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1
Q

Nervous Sys

A

Master controlling and communicating system of body

2
Q

How does nervous sys communicate?

A

Cells communicate via electrical and chemical signals,

3
Q

How are the those signals described?

A

Rapid and specific

4
Q

Primary cell of the nervous system

A

is the neuron

5
Q

Neurons are the key to what?

A

The key to neural transmission

6
Q

Sensory input –

A

info gathered by sensory receptors about internal and external changes (cold or hot)

7
Q

Integration-

A

processing and interpretation of sensory input and decides what actions are required

8
Q

Motor output-

A

activation of effector organs (muscles and glands) yields a response

9
Q

5 parts after stimulus but before response in simple reflect arc

A
  1. Receptor
  2. sensory neuron
  3. integration center
  4. motor neuron
  5. effector
10
Q

Central nervous system (CNS) parts and location

A

Brain and spinal cord of dorsal body cavity

11
Q

CNS job 3 parts

A
  1. Integration and control center
  2. Interprets sensory input and dictates motor output
  3. Motor output is based on reflexes, past experience, and/or current situation
12
Q

Peripheral nervous system (PNS) Location

A

The portion of the nervous system outside CNS

13
Q

PNS Consists mainly of

A

nerves that extend from brain and spinal cord

14
Q

Two types of nerves in PNS

A

Spinal and Cranial Nerves

15
Q

Spinal nerves

A

to and from spinal cord

16
Q

Cranial nerves

A

to and from brain

17
Q

PNS response simple term (common)

A

FIGHT OR FLIGHT

18
Q

Histology of nervous tissue

A

Highly cellular; little extracellular space

Tightly packed

19
Q

What are the 2 principal nervous cell types?

A

Neuroglia

Neurons (nerve cells )

20
Q

Neurons (nerve cells )

A

excitable cells that transmit electrical signals

21
Q

Neuroglia

A

small cells that surround and wrap delicate neurons: AKA glial cells, 6 types

22
Q

6 types of neuroglia

A
Astrocytes (CNS)
Microglial cells (CNS)
Ependymal cells (CNS)
Oligodendrocytes (CNS)
Satellite cells (PNS)
Schwann cells (PNS)
23
Q

What neuroglia is most abundant?

A

Astrocytes (CNS)

24
Q

Astrocytes (CNS)

A

Most abundant, versatile, and highly branched glial cells with radiating processes that

25
Q

What do astrocytes cling to?

A

Cling to neurons, synaptic endings, and capillaries

26
Q

Astrocyte function

A

Functions include
Support and brace neurons and anchor them to their nutrient supply
Play role in exchanges between capillaries and neurons
Guide migration of young neurons
Control chemical environment around neurons and calcium concentration
Respond to nerve impulses and recycle neurotransmitters
Influence neuronal functioning
Participate in information processing in brain

27
Q

Describe Microglial cells (CNS)

A

Small, ovoid cells with thorny processes that touch and monitor neurons

28
Q

Microglial cells (CNS) monitor

A

Monitor the health of neurons then migrate toward injured neurons

29
Q

Microglial cells (CNS) transform

A

Can transform into a type of macrophage to phagocytize microorganisms and neuronal debris

30
Q

Why are microglial cells vital?

A

Important because immune cells aren’t very permeable through the blood-brain barrier

31
Q

Describe Ependymal Cells

A

Range in shape from squamous to columnar

32
Q

Ependymal Cells may be

A

ciliated

33
Q

Ependymal Cells line

A

Line the central cavities of the brain and spinal column

34
Q

Ependymal Cells form

A

Form permeable barrier between cerebrospinal fluid (CSF) in cavities and tissue fluid bathing CNS cells

35
Q

Oligodendrocytes are

A

branched cells

36
Q

Oligodendrocytes processes

A

Processes wrap CNS nerve fibers, forming insulating myelin sheaths thicker nerve fibers

37
Q

What gets damaged in MS?

A

Oligodendrocytes

38
Q

Autoimmune disease is when

A

immune system attacks itself, they use chemo to stop immune response they don’t know why human body does this.
Different types of MS

39
Q

Satellite cells Function

A

similar to astrocytes of CNS

40
Q

Surround neuron cell bodies in PNS

A

Satellite cells

41
Q

Surround all peripheral nerve fibers and form myelin sheaths in thicker nerve fibers

A

Schwann cells (neurolemmocytes)

42
Q

Schwann cells (neurolemmocytes) Function

A

Similar function as oligodendrocytes

43
Q

Schwann Cells (neurolemmocytes) vital to what?

A

Vital to regeneration of damaged peripheral nerve fibers

44
Q

Satellite cells anchor

A

neurons nerves need constant blood flow

45
Q

Schwann cells have different

A

mylein sheath in some

46
Q

Nerve cell are

A

amitotic, they don’t divide

47
Q

Neurons

A

Structural units of nervous system

48
Q

Neurons size and f(x)

A

Large, highly specialized cells that conduct impulses

49
Q

How long do neurons last?

A

Extreme longevity ( 100 yrs or more if healthy)

50
Q

Neurons are Amitotic but?

A

with few exceptions (hippocampus: involved with memory and recall)

51
Q

Neuron high metabolic rate why?

A

High metabolic rate—requires continuous supply of oxygen and glucose

52
Q

All neurons have this?

A

All have a cell body and one or more processes

53
Q

Biosynthetic center of neuron does what?

A

Synthesizes proteins, membranes, and other chems

54
Q

Biosynthetic center of neuron has what?

A
Rough ER (chromatophillic substance or nissel bodie)
Most active and best developed in body
55
Q

Neuron cell body has?

A

Biosynthetic center of neuron
Spherical nucleus with nucleolus
Some contain pigments
In most, plasma membrane part of receptive region
Most neuron cell bodies in CNS
Nuclei – clusters of neuron cell bodies in CNS
Ganglia – lie along nerves in PNS (ganglion)

56
Q

Ganglia –

A

lie along nerves in PNS (ganglion

57
Q

Nuclei –

A

clusters of neuron cell bodies in CNS

58
Q

Nucleolus develops what?

A

ribosomes

59
Q

Chromatophilc-

A

stains easily

60
Q

Neuron Processes

A

Armlike processes extend from body

61
Q

Neuron Processes in CNS

A

Both neuron cell bodies and their processes

62
Q

Neuron Processes PNS

A

Chiefly neuron processes

63
Q

Tracts

A

Bundles of neuron processes in CNS

64
Q

Nerves

A

Bundles of neuron processes in PNS

65
Q

Two types of neuron processes

A

Dendrites (afferent**)

Axon (efferent**)

66
Q

Dendrites In motor neurons how many?

