Exam 1 Info- Slides Contd Flashcards
(90 cards)
1
Q
(functions of the NS) sensory input:
information gathered by sensory receptors about … and … changes
A
internal; external
2
Q
(functions of the NS)
…: interpretation of sensory input
A
integration
3
Q
(functions of the NS) motor output:
activation of … (.. and …) produces a response
A
effector organs; muscles; glands
4
Q
central nervous system:
… and …
… and … center
A
brain; spinal
integration; command
5
Q
peripheral nervous system (PNS)
paired … and … carry messages to and from the CNS
A
spinal and cranial nerves
6
Q
(peripheral nervous system- PNS) two functional divisions:
1. sensory (…) division:
somatic afferent fibers – convey impulses from …, …, and …
visceral afferent fibers - convey impulses from …
A
afferent;
skin; skeletal muscles; joints;
visceral organs
7
Q
(peripheral nervous system- PNS) motor (efferent) division:
transmits impulses from the .. to …
A
CNS; effector organs
8
Q
(motor division of PNS) … (…) NS:
conscious control of skeletal muscles
A
somatic; voluntary
9
Q
(motor division of PNS) … (…) NS (ANS):
visceral motor nerve fibers
regulates …, …, and …
two functional subdivisions: …, …
A
autonomic; involuntary;
smooth muscle; cardiac muscle; glands;
sympathetic; parasympathetic
10
Q
two principal cell types in NS:
…: excitable cells that transmit electrical signals
… (… cells): supporting cells
A
neurons;
neuroglia; glial
11
Q
(neuroglia) glial cells include: ... (CNS) ... (CNS) ... (CNS) ... (CNS) ... (PNS) ... (PNS)
A
astrocytes; microglia; ependymal cells; oligodendrocytes; satellite cells; schwann cells;
12
Q
(neuroglia) astrocytes:
most abundant, versatile, and highly branched glial cells
cling to …, …, and …
… and … neurons
A
neurons; synaptic endings; capillaries;
support; brace
13
Q
(neuroglia) astrocytes: help determine ... guide ... of young neurons control the ... participate in ... int he brain
A
capillary permeability;
migration;
chemical environment;
information processing
14
Q
(neuroglia) … are the most abundant CNS neuroglia
A
astrocytes
15
Q
(neuroglia) microglia:
small, ovoid cells with thorny processes
migrate toward … neurons
… microorganisms and neuronal debris
A
injured;
phagocytize
16
Q
(neuroglia) … are defensive cells in the CNS
A
microglial cells
17
Q
(neuroglia) ependymal cells:
range in shape from … to …
may be …
A
squamous; columnar; ciliated
18
Q
(neuroglia) ependymal cells:
may be ciliated:
line the … of the brain and spinal column
separate the … from the … in the cavities
A
central cavities;
CNS interstitial fluid;
cerebrospinal fluid
19
Q
(neuroglia) ependymal cells line … cavities
A
cerebrospinal fluid-filled
20
Q
(neuroglia) oligodendrocytes:
… cells
processes wrap CNS nerve fibers, forming …
A
branched;
insulating myelin sheaths
21
Q
(neuroglia) satellite cells:
surround … in the PNS
A
neuron cell bodies
22
Q
(neuroglia) schwann cells:
surround … and form …
vital to regeneration of
A
peripheral nerve fibers; myelin sheaths
23
Q
(neuroglia) schwann cells:
vital to … of damaged peripheral nerve fibers
A
regeneration
24
Q
(neurons-nerve cells) special characteristics:
long-llived (100 yrs or more)
…
high … rate - depends on continuous supply of oxygen and glucose
A
terminal differentiation;
metabolic
25
```
(neurons-nerve cells)
special characteristics:
plasma membrane functions in:
...
... during development
```
electrical signaling;
| cell-to-cell interactions
26
```
(neurons-nerve cells)
cell body (... or ...)
biosynthetic center of a neuron
spherical ... with ...
well-developed ...
network of ... (...)
