (charged) regions facing outward and the non-polar (uncharged)

regions facing inward. The neuronal membrane serves as a barrier to enclose the

cytoplasm within the neuron and to exclude specific substances. The membrane

contains a mosaic of proteins responsible for:

Containing specific ions and small molecules within the cell and excluding

other ions and small molecules

Catalyzing enzymatic reactions

Accumulating nutrients and rejecting harmful substances

Establishing an electrical potential within the cell

Conduction of an impulse

Sensitivity to particular neurotransmitters and modulators

TERM 39

Explain the axon of a neuron

DEFINITION 39

The axon is the main conducting unit of a neuron; capable of conveying

electrical signals across a variety of distances (an axon can be either

short, long or absent=amacrine neurons) and affecting different targets

(major arm of the neuron extending from the body)*Axons are typically

very short, but can be long (ranging from a few centimeters to 3 or 4

feet). A shorter neuron has a smaller axon and axon hillock, while a

longer neuron has a larger axon and axon hillock.*Axons also typically

branch forming axon collaterals; terminal branches of axons form

telodendrions. Axons can be myelinated or unmyelinated.

TERM 40

Explain the axon hillock of a neuron

DEFINITION 40

The axon hillock of a neuron the point at which the axon is

joined to the cell; electrical firing known as an action

potential typically occurs (a nerve impulse is generated).*The

axon hillock is the site of origination for a nerve impulse

within a neuron.

What systems (CNS, PNS or ANS) contain

myelinated axons?

The central nervous system (CNS) and peripheral nervous

system (PNS) contain myelinated axons, because the need

for a faster stimulation and generated impulse is greater.

TERM 47

What are the three classes of neurons? How

many processes does each class contain?

Explain the three classes of neurons.

DEFINITION 47

The three classes of neurons are:

Multipolar Neurons: contains three or more processes; multipolar neurons are

the most numerous in the body (99%) and are mainly located in the central

nervous system (CNS)

Bipolar Neurons : contains two processes (an axon and a dendrite); typically

located in special sense organs (vision and olfactory)

Unipolar Neurons : contains a single, short process; unipolar neurons branch

into two peripheral branches (a proximal and a distal branch). The proximal

branch of a unipolar neuron conducts action potentials from the dendrite

(self-definition). The distal branch of a unipolar neuron is always associated

with sensory information and is found in the peripheral nervous system

(PNS).

TERM 48

Explain the difference between white matter

and grey matter

DEFINITION 48

The white matter of a neuron refers to dense collections of

myelinated fibers, typically located in regions of the brain

and spinal cord. The grey matter of a neuron contains mostly

unmyelinated fibers and neuronal cell bodies.

TERM 49

Explain a pseudomonopolar

neuron

DEFINITION 49

A pseudomonopolar neuron is a different type of unipolar

neuron that originates as a bipolar neuron, but the bipolar

section fuses and becomes a single/unipolar neuron.

TERM 50

Which class of neuron is the most numerous

in nature?

DEFINITION 50

Multipolar Neurons (99% of all neurons)

Which class of neuron is typically associated

with special senses?

Bipolar Neurons

TERM 52

Which type of neuron lie between a sensory

neuron and a motor neuron?

DEFINITION 52

Interneurons or Association Neurons

TERM 53

Where are interneurons or association

neurons located?

DEFINITION 53

The interneurons or association neurons lie between sensory

and motor neurons.

TERM 54

What does irritability of a neuron refer

to?

DEFINITION 54

The irritability of a neuron refers to the response to a

stimulus.

TERM 55

What is the definition of a potential

difference, in reference to a neuron?

DEFINITION 55

A potential difference in a neuron, refers to the difference in

charges (electrical potential) between two points (the

outside of a neuron is positive and the inside of a neuron is

negative).

What is the difference of a resting membrane

potential, in reference to a neuron?

The resting membrane potential of a neuron is the potential

difference of charges in a neuron (the neuron is positively charged

on the outside and negatively charged on the inside); the

membrane is said to be polarized and the resting potential only

exists across the membrane. The average resting membrane

potential of a neuron is -70mV. The two factors that generate the

resting membrane potential are the differences in ionic

composition of the intracellular and extracellular fluids; the

differences in the permeability of the plasma membrane to these

specific ions.