A

100s of short, tapering, diffusely branched processes

67
Q

Receptive (input) region of neuron
Large surface area for information collection
Synapses with other neurons (bring info to dend)
Convey incoming messages toward cell body as graded potentials (short distance signals)
In many brain areas fine dendrites specialized
Collect information with dendritic spines
Appendages with bulbous or spiky ends

A

Dendrites

68
Q

Receive info from sensory receptors or other neurons
Processes allow large surface cuz a lot of info
Graded potential = ap but shorte distance r, ap goes a meter about
Slightly mylienated, no schwann cells
Specialized due to information goes to specific motor movement ex) vision different from moving arm or leg

A

Dendrites

69
Q

Describe Axon Structure

A

One axon per cell arising from axon hillock
Cone-shaped area of cell body
In some neurons, the axon is short or absent (no msg)
In others, encompasses most of the length of neuron
Some 1 meter long
Long axons called nerve fibers
Occasional branches (axon collaterals)
Branches profusely at end (terminus)
Can be 10,000 terminal branches
Distal endings called axon terminals or terminal boutons

70
Q

Long axons are called ?

A

nerve fibers

71
Q

axon collaterals

A

Occasional branches

72
Q

Branches profusely at end

A

terminus

73
Q

distal endings are called what?

A

axon terminals or terminal boutons

more common is axon terminals

74
Q

Axon absent are during

A

depol for other cells

75
Q

Nerve fibers are collections

A

of axons

76
Q

axon functional characteristics

A

Conducting region of neuron
Generates nerve impulses
Transmits them along axolemma (neuron cell membrane) to axon terminal
Secretory region (not where they are produced)
Neurotransmitters released into extracellular space
Either excite or inhibit neurons with which axons in close contact
Carries on many conversations with different neurons at same time (through electrical gradients)
Lacks rough ER and Golgi apparatus (don’t create protein)
Relies on cell body to renew proteins and membranes
Efficient transport mechisms for proteins and memrbanes
Quickly decay if cut or damaged (take a long time to regenerate)

77
Q

What is the conducting region of the neuron?

A

axon

78
Q

What part of neuron generates nerve impulses?

A

axon

79
Q

What part of neuron transmits nerve impulses along the axolemma (neuron cell membrane) to axon terminal?

A

axon

80
Q

What part of neuron is the secretory region of nerve impulses?

A

axon

81
Q

Neurotransmitters released into extracellular space

and cause?

A

Either excite or inhibit neurons with which axons in close contact

82
Q

What carries on many conversations with different neurons at same time (through electrical gradients)?

A

axon

83
Q

What Lacks rough ER and Golgi apparatus (don’t create protein)?

A

axon

84
Q

What Relies on cell body to renew proteins and membranes

A

axon

85
Q

What Efficient transport mechisms for proteins and memrbanes?

A

axon

86
Q

What will Quickly decay if cut or damaged (take a long time to regenerate)?

A

axon

87
Q

Axons conduct info

A

away from the body

88
Q

The myelin sheath is comprised of

A

mylein

89
Q

Mylein

A

Whitish, protein-lipoid substance

90
Q

Segmented sheath around most long or large-diameter axons
Dendrites are always non-myelinated (they have shwann cells)
Myelinated fibers
Function of myelin
Protects and electrically insulates axon
Increases speed of nerve impulse transmission

Nonmyelinated fibers conduct impulses more slowly

A

Mylein sheath

91
Q

What is a Segmented sheath around most long or large-diameter axons?

A

mylein sheath

92
Q

Dendrites are always non-myelinated or myelinated?

A

Dendrites are always non-myelinated (they have shwann cells)

93
Q

2 functions of mylein

A

Protects and electrically insulates axon

Increases speed of nerve impulse transmission

94
Q

What fiber conducts nerve impulses more slowly?

A

nonmyleninated fibers

95
Q

mylein sheath is similar to what in your afsc?

A

welding coat on electrode that insulates the weld

jumps arc

96
Q

Myelination in the PNS

A

Formed by schwann cells
Wrap around axon in jelly roll fashion
One cell forms one segment of myelin sheath
Myelin sheath
Concentric layers of schwann cell plasma membrane around axon
Outer collar of perinuclear cytoplasm (formerly called neurilemma)
Peripheral bulge of schwann cell containing nucleus and most of cytoplasm

97
Q

How is myelination formed in PNS?

A

Formed by schwann cells
Wrap around axon in jelly roll fashion
One cell forms one segment of myelin sheath

98
Q

What makes up myelin sheath in PNS?

A

Concentric layers of schwann cell plasma membrane around axon

99
Q

Outer collar of perinuclear cytoplasm (formerly called neurilemma) is made of what?

A

Peripheral bulge of schwann cell containing nucleus and most of cytoplasm

100
Q

Process of Myelination in PNS 3 steps

A

1.) Schwann cell develops an axon

2.) The Schwann cell then rotates
around the axon, wrapping its
plasma membrane loosely around
it in successive layers.


101
Q

What gets damaged in ALS?

A

Myelination in PNS because Schwann cells get damaged and messes everything else up

102
Q

Plasma membranes of myelinating cells have

A

less protein

103
Q

Why do Plasma membranes of myelinating cells have

less protein?

A

No channels or carriers (don’t conduct electrical impulse)
Good electrical insulator
Interlocking proteins bind adjacent myelin membranes

104
Q

Nodes of ranvier

A

(conduction of electrical impulse across the axon)

like arc welding

105
Q

2 aspects of nodes of ranvier

A

Myelin sheath gaps between adjacent schwann cells

Sites where axon collaterals can emerge

106
Q

Nonmyelinated fibers are

A

Thin fibers not wrapped in myelin; surrounded by schwann cells but no coiling; one cell may surround 15 different fibers

107
Q

Myelin Sheaths in the CNS formed by

A

Formed by multiple, flat processes of oligodendrocytes, not whole cells

108
Q

Myelin Sheaths in the CNS wrap how many axons at once

A

60 axons at once

109
Q

Are nodes of ranvier present in Myelin Sheaths in the CNS formed by

A

Nodes of ranvier are present

110
Q

No outer collar of perinuclear cytoplasm in Myelin Sheaths in the CNS

A

No outer collar of perinuclear cytoplasm

111
Q

size of fibers and covered by what in Myelin Sheaths in the CNS

A

Thinnest fibers are unmyelinated

Covered by long extensions of adjacent neuroglia

112
Q

White matter

A

Regions of brain and spinal cord with dense collections of myelinated fibers – usually fiber tracts

113
Q

Gray matter

A

Mostly neuron cell bodies and nonmyelinated fibers

114
Q

Function in gray matter

A

processing

115
Q

What matter has role in MS and axons ?

