Chapter 12 - Neural Tissue

Front 1

Organs of the Nervous system

Back 1

Brain and spinal cord

sensory receptors

Front 2

What connects the nervous system with other parts of the body

Back 2

nerves

Front 3

What are the two kinds of cells in nervous tissue

Back 3

nueron and neuroglia

Front 4

Cells that send and receive messages are called

Back 4

neurons

Front 5

cells that support and protect neurons are called

Back 5

Neuroglia aka glial cells

Front 6

Central Nervous system consists of

Back 6

Brain and spinal cord

Front 7

Functions of CNS

Back 7

Gathers sensory date from inside and outside body, controls activities of PNS, Higher functions of brain intelligence, memory learning and emotion

Front 8

What is included in the PNS

Back 8

Crainal nerves, spinal nerve and ganglia

Front 9

This is a collection of cell bodies

Back 9

Ganglia

Front 10

What are nerves

Back 10

Bundles of axons with connective tissues and blood vessels

Front 11

What do the nerves of the PNS do:

Back 11

carry Sensory info and motor commands in PNS

Front 12

What are functions of PNS

Back 12

Deliver Sensory Info to CNS

Carry motor commands to Peripheral tissues and systems

Front 13

What are the functional division of PNS

Back 13

Afferent and efferent

Front 14

What does efferent division of PNS do:

Back 14

Carriers motor commands from CNS to PNS muscles and glands

Front 15

What does the afferent division of PNS do:

Back 15

Carries Sensory information from PNS sensory receptors to CNS

Front 16

What do the receptors of afferent division of PNS do:

Back 16

Detect changes or respond to stimuli

in neurons, specialized cells, and complex sensory organs

Front 17

What do effectors of afferent division in PNS do:

Back 17

respond to efferent signals of cells and organs

Front 18

Three general functions of CNS and PNS:

Back 18

1.Collect information via receptors in PNS and pass on to CNS

2. CNS processes and evaluates info and determines if response needed

3. CNS initiates specific nerve impulses, called motor oupt to effectors (muscles or glands) to react to changes in body's enviroment

Front 19

This PNS functional division controls voluntary and involuntary reflexs of skeletal muscle in the efferent division of the

Back 19

Somatic Nervous System

Front 20

This PNS functional division controls subconscious actions, contractions of smooth muscle, cardiac muscle and glandular secretions

Back 20

Autonomic Nervous system

Front 21

This Sympathetic division of the autonomic nervous system of PNS has what effect

Back 21

stimulating

Front 22

This Parasympathetic division of the autonomic nervous system of PNS has what effect

Back 22

relaxing

Front 23

What are the parts of the Multipolar neuron in common in the CNS

Back 23

Cell body aka soma

Large nucleus and nucleolus

perikaryon (cytoplasm)

Short, branched dendrites

Front 24

The neurofilaments and neurotubules are contained in the ___________ along with the neurobrils

Back 24

cytoskeleton

Front 25

These are bundles of neurofilaments that provide support for dendrites and axon

Back 25

neurofibrils

Front 26

These are dense areas of RER and ribosomes located in ______. The make neural tissue look gray and are also called _____________

Back 26

Neuron

Gray matter

Front 27

This carries electrical signal of action potential to target

Back 27

Axon

Front 28

These are highly branched, receive info from other neurons. 80-90 percent of neuron surface area

Back 28

Dendrites

Front 29

Structures of Axon

Back 29

Axoplasm

axolema

axon hillock

initial segment

collaterals

telodendria

axonterminals

Front 30

This contains cytoplasm of axon, contains neurofibrils, neurotubules, enzymes and organelles

Back 30

axoplasm

Front 31

Specialized cell membrane of axon, covers axoplasm

Back 31

axolemma

Front 32

This is thick section of axon of cellbody, attaches to initial segment

Back 32

axon hillock

Front 33

This attaches to axon hillock

Back 33

initial segment

Front 34

These are branches of single axon

Back 34

collaterals

Front 35

These are fine extensions of distal axon

Back 35

telodendria

Front 36

These are tips of telodendria

Back 36

axon terminals

Front 37

Why must protiens made in soma aka cell body be transported to axon and axon terminal

Back 37

to repair axolemma, they serve as gated ion channel proteins and as enzymes or neurotransmitters

Front 38

What are the modes of axon transport

Back 38

Anterograde - movement down axon away from cell/soma

Retrograde - Movement up axon toward soma

Front 39

What are the motor protiens of microtubles, how do they transport materials and what type of transport are they involved in

