fundamentals of the nervous system (ch 11) Flashcards
1
Q
all information has to go through…
A
the CNS
2
Q
steps of the information pathway
A
sensory (different) –> integration –> motor (efferent)
AKA
stimulus - receptor - CNS - effector - response
3
Q
divisions of the PNS
A
sensory and motor
4
Q
the CNS consists of…
A
the brain and spinal cord
5
Q
the PNS is…
A
the peripheral nervous system
6
Q
the sensory PNS deals with…
A
bringing info in
7
Q
the motor PNS deals with…
A
info going out
8
Q
divisions of the motor PNS
A
autonomic and somatic
9
Q
the autonomic motor PNS consists of…
A
smooth muscle
cardiac muscle
glands
(is self governed)
10
Q
the somatic motor PNS consists of
A
skeletal muscle
(is voluntary)
11
Q
somatic refers to…
A
surface
12
Q
visceral refers to…
A
inside
13
Q
special sense example
A
sight
14
Q
divisions of the autonomic motor PNS
A
sympathetic and parasympathetic
15
Q
sympathetic refers to…
A
working together (fight or flight)
16
Q
parasympathetic refers to…
A
around the sympathetic (rest and digest)
17
Q
neurons are…
A
nerve cells
18
Q
somas are…
A
cell bodies
19
Q
somas consist of…
A
a nucleus and organelles
20
Q
in the CNS, somas are located in…
A
gray matter
21
Q
in the PNS, somas are located in…
A
ganglia
22
Q
ganglia are…
A
collections of somas outside the brain/spinal cord
23
Q
dendrites are…
A
branches off the soma
24
Q
function of dendrites
A
increases surface area for receiving messages
25
axon means...
axis
26
axons come off the soma at...
the axon hillock
27
the axon hillock is...
where most neuron APs form/start
28
axons are _____ process
single
29
axons end at...
terminal branches with synaptic knobs containing a NT
30
in the CNS, axons are located in...
white matter
31
in the PNS, axons are located in...
nerves
32
myelin consists of...
the wrapping of cell membranes which are phospholipids (fatty/nonpolar)
33
function of myelin
increases AP transmission speed and rate
34
neuroglia means...
glue
35
neuroglia are...
supporting cells
36
neuroglia to neuron ratio
10:1
37
astrocyte means...
star cell
38
astrocytes are most commonly found in...
the CNS
39
function of astrocytes
bracing and supporting neurons and BVs (aka the blood-brain barrier)
40
microglial cells mean...
small glue cells
41
characteristics of microglial cells
motile (moves)
defends CNS
cleans up damage
42
ependymal means...
put over/on
43
function of ependymal cells
lining CNS fluid-filled cavities
44
ependymal cells are made of...
epithelium with cilia
45
oligodendrocyte means...
few branch cell
46
function of oligodendrocytes
processes/projections form CNS myelin that wrap a few different axons
47
multiple sclerosis is...
an autoimmune disease against CNS myelin, means "many scars"
48
function of schwann cells
forming PNS myelin
multiple small single cells wrap their membranes along the axon
can support/surround multiple unmyelinated axons
49
function of satellite cells
surrounds/supports somas in ganglia
50
neuroglia found in CNS
astrocytes, microglial cells, ependymal cells, oligodendrocytes
51
neuroglia found in PNS
schwann cells, satellite cells
52
neuron structure classifications
multipolar
bipolar
unipolar
53
multipolar neurons make up _____% of neurons
over 99
54
bipolar neurons are...
rare, sensory
part of the retina and nose
55
unipolar neurons are...
sensory
56
neuron function classifications
sensory
motor
interneurons/association neurons
57
function of sensory neurons
bringing info into the CNS
58
function of motor neurons
carrying info out of the CNS
59
interneurons are found...
within the CNS, and are the most common neuron
60
voltage is...
the separation of charged particles (ions)
61
how are ions separated
across the membrane
62
resistance is...
the hinderance of charged particle flow
63
current is...
the flow of charged particles
64
equation for Ohm's law
I = V/R
65
result of ion channel leakage
allows for a slow current because they are always open
66
gated ion channels can be ____ or ____
open, closed
67
ways to open/close gated ion channels
ligand/chemical
voltage
mechanical
68
in ligand gated ion channels...
a chemical binds to open or close ion channels
69
in voltage gated ion channels...
voltage changes on the membrane open or close the channel
70
in mechanically gated ion channels...
a pull on the membrane will open or close it
71
potential is...
the charge across a membrane
72
concentrations of the Na+ K+ ATP pump
more Na+ is outside
more K+ is inside
73
the charge inside of a neuron is around...
-70 mV
74
why is the inside of a neuron negative
leakage channels
75
at rest, the membrane is more permeable to ___ than ___
K+ than Na+
76
result of membrane permeability
K+ diffuses out until the inside membrane becomes more negative, continues until the charge reaches K+ equilibrium
77
graded (local) potentials are measured by...
voltage
78
graded potentials are...
a localized change to membrane Voltage
79
the current sink is...
where ions diffuse
80
steps of graded potentials
stimulus to cell induces ion channels to open, ions diffuse across the membrane at the current sink, which changes the charge across a membrane in a localized region
81
when Na+ channels are opened...
Na+ diffuses in, and charge becomes less negative
82
when K+ channels are opened...
K+ diffuses out, charge becomes more negative
83
when Cl- channels are opened...
Cl- diffuses in, charge becomes more negative
84
when Ca++ channels are opened...
