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Anaphy Lec > Unit 4 Part 1 > Flashcards

Unit 4 Part 1 Flashcards

1
Q

The master controlling and communication system of the body

A

Nervous System

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2
Q

Controls and integrates all body activities within limits that maintain life

A

Nervous System

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3
Q

Three basic functions of nervous system

A
  1. Sensory Function
  2. Integrative function
  3. Motor function
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4
Q

▪ Monitors internal and external stimuli (changes)
▪ Afferent pathway to the brain
▪ Receptors

A

Sensory Function

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5
Q

▪ Process and interprets information
▪ Decides appropriate response

A

Integrative Function

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6
Q

▪ Efferent pathway to effector organs (muscles or glands), effects a response

A

Motor Function

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7
Q

Basic divisions of the nervous system

A

Central Nervous System
Peripheral Nervous System

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8
Q

Central Nervous System includes

A

brain and spinal cord

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9
Q

Peripheral Nervous System includes

A

cranial nerves, spinal nerves, ganglia, enteric plexuses, sensory receptors

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10
Q

Functional Classification of the PNS

A

Sensory (afferent) division
Motor (efferent) division

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11
Q
  • carrying toward a center (usually integrating center, the CNS)
    -Nerve fibers that carry information to the central nervous system
    -Somatic sensory
    -Visceral sensory
A

Sensory (afferent) division

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12
Q

Somatic sensory includes

A

(skin, skeletal muscle)

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13
Q

Visceral sensory includes

A

(visceral organs)

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14
Q

-Nerve fibers that carry impulses away from the central nervous system
-Activate (effect) muscles or glands to bring about a response.

A

Motor (efferent) division

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15
Q

Motor (efferent) = 2 divisions

A

Somatic nervous system
Autonomic nervous system

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16
Q

voluntary (skeletal muscles)

A

Somatic nervous system

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17
Q

involuntary (smooth and cardiac muscles, glands)

A

Autonomic nervous system

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18
Q

-basic structural units of the nervous system
-highly specialized cells
-conduct electrical signals from one part of the
body to another
-signals are transmitted along the plasma membrane in the form of nerve impulses or action potentials

A

Neuron

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19
Q

Characteristics of Neurons

A

-They have extreme longevity.
-They do not divide
-They have an exceptionally high metabolic
rate
-Neurons cannot survive for more than a few
minutes without oxygen

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20
Q

– metabolic center

A

Cell body

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21
Q

info for protein synthesis

A

Nucleus

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22
Q

Nissl bodies location

A

in ER

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23
Q

maintain structure

A

Neurofilaments

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24
Q

Cell processes

A

a) Dendrites
b) Axons

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25
Q

-Conducts impulses towards
the cell body (from other neurons or sensory receptors)
- short, highly branched & unmyelinated
- Surfaces specialized for contact with other neurons
-Most are extensions from the neuron cell body; others project from the peripheral ends of some axons
-Contains neurofibrils & Nissl bodies

A

Dendrites

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26
Q

-Conduct impulses away from cell body
-Long, thin cylindrical process of cell, branched or unbranched
-Arises at axon hillock
- Impulses arise from initial segment (trigger zone)
-Side branches (collaterals) end in fine processes called axon terminals
-Swollen tips called synaptic end bulbs contain vesicles filled with neurotransmitters

A

Axons

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27
Q

Neurons can be classified ___ or ____

A

structurally, functionally

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28
Q

Neurons are grouped ____ according to
the number of ___ that extend from the
cell body

A

structurally, processes

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29
Q

Structural Classification of Neurons

A

-Multipolar
-Bipolar
-Unipolar

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30
Q

-several dendrites & one axon
-most common cell type

A

multipolar

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31
Q

-one main dendrite & one axon
-found in retina, inner ear & olfactory

A

bipolar neurons

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32
Q

-one process only (develops from a bipolar)
-are always sensory
neurons

A

unipolar neurons

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33
Q

The ___ classification scheme groups neurons
according to the ___ in which the nerve impulse ___ relative to the CNS

A

functional; direction; travels

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34
Q

Functional Classification

A

▪ Sensory neurons

▪ Motor neurons

▪ Interneurons

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35
Q

-afferent neurons
-They transmit impulses toward the CNS from
sensory receptors in the PNS
-The single (unipolar) process is divided into the
central process and the peripherial process