```
perikaryon; soma;
nucleus; nucleolus;
Golgi apparatus;
neurofibrils; neurofilaments
27
(neurons-nerve cells) cell body:
... - cone-shaped area from which axon arises
clusters of cell bodies are called ... in the CNS, ... in the PNS
axon hillock;
| nuclei; ganglia
28
(neurons- Processes)
... and ...
bundles of processes are called ... in the CNS, ... in the PNS
dendrites; axons
| tracts; nerves
29
(dendrites)
short, tapering, and diffusely branched
... (...) region of a neuron
convey ... signals toward the cell body as ...
receptive; input;
| electrical; graded potentials
30
```
(the axon) one axon per cell arising from the ...
long axons (...)
occasional branches (...)
```
axon hillock;
nerve fibers;
axon collaterals
31
(the axon)
numerous ... branches
knoblike ... (... or ..)
terminal;
| axon terminals; synaptic knobs; boutons
32
(the axon) axon terminals:
... region of neuron
release ... to excite/inhibit other cells
secretory; neurotransmitters
33
(the axon)
... region of a neuron
generates and transmits ... (...) away from the cell body
conducting;
| nerve impulses; action potentials
34
(the axon)
molecules and organelles are moved along axons by motor molecules in two directions:
... - toward axonal terminal (e.g. mitochondria, membrane components, enzymes)
... - toward the cell body (e.g. organelles to be degraded, signal molecules, viruses, bacterial toxins)
anterograde;
| retrograde
35
cells of nervous system: axons transport
... axonal transport: moves material by ... (cytoplasmic) flow at 0.2-2.5 mm/day
... axonal transport: moves organelles at rates of up to 400 mm/day
slow; axoplasmic;
| fast
36
cells of nervous system: axons transport
fast axonal transport:
... (or ... ) transport: from cell body to axon terminal
... (or ...) transport: from axon terminal to cell body
forward; anterograde;
| backward; retrograde
37
fast axonal transport of membranous organelles:
1. peptides synthesized and packaged
2. fast axonal transport along ... network
3. vesicle contents released by ...
4. ....
5. ... fast axonal transport
6. old membrane components digested in ...
```
microtubule;
exocytosis;
synaptic vesicle recycling;
retrograde;
lysosomes
```
38
(myelin sheath) segmented ... sheath most long or large-diameter axons
it functions to:
... and ... the axon
increase ... of nerve impulse transmission
protein-lipoid;
protect; electrically insulate;
speed
39
(myelin sheath) in PNS:
Schwann cells wrap many times around the axon --> ...: concentric layers of schwann ...
...: peripheral bulge of Schwann cell cytoplasm
myelin sheath; cell membrane;
| neurilemma
40
(myelin sheath) in PNS:
| ...: myelin sheath gaps between adjacent Schwann; sites where ... can emerge
nodes of Ranvier; axon collaterals
41
(myelin sheath) 1. a schwann cell envelopes an axon
2. the schwann cell then rotates around the axon, wrapping its plasma membrane loosely around it in ...
4. the schwann cell ... is forced from between the membranes. the tight ... surrounding the axon form the myelin sheath
succesive layers;
cytoplasm;
membrane wrappings
42
thin nerve fibers are ...
| one schwann cell may incompletely enclose 15 or more ...
unmyelinated;
| unmyelinated axons
43
```
myelin sheaths in the CNS:
formed by processes of ..., not the whole cells
... are present
no ...
thinnest fibers are ...
```
oligodendrocytes;
nodes of ranvier;
neurilemma;
unmyelinated
44
...: dense collections of myelinated fibers
| ...: mostly neuron cell bodies and unmyelinated fibers
white matter;
| gray matter
45
structural classification-three types of neurons:
... - 1 axon and several dendrites
... - 1 axon and 1 dendrite
... (...) - single, short process that has two branches
multipolar;
bipolar;
unipolar; pseudounipolar
46
structural classification-three types of neurons:
| multipolar neurons are the most ... and are .. neurons and ..