A

white matter

116
Q

Sensory Neurons

A

Transmit impulse from sensory receptors in skin/organs twd cns (integration)

Almost all are Unipolar

117
Q

Sensory Neurons are what kind of polar?

A

unipolar

118
Q

Where are the sensory neuron cell bodies located?

A

Cell bodies in ganglia in PNS

119
Q

Motor Neurons Carry impulsess

A

from CNS to effectors

120
Q

Motor Neurons are what polar?

A

Multipolar

121
Q

Where are cell bodies of motor neurons located?

A

Most cell bodies in CNS (except some autonomic neurons)

122
Q

Interneurons

A

(association neurons)

123
Q

Where are interneurons located?

A

Lie btw motor and sensory neurons

124
Q

What do interneurons do? Where?

A

Shuttle signals through CNS pathways where integration of information occurs; most are entirely within CNS

125
Q

What are 99% of body’s neurons?

A

interneurons

126
Q

Where are interneurons confined?

A

Most confined in CNS

127
Q

Neurons are highly what (membrane potential)?

A

irritable

128
Q

Neurons respond to what > (membrane potential)?

A

Respond to adequate/threshold stimulus by generating an action potential (nerve impulse) along the axon length

129
Q

What is the impulse always in neurons regardless of what?

A

Impulse is always the same regardless of stimulus

130
Q

what is the resting membrane potential?

A

Potential difference across membrane of resting cell

131
Q

Numeric value for resting membrane potential and how come?

A

Approximately –70 mV in neurons (cytoplasmic side of membrane negatively charged relative to outside)

132
Q

What is the actual voltage difference numeric value in resting membrane potential?

A

Actual voltage difference varies from -40 mV to -90 mV

133
Q

What is membrane in resting potential termed?

A

Membrane termed polarized

134
Q

What is the resting membrane potential generated by? 2 things

A

Generated by:
Differences in ionic makeup of ICF and ECF
Differential permeability of the plasma membrane

135
Q

How is that generated by Differences in ionic makeup of ICF and ECF
Differential permeability of the plasma membrane? 2 things again

A

Higher K concentration inside the cell with protein anions creating a negative membrane charge

Large concentration of Na+ outside the cell making the outside environment more positive

136
Q

Differences in Plasma Membrane Permeability Characteristics in Nerve cell

A

Impermeable large anionic proteins
Slightly permeable to Na+ (through leakage channels)

25 times more permeable to K+ than sodium (more leakage channels)
Potassium diffuses out of cell down concentration gradient
Quite permeable to Cl–

137
Q

What happens with K+ during plasma membrane resting potential in nerve cell?

A

More potassium diffuses out than sodium diffuses in

138
Q

What does Na+ K+ Pump do in resting membrane potential of nerve cell?

A

Sodium-potassium pump stabilizes resting membrane potential

139
Q

How does sodium potassium pump work in resting memb potential in nerve cell?

A

Maintains concentration gradients for Na+ and K+

3 Na+ pumped out of cell; 2 K+ pumped in

140
Q

Membrane potential changes when

A

Concentrations of ions across membrane change

Membrane permeability to ions changes

141
Q

Changes produce two types signals

A

Graded potentials

Action potentials

142
Q

Graded potentials

A

Incoming signals operating over short distances

143
Q

Action potentials

A

Long-distance signals of axons

144
Q

What do changes in membrane potential do in nerve cells?

A

Changes in membrane potential used as signals to receive, integrate, and send information

145
Q

Terms of change of membrane potential are relative to what potential?

A

Terms describing membrane potential changes relative to resting membrane potential

146
Q

What is occurring in depolarization of nerve cell membrane?

A

Decrease in membrane potential (toward zero and above)
Inside of membrane becomes less negative than resting membrane potential
Increases probability of producing a nerve impulse
Either graded or action potential

147
Q

depolarization increases the probablity of what? what are they called?

A

Increases probability of producing a nerve impulse

Either graded or action potential

148
Q

Hyperpolarization what occurs?

A

An increase in membrane potential (away from zero)

Inside of cell becomes more negative than resting membrane potential)

149
Q

Hyperpolarization reduces probablity of ?

A

Reduces probability of producing a nerve impulse

150
Q

Hyperpolarization is the action of what kind of drugs?

A

Action of anti-anxiety medicine

151
Q

Why does hyperpolarization provide the reaction that it does?

A

No neural stimulus, keeps you relaxed since it reduces probability of producing a nerve impulse

152
Q

How long are grade potentials and why?

A

Short-lived, localized changes in membrane potential
Magnitude varies with stimulus strength
Stronger stimulus  more voltage changes; farther current flows

153
Q

Graded potential is what polarization wave?

A

Either depolarization or hyperpolarization

154
Q

Graded potential are triggered by what?

A

Triggered by stimulus that opens gated ion channels

155
Q

GRADED POTENTIAL current flows and how?

A

Current flows but dissipates quickly and decays
Graded potentials are signals only over short distances
Positive ions move toward negative charges, therefore the charge flows in one direction

156
Q

Why does Membrane potential decays with distance?

A

Because current is
lost through the “leaky” plasma membrane, the voltage declines with
distance from the stimulus (the voltage is decremental).
Consequently, graded potentials are short-distance signals.

157
Q

What is AP?

A

Brief reversal of membrane potential with a change in voltage of ~100 mV

158
Q

How are AP different from GP?

A

Do not decay over distance as graded potentials do

159
Q

How does depolarization activate AP?

A

Depolarizing local currents open voltage-gated Na+ channels

Na+ influx causes more depolarization which opens more Na+ channels  ICF less negative

160
Q

What happens at threshold for depolarizaton to activate AP?

A
At threshold (–55 to –50 mV) positive feedback causes opening of all Na+ channels  a reversal of membrane polarity to +30mV
Spike of action potential
161
Q

Repolarizing phase what happens?

A

Na+ channel slow inactivation gates close
Membrane permeability to Na+ declines to resting state

Slow voltage-gated K+ channels open
K+ exits the cell and internal negativity is restored

162
Q

What stops increasing during repolarization

A

AP spike stops rising

163
Q

What happens during hyper polarization?

A

Some K+ channels remain open, allowing excessive K+ efflux

This causes hyperpolarization of the membrane (slight dip below resting voltage)
Na+ channels begin to reset

164
Q

What does hyperpolzartion do resting voltage?

A

This causes hyperpolarization of the membrane (slight dip below resting voltage)

165
Q

What is constantly leaving during hyper polarization?

A

K constnaly leaving cell causes hyperpolarization

166
Q

What happens with ions in Resting state?

A

No ions move through voltage-gated

channels.

167
Q

Depolarization is caused by what ion?

A

Na+ flowing into the cell

168
Q

Repolarization is caused by ion?

A

K+ flowing

out of the cell.