A

Sensory Neurons

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36
Q

Sensory neurons have their cell bodies in __
outside of the ____

A

ganglia; cns

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37
Q

specialized to respond to changes in environment

A

Sensory receptors

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38
Q

Three ways to classify receptors:

A
  • type of stimulus
  • body location
  • structural complexity
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39
Q

Classification by Stimulus Type

A

▪ Mechanoreceptors
▪ Thermoreceptors
▪ Photoreceptors
▪ Chemoreceptors
▪ Nociceptors

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40
Q

respond to touch, pressure, vibration, and stretch

A

Mechanoreceptors

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41
Q

sensitive to changes in temperature

A

Thermoreceptors

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42
Q

respond to light energy (example: retina)

A

Photoreceptors

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43
Q

respond to chemicals (examples: smell, taste, changes in blood chemistry)

A

Chemoreceptors

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44
Q

sensitive to pain-causing stimuli
(examples: extreme heat or cold, excessive pressure, inflammatory chemicals)

A

Nociceptors

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45
Q

Classification by Location

A

Exteroceptors
Interoceptors (visceroceptors)
Proprioceptors

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46
Q

-Respond to stimuli arising outside body
-Receptors in skin for touch, pressure, pain, and
temperature
-Most special sense organs

A

Exteroceptors

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47
Q

-Respond to stimuli arising in internal viscera and
blood vessels
-Sensitive to chemical changes, tissue stretch, and
temperature changes
-Sometimes cause discomfort but usually person is
unaware of their workings

A

Interoceptors (visceroceptors)

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48
Q

▪ Respond to stretch in skeletal muscles, tendons,
joints, ligaments, and connective tissue coverings of bones and muscles
▪ Inform brain of one’s movements

A

Proprioceptors

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49
Q

Majority of sensory receptors belong to one of two
categories:

A

▪ Simple receptors of the general senses
▪ Receptors for special senses

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50
Q

▪ Modified dendritic endings of sensory neurons
▪ Are found throughout body and monitor most
types of general sensory information

A

Simple receptors of the general senses

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51
Q

▪ Vision, hearing, equilibrium, smell, and taste
▪ All are housed in complex sense organs

A

Receptors for special senses

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52
Q

▪ Neurons that carry impulses away from the CNS to effector organs (muscles and glands) are called motor or efferent neurons
▪ Upper motor neurons are in the brain
▪ Lower motor neurons are in PNS
▪ multipolar and their cell bodies are located in the CNS (except autonomic)
▪ form junctions with effector cells, signaling muscle to contract or glands to secrete

A

Motor Neurons

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53
Q

▪ lie between the motor and sensory neurons
▪ Form complex neural pathways
▪ Confined to CNS
▪ Make up 99.98% of the neurons of the body and are the principle neuron of the CNS
▪ Almost all are multipolar
▪ show great diversity in the size and branching patterns of their processes

A

Interneuron or Association Neurons

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54
Q

is the large neuron found in the primary motor cortex of the cerebrum

A

Pyramidal cell

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55
Q

interneuron from the cerebellum

A

Purkinje cell

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56
Q

-Supporting Cells
-Half of the volume of the CNS
-Smaller cells than neurons
-50X more numerous
-Not conduct impulses
-Cells can divide

A

Neuroglial Cells

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57
Q

▪ Star-shaped
▪ Most abundant
▪ Form blood-brain barrier
▪ Metabolize neurotransmitters (glutamate)
▪ Recapture and Recycle K+ ions
▪ Provide structural support
▪ Play a role in exchanges of ions between capillaries and neurons
▪ Involved with synapse formation in developing
neural tissue
▪ Produce molecules necessary for neural growth (brain-derived trophic factor BDTF)
▪ Propagate calcium signals that may be involved in memory

A

Astrocytes

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58
Q

Metabolize neurotransmitters

A

(glutamate)

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59
Q

Produce molecules necessary for neural growth

A

(brain-derived trophic factor BDTF)

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60
Q

Propagate ___ signals that may be involved in
memory

A

calcium

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61
Q

▪ Most common glial cell type
▪ Each forms myelin sheath around more than one axons in CNS
▪ Analogous to Schwann cells of PNS

A

Oligodendrocytes

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62
Q

▪ Smallest and least abundant cells found near
blood vessels
▪ Phagocytic role
▪ Derived from cells that also gave rise to macrophages & monocytes; migrate to the CNS during embryonic and fetal development