.abundant; motor; interneurons
47
structural classification-three types of neurons:
| ... are rare; an example is retinal neurons
bipolar
48
structural classification-three types of neurons:
unipolar branches:
... process - more distal branch, often associated with a sensory receptor
... process - branch entering the CNS
peripheral;
| central
49
functional classification-three types of neurons:
... (...): transmit impulses from sensory receptors toward the CNS
... (...): carry impulses from the CNS to effectors
... (... neurons): shuttle signals through CNS pathways; most are entirely within the CNS
sensory; afferent;
motor; efferent;
interneurons; association
50
neuron function:
neurons are highly ...
respond to adequate stimulus by generating an ... (nerve impulse)
impulse is always the same regardless of ...
irritable;
action potential;
stimulus
51
(principles of electricity)
opposite charges attract each other
... is required to separate opposite charges across a membrane
... is liberated with the charges move toward one another
if opposite charges are separated, the system has ...
energy;
energy;
potential energy
52
...: measure of potential energy generated by separated charge
voltage (V)
53
...: voltage measured between two points
potential difference
54
...: the flow of electrical charge (ions) between two points
current (I)
55
...: hindrance to charge flow (provided by the plasma membrane)
Resistance (R)
56
...: substance with high electrical resistance
| ...: substance with low electrical resistance
insulator;
| conductor;
57
Ohm's Law:
```
V = IR
I = V/R
```
58
... serve as membrane ion channels
two main types of ion channels:
... (...) channels - always open
... channels (three types)
proteins;
leakage; nongated;
gated
59
gated ion channels:
... (...) channel: open with binding of a specific neurotransmitter
... channels: open and close in response to changes in membrane potential
... channel: open and close in response to physical deformation of receptors
chemically gated; ligand-gated;
voltage-gated;
mechanically gated
60
when gated channels are open:
ions diffuse quickly across the membrane along their ...:
along chemical conc gradients from .. conc to ... conc
along electrical gradients toward ...
electrochemical gradients;
higher; lower
opposite electrical charge
61
when gated channels are open:
| ion flow creates an ... and ... changes across the membrane
electrical current; voltage
62
(resting membrane potential - Vr) potential difference across the membrane of a resting cell:
approximately ... in neurons (... side of membrane is negatively charged relative to other side)
-70 mV; cytoplasmic
63
(resting membrane potential - Vr)
generated by:
differences in ionic makeup of ... and ...
... of the plasma membrane
intracellular fluid (ICF); extracellular fluid (ECF); differential permeability
64
differences in ionic makeup:
ICF has lower conc of ... and ... than ECF
ICF has higher conc of ... and ... (A-) than ECF
Na+; Cl-;
| K+; negatively charged proteins
65
differential permeability of membrane:
impermeable to ...
slightly permeable to ... (through leakage channels--higher ...)
75 times more permeable to .. (more ..., higher ...)
freely permeable to ...
A- (anionic proteins);
Na+; out of the cell
K_; leakage channels; in the cell;
Cl-
66
negative interior of the cell is due to much greater diffusion of ... than ...
... stabilizes the membrane potential by maintaining the concentration gradients for Na+ and K+
K+ out of the cell; Na+ diffusion into the cell;
| sodium-potassium pump
67
membrane potential changes when:
... across the membrane change
... of membrane to ... changes
changes in membrane potential are signals used to ..., ..., and ... information
concentrations of ions;
permeability; ions;
receive; integrate; send
68
two types of signals:
... --> incoming short-distance signals
... --> long-distance signals of axons
graded potentials;
| action potentials
69
depolarization
a ... in the membrane potential (toward ...)
inside of the membrane becomes less ... than the resting potential
... the probability of producing a nerve impulse
reduction; zero;
negative;
increases
70
hyperpolarization:
an ... in membrane potential (away from ..)