TERM 62

What is an action potential?

DEFINITION 62

An action potential is a change in membrane potential (a signal

type) that signals over long distances; a brief reversal of

membrane potential (depolarization follows the action potential;

followed by repolarization and typically a brief period of

hyperpolarization; lasting only a few milliseconds). An action

potential doesn't decay with distance like a graded potential. An

action potential is stronger than a graded potential and is the

primary way of communication for a neuron.

TERM 63

What is a graded potential?

DEFINITION 63

A graded potential is a short-lived, localized change in

membrane potential; weaker than an action potential and

only capable of signaling over short distances (local)

(decreases in magnitude with distance). A graded potential

can either be depolarization or hyperpolarization and are

triggered by a change in the neuron's environment.

TERM 64

What occurs if a neuron depolarizes? What

are the ions involved in depolarization?

DEFINITION 64

A neuron's depolarization is a reduction in membrane potential (a

decrease); the inside of the membrane becomes less negative,

than resting potential. A change in resting potential from -70mV to

-65mV is depolarization. Depolarization also includes events in

which the membrane potential reverses and moves above zero to

become positive. Depolarization increases the production of nerve

impulses. The ions involved in depolarization are sodium and

potassium.

TERM 65

Is the firing threshold the same for all neurons

of the body?

DEFINITION 65

No, the firing threshold is not the same for all neurons of the

body because all neurons (like muscles) have a different

point at which depolarization will occur; a sufficient stimulus

has to occur for a neuron's threshold to be met (the neuron

has to be moved from resting membrane potential).

What does repolarization of a neuron refer

to?

The repolarization of a neuron refers to a return to resting

membrane potential; a decrease in sodium permeability

occurs. The cause of repolarization is an abrupt decline of

sodium permeability and an increase in potassium

permeability. During repolarization, the internal negativity of

a neuron returns.

TERM 67

What is hyperpolarization of a neuron?

DEFINITION 67

The hyperpolarization of a neuron is an increase in membrane

potential; the inside of the membrane becoming more negative. A

change from -70mV to -75mV is hyperpolarization.

Hyperpolarization reduces the probability of nerve impulses.

Hyperpolarization of a nerve refers to the continuation of

potassium permeability outside of the neuron; caused by

excessive potassium efflux (leaving the cell) (the flowing of

positive ions outside of the neuron; causing the membrane

potential inside of the cell, to become more negative).

TERM 68

What does saltatory conduction refer to?

Which neuron uses saltatory conductions

(myelinated or unmyelinated)?

DEFINITION 68

A saltatory conduction is used by myelinated neurons and is

the jumping from each Node of Ranvier, to a subsequent

Node of Ranvier(each subsequent gap of the myelin sheath)

(a quicker traveling of the impulse)

TERM 69

Which method of conduction is faster,

saltatory or continuous conduction?

DEFINITION 69

Saltatory Conductions used by Myelinated Neurons

TERM 70

What does continuous conduction refer to?

Which neuron uses continuous conduction

(myelinated or unmyelinated)?

DEFINITION 70

A continuous conduction is used by unmyelinated neurons

and is the continuous conduction (continuous travel) of an

impulse, down the entire unmyelinated neuron.

What are the two different methods, in which

synaptic transmissions occur? Explain the two

varieties of synaptic transmissions.

The two different varieties of synaptic transmissions are:

Chemical Synapses: the most common type of synapse; allowing the release

and reception of chemical messengers known as neurotransmitters into the

synaptic cleft (a fluid-filled gap or space). A typical chemical synapse is

made up of an axon terminal (containing synaptic vesicles full of

neurotransmitters) and a neurotransmitter receptor region on the post-

synaptic neuron's membrane (typically located on the dendrite or soma).

Chemical synapses prevent a nerve impulse from being directly transmitted

from one neuron to another; instead depending on the release, diffusion and

receptor-binding of neurotransmitter molecules (unidirectional

communication).

Electrical Synapses: much less common than chemical synapses; consisting

of gap junctions and the connexons (the channel protein); connects the

cytoplasm of adjacent neurons, allowing ions and small molecules to flow

directly from one ion to the next (electrically coupled) (rapid transmissions of

either unidirectional or bidirectional movements) (synchronizing the activity

of all interconnected neurons). Electrical synapses are far more abundant in

embryonic nervous tissue; retina and hippocampus. TERM 77

What is a pre-synaptic neuron?