Back 39

Kinesin - carry materials on thier back and crawl, involved in antergrade transport

Dynein - also carry protiens on back and are involved in retrograde transport

Front 40

two types of axonal transport

Back 40

Fast - up to 400 mm day involve anterograde and retrograde

Slow - up to 10 mm day always anterograde involved in nerve fiber repair

Front 41

What are structures of neuro

Back 41

Presynaptic cell

post synaptic cell

synaptic cleft

Front 42

This are of neuro sends message

Back 42

presynaptic cell

Front 43

This area receives message

Back 43

postsynaptic cell

Front 44

This is small gap that separates the presynaptic membrane and postsynaptic membrane

Back 44

Synaptic cleft

Front 45

Types of Snyapes of Neurons

Back 45

Neuromusclular - synapse between neuron and muscle

Neuroglandular - Synapse between neuron and gland

Front 46

These have more than two processes and are all dendrites. Found in brain and sense organs

Back 46

Anaxonic Neuro

Front 47

These have two process seperated by one sense organ, found in special sense organs - sight, smell, hearing

Back 47

Bipolar neuron

Front 48

These have unipolar neurons and have single elongated process with cell body located off to side, found in PNS sensory neurons

Back 48

unipolar

Front 49

These have two or more processes, single axon and multiple dendrites, common in CNS

Back 49

multipolar neuron

Front 50

Skeletal muscle comprised of what kind of neuron

Back 50

multipolar

Front 51

what kind of neurons of PNS detect stimuli and transmit info about CNS

Back 51

Sensory

Front 52

These are located entirely within CNS, Receive signals and make decisions on response ect.

Back 52

Interneurons

Front 53

Interneurons are what percentage of all neurons

Back 53

90%

Front 54

What are the three types of Sensory Receptors of Neurons

Back 54

Interoceptors

Exteroceptors

Proprioceptors

Front 55

This type of sensory neuron monitors internal systems (digestive, respitory, cardiac, urinary, reproductive )and internal senses (ex. taste, deep pressure, pain)

Back 55

interoceptors

Front 56

This sensor receptor monitors Externalsenses (touch, temperature, pressure) Distancesenses (sight, smell, hearing)

Back 56

Exteroceptors

Front 57

This sensory receptor monitors position and movement (skeletal muscles and joints)

Back 57

proprioceptors

Front 58

This Glial Cell is large cell with many cell processes, maintains blood brain barrier, regulates fluid composition, structural support to CNS, replaces damaged neurons, assists with neuronal development

Back 58

Astrocyte

Front 59

This glial cellis found in brain or spinal cord, has cilia on apical surface

Back 59

Assists in production and circulation of spinal fluid

Front 60

This glial cell is least common and has small slender branches, defends against pathgens, removes debris, phagocytizes waste

Back 60

Microglial Cell

Front 61

This glial cells cytoplasmic extensions wrap around and mylinates CNS axons to allow faster conduction of nerve impulses through axons

Back 61

Oligodendrocyte

Front 62

This flattended glial cell clusters around cell bodies, protects and regulates nutrients for cell bodies in ganglia

Back 62

Satellite cell

Front 63

This glial cell insulates and protects PNS axons

Back 63

Neurolemmocyte

Front 64

These are Oliogdencrocytes that myelinate segments of axon called

Back 64

internodes

Front 65

These Oligodendrocytes called nodes of Ranvier, gaps between internodes where axons may branch

Back 65

nodes

Front 66

This mylination is a region of CNS with many myelinated nerves

Back 66

White Matter

Front 67

This unmyelinated area of CNS is called

Back 67

gray matter

Front 68

This cell wraps hundreds of layers of myelin around its own membrane, no cytoplasm betweeen membranes, has neurilemma which is thick outermost coil contains nucleus and cytomplasm and is located in PNS

Back 68

Schwan cell

Front 69

External to Neurilemma is basal lamina and thin layer of fiborous connective tissue called

Back 69

endoneurium

Front 70

These in CNS reach out to myelinate several nerve fibers in immediate vicinity. Anchored to multiple nerve fibers, cannot migrate, spiral inward, there is no neurilemma or endoneurim

Back 70

Oligdendrocytes

Front 71

Neuroglia are found in the ______ and contain _____

Back 71

PNS

Satellite and schwann cells

Front 72

These are flattend cells arranged around neuronal cell bodies in ganglia of Glial Cell in PNS