169
Q

Hyperpolarization is

caused by

A

K+ continuing to

leave the cell.

170
Q

What do not all depolarization events yield?

A

Not all depolarization events produce APs

171
Q

What does an axon need to get triggered by?

A

For axon to “fire”, depolarization must reach thresholdThat voltage at which the AP is triggered

172
Q

What happens at threshold during depolarization?

A

At threshold:
Membrane has been depolarized by 15 to 20 mV
Na+ permeability increases
Na influx exceeds K+ efflux

173
Q

What cycle begins after threshold?

A

The positive feedback cycle begins

174
Q

What kind of phenomenon is threshold?

A

All-or-None phenomenon

An AP either happens completely, or it does not happen at all

175
Q

What is ALL or none phenomenon ?

A

All-or-None phenomenon

An AP either happens completely, or it does not happen at all

176
Q

propagation

A

increase in numbers

spreading

177
Q

Propagation allows

A

AP to serve as a signaling device

178
Q

AP is a

A

signaling device

179
Q

By propagation, what happens with ions?

A

Na+ influx causes local currents (electrical flow)

180
Q

how does Na+ influx causes local currents (electrical flow)?

A

Local currents cause depolarization of adjacent membrane areas in direction away from AP origin (toward axon’s terminals)
Local currents trigger an AP there: From positive to negative, one way propagation
This causes the AP to propagate AWAY from the AP origin

181
Q

Since Na+ channels closer to AP origin are (propagation)

A

inactivated no new AP is generated there

182
Q

Once initiated an AP is what and how so?

A

self-propagating
In nonmyelinated axons each successive segment of membrane depolarizes, then repolarizes
Propagation in myelinated axons differs

183
Q

Absolute refractory period is?

A

When voltage-gated Na+ channels open neuron cannot respond to another stimulus

184
Q

Absolute refractory period Ensures

A

that each AP is an all-or-none event

185
Q

Absolute refractory period Enforces

A

one-way transmission of nerve impulses

186
Q

Conduction velocities of neurons

A

vary widely

187
Q

Rate of AP propagation depends on

A

Axon diameter

188
Q

Degree of myelination

A

Continuous conduction in unmyelinated axons is slower than saltatory conduction in myelinated axons

189
Q

Function/ role of myelin sheath

A

Myelin sheaths insulate and prevent leakage of charge

190
Q

Fasted conduction

A

Saltatory conduction (possible only in myelinated axons) is about 30times faster

191
Q

Why is saltatory conduction the fastest?

think about arc welding

A

Voltage-gated Na+ channels are located at myelin sheath gaps
APs generated only at gaps
Electrical signal appears to jump rapidly from gap to gap

192
Q

In bare plasma membranes, voltage decays.

A

Without voltage-gated channels, as on a dendrite,
voltage decays because current leaks across the
membrane.

193
Q

In nonmyelinated axons, conduction is slow

continuous conduction

A

Voltage-gated Na+ and K+
channels regenerate the action potential at each point
along the axon, so voltage does not decay. Conduction
is slow because it takes time for ions and for gates of
channel proteins to move, and this must occur before
voltage can be regenerated.

194
Q

In myelinated axons, conduction is fast (saltatory

conduction).

A

Myelin keeps current in axons
(voltage doesn’t decay much). APs are generated only
in the myelin sheath gaps and appear to jump rapidly
from gap to gap.

195
Q

Group A fibers

A

Large diameter, thickly myelinated somatic sensory and motor fibers of skin, skeletal muscles, joints

196
Q

Group B fibers

A

Intermediate diameter, lightly myelinated fibers

197
Q

Group C fibers

A

Smallest diameter, unmyelinated ANS fibers

198
Q

Why does nervous system work?

A

Nervous system works because information flows from neuron to neuron

199
Q

What are Neurons functionally connected by ?

A

synapses

200
Q

Synapses are what? how?

A

Junctions that mediate information transfer From one neuron to another neuron Or from one neuron to an effector cell

201
Q

Presynaptic neuron role

A

Sends the information

202
Q

Postsynaptic neuron location

A

(in PNS may be a neuron, muscle cell, or gland cell)

203
Q

Postsynaptic neuron function

A

Receives the information

204
Q

Postsynaptic neuron and Presynaptic neuron can what?

A

Most function as both

205
Q

Transmission crosses what?

A

synaptic cleft

206
Q

Tranmission across the synaptic cleft is what kind of event?

A

Chemical event (as opposed to an electrical one)

207
Q

Synaptic cleft depends on what?

A

Depends on release, diffusion, and receptor binding of neurotransmitters

208
Q

Synaptic cleft Ensures

A

Ensures unidirectional communication between neurons

209
Q

AP arrives at what during transmission across chem synapsis?

A

axon terminal of presynaptic neuron

210
Q

Info transfer across synaspes causes what? and how?

A

Causes voltage-gated Ca2+ channels to open

Ca2+ floods into cell

211
Q

Synaptotagmin protein binds (info transfer chem synapse)

A

Ca2+ and promotes fusion of synaptic vesicles with axon membrane

212
Q

What occurs after synaptotagmin protein binding during info transfer chem synapse ? and higher what ?

A

Exocytosis of neurotransmitter into synaptic cleft occurs

Higher impulse frequency –> more released

213
Q

What diffuses across synapse during info chem transfer ?

A

Neurotransmitter diffuses across synapse

214
Q

Neurotransmitter does what in chem transfer in synapse? how so?

A

Binds to receptors on postsynaptic neuron

Often chemically-gated ion channels

215
Q

What are opened when there are neurotransmitter transmitted across synapse chem? What does that cause?

A

Ion channels are opened
Causes an excitatory or inhibitory event (graded potential)
Neurotransmitter effects terminated

216
Q

Neurotransmitters are considered to be what of the nervous system?

A

Language of nervous system

217
Q

How many neurotransmitter have been id?

A

50 or more neurotransmitters have been identified

218
Q

What are neurotransmitters made up of? this exerts what?

A

Most neurons make two or more neurotransmitters

Neurons can exert several influences

219
Q

When are neurotransmitters usually released?

A

Usually released at different stimulation frequencies

220
Q

Neurotransmitters are classified by what?

A

Classified by chemical structure and by function

221
Q

Acetylcholine

A

(ACh)

222
Q

What neurotransmitter was the first identified?

A

ACh

223
Q

What neurotransmitter is the best understood?

A

ACh

224
Q

ACh is released by what?

A

Released at neuromuscular junctions ,by some ANS neurons, by some CNS neurons

225
Q

ACh is synthesized from what?

A

Synthesized from acetic acid and choline by the enzyme choline acetyltransferase

226
Q

ACh is degraded by what?

