Chapter 11 Flashcards
1
Q
consists of: brain and spinal cord
function: process and coordinate sensory data from inside and outside the body, motor commands to control skeletal muscles, higher functions of the brain
A
central nervous system
2
Q
includes: all nervous tissue outside CNS, excluding ENS
functions: deliver sensory information to the CNS and carry motor commands to peripheral tissues and systems
A
peripheral nervous system
3
Q
detect changes or respond to stimuli. Neurons and specialized cells. Complex sensory organs
A
receptor
4
Q
repsond to efferent signals. cells and organs
A
effectors
5
Q
Afferent division:
carries _______ info from PNS sensory receptors to CNS
A
sensory
6
Q
Efferent division:
carries _______ commands from CNS to PNS muscles and glands
A
motor
7
Q
Controls voluntary and involuntary (reflexes) skeletal muscles contractions
A
somatic nervous system
8
Q
Controls subconscious actions, contractions of smooth muscle and glandular secretions; has 2 more divisions
A
autonomic nervous system
9
Q
What are the two other divisions of the autonomic nervous system?
A
- sympathetic nervous system
2. parasympathetic nervous system
10
Q
stimulating effect: “fight or flight”
A
sympathetic nervous system
11
Q
relaxing effect: “rest or digest”
A
parasympathetic nervous system
12
Q
detect changes in internal or external environment
A
receptors
13
Q
information is sent to the CNS by sensory division of the PNS. Affront
A
Sensory division of the PNS
14
Q
Information is processed occurs in the
A
CNS
15
Q
motor commands are carried by the motor division of the PNS. efferent
A
Motor division of the PNS
16
Q
respond to those commands and change their activities
A
effectors
17
Q
the basic functional units of the nervous system
A
neurons
18
Q
the most common type of neuron in the CNS
A
multipolar neuron
19
Q
receive stimuli from environment/other neurons. Highly branched. CNS neurons receive most information here. Receive info from other neurons
A
dendrites
20
Q
The cell body contains the
A
nucleus and nucleolus
21
Q
The cytoplasm of a neuron is given the name:
A
perikaryon
22
Q
Mitochondrias are present to produce ________
A
energy
23
Q
RER and ribosomes produce proteins known as
A
neurotransmitter
24
Q
dense areas of RER and ribosomes. Male neural tissue appear gray
A
Nissl bodies
25
carries information toward other cells
Axon
26
Axon carries the electrical signal to ________
target
27
cytoplasm of axon. Contains neurofibrils, neurotubules, enzymes, organelles
axoplasm
28
specialized cell membrane. covers the axoplasm
axolemma
29
orgin of axon from cell body
axon hillock
30
where action potential is intimated
initial segment
31
fire extensions, end at axon terminals
telodendria
32
communicate with other cells
axon terminals
33
area where neuron communicates with another cell
synapse
34
neuron that sends message
presynaptic cell
35
cell that receives that message
postsynaptic cell
36
small gap that separates presynaptic cell and postsynaptic membrane
the synaptic cleft
37
is expanded are on axon of presynaptic neuron. Contains synaptic vessels of neurotransmitters
the synaptic terminal
38
the synaptic terminal contains synaptic vesiscles of ____________
neurotransmitters
39
Neurotransmitters are ________ _________.
chemical messengers
40
Neurotransmitters are released at the
presynaptic membrane
41
Neurotransmitters are affect receptors of
postsynaptic membrane
42
Neurotransmitters are broken down by
enzymes
43
synapse between neuron and muscle
neuromuscular junction
44
synapse between neurons and gland
neuroglandular junction
45
allow a single neuron to communicate with more than one other cell
collateral branches
46
Most CNS neurons lack _________
centrioles
47
If lost to injury or disease, they are ________ replaced by cell division
seldom
48
Some neural stem cells exist, but most are inactive except
olfactory epithelium, retina of the eye, and hippocampus
49
located in brain and special sense organs. Small. All cell processes look alike. Functions are poorly understood
anaxonic
50
two distinct process. 1) Dendritic process that branches 2) Axon, rare, but occur in a special sense organ. small
bipolar
51
found in sensory neurons of PNS. Very long axon. Axon may extend a meter or more-longest carry sensations from toes to spinal cord . Dendrites and axons continous (fused) cell body off to one side
unipolar
52
Most common neurons in CNS. Include all skeletal muscle motor neurons. Very long axons. Can be as long as unipolar neurons-longest carry motor signals from spinal cord to muscles that move toes. Multiple dendrites, one axon
Multipolar
53
Afferent neurons of PNS
sensory neurons
54
Sensory neurons cell bodies are grouped in
sensory ganglia
55
Sensory neurons are ________ .