Ca++ diffuses in, charge becomes less negative
85
characteristics of local/graded potential
graded
local
decremental
reversible
excitatory or inhibitory
86
graded refers to...
bigger stimuli open more ion channels, more ion flow, and a bigger voltage change
87
local means...
one area of the membrane
88
decremental means...
potential/voltage change decreases over distance
89
reversible means...
ions diffuse away, are pumped, and return to their original gradients
90
excitatory means...
chance of AP is increased (depolarization)
91
inhibitory means...
chance of AP is decreased (hyperpolarization)
92
APs are found in...
muscle cells and neurons
93
APs are...
brief, large depolarizations that are recreated along the membrane and acts as a signal over a distance
94
what happens in an AP
a stimulus depolarizes the membrane to threshold, opening voltage-gated channels for Na+ and K+, with Na+ first flowing in to depolarize the cell, then K+ flowing out to repolarize the cell
95
threshold is around ___ mV
-55
96
Na+ channels open up _____ and _____
quickly and briefly
97
K+ channels open up _____ and _____
slowly and for a longer period of time
98
depolarization stops at ___ mV
30
99
after a cell is repolarized, _____ occurs
after-hyperpolarization
100
characteristics of APs
non-decremental
irreversible
all or none rule
refractory periods
101
non-decremental means...
APs are recreated at the same voltage down a membrane
102
irreversible means...
once an AP starts, it keeps going
103
the all or none rule means...
there either is or isn't an AP, and all APs will be the same
104
types of refractory periods
absolute and relative
105
absolute refractory period
occurs while Na+ channels are open
the time during which there cannot be another AP
106
relative refractory period
occurs while K+ channels are open
the time during after an AP when the stimulus needed to get to threshold is increased (encoded by increase in AP frequency)
107
factors in AP propagation/conduction
size of neuron
myelination
108
bigger axons mean...
more ion flow and increased speed
109
unmyelinated neurons have APs...
recreated along every membrane part
110
myelinated neurons have APs...
only formed at the nodes (APs will leap)
111
synapse means...
clasp or join
112
general structure of a synapse
presynaptic neuron sends
synapse acts as an NT in the synaptic cleft
post synaptic cell receives the signal
113
types of synapses
electrical and chemical
114
electrical synapses have _____ and are important in ____
gap junctions, nervous system development
115
chemical synapses predominate in _____ and use _____
the nervous system, neurotransmitters
116
a synapse is located where on a post-synaptic cell
where the axon attaches
117
what is ACh
a neurotransmitter for the brain and autonomic nervous system
118
function of Alzheimer's medication
decreasing ACh breakdown by AChE in the CNS
119
types of amino acids
GABA
glycine
aspartic acid
glutamate
120
what is GABA/what does it do
the primary inhibitory NT in the CNS
opens channels for Cl-, resulting in hyperpolarization
121
amines mean...
nitrogen containing
122
types of neurotransmitters
ACh, amino acids, amines, neuropeptides, gases
123
types of amines
catecholamines
serotonin
histamines
124
types of neuropeptides
substance P
endorphins
enkephalins
125
types of catecholamines
made from tyrosine, can get converted to dopamine, to norepinephrine, to epinephrine
126
function of serotonin
mood
sleep/wake
balance/coordination
127
function of histamines
works within hypothalamus
128
neuropeptides are...
chains of amino acids
129
function of substance P
pain signals
130
function of endorphins and enkephalins
inhibiting pain
131
function of gases
most are neuromodulators, such as NO, CO, and H2S
132
neuromodulators are...
any chemical that can change or regulate any neuron activity not released at the synapse
133
synaptic transmission is...
a chemical synapse
134
steps of synaptic transmission
AP arrives at the synaptic knob, opening voltage gated Ca+ channels, diffusing in the presynaptic neuron, inducing exocytosis of synaptic vesicles containing an NT, which then diffuses across the synaptic cleft, binding to receptors to give its effect
135
the ionotropic effect...
uses ions
NT opens ion channels
ions diffuses across the postsynaptic membrane
136
the metabotropic effect...
is more common
NT binds to receptors on membrane of postsynaptic cell, receptor stimulates G protein, stimulating enzymes to create a second messenger
137
second messenger examples
cAMP, cGMP, Ca++
138
how does synaptic transmission stop
diffusion (of NT away)
enzyme (NT breakdown)
reuptake (by presynaptic neuron)
139
most common antidepressant meds are...
amine reuptake inhibitors
140
synaptic delay is...
when the synapse is the rate-limiting step for nervous information
141
EPSPs are...
excitatory post-synaptic potentials
when local depolarizations increase the chance of an AP
142
IPSPs are...
inhibitory post-synaptic potentials
when local hyperpolarizations decrease the chance of an AP
143
summation is...
adding up all the EPSPs and IPSPs
144
if summation reaches threshold (___ mV), then ____ occurs.
-55, an AP
145
temporal summation is...
"time", involves one synapse firing repeatedly within a short timeframe
146
spatial summation is...
"space", involves more that one synapse firing near similar time
147
synaptic plasticity means...
things change
148
process of synaptic plasticity
new synapses are formed
old synapses are lost
synapses work more effectively
149
types of neural processing
serial and parallel
150
types of neuron pools
divergent pathway
convergent pathway
reverberating circuit
parallel after-discharge
151
divergent pathways are...
when few neurons output many neurons
ex: motor cortex to skeletal muscle
152
convergent pathways are...
when many neurons output few neurons
ex: sensations to memories
153
reverberating circuits are...
when neurons can loop back to repeat or continue
ex: breathing and walking
154
parallel after-discharge is...
when neurons split off then recombine (prolonged message)
ex: math