Back 72

Satellite cells

Front 73

This cell encloses unmyelinated axons by single cell and a series is required to cover entire length

Back 73

Schwan Cell

Front 74

A regeneration of a damaged peripheral nerve fiber can occur only if:

Back 74

Soma is intact and

some neurilemma must remain

Front 75

In the ______ regeneration of nerve fibers cannot occur at all

Back 75

CNS

Front 76

In CNS nerve regeneration limited to

Back 76

Chemicals released by astrocytes that block growth and produce scar tissue

Front 77

This is a process that results when a nerve fiber is cut or crushed, in which the part of the axon separated from the neuron's cell body degenerates distal to the injury.

Back 77

Wallerian degenration

Front 78

In wallerian degeneration what type of cells provide path for new grown and wrap axon in myelin

Back 78

Schwann cells

Front 79

These fibers are myelinated, large diameter, high speed fibers that carry info from/to CNS regarding postion, balance, touch and motor impulses

Back 79

A fibers

Front 80

These fibers are myelinated, medium diameter, medium speed, carry intermediate signals of sensory info for peripheral effectors

Back 80

B fibers

Front 81

These fibers are unmyelinted carry slower information, involuntary muscle and control glands

Back 81

C Fibers

Front 82

All Plasma cell membranes produce electrical signals by

Back 82

ION Movements

Front 83

What are the five membrane potentials:

Back 83

Resting Potential

Graded Potential

Action Potential

Synaptic activity

Information Processing

Front 84

This is potential of a resting cell

Back 84

Resting potentital

Front 85

This is temporary, localized change in resting potential, caused by stimulus

Back 85

garded potential

Front 86

This is an electrical impulse, produced by graded potential, propagates along surface of axon to synapse

Back 86

Action Potential

Front 87

This releases neurotransmitters at presynaptic membrane and produces graded potentials in postsynaptic membrane

Back 87

Synaptic activity

Front 88

This is response to intergration of stimuli of postsynaptic cell

Back 88

information processing

Front 89

What are three important concepts of membrane potental

Back 89

1. Extracellular fluid and interacellular fluid (Cytosol) differ greatly in ionic composition of NA and K.

2. Cell membrane is selectively permeable

3. Membrane permeability varies by ion

Front 90

The intracellular (cytosol) concentration is high in what type of ions which tend to move out of cell through leak channels driven by concentration gradient

Back 90

Potassium (K)

Front 91

The extracellular concentration of this ino is high so it moves through leak cells driven by concentration gradient

Back 91

Sodium (NA)

Front 92

These maintain NA and K concentration across plasma membrane and are not drive by concentration gradient

Back 92

Sodium-potassium exchange pumps

Front 93

The plasma membrane is more permeable to what type of ions resulting in more positive charges outside membrane

Back 93

Potassium (K)

Front 94

Inside the membrane protien membrane are ____ charged and cannot ____ membrane

Back 94

negatively

leave

Front 95

The difference in positive and negative ions on each side of membrane results in __________ acros membrane

Back 95

Electrical gradiant

Front 96

The membrane potential at which there is no net movement of a particular ion across the cell membrane is called

Back 96

Equilibrium potential

Front 97

Examples of equalibrium potential are

Back 97

K = -90 mv

NA + 66 mv

Front 98

What is the charge of a resting membrane and the equilibrium potential for K is which are very fairly close

Back 98

-70MV

-90 mv

Front 99

Sodium has what type of effect on eletrochemical gradient of membrane

Back 99

small

Front 100

The sodium potassium exchagne pum eject ___ NA ions for every ____ K ions it brings into the cell.

Back 100

3

2

Front 101

A typical neuron has a resting cell potential of

Back 101

-70mv

Front 102

When neuron is stimulated _____ gates open allowing ions to rush into cell, this ______ negative charge and membrane potential drifts to ____.