A

Microglia

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63
Q

clear away dead cells

A

Phagocytic role

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64
Q

▪ Form epithelial membrane lining cerebral cavities & central canal
▪ Produce cerebrospinal fluid (CSF)
▪ Cilia aid circulation of CSF

A

Ependymal cells

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65
Q

▪ These cells are similar in type and differ mainly in location

A

Neuroglia in the PNS

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66
Q

There are two supporting cells in the PNS

A

▪ Satellite cells
▪ Schwann cells

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67
Q

▪ Flat cells surrounding neuronal cell bodies in peripheral ganglia
▪ controlling the chemical environment of neurons
▪ Support neurons in the PNS ganglia; ACT AS
PROTECTIVE CUSHIONING

A

Satellite Cells

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68
Q

▪ produces part of the myelin sheath in the PNS
▪ protective role: aid in maintaining the integrity of normally functioning nerve fibers
▪ vital to peripheral nerve fiber regeneration – PNS only,

A

Schwann Cell

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69
Q

▪ Insulation of axon
▪ Increase speed of nerve impulse
▪ Makes impulse propagation more energy efficient
▪ White lipid protein substance

A

Myelination

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70
Q

▪ Prevents the leakage of electrical current from the axon
▪ Increases the speed of impulse conduction

A

Insulation of axon

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71
Q

All axons surrounded by a lipid & protein covering (myelin sheath) produced by

A

Schwann cells

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72
Q

cytoplasm & nucleus of Schwann cell

A

Neurilemma

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73
Q

gaps that occur at regular intervals about 1mm apart

A

nodes of ranvier

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74
Q

-found in portions of the autonomic nervous system as well as in some sensory fibers
-Thin, slowly conducting axons lack a myelin sheath

A

Unmyelinated fibers

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75
Q

▪ Neurilemma is found
▪ nodes of ranvier
▪ Only thick, rapidly conducting axons are sheathed in myelin
▪ nerve impulses do not travel along the myelin-covered regions of the axonal membrane, but instead jumps from the membrane of one Node of Ranvier to the next greatly increasing impulse conduction

A

Myelination: PNS

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76
Q

myelinated axons in PNS, nerve impulses do not travel along the myelin-covered regions of the axonal membrane, but instead____

A

jumps from the membrane of one Node of Ranvier

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77
Q

Myelinated axons transmit nerve impulses rapidly at what speed

A

150 meters/second

78
Q

Unmyelinated axons transmit quite slowly at what speed

A

1 meter/second

79
Q

▪ Oligodendrocytes myelinate axons
▪ Broad, flat cell processes wrap about ___ axons, but the cell bodies do not surround the axons
▪ No neurilemma is formed
▪ Little regrowth after injury is possible

A

Myelination: CNS

80
Q

Little regrowth in CNS after injury is possible due to the

A

lack of a distinct tube or neurilemma

81
Q

▪ Structure that contain a number of cell bodies in the
PNS
▪ Occurs in the PNS
▪ Form the plexuses
▪ Dorsal root ganglia, autonomic ganglia, cranial nerve ganglia

A

GANGLIA

82
Q

▪ Structure that contain a number of cell bodies in the CNS
▪ Occur in the CNS
▪ Occur in the gray matter of the brain
▪ Caudate, putamen, dentate, emboliform, pallidum, substantia nigra, subthalamic nuclei

A

NUCLEI

83
Q

Bundles of nerve fibers running through CNS

A

Tracts

84
Q

Bundles of nerve fibers running through PNS

A

Nerves

85
Q

Nerve Fibers

A

Tracts
Nerves

86
Q

myelinated processes

A

White matter

87
Q

nerve cell bodies, dendrites, axon terminals,
bundles of unmyelinated axons and neuroglia

A

Gray matter

88
Q

Neurons are electrically excitable due to the

A

voltage difference across their membrane

89
Q

Excitable cells communicate with 2 types of electric signals

A

Action potentials
Graded potentials

90
Q

electric signal that can travel long distances

A

Action potentials

91
Q

electric signal that are local membrane changes only

A

Graded potentials

92
Q

In living cells, production of action potential or graded potential depends upon

A

upon the existence of resting membrane
potentials and existence of certain ions

93
Q

Leakage (nongated)
channels are always

A

open

94
Q

Gated channels can

A

open and close

95
Q

gated channels can be:

A

a. Chemically (ligand)-gated
b. Mechanically-gated
c. Voltage-gated

96
Q

-Leakage channels alternate between open
and closed
-K+ channels are more numerous than Na+ channels

A

Ion Channels in Neurons - Leakage

97
Q

-Ligand-gated channels respond to chemical
stimuli (ligand binds to receptor)\
-Mechanically-gated channels respond to
mechanical vibration or pressure stimuli
-Voltage-gated channels respond to direct
changes in membrane potential

A

Ion Channels in Neurons - Gated

98
Q

Nerve & Muscle cells are

A

“excitable”

99
Q

Capable of self-generating electrical impulses
at their membranes

A

“excitable”

100
Q
  • Electrical potentials exist across the
    membranes of essentially all cells of the
    body
  • Nerve & Muscle cells are “excitable” - -
    Capable of self-generating electrical impulses
    at their membranes
  • Concentration difference of ions across a
    selectively permeable membrane can
    produce a membrane potential.
A

Membrane Potentials

101
Q

difference in potential ( voltage ) between
the inner side & outer side of the membrane

A
  • Inside cell more negative and more K+
  • Outside cell more positive and more Na+
102
Q

– Must exist for action
potential to occur
– The value for Vm in
inactive muscle cells is
typically btwn –80 and
–90 millivolts.
– Cells that exhibit a Vm
are said to be
polarized.
– Vm can be changed by
influx or efflux of
charge.

A

Membrane Potentials

103
Q

It ranges between -70 and -90 mV in different
excitable tissue cells

A

Resting Membrane Potential ( RMP)

104
Q

MP in a stimulated cell that is producing a local, non-propagated potential;
-an electrical change which is measurable only in the immediate vicinity of the cell but not far
from it.

A

Graded Potential (Local Response )

105
Q

Small deviations in
resting membrane
potential of

A

-70mV
(more negative
inside)

106
Q

occurs in response to the
opening of a mechanically-gated or ligand-
gated ion channel

A

Graded Potentials

107
Q

The amplitude of a graded potential
depends on the

A

stimulus strength

108
Q

Graded potentials can be add together to
become larger

A

amplitude

109
Q

MP in case of a
nerve/muscle that is generating a propagated
electrical potential after stimulation by effective
stimulus

A

Action potential ( AP)

110
Q

– Large changes in cell membrane potential (charge)
– Inside of the cell becomes more positive relative
to the outside of the cell
– Function to transmit information over long
distances
– Electrical signal that travels along the nerve axon
and ends at the synaptic terminal
– All-or-none principle - Like camera flash system
– RESULTS IN: Releases neurotransmitter
(acetylcholine or ACh)

A

Action Potentials

111
Q

level of depolarization
needed to trigger an action potential. Action
potential does not occur until
threshold potential has been reached.

A

Threshold potential

112
Q

state membrane
suddenly becomes permeable to Na+ ions;
Allows tremendous numbers of (+) charged
Na+ ions to flow to the interior of the axon;
Potential rises rapidly in the (+) direction

A

Depolarization stage

113
Q

Na channels begin to close; K
channels open more than they normally
do; Rapid diffusion of K+ ions to the exterior
re-establishes the normal negative resting
membrane potential

A

Repolarization

114
Q

Membrane potential may
briefly become over negative; due to opened
voltage-gated K channels

A

Hyperpolarization

115
Q

Ion channels open:
1. Na+ rushes ___
(__polarization)
2. K+ rushes ___
(__polarization)

A

in; de
out; re

116
Q

Action potentials can only occur if the
membrane potential reaches

A

threshold

117
Q

Period of time during which neuron can
not generate another action potential

A

Refractory Period of Action Potential

118
Q

▪ even very strong stimulus will
not begin another AP
▪ From beginning of action potential
until near end of repolarization
▪ Na+ channels are open or
recovering

A

Absolute refractory period

119
Q

▪ a suprathreshold stimulus will be
able to start an AP
▪ Occurs when the membrane is
hyperpolarised (-80mV), where the
K+ channels are open

A

▪ Relative refractory period

120
Q

Resting membrane
potential is at

A

-70mV

121
Q

Depolarization is the
change from

A

-70mV to
+30 mV

122
Q

Repolarization is the
reversal from

A

+30 mV
back to -70 mV)