A

Degraded by enzyme acetylcholinesterase (AChE)

227
Q

ACh is released by ?

A

Released by all neurons that stimulate skeletal muscles

228
Q

ACh excitatory by what muscle?

A

Excitatory: Skeletal muscle

229
Q

ACh inhibitory by what tissue?

A

Inhibitory: Cardiac tissue

230
Q

How are neurotransmitters classified by?

A

chem structure

231
Q

4 Chem structure classifications of neurotransmitters

A
  1. ) Biogenic Amines
  2. ) Amino Acids
  3. ) Peptides (Neuropiptides)
  4. ) Gases and Lipids (gasotransmitters)
232
Q

Biogenic Amines 2 groups that make them up

A

Catecholamines

Indolamines

233
Q

Catecholamines consist of …?

A

Dopamine, norepinephrine (NE), and epinephrine

234
Q

Catecholamines are synthesized from?

A

Synthesized from the amino acid tyrosine

235
Q

Indolamines

A

Serotonin and histamine

236
Q

What is serotonin synthesized from ?

A

Serotonin synthesized from amino acid tryptophan;

237
Q

What is histamine synthesized?

A

histamine synthesized from amino acid histidine

238
Q

Biogenic Amines are distributed in brain how?

A

Broadly distributed in brain

239
Q

Biogenic amines play a role in what?

A

Play roles in emotional behaviors and biological clock

240
Q

Some ANS motor neurons release (especially NE)

A

Biogenic amines

241
Q

What type of chem functional enzyme has Imbalances associated with mental illness

A

Biogenic amines

242
Q

What 4 amino acids are chemical structure neurotransmitters?

A

Glutamate
Aspartate
Glycine
GABA—gamma ()-aminobutyric acid

243
Q

Neuropeptides consist of what 3 ?

A

Substance P

Endorphins

Gut-brain peptides

244
Q

Substance P role

A

Mediator of pain signals

245
Q

Endorphins kinds

A

Beta endorphin, dynorphin and enkephalins

246
Q

Endorphins act as what?

A

Act as natural opiates; reduce pain perception

247
Q

Example of endorphins

A

Runners high

248
Q

Gut-brain peptides types

A

Somatostatin and cholecystokinin

249
Q

Examples of gasotransmitters

A

Nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide gases (H2S)

250
Q

Gasotransmitters bind with what?

A

Bind with G protein–coupled receptors in the brain

251
Q

gasotransmitters are what soluble?

A

Lipid soluble

252
Q

Gasotransmitters are synthesized how?

A

Synthesized on demand

253
Q

NO (g) gasotransmitter is involved in ?

A

NO involved in learning and formation of new memories; brain damage in stroke patients, smooth muscle relaxation in intestine

254
Q

H2S acts as how?

A

H2S acts directly on ion channels to alter function

255
Q

Effects of Neurotransmitter (two things)

A

excitatory versus inhibitory

256
Q

Neurotransmitter effect can be what?

A

Neurotransmitter effects can be excitatory (depolarizing) and/or inhibitory (hyperpolarizing)

257
Q

How is neurotransmitter effected by?

A

Effect determined by receptor to which it binds

258
Q

GABA and glycine usually are what neurotransmitter effect?

A

inhibitory

259
Q

Glutamate usually are what neurotransmitter effect ?

A

excitatory

260
Q

How do ACh an NE work?

A

Acetylcholine and NE bind to at least two receptor types with opposite effects

261
Q

ACh works how for skel muscle?

A

ACh excitatory at neuromuscular junctions in skeletal muscle

262
Q

ACh functions how for cardiac muscle?

A

ACh inhibitory in cardiac muscle

263
Q

How do neurons function?

A

Neurons function in groups

264
Q

The neuron groups contribute to what?

A

Groups contribute to broader neural functions

265
Q

Where are there billion of neurons?

A

There are billions of neurons in CNS

266
Q

Why are there billions of neurons?

A

Must be integration so the individual parts fuse to make a smoothly operating whole

267
Q

CNS is made up?

A

brain and spinal cord

268
Q

What are the 4 adult brain regions?

A

1) Cerebral hemispheres
2) Diencephalon
3) Brain stem (midbrain, pons, and medulla)
4) Cerebellum

269
Q

Brain

A

Similar pattern
Additional areas of gray matter in brain
Cerebral hemispheres and cerebellum

Cortex disappears in brain stem

Ventricles: 4 ventricles

270
Q

What are ventricles of brain filled with?

A

Filled with cerebrospinal fluid (CSF)

271
Q

Ventricles in brain are connected how?

A

Connected to one another and to central canal of spinal cord

272
Q

Lateral ventricleS and third ventricle connected by what?

A

Lateral ventricles  third ventricle via interventricular foramen

273
Q

Third and and fourth ventricle are connected via?

A

Third ventricle  fourth ventricle via cerebral aqueduct

274
Q

Cerebral Hemispheres are what?

A

Surface markings

275
Q

What are the cerebral hemispheres are surface markings identified by?

A
Elevated ridges (gyri), shallow grooves (sulci), and deep grooves (fissures)
Longitudinal fissure

Transverse cerebral fissure

276
Q

What are the 5 lobes of the cerebral hemispheres?

A

1) Frontal
2) Parietal
3) Temporal
4) Occipital
5) Insula

277
Q

Central sulcus of cerebral hemispheres is what ?

A

Separates precentral gyrus of frontal lobe and postcentral gyrus of parietal lobe

278
Q

Parieto-occipital sulcus Separates

A

occipital and parietal lobes

279
Q

Lateral sulcus outlines the?

A

temporal lobes

280
Q

Insula is what?

A

Fifth lobe of the cerebral hemisphere, buried within the lateral sulcus

281
Q

Three basic regions of Cerebral Hemispheres

A

Cerebral cortex of gray matter superficially
White matter internally (communication)
Basal nuclei deep within white matter

282
Q

Cerebral cortex

A

of gray matter superficially

283
Q

White matter

A

internally (communication)

284
Q

Basal nuclei deep

A

within white matter

285
Q

Thin (2–4 mm) superficial layer of gray matter
40% mass of brain
Site of conscious mind: awareness, sensory perception, voluntary motor initiation, communication, memory storage, understanding

A

Cerebral Cortex

286
Q

What is the Thin (2–4 mm) superficial layer of gray matter

A

Cerebral cortex

287
Q

What is 40% mass of brain?

A

Cerebral cortex

288
Q

What part of the region of the cerebral hemisphere is the site of conscious mind: awareness, sensory perception, voluntary motor initiation, communication, memory storage, understanding?