unipolar
56
Sensory neurons monitor the _________ environment
internal
57
3 types of sensory receptors:
1. Interoceptors
2. Proprioceptors
3. Exteroceptors
58
Type of sensory receptor:
| monitor internal systems such as detect dissension (stretch), deep pressure, pain
Interoceptors
59
Type of sensory receptor:
| monitor position and movement
proprioceptors
60
Type of sensory receptor:
| Monitor external senses such as touch, temperature, pressure, input or special senses
exteroceptors
61
efferent neurons of PNS
motor neurons
62
Motor neurons carry instructions from CNS to peripheral _________ via _________ fibers (axons).
effectors, efferent
63
2 major efferent systems:
1. Somatic nervous system
| 2. Autonomic nervous system
64
Type of efferent system:
includes all somatic motor neurons that innervate skeletal muscles. Cell body lies in CNS; axon extends within a peripheral nerve
Somatic nervous system
65
Type of efferent system:
| includes all other peripheral effectors (smooth muscle, cardiac muscle, glands, adipose tissue)
autonomic nervous system
66
association neurons
interneurons
67
Interneurons:
| Most are located in brain, spinal cord, and autonomic ganglia in between ________ and motor neurons
sensory
68
Interneurons:
| Responsible for distributing sensory information and coordinating _______ activity
motor
69
interneurons are involved in _______ functions such as memory, planning, and learning
higher
70
Neuroglia are found in the ______ and ______.
CNS and PNS
71
4 types of Central Nervous System Neuroglia
1. Ependymal cells
2. Astrocytes
3. Oligodendrocytes
4. Microglia
72
What type of CNS neuroglia:
| form epithelium called ependyma. Lines central canal (spinal cord) and ventricles (brain). Secrete cerebrospinal fluid
ependymal cells
73
What type of CNS neuroglia:
| maintain the blood-brain barrier (isolates CNS from chemicals/hormones in the blood)
astrocytes
74
What type of CNS neuroglia:
| Myelinaiation of CNS. Increases speed of action potentials. Myelin insulates myelinated axon. Makes nerds appear white.
Oligodendrocytes
75
What type of CNS neuroglia:
smallest and least humerus neuroglia. migrate through neural tissue. Devlopmentally related to monocytes and macrophages. Mobile phagocytic cells that remove cellular debris
Microglia
76
Myelination increases speed of _______ _________.
action potentials
77
Myelination makes nerves appear ?
white
78
myelin-wrapped areas of axon
internodes
79
nodes= _____ between internodes where axons may branch
gaps
80
a "gang of neuron cell bodies surrounded by neuroglia in the PNS
ganglia
81
2 types of PNS neuroglia:
1. satellite cells
| 2. Schwann cells
82
type of PNS neuroglia:
| surround ganglia. regulate environment around neurons, similar to astrocyte role in CNS
Satellite cells
83
Neurons perform all ________ information processing, and control functions of the nervous system
communication
84
Neuroglia are essential to _______ and ______ of neurons
survival and function
85
axon and myelin degenerate distal to the injury (PNS)
Wallerian degeneration
86
Schwann cells proliferate along the original _______ path
axon
87
The axon grows along path created by
Schwann cells
88
Schwann cells wrap around the elongating _____
axon
89
If normal synaptic contacts are reestablished:
normal function may return
90
If axon stops growing or grows in wrong direction :
normal function will be different
91
Nerve regeneration is limited in the CNS because many more _____ are involved
axons
92
Astrocytes produce ____ ________ that can block axon growth in damaged area
scar tissue
93
Astrocytes release ________ that block axon regrowth
chemicals
94
the cause of many neurological disorders
Demyelination
95
Characterized by recurrent incidents of demyelination. Affects axons in optic nerve, brain and spinal cord. Common signs and symptoms: partial loss of vision, problems with speech and balance, cases are progressive
Multiple Sclerosis
96
Demyelination of peripheral nerves. Usually triggered by a virus. Signs/Symptoms: weakness or tingling of legs, increases in severity and leads to paralysis . Most patients fully recover, but some continue to have residual weakness
Guillain- Barre syndrome
97
All plasma (cell) e=membrane produce electrical signals by ion movements. Membrane potential is particularly important to neurons
Membrane potentials
98
4 Main Membrane Processes in Neural Activities:
1. Resting Potential
2. Graded Potential
3. Action Potential
4. Synaptic activity
99
membrane processes:
membrane potential of an undistributed cell; starting point
resting potential
100
Value of resting membrane potential:
-70 mV
101
Resting potential: inside is slightly ______ compared to outside
negative
102
Membrane process:
temporary, localized change in resting potential.