123
Q

▪ nerve is -70mV

▪ skeletal & cardiac muscle is closer to -90mV

A

Resting membrane potential

124
Q

Duration of nerve impulse is

A

1/2 to 2 msec

125
Q

Duration muscle action potential
skeletal
cardiac & smooth

A

1-5 msec
10-300msec

126
Q

Fastest nerve conduction velocity is ___ times faster than velocity over skeletal muscle fiber

A

18

127
Q

Propagation of An Action Potential

A

▪ as Na+ flows into the cell
during depolarization, the
voltage of adjacent areas
is effected and their
voltage-gated Na+
channels open
▪ self-propagating along the
membrane

128
Q

nerve
impulse

A

traveling action
potential

129
Q

Nerve impulse conduction
in which the impulse jumps
(Salta) from node to node

A

Saltatory Conduction

130
Q

The propagation speed of a nerve impulse is not related to__

A

stimulus strength.

131
Q

the___, myelinated fibers conduct impulses __ due to size & saltatory conduction

A

larger; faster

132
Q

myelinated somatic sensory & motor to skeletal muscle
largest

A

A fibers

133
Q

a fibers speed

A

(5-20 microns & 130 m/sec)

134
Q

myelinated visceral sensory & autonomic preganglionic
medium

A

B fibers

135
Q

B fibers speed

A

(2-3 microns & 15 m/sec)

136
Q

▪ unmyelinated sensory & autonomic motor
smallest

A

C fibers

137
Q

C fibers speed

A

.5-1.5 microns & 2 m/sec

138
Q

Action potentials can travel along axons at speeds of

A

of 0.1-100m/s.

138
Q

Action potentials can travel along axons at speeds of

A

of 0.1-100m/s.

139
Q

The speed is affected by 3 factors:

A

Temperature
Axon diameter
Myelin sheath

140
Q

increases the speed
of propagation dramatically,

A

saltatory propagation

141
Q

Application : Local Anesthetics

A

▪ Prevent opening of voltage-gated Na+ channels

▪ Nerve impulses cannot pass the anesthetized region

▪ Novocaine and lidocaine

142
Q

(1)May be blocked in its transmission from one neuron
to the next
(2)May be changed from a single impulse into
repetitive impulses
(3)May be integrated with impulses from other
neurons to cause highly intricate patterns of
impulses in successive neurons.

A

Fate of Action Potentials

143
Q

*A connection between a neuron and a second cell
*In the CNS, this other cell is also a neuron.
*In the PNS, the other cell may be either a neuron or an effector cell e.g. gland or muscle

A

Synapse

144
Q

from axon to dendrite

A

axodendritic

145
Q

from axon to cell body

A

axosomatic

146
Q

from axon to axon

A

axoaxonic

147
Q

from dendrite to dendrite

A

dendrodenritic

148
Q

from dendrite to cell body

A

dendrosomatic

149
Q

2 Types of synapses

A

electrical
chemical

150
Q

▪ ionic current spreads to next cell through gap
junctions
▪ faster, two-way transmission & capable of
synchronizing groups of neurons

A

electrical

151
Q

one-way information transfer from a presynaptic
neuron to a postsynaptic neuron

A

chemical

152
Q

both electrical and chemical,
e.g. neurons in lateral vestibular nucleus

A

CONJOINT SYNAPSE

153
Q
  1. Have direct open fluid channels that conduct electricity from one cell to the next without interruption
  2. Have gap junctions which allow the movement of ions
  3. Very few in the CNS (brain and glial cells) but are the
    predominant type in the periphery of the body (i.e.
    skeletal, cardiac and smooth muscle contraction)
  4. The bidirectional transmission of electrical synapses
    permits them to help coordinate the activities of large
    groups of interconnected neurons.
  5. Promotes synchronous firing of a group of interconnected
    neurons - For example, in Mental attention, Emotions and
    Memory, Arousal from sleep
A

Electrical Synapse

154
Q
  1. Almost all of the synapses in the CNS
  2. First neuron secretes a neurotransmitter
  3. Neurotransmitter binds to receptors on the second neuron
    (excites, inhibits, or modifies its sensitivity)
  4. Always transmit signals in one direction (from the pre-synaptic neuron (releases neurotransmitter) to the post-
    synaptic neuron - Called the principle of one way conduction
A

Chemical Synapse

155
Q

Factors Affecting Synaptic Transmission

A
  1. pH of the interstitial fluid
  2. Hypoxia – depresses neurons
  3. Drugs, toxins and diseases
156
Q

neuronal excitability; causes cerebral epileptic seizures (Increased excitability cerebral neurons) e. g. overbreating in person with
epilepsy