A

Cerebral cortex

289
Q

4 General Considerations of Cerebral Cortex

A

1) Three types of functional areas
1. ) Motor areas
2. ) Sensory areas
3. ) Association areas
2) Each hemisphere concerned with contralateral side of body

3) Lateralization (specialization)of cortical function in hemispheres

4) Conscious behavior involves entire cortex in some way
- No functional region of the brain acts alone

290
Q

What is the Primary Motor Cortex located?

A

Located in the large pyramidal cells of precentral gyri

291
Q

In Primary Motor Cortex there are Long axons that are called

A

pyramidal (corticospinal) tracts of spinal cord: Voluntary motor tracts

292
Q

Function of Primary Motor Cortex

A

Allows conscious control of precise, skilled, skeletal muscle movements

293
Q

In Primary Motor Cortex, Motor homunculi -

A

upside-down caricatures represent contralateral motor innervation of body regions

294
Q

Premotor cortex does what?

A

Helps plan movements; staging area for skilled motor activities

295
Q

Premotor cortex controls what?

A

Controls learned, repetitious, or patterned motor skills (typing, musical instrument) , and Controls voluntary actions that depend on sensory feedback

296
Q

Premotor cortex coordinates what?

A

Coordinates simultaneous or sequential actions

297
Q

Broca’s Area location

A

Present in one hemisphere (usually the left)

298
Q

Broca’s area functions

A

Motor speech area that directs muscles of speech production

299
Q

Broca’s area active in?

A

Active in planning speech and voluntary motor activities

300
Q

Frontal Eye Field Controls

A

Controls voluntary eye movements

301
Q

What are the sensory areas of the cerebral cortex?

A
Conscious awareness of sensation
Occur in parietal, insular, temporal, and occipital lobes
�Primary somatosensory cortex
Somatosensory association cortex
Visual areas
Auditory areas 
�Vestibular cortex
Olfactory cortex
Gustatory cortex
Visceral sensory area�
302
Q

Anterior Association Area is aka what?

A

Prefrontal Cortex

303
Q

What is the most common cortical region?

A

(Prefrontal Cortex) Anterior Association Area

304
Q

(Prefrontal Cortex)Anterior Association Area is involved in what?

A

Involved with intellect, cognition, recall, and personality

305
Q

What contains working memory needed for abstract ideas, judgment, reasoning, persistence, and planning ?

A

(Prefrontal Cortex)Anterior Association Area

306
Q

Development depends on what in Prefrontal Cortex or Anterior Association Area?

A

feedback from social environment

307
Q

Posterior Association Area is what region? and size?

A

Large region in temporal, parietal, and occipital lobes

308
Q

What Plays role in recognizing patterns and faces and localizing us in space?

A

Posterior Association Area

309
Q

What is Involved in understanding written and spoken language (Wernicke’s area)?

A

Posterior Association Area

310
Q

Limbic Association Area is part of what?

A

Part of limbic system

311
Q

What Involves cingulate gyrus, parahippocampal gyrus, and hippocampus?

A

Limbic Association Area

312
Q

What provides emotional impact that makes scene important and helps establish memories ?

A

Limbic Association Area

313
Q

In Lateralization of Cortical Function what are almost identical?

A

hemispheres

314
Q

Lateralization -

A

division of labor between hemispheres

315
Q

What is lateralization also called?

A

Also called split-brain concept

316
Q

Cerebral dominance -

A

hemisphere dominant for language (left hemisphere - 90% people), mathematics, and logic

317
Q

Left hemisphere (Lateralization of Cortical Function)

A

tba

318
Q

Right hemisphere (Lateralization of Cortical Function)

A

tba

319
Q

How quickly do the hemispheres communicate and how they do this?

A

Hemispheres communicate almost instantaneously via fiber tracts and functional integration

320
Q

Cerebral White Matter is what?

A

Myelinated fibers and tracts

321
Q

Cerebral White Matter does what?

A

Communication between cerebral areas, and between cortex and lower CNS

322
Q

What 3 fibers make up Cerebral white matter?

A

Association fibers
Commissural fibers
Projection fibers

323
Q

Association fibers—

A

horizontal; connect different parts of same hemisphere

324
Q

Commissural fibers—

A

horizontal; connect gray matter of two hemispheres

325
Q

Projection fibers—

A

vertical; connect hemispheres with lower brain or spinal cord

326
Q

what makes up the Basal nuclei/ganglia?

A

Subcortical nuclei

  • Caudate nucleus
  • Putamen
  • Globus pallidus
327
Q

Caudate nucleus + putamen =

A

striatum

328
Q

Putamen + globus pallidus =

A

lentiform nucleus

329
Q

What is basal nuclei/ganglia associated with?

A

Associated with subthalamic nuclei (diencephalon) and substantia nigra (midbrain)

330
Q

Basal nuclei 5 functions

A

Functions thought to be
1 Influence muscle movements
2 Role in cognition and emotion
3 Regulate intensity of slow or stereotyped movements
4 Filter out incorrect/inappropriate responses
5 Inhibit antagonistic/unnecessary movements

331
Q

What Influence muscle movements?

A

Basal Nuclei

332
Q

What part of brain has role in cognition and emotion?

A

Basal Nuclei

333
Q

What Regulate intensity of slow or stereotyped movements?

A

Basal Nuclei

334
Q

what Filter out incorrect/inappropriate responses?

A

Basal nuclei

335
Q

What Inhibit antagonistic/unnecessary movements?

A

basal nuclei

336
Q

What Three paired structures make up the Diencephalon ?

A

Thalamus
Hypothalamus
Epithalamus

337
Q

What Encloses third ventricle?

A

Diencephalon

338
Q

What is Gateway to cerebral cortex?

A

Thalamus

339
Q

What Sorts, edits, and relays ascending input?

A

Thalamus

340
Q

The Thalamus sorts, edits, and relays ascending inputs that what??

A

Impulses from hypothalamus for regulation of emotion and visceral function
Impulses from cerebellum and basal nuclei to help direct motor cortices
Impulses for memory or sensory integration

341
Q

What Mediates sensation, motor activities, cortical arousal, learning, and memory?

A

Thalamus

342
Q

What Controls autonomic nervous system (e.g., blood pressure, rate and force of heartbeat, digestive tract motility, respiration, pupil size, etc.)?

A

Hypothalamus

343
Q

What takes a part in the Physical responses/manifestations to emotions (limbic system)?

A

Hypothalamus

344
Q

Example of the hypothalamus with Physical responses/manifestations to emotions (limbic system):

A

Perception of pleasure, fear, and rage, and in biological rhythms and drives (sex drive)

345
Q

What Regulates body temperature – sweating/shivering?

A

Hypothalamus

346
Q

What Regulates hunger and satiety in response to nutrient blood levels or hormones?

A

Hypothalamus

347
Q

What Regulates water balance and thirst?

A

hypothalamus

348
Q

What is example of how the hypothalamus Regulates water balance and thirst?