Back 102

NA

neutralizes

0

Front 103

_______ results when membrane voltage shifts to less than a negative value

Back 103

Depolarization

Front 104

The diffusion of NA inside Plasma membrane for short time move potential towards cells trigger zone. This short range change in voltage is called

Back 104

local potential

Front 105

Characteristics of local potential

Back 105

graded, decremental, reversible, excitory or inhibitory

Front 106

What are the types of Graded potentials

Back 106

Repolarization

Hyperpolarization

Front 107

When stimulus is removed and membrane returns to normal this graded potential is called

Back 107

repolarization

Front 108

When negativity of resting potential increases which results in opening of a potassium channel, positive ions move out of cell instead of in. This graded potential is called

Back 108

Hyperpolarization

Front 109

Graded potentials occur at _____ or _______ and _____ specific cell functions. Ex. Exocytosis of glandular secretions

Back 109

Cell dendrites or Cell bodies

trigger

Front 110

Graded potential also occur at the motor end plate and release _____ into synaptic cleft

Back 110

ACH

Front 111

In graded potential the membrane is most changed at

Back 111

site of stimulation

Front 112

The effects of a membrane potential spread due to

Back 112

local currents

Front 113

Graded change in membrane potential involves _________ or _____________

Back 113

depolarization or hyperpolarization

Front 114

In graded potential a stronger stimulus results in ________ change and a ________ area is affected

Back 114

Greater

Larger

Front 115

This affects entire membrane and link graded potentials at cell body with motor end plate

Back 115

action potential

Front 116

In order for action potential to initial the _______must depolarize and change resting potential of -70mv to _______level of sodium gated channels to -60 to -55 mv and increase of 10-15 mv

Back 116

axon hillock

threshold

Front 117

This is called the _____________ as once action potential is inititated it is the same no matter how large the stimulus.

Back 117

all or non principle

Front 118

If excitatory local potential spreads all the way to the ______ zone, and is still strong enough when it arrives, it can open these gates and generate an action potentail

Back 118

Trigger

Front 119

What is the critical voltage to reach local potential must rise to open voltage regualted gates

Back 119

-55 MV

Front 120

Once rising membrane potential passes 0 MV the ____ gates are inactivated. This takes time so end result is membrane volated of

Back 120

NA

+35 mv

Front 121

In order to repolarize and shift membrane potential back to negative number and or resting number _____ is expelled from intracellular fluid

Back 121

k

Front 122

More ___ leaves cell than ____ entering

Back 122

k

NA

Front 123

NA and K _____ places across membrane during an action potential

Back 123

NA and K

Front 124

4 Steps of action potential

Back 124

1. Depolarization to Threshold

2. Activation of NA channels

3. Inactivation of NA channels then activation of K channels

4. Return to normal resting potential - K channels close

Front 125

Action potential always

Back 125

depolarize

Front 126

Graded potential can _____________ or _____________

Back 126

de or hyperpolarize

Front 127

There is no _____value involved in graded potentials

Back 127

threshold

Front 128

In graded potential amount of depolorization or hyperpolarization depends on ____________

Back 128

intensity of stimulus

Front 129

Grade potential effect _____ as it moves away from site of stimulation where as an action potential does not _____ and extends along entire membrane surface

Back 129

decreases

decrease

Front 130

Graded potentials do not have ___________ period but action potential do have one.

Back 130

refractory

Front 131

Graded potentials occur mostly in ________ membranes whereas Action potential occur only in _________ membranes of specialized cells such as neurons and muscle cells.

Back 131

Plasma

Excitable

Front 132

What is the refractory period of action potential

Back 132

Time from begining of action potential to resting state when membrane will not respond to additional stimulli

Front 133

This is period when sodium channels open or inactivated, no action possible

Back 133

refractory

Front 134

This period is when membrane potential is almost normal and very large stimulus can initiate action potential

Back 134

Relative Refractory Period

Front 135

During refractory period the membrane can only respond to a ______________ stimulus

Back 135

large-than-normal

Front 136

This moves action potentials generated in axon hillock along entire length of axon

Back 136

Propogation

Front 137

What are the two types of propogation action potentials

Back 137

Continuous (unmyelinated axons)

Saltatory (myelinated axons)

Front 138

In __________ conduction signal jumps from node to node and depolarization occurs only at nodes and is much faster than in unmyelinated fibers

Back 138

Saltatory

Front 139

Chemical synapses are the ______ making devices of the nervous system

Back 139

decision

Front 140

The more synapses a neuron has the _____ info processing capabilities

Back 140

more

Front 141

Pyramidal cells in cerebral cortex have _______ synaptic contacts with other neurons

Back 141

40k

Front 142

Cerebral cortex of brain has ______ synapses

Back 142

100 Trillon

Front 143

Grade potentials developed in postsynaptic cell are in response to _________

Back 143

neurotransmitters

Front 144

What are the two types of postsynaptic potentials

Back 144

Excitatory synaptic potential (EPSP)

Inhibitory Postsynaptic Potential (IPSP)