produced by: typical stimulus
Graded potential
103
Membrane Process:
| electrical impulse. produced by a graded potential that large enough. Propagates along surface of axon to the synapse
Action potential
104
Synaptic activity: releases __________ at presynaptic membrane
neurotransmitter
105
Synaptic activity: produces graded potentials in ___________ membrane
post synaptic
106
Synaptic activity:
Information processing is the response (integration of stimuli) of the ________ cell.
postsynaptic
107
Extracellular environments contain high concentrations of:
```
sodium ions (Na+)
chloride ions (Cl-)
```
108
Cell membranes are ________ __________.
selectively permeable
109
Membrane permeability varies by _____
ion
110
Resting membrane potential is
-70 mV
111
Leak channels are always _____
open
112
concentration gradient =
chemical gradient
113
postitive and negative charges are ________ to each other
attracted
114
like charges are ________
repulsed
115
the sum of chemical and electrical forces that act on the plasma membrane
the electrochemical gradient
116
The point where there would be no net movement of a particular ion across the cell membrane
equilibrium potential
117
K+=
-90mV
118
Na+=
+66mV
119
3 Classes of Gated Channels
1. Chemically gated channels
2. Voltage-gated channels
3. Mechinally gated channels
120
Name the gated channel:
| open in the presence of specific chemicals at a binding site. Found on neuron cell body and dendrites
Chemically gated channels
121
Name the gated channel:
Respond to charges in membrane potential. Have activation gates (open) and inactivation gates (close). An excitable membrane is a membrane capable of generating and conducting an action potential. Found in neural axons, skeletal muscle sarcolemma, cardiac muscle
Voltage-gated channels
122
Name the gated channel:
| Respond to physical distortion of membrane surface. Found in sensory receptors such as touch, pressure, vibration
Mechanically gated channels
123
local potentials =
graded potentials
124
A change in membrane potential that cannot spread far from site of stimulation. Any stimulus that opens a gated channel produces a graded potential
graded potentials
125
Depolarization to threshold:
| threshold amount:
-60mV to -55mV
126
4 Steps in the generation of an Action Potential
1. Depolarization to threshold
2. Activation of Na+ channels
3. Inactivation of Na+ channels and activation of K+ channels
4. Return to normal permeability
127
What step in generation of Action Potential?
| Rapid depolarization. Na+ ions rush into cytoplasm
Activation of Na+ channels;s
128
What step in generation of Action Potential?
| This happens at 30 mV . Inactivation gates close. K+ channels open. repolarization begins
Inactivation of Na+ channels and activation of K+ channels
129
What step in generation of Action potential?
K+ channels begin to close when the membrane reaches -70 mV. K+ closes but hyperpolarized at -90mV but returns to normal.
Return to normal permeability
130
During the refractory period, the membrane will _____ response normally to additional stimuli
not
131
Time during which the membrane cannot respond to any further stimulation. Na+ channels are open or inactivated
Absolute refractory period
132
Time during which the membrane can respond, but has to have a really strong stimulus
Relative refractory period
133
moves the action potentials along the length of the axon
Propagation of action potentials
134
action potential appears to move step by step through the entire axon. occurs in unmyelinated axons. Slower
continuous propagation
135
occurs in myelinated axons; depolarizes are the nodes. skips internodes. faster
Saltatory propagation