DEFINITION 77

A pre-synaptic neuron brings the impulse to the synapse

(pre-synaptic cleft); conducting impulses towards the

synapse.

TERM 78

What is a post-synaptic neuron?

DEFINITION 78

A post-synaptic neuron receives the impulse and may

undergo an action potential; transmitting the impulse away

from the synapse.*A post-synaptic neuron can be a pre-

synaptic neuron to a different neuron, with enough

stimulation.

TERM 79

What chemicals move across the synaptic

cleft (a fluid-filled space), to bind with

receptors on the post-synaptic neuron?

DEFINITION 79

Neurotransmitters

TERM 80

What happens to extra neurotransmitters in

the synaptic cleft?

DEFINITION 80

The enzyme cholinesterase (located within the synaptic cleft) will

degrade neurotransmitters once an action potential has been

established, to prevent constant stimulation. Once degradation

occurs, the re-uptake of neurotransmitters back into the pre-

synaptic neuron occurs as well; the neuron is then read for another

synaptic potential (the cycle then continues).

What is an excitatory post-synaptic potential

(EPSP)?

An excitatory post synaptic potential (EPSP) (a gas pedal) excites

the nerve up to the point of firing (an action potential occurring),

so an action potential can occur very quickly. The action potential

will then occur as soon as a small amount of sodium influxes

(enters the cell) and a small amount of potassium effluxes (leaves

the cell).*Both excitatory and inhibitory post-synaptic potentials

(EPSP's and IPSP's) are required for fine motor control of the body;

the ability to control nervous conductions (a brake and gas pedal

for a car offers fine control of the vehicle).

TERM 82

What is an inhibitory post-synaptic potential

(IPSP)?

DEFINITION 82

An inhibitory post-synaptic potential (IPSP) (a brake pedal) moves the neuron

away from threshold and will result in hyperpolarization (the nerve shutting

down); reducing a post-synaptic neuron's ability to generate an action potential.

An IPSP is based around the permeability of potassium and chloride ions;

potassium begins to efflux (leaving the cell) and chloride begins to influx (coming

into the cell). The two neurotransmitters that affect chloride channels to inhibit

neurons are GABA and Glycine.*Both excitatory and inhibitory post-synaptic

potentials (EPSP's and IPSP's) are required for fine motor control of the body; the

ability to control nervous conductions (a brake and gas pedal for a car offers fine

control of the vehicle).

TERM 83

Which post-synaptic potential (response) are

chloride ions associated with, excitatory or

inhibitory?

DEFINITION 83

Inhibitory Post-Synaptic Potential (IPSP)

TERM 84

Why would an excitatory post-synaptic

potential (EPSP) come into summation?

DEFINITION 84

The summation of an excitatory post-synaptic potential

(EPSP) would generate a pre-excitation of the neuron; the

function of a summation is to enhance depolarization

(facilitate depolarization). A single EPSP can't induce an

action potential in the post-synaptic neuron (nerve impulses

would never result without summation).

TERM 85

What are the two types of summation for an

excitatory post-synaptic potential (EPSP)?

Describe the two types of summation.

DEFINITION 85

The two types of summation for an excitatory post-synaptic potential are:

Temporal Summation: a summation of the EPSP when one or more pre-

synaptic neurons fires (starting the summation); creating another EPSP

before the first one dissipates (essentially keeping the nerve excited; directly

before threshold). The post-synaptic membrane depolarizes more than it

would from a single EPSP.

Spatial Summation: the summation of an EPSP when the post-synaptic

neuron is stimulated by a large amount of pre-synaptic neurons; huge

amounts of receptors bind neurotransmitters/simultaneously initiating

EPSP's, which summate and dramatically enhance depolarization.

*The efficiency of nerve conduction is tremendously enhanced with the

summation of EPSP's.

Explain acetylcholine (a neurotransmitter

pertaining to a neuron)

The locations (secretions) of acetylcholine are in the central nervous system

(CNS), autonomic ganglia and visceral effectors. The functional classes of

acetylcholine are excitatory with direct action in the central nervous system

(CNS); excitatory or inhibitory (depending on sub-type of receptor) with indirect

action (via second messengers) in the peripheral nervous system (PNS).