Front 145

This is graded depolarization of postsynaptic membrane

Back 145

Excitatory synpatic Potential

Front 146

This is graded hyperpolorization of post synaptic membrane

Back 146

Inhibitory Postsynaptic potential

Front 147

This is likely to occur in any voltage change in the direction of the threshold that makes a neuron fire, usually results from NA flowing into cell canceling some negative charges on inside of membrane

Back 147

Excitatory Postsynaptic Potential

Front 148

Glutamate and aspartate are excitatory brain neurotransmitters taht produce

Back 148

Excitatory PSP's

Front 149

This is any voltage change away from threshold that makes neuro less likely to fire. Causing inflow of CL that makes cytsol more negative

Back 149

Inhibitory Postsynaptic potentials

Front 150

ach is _________ to some cells like skeletal muscle but ______ cardiac muscle

Back 150

excitatory

inhibitory

Front 151

Glycine and GABA are

Back 151

Inhibitory PSP's

Front 152

This is called ________ as EPSP accumulate, raising membrane potential to threshold and until small stimulus can trigger action potential

Back 152

Facilitation

Front 153

This is shifting balance between EPSP and IPSP as Neurotransmitter an change membrane sensitivity

Back 153

Summation

Front 154

A neuron who receives many ISPS is _______ from producing an action potential because stimulation to reach threshold has been increased

Back 154

inhibited

Front 155

One epsp is not enough to trigger action potential, they must combine through

Back 155

temporal and spatial summation

Front 156

This is rapid, repeated stimuli at one snyapse

Back 156

Temporal summation

Front 157

This is many stimuli arriving at multiple synapses

Back 157

spatial summation

Front 158

A ______ circuit has one nerve fiber and synapses with several postsynaptic cells.

Back 158

diverging

Front 159

This __________ circuit has input from many different nerve fibers and can be funneled to one neuron or neural pool

Back 159

Converging

Front 160

This circuit stimulates each other in linear sequence but one cell restimulates the first cell to start the process all over - occurs in diaphram and intercostal muscles

Back 160

reverberating circuits

Front 161

This circut involves input neurons diverging to stimulate several chains of neurons

Back 161

Parallel after discharge circuits

Front 162

Synaptic plasticity is

Back 162

The ability of synapses to change

Front 163

This is the process of making transmission easier

Back 163

synaptic potentiation

Front 164

Long term memory that allows one to retain events that can be put into words

Back 164

declarative

Front 165

Long term memory that involves retention of motor skills

Back 165

procedural

Front 166

Synapses that are located together by gap junctions that produce local continuous current and action potential found in brain, eye, ciliary ganglia are called

Back 166

Electrical

Front 167

Synapses transmitted by chemical neurotransmitters in which cells are not in direct contact and an action potential may or may not be produced are called:

Back 167

Chemical Synapses

Front 168

Effect of neurotransmitter on postsynaptic membrane depends on _______ and not on the neurotransmitter

Back 168

receptor

Front 169

This type of synapse occurs at all neuromuscular junction involving skeletal muscles

Back 169

Cholinergic Synapses

Front 170

This occurs when neurotransmitter cannot recycle fast enough to meet demands of intense stimuli

Back 170

Synpatic fatigue`

Front 171

This occurs between arrival of action potential and effect on postsynaptic membrane

Back 171

synaptic delay

Front 172

There are at least _____ neurotransmitters other than ach including ___________, ___________, _________ and _________.

Back 172

50

biogenic amines

amino acids

neuropeptides

dissolved gases

Front 173

Important neuro transmitters other than ach (4)

Back 173

Norepinphrine

dopamine

serotonin

Gamma aminogutyric acid (GABA)

Front 174

These _________ have long term effects, involve multiple steps, after either or both post or pre synaptic membranes, released alone or with neuro transmitter.

Back 174

Neurodoulators

Front 175

These are neuromodulators that bind to receptor and activate enzymes

Back 175

Neuropeptides

Front 176

These are neuromodulators in CNS, bind to Same receptors as opium and morphine, relieve pain

Back 176

opiods

Front 177

Neurotransmitter and neuromodulators have what effects

Back 177

Direct effects on membrane channels

indirect effects on G protiens

Indirect effects on Intracellular enzymes

Front 178

______________ work through second messengers, enzyme complex that binds to GTP, link between neurotransmitter and second messenger, activate enzyme Adenylyl cyclase

Back 178

G protiens