A

ADH from pituitary to increase water concentration

349
Q

What Regulates sleep-wake cycles?

A

Hypothalamus

350
Q

Suprachiasmatic nucleus

A

(biological clock)

351
Q

What Controls endocrine system?

A

hypothalamus

352
Q

How does hypothalamus control endocrine sys?

A

Produces releasing hormones
Controls hormone secretions of anterior pituitary gland (adenohyp)
Produces posterior pituitary (neurohypophosis) hormones

353
Q

What are posterior pit hormones?

A

ADH

Oxytocin

354
Q

What are 3 regions of the brain stem?

A

Midbrain
Pons
Medulla oblongata

355
Q

How is the brain stem different to spinal cord?

A

Similar structure to spinal cord but contains nuclei embedded in white matter

356
Q

what Controls automatic behaviors necessary for survival

A

Brain stem

357
Q

What Contains fiber tracts connecting higher and lower neural centers?

A

brain stem

358
Q

The nuclei of brain stem are associated with what?

A

Nuclei associated with 10 of the 12 pairs of cranial nerves

359
Q

What separates pons and cerebellum?

A

Fourth ventricle seperates pons and cerebellum

360
Q

Fibers of pons do what?

A

Connect higher brain centers and spinal cord

Relay impulses between motor cortex and cerebellum

361
Q

Origin of cranial nerves are (pons) ?

A

V (trigeminal), VI (abducens), and VII (facial)

362
Q

Pons nuclei 2 things about them

A

Some nuclei of reticular formation

Nuclei help maintain normal rhythm of breathing

363
Q

Medulla oblongata Joins?

A

spinal cord at foramen magnum

364
Q

Medulla oblongata forms?

A

Forms part of ventral wall of fourth ventricle

365
Q

Medulla oblongata contains?

A

Contains choroid plexus of fourth ventricle

366
Q

Medulla oblongata pyramids have what?

A

Pyramids—contains two ventral longitudinal ridges formed by pyramidal tracts

367
Q

MEdulla oblongata Decussation of the pyramids—

A

crossover of corticospinal tracts

368
Q

Inferior olivary nuclei of medulla oblongata

A

—relay sensory information from muscles and joints to cerebellum

369
Q

Cranial nerves VIII, IX, X, and XII are associated with what?

A

medulla

370
Q

Vestibular nuclei (pons and medulla)—

A

mediate responses that maintain equilibrium

371
Q

Several nuclei (e.g., nucleus cuneatus and nucleus gracilis) does what ?

A

relay sensory information to the somatosensory cortex

372
Q

Functions of Medulla oblongata

A
Autonomic reflex center
Functions overlap with hypothalamus
Hypothalamus relays instructions via medulla
Cardiovascular center
Cardiac center 
Vasomotor center
 Respiratory centers
Generate respiratory rhythm
Control rate and depth of breathing (with pontine centers)
Additional centers: Regulate
Vomiting
Hiccuping
Coughing
Swallowing
Sneezing
373
Q

11% of brain mass is what?

A

Cerebellum

374
Q

What is Dorsal to pons and medulla?

A

cerebellum

375
Q

What gets Input from cortex, brain stem and sensory receptors ?

A

cerebellum

376
Q

What

Allows smooth, coordinated movements?

A

cerebellum

377
Q

Cerebellar hemispheres connected by?

A

vermis

378
Q

Folia (of cerevellum) —

A

transversely oriented gyri

379
Q

Each hemisphere of cerebellum has what?

A

three lobes

380
Q

What are 3 lobes of each hemisphere of the cerebellum called?

A

Anterior, posterior, and flocculonodular

381
Q

Arbor vitae— (cerebellum)

A

treelike pattern of cerebellar white matter

382
Q

Cerebellum receives impulses from what ?

A

cerebral cortex of intent to initiate voluntary muscle contraction

383
Q

Cerebellum signals are from?

A

Signals from proprioceptors and visual and equilibrium pathways continuously “inform” cerebellum of body’s position and momentum

384
Q

Cerebellar cortex calculates what?

A

the best way to smoothly coordinate muscle contraction

385
Q

Last step of cerebellum processing?

A

“Blueprint” of coordinated movement sent to cerebral motor cortex and brain stem nuclei

386
Q

2 Cognitive Functions of Cerebellum�

A

Role in thinking, language, and emotion
May compare actual with expected output and adjust accordingly

387
Q

Limbic System is what part of the brain?

A

Emotional or affective brain

388
Q

What 2 are two parts of limbic system?

A

Amygdaloid body

Cingulate gyrus

389
Q

Amygdaloid body—

A

recognizes angry or fearful facial expressions, assesses danger, and elicits fear response

390
Q

Cingulate gyrus—

A

role in expressing emotions via gestures, and resolves mental conflict

391
Q

What Puts emotional responses to odors?

Example: skunks smell bad

A

Limbic system

392
Q

Where is Most output relayed via hypothalamus?

A

Limbic sys

393
Q

What interacts with prefrontal lobes?

A

Limbic sys

394
Q

What does the limbic sys interacts with prefrontal lobes do?

A

React emotionally to things we consciously understand to be happening
Consciously aware of emotional richness in our lives

395
Q

Hippocampus and amygdaloid body play a role in what?

A

play a role in memory

396
Q

What Sends impulses to cerebral cortex to keep it conscious and alert?

A

Reticular activating system (RAS)

397
Q

This Filters out repetitive, familiar, or weak stimuli (~99% of all stimuli!)

A

Reticular activating system (RAS)

398
Q

What has Strong impulses reach our consciousness?

A

RAS

399
Q

What is Inhibited by sleep centers, alcohol, drugs?

A

RAS

400
Q

A Severe injury of what results in permanent unconsciousness (coma)?

A

RAS

401
Q

What RAS motor function?

A

Helps control coarse limb movements

Reticular autonomic centers regulate visceral motor functions

402
Q

What are centers in RAS for motor function?

A

Vasomotor centers
Cardiac center
Respiratory centers

403
Q

Memory

A

Storage and retrieval of information

404
Q

What are the 2 stages of memory?

A

Short-term memory

Long-term memory

405
Q

Short-term memory

A

(STM, or working memory)—temporary holding of information; limited to seven or eight pieces of information

406
Q

Long-term memory has

A

limitless capacity (LTM)

407
Q

Brain Structures Involved in Memory

A

Hippocampus and surrounding temporal lobes function in consolidation and access to memory

408
Q

ACh from basal forebrain is necessary what?

A

for memory formation and retrieval

409
Q

4 protections of BRain

A
  1. )Bone (skull)
  2. )Membranes (meninges)
  3. )Watery cushion (cerebrospinal fluid)
  4. ) Blood brain barrier
410
Q

Membranes (meninges) cover and protect?