Acetylcholine is widespread throughout the CNS; occurring in the cerebral cortex,

hippocampus and brain stem. Acetylcholine is within all neuromuscular junctions

and some autonomic motor endings of the PNS. The effects of acetylcholine

include functioning as a neurotransmitter; a chemical released by nerve cells to

signal different nerve cells

TERM 92

Explain epinephrine (a neurotransmitter

pertaining to a neuron)

DEFINITION 92

The neurotransmitter epinephrine is also commonly known as

adrenaline; epinephrine is a hormone released by the adrenal

medulla and aids in the regulation of a sympathetic branch of the

ANS. Epinephrine typically increases blood pressure, heart rate

and cardiac output; increases the release of glucose from the liver

(increased feeling of muscular strength and aggressiveness).

TERM 93

Explain norepinephrine (a neurotransmitter

pertaining to a neuron)

DEFINITION 93

The neurotransmitter norepinephrine is secreted in the brain stem

and areas of the cerebral cortex of the CNS; the main

neurotransmitter of postganglionic neurons in the

parasympathetic nervous system of the PNS. Norepinephrine is

either excitatory or inhibitory (depending on receptor type) in the

CNS; expresses indirect action (through second messengers) in

the PNS. A neurotransmitter typically causing the effect of

happiness (feeling good).

TERM 94

Explain dopamine (a neurotransmitter

pertaining to a neuron)

DEFINITION 94

The neurotransmitter dopamine is secreted in the midbrain and

hypothalamus of the CNS; located occasionally in sympathetic

ganglia of the PNS. Dopamine is either excitatory or inhibitory

(depending on receptor type) in the CNS; expresses indirect action

(through second messengers) in the PNS. A neurotransmitter

typically causing the effect of happiness (feeling good).

TERM 95

Explain serotonin (a neurotransmitter

pertaining to a neuron)

DEFINITION 95

The neurotransmitter serotonin is secreted in the brain stem,

midbrain, hypothalamus, cerebellum, pineal gland and spinal

cord of the CNS. Serotonin is mainly inhibitory (indirect

action via second messengers with direct action at

receptors). Serotonin plays a role in sleep, appetite, nausea,

migraine headaches and regulating mood.

Explain GABA (a neurotransmitter pertaining

to a neuron)

GABA is secreted from the cerebral cortex, hypothalamus,

spinal cord and retina of the CNS. GABA is generally

inhibitory (direct and indirect actions via second

messengers). GABA is a principal inhibitory neurotransmitter

in the brain; important in pre-synaptic inhibition at

axoaxonal synapses.

TERM 97

Explain glycine (a neurotransmitter pertaining

to a neuron)

DEFINITION 97

The neurotransmitter glycine is secreted in the brain stem,

spinal cord and retina of the CNS. Glycine is typically

inhibitory with direct actions. Glycine is the principal

inhibitory neurotransmitter of the spinal cord.

TERM 98

Homeostatic Imbalance: What type of

transport do specific viruses and bacterial

toxins (that damage neuronal tissues) use to

reach the cell body?

DEFINITION 98

Specific viruses and bacterial toxins (that damage neuronal

tissues) use retrograde axonal transport to reach the cell

body (soma). The retrograde axonal transport system has

been demonstrated in polio, rabies, herpes simplex viruses

and for the tetanus toxin.

TERM 99

Homeostatic Imbalance: What is the cause of

impaired impulse propagation?

DEFINITION 99

The cause of impaired impulse propagation is a variety of chemical and

physical factors. Local anesthetics (used by medical professionals) act by

blocking voltage gated sodium channels; no sodium entry into the

cell=no generation of an action potential. Cold and continuous pressure

interrupts blood circulation, by hindering the delivery of oxygen and

nutrients to neuron processes and impairing the neurons ability to

conduct impulses (numbing of a finger with an ice cue or an appendage

becoming numb after sitting on the appendage for a long period of time).

Removing the cold object or pressure, leads to the transmission of

impulses again; leading to an unpleasant prickly feeling.

TERM 100

What is the definition of the nervous system?

DEFINITION 100

The nervous system is the master controlling and

communicating system of the body.