inside of the membrane becomes more ... than the resting potential
... the probability of producing a nerve impulse
increase; zero;
negative;
reduces
71
graded potentials:
short-lived, ... changes in membrane potential
... or ...
spreads as ... change the membrane potential of adjacent regions
localized;
depolarizations; hyperpolarizations;
local currents
72
(Action Potential- AP) brief reversal of membrane potential with a total amplitude of ... mV
occurs in ... cells and ...
does not ... over distance
principal means of ... neural communication
about 100;
muscle; axons of neurons;
decrease in magnitude;
long-distance
73
properties of gated channels:
each Na+ channel has two voltage-sensitive gates:
...: closed at rest; open with depolarization
...: open at rest; block channel once it is open
activation gates;
| inactivation gates
74
properties of gated channels:
each K+ channel has ... gate
... at rest
opens slowly with ...
one voltage-sensitive;
closes;
depolarization
75
depolarizing phase:
depolarizing local currents open ...
... causes more depolarization
at threshold (... to ... mV) positive feedback leads to opening of all ... and a reversal of membrane polarity to ... (spike of AP)
```
voltage-gated Na+ channels;
Na+ influx;
-55 to -50;
Na+ channels;
+30 mV
```
76
repolarizing phase:
Na+ channel ... close
membrane permeability to ... declines to resting levels
slow ... open
... exits the cell and internal negativity is restored
slow inactivation gates;
Na+;
voltage-sensitive K+ gates;
K+
77
hyperpolarization:
some ... channels remain open, allowing excessive ..
this causes ... of the membrane (...)
K+; K+ efflux;
| after-hyperpolarization; undershoot
78
```
Na+-K+ pump:
1. Na+ binding
2. ...
3. ... causes Na+ release and K+ binding
4. ... induced ... leads to K+ release
process repeats
```
phosphorylation;
conformational change;
dephosphorylation; conformational change
79
propagation of an action potential:
Na+ influx causes a patch of the axonal membrane to ...
... occur
Na+ channels toward the point of origin are ... and not affected by the ...
depolarize;
local currents;
inactivated;
local currents
80
propagation of an action potential:
local currents affect adjacent areas in the ... direction
depolarization opens ... and triggers an AP
... wave follows the depolarization wave
forward;
voltage-gated channels;
repolarization
81
```
at threshold:
membrane is depolarized by ... to ... mV
... increases
... exceeds ...
the positive feedback cycle begins
```
15; 20;
Na+ permeability;
Na+ influx; K+ efflux
82
...: weak local depolarization that does not reach threshold
subthreshold stimulus
83
...: strong enough to push the membrane potential toward and beyond threshold
threshold stimulus
84
AP is an ... phenomenon -- action potentials either happen completely, or not at all
all-or-none
85
all actions potentials are alike and are independent of ...
strong stimuli can generate action potentials ... than weaker stimuli
the CNS determines stimulus intensity by the ...
stimulus intesnity;
more often;
frequency of impulses
86
...: time from the opening of the Na+ channels until the resetting of the channels
ensures that each AP is an ... event
enforces ... of nerve impulses
absolute refractory period;
all-or-none;
one-way transmission
87
...: follows the absolute refractory period
most Na+ channels have returned to their resting state
some K+ channels are still open
... is occurring;
relative refractory period; repolarization
88
relative refractory period:
threshold for AP generation is ...
... may generate an AP
elevated;
| exceptionally strong stimulus
89
conduction velocities of neurons vary widely:
larger diameter fibers have ... resistance to local current flow and have ... impulse conduction
continuous conduction in unmyelinated axons is ... than ... in myelinated axons
less; faster;
slower;
saltatory conduction
90
conduction velocity:
myelin sheaths ... and prevent ...
saltatory conduction in myelinated axons is more than ... faster --> ... are located at the nodes; APs appear to jump rapidly from node to node
insulate; leakage of charge;
| 30 times; voltage-gated Na+ channels;