A

CNS

Protect blood vessels and enclose venous sinuses

411
Q

Membranes (meninges) contain

A

Contain cerebrospinal fluid (CSF)

412
Q

Membranes (meninges) form

A

Form partitions in skull

413
Q

How many layers do Membranes (meninges) have and what are they called?

A

Dura mater
Arachnoid mater
Pia mater

414
Q

Meningitis

A

Inflammation of meninges

415
Q

Dura Mater latin words

A

Tough Mother

416
Q

What is the Strongest meninx?

A

Dura Mater

417
Q

Dura Matter definition

A

Two layers of fibrous connective tissue (around brain) separate to form dural venous sinuses

418
Q

Middle layer with weblike extensions is what?

A

Arachnoid Mater

419
Q

What is Separated from dura mater by subdural space?

A

Arachnoid Mater

420
Q

What has Subarachnoid space ?

A

Arachnoid Mater

421
Q

Subarachnoid space contains

A

contains CSF and largest blood vessels of brain

422
Q

Arachnoid villi of Arachnoid Mater protrude into superior sagittal sinus and permit . . .?

A

CSF reabsorption into the venous blood

423
Q

Pia Mater latin

A

Gentle mother

424
Q

What is Pia Matter?

A

Delicate vascularized connective tissue that clings tightly to brain

425
Q

CSF is Synthesized by what?

A

choroid plexus in epithalamus

426
Q

CSF composition

A

Watery solution formed from blood plasma

Less protein and different ion concentrations than plasma

427
Q

CSF has a constant what?

A

Constant volume

428
Q

CSF provides? ow?

A

Gives buoyancy to CNS structures

Reduces weight by 97%

429
Q

CSF function/ role

A

Protects CNS from blow and other trauma

Nourishes the brain and carries chemical signals

430
Q

Blood Brain Barrier helps?

A

Helps maintain stable environment for brain

431
Q

Blood brain barrier separates what?

A

Separates neurons from some bloodborne substances

432
Q

Cellular make up Blood brain barrier?

A

Continuous endothelium of capillary walls

Tight junctions

433
Q

What kind of barrier does the blood brain barrier have?

A

selective barrier

434
Q

The selected barrier of blood brain barrier allows what by how?

A

Allows nutrients to move by facilitated diffusion

435
Q

What does Blood Brain Barrier deny?

A

Metabolic wastes, proteins, toxins, most drugs, small nonessential amino acids, K+ denied

436
Q

What substances are allowed through the blood brain barrier?

A

Allows any fat-soluble substances to pass, including alcohol, nicotine, and anesthetics

437
Q

WHERE IS blood brain barrier absent?

A

Absent in some areas, e.g., vomiting center and hypothalamus, where necessary to monitor chemical composition of blood

438
Q

Where does spinal cord begin?

A

Begins at the foramen magnum (C1)

439
Q

Where does spinal cord end?

A

Ends at L1 or L2 vertebra

440
Q

2 functions of the spinal cord?

A

Provides two-way communication to and from brain

Contains spinal reflex centers

441
Q

Protection of spinal cord has what three things?

A

Bone, meninges, and CSF

442
Q

Epidural space of spinal cord

A

Cushion of fat and network of veins in space between vertebrae and spinal dura mater

443
Q

Where is CSF in spinal cord?

A

CSF in subarachnoid space

444
Q

Dural and arachnoid membranes extend to what?

A

sacrum, beyond end of cord at L1 or L2

445
Q

Where is site of lumbar puncture or tap?

A

sacrum, beyond end of cord at L1 or L2

446
Q

Spinal nerves of spinal cord is part of what ?

A

PNS

447
Q

Spinal nerves have how many pairs?

A

31

448
Q

Cervical and lumbosacral enlargements of spinal cord

A

Nerves serving upper and lower limbs emerge here

449
Q

Cauda equina of gray matter

A

Collection of nerve roots at inferior end of vertebral canal

450
Q

Dorsal horns of gray matter-

A

interneurons that receive somatic and visceral sensory input

451
Q

Ventral horns of gray matter

A

some interneurons; somatic motor neurons; axons exit cord via ventral roots

452
Q

Lateral horns of gray matter

A

sympathetic neurons

(only in thoracic and superior lumbar regions) -

453
Q

Dorsal roots of gray matter

A

– sensory input to cord (afferents)

454
Q

Dorsal root (spinal) ganglia gray matter—

A

cell bodies of sensory neurons

455
Q

Motor pathways involve two neurons:

A

Upper motor neurons

Lower motor neurons

456
Q

Upper motor neurons

A

Pyramidal cells in primary motor cortex

457
Q

Lower motor neurons

A

Ventral horn motor neurons

Innervate skeletal muscles

458
Q

Peripheral Nervous Sys provides what?

A

Provides links from and to world outside body

459
Q

What sys is All neural structures outside brain and spinal column?

A

PNS

460
Q

What does PNS All neural structures outside brain and spinal column include?

A

Sensory receptors
Peripheral nerves and associated ganglia
Efferent motor endings

461
Q

What are Specialized to respond to changes in environment (stimuli)?

A

Sensory Receptors

462
Q

Activation of what results in graded potentials that trigger nerve impulses?

A

Sensory Receptors

463
Q

Sensation (awareness of stimulus) and perception (interpretation of meaning of stimulus) occur in brain is what neural structure?

A

Sensory Receptors

464
Q

Mechanoreceptors—

A

respond to touch, pressure, vibration, and stretch (tissue deformation)

465
Q

Thermoreceptors—

A

sensitive to changes in temperature

466
Q

Photoreceptors—

A

respond to light energy (e.g., retina)

467
Q

Chemoreceptors—

A

respond to chemicals (e.g., smell, taste, changes in blood chemistry)

468
Q

Nociceptors—

A

sensitive to pain-causing stimuli (e.g. extreme heat or cold, excessive pressure, inflammatory chemicals)

469
Q

What are 5 sensory receptors by stimulus type?

A
Mechanoreceptors
Thermoreceptors
Photoreceptors
Chemoreceptors
Nociceptors
470
Q

Exteroceptors

A

Receptors in skin for touch, pressure, pain, and temperature

Most special sense organs

471
Q

Interoceptors (visceroceptors)

A

Sensitive to chemical changes, tissue stretch, and temperature changes
Sometimes cause discomfort, hunger, thirst, but usually unaware of their workings

472
Q

Proprioceptors

A

Respond to stretch in skeletal muscles, tendons, joints, ligaments, and connective tissue coverings of bones and muscles

473
Q

3 Sensory Receptor by location?

A

Proprioceptors
Interoceptors (visceroceptors)
Exteroceptors