A

Alkalosis

157
Q

–decreased neuronal activity; pH around 7.0 usually causes a coma
(e.g.severe diabetic or uremic acidosis)

A

Acidosis

158
Q

depresses neurons

A

Hypoxia

159
Q

caffeine found in coffee, tea,
strychnine, theophylline, theobromine increases neuronal
excitability by decreasing the threshold for excitation of neurons

A

Drugs, toxins and diseases

160
Q

▪ More than 50 chemical substances have been proven
▪ Two groups: small molecule (rapidly acting) and neuropeptides (slowly acting)

A

Neurotransmitters

161
Q

▪ Synthesized in the cytosol of the presynaptic
terminal

▪ Absorbed by means of active transport intro
transmitter vehicles

▪ Continuous recycling of vesicles

A

Small-Molecule Transmitters

162
Q

▪ Typical small-molecule
transmitter
▪ released by many PNS neurons & some CNS
▪ Excitatory in the central nervous system
▪ Excitatory on NMJ but inhibitory at others – mixed action depending on receptor
▪ inactivated by acetylcholinesterase

A

Acetylcholine (ACh)

163
Q
  • modified
    amino acids (tyrosine)
A

Biogenic Amines

164
Q

regulates mood,
dreaming, awakening
from deep sleep

A

norepinephrine

165
Q

regulating skeletal muscle tone

A

dopamine

166
Q

control of mood, temperature regulation, & induction of sleep

A

serotonin

167
Q

removed from synapse &
recycled or destroyed by
enzymes (monoamine
oxidase or catechol-0-
methyltransferase)

A

Biogenic Amines

168
Q

secreted at the
synapses of spinal cord,
inhibitory

A

Glycine

169
Q

released by nearly
all excitatory neurons in the
brain – sensory pathways
entering the CNS and spinal
cortex

A

Glutamate

170
Q

inhibitory
neurotransmitter for 1/3 of all
brain synapses and spinal
cord

A

GABA Gamma Amino Butyric
Acid

171
Q

Gamma Amino Butyric
Acid

A

Valium

172
Q

▪ excitatory in both CNS & PNS
▪ released with other neurotransmitters (ACh & NE)

A

ATP and other purines (ADP, AMP & adenosine)

173
Q

▪ formed from amino acid arginine by an enzyme
▪ formed on demand and acts immediately
▪ diffuses out of cell that produced it to affect
neighboring cells
▪ may play a role in memory & learning
▪ first recognized as vasodilator that helps lower blood pressure (cerebral and peripheral)

A

Gases (nitric oxide or NO)

174
Q

▪ 3-40 amino acids linked by peptide bonds
▪ Slow acting→more prolonged actions
▪ Synthesized as integral parts of large-protein
molecules by ribosomes in the cell body
▪ Substance P
▪ Pain relief

A

Neuropeptides

175
Q

enhances our
perception of pain

A

Substance P

176
Q

pain-relieving effect by blocking the release of
substance P

A

enkephalins

177
Q

___ may produce loss of pain sensation
because of release of ____ substances
such as ___ or ___

A

acupuncture, opioids-like, endorphins, dynorphins

178
Q

Action potential travels from

A

axon

179
Q

Action potential reaches

A

end bulb and voltage-gated Ca+ 2
channels open

180
Q

Ca+2 flows___ the
concentration gradient

A

inward down

181
Q

causes triggers
rapid fusion of synaptic
vesicles triggering release of
neurotransmitter

A

Inward diffusion

182
Q

crosses synaptic cleft & binding to
ligand-gated receptors in the
post-synaptic membrane

A

Neurotransmitter

183
Q

Quantity of transmitter
released is directly related to

A

the amount of Ca that enters

184
Q

The effect of a
neurotransmitter can be either

A

excitatory or inhibitory

185
Q

a depolarizing postsynaptic
potential is called

A

an EPSP

186
Q

an inhibitory postsynaptic
potential is called

A

an IPSP

187
Q

Diffusion out of synaptic
cleft into surrounding fluid

A

move down
concentration gradient

188
Q

Enzymatic degradation

A

acetylcholinesterase

189
Q

Uptake by neurons or glia
cells – active transport back
into pre-synaptic terminal
(norepinephrine)

A

neurotransmitter
transporters

Anaphy Lec (13 decks)

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