NERVOUS SYSTEM Flashcards
1
Q
What does the PNS consist of?
A
Spinal & cranial nerves , visceral nerves and plexuses as well as the enteric system
2
Q
What is the autonomic system made up of?
A
Nerves supplying viscera along with parts of the brain and spinal cord
3
Q
What are the divisions of the ANS?
A
sympathetic and parasympathetic divisions
4
Q
Terminology - INPUT : sensory function =
A
sensory input
5
Q
Which organ or cell monitors changes [ e.g. blood pressure rising , increased heart rate]?
A
The receptor
6
Q
What are those changes called?
A
Stimuli [singular stimulus]
7
Q
What is the info sent by?
A
The afferent nerves
8
Q
What takes place at the integration center?
A
- The info is processed
2. A decision is made on what needs to be done
9
Q
Output : motor function =
A
motor output
10
Q
Which organs are activated?
A
The effector organs - muscles or glands
11
Q
What is the motor output effected by?
A
The efferent nerves
12
Q
‘The music affected her deeply’. What type of input is this? Why?
A
A sensory input ; the girl experienced something
13
Q
‘His protests had no effect’ What type of output is this? Why?
A
A motor output ; something is done or not done
14
Q
Nervous tissue - name the 2 type of cells and describe those cells.
A
- Neurons : excitable nerve cells
2. Supporting cells : neuroglia or just glia
15
Q
What does neuroglia mean?
A
“nerve glue”
16
Q
What is the function of neurons?
A
Neurons transmits electrical signals
17
Q
All neurons have a cell body that contains :
A
A nucleus and cytoplasm
18
Q
Cell bodies are in …
A
Clusters
19
Q
What are those clusters called in the CNS?
A
nuclei
20
Q
What are those clusters called in the PNS? what are those clusters located?
A
ganglia. the ganglia are located outside the CNS
21
Q
how long can neurons live for?
A
a lifetime , i.e. over 100 years
22
Q
Neurons don’t divide. what is the exception?
A
recent neural stem cells that have been identified
23
Q
What can’t neurons do?
A
Neurons can’t replace themselves
24
Q
Neurons have a high metabolic rate. What do neurons require continuously?
A
oxygen and glucose
25
How long does it take for neurons to survive without oxygen?
A short amount of time. neurons die within a few minutes without oxygen
26
describe the neuron 'processes'
the neuron 'processes' are armlike and they extend from the cell body
27
neuron fibers are ...
axons
28
What do neuron fibers do?
neuron fibers generate and transmit nerve impulses
29
how many neuron fibers are there per neuron?
1 , although the neuron fibers can branch into "collaterals"
30
What do neuron fibers do at the terminal end?
the neuron fibers branch a lot at the terminal end[e.g. 10000/terminus]
31
What are the receptive regions of a neuron called?
dendrites
32
What do the dendrites have?
the dendrites have receptors for neurotransmitters
33
what are neurotransmitters?
chemicals released by other neurons
34
what is another name for the cell body?
soma
35
what is the function of dendrites?
dendrites receive messages from other cells
36
what is the functions of an axon?
an axon passes messages away from the cell body to other neurons , muscles , or glands
37
what is an action potential?
an action potential is an electrical signal travelling down the axon
38
what is the function of the myelin sheath?
the myelin sheath covers the axon of some neurons and helps speed neural impulses
39
what is the function of the terminal buttons?
the terminal buttons form junctions with other cells
40
neuron processes run through the CNS in...
tracts of white matter
41
what neuron processes form when they run through the PNS?
Peripheral nerves
42
direction of the impulse :
dendrites - cell body - axon
43
List the glial cells/neuroglia[SUPPORTING CELLS] in the CNS and PNS.
CNS - astrocytes , oligodendrocytes , microglia , ependymal cells
PNS - schwann cells , satellite cells
44
compare the neuroglia to the neurons.
neuroglia are smaller and darker than neurons
45
What do the other glial cells do?
The other glial cells regulate extracellular fluid metabolism of neurons
46
CNS glial cells. Describe the astrocyte.
the astrocyte is star shaped ; it is most numerous
47
what is an astrocyte involved in?
an astrocyte is involved in metabolism and synapse formation
48
CNS glial cells : microglia are ...
phagocytes
49
CNS glial cells : ependymal cells function
Ependymal cells line the cavities of the CNS and spinal cord ; cilia
50
CNS glial cells : Oligodendrocytes function
oligodendrocytes produce myelin sheaths in the CNS
51
PNS supporting cells
| what is the function of satellite cells?
satellite cells surround the neuron cell body
52
PNS supporting cells : schwann cells functions
schwann cells form myelin in the PNS
53
what is neurolemma also known as?
Neurilemma , sheath of Schwann, or Schwann's sheath
54
What is neurolemma?
nucleus and most of the cytoplasm squeezed to the outside
55
what is myelin?
myelin is lipoprotein
56
functions of myelin
myelin increases the speed of conduction
57
what are the functions of large axons ?
large axons provide insulation ; prevent the leakage of the electric current
58
what are the layers with spaces called and where are they found?
the layers with spaces are called nodes of Ranvier ; they are found between cells
59
impulse "jumps" from...
node to node
60
describe "unmyelinated" axons
"unmyelinated" axons are smaller and slower
61
how do neurons communicate with neurons ?
via synapes
62
what are synapses?
synapses are junctions between neurons
63
how is info passed?
info usually passed chemically
64
describe the direction of a synapse.
the direction of a synapse is unidirectional
65
Presynaptic means :
toward the synapse
66
Postsynaptic means :
away from the synapse
67
what is a synaptic cleft?
a synaptic cleft is a tiny gap
68
give a brief description of a synapse
info is passed between the neurons by chemicals - neurotransmitters.
69
name the 2 types of neurotransmitters.
excitatory and inhibitory
70
how is info passed along the axons?
info passes electrically along the axons
71
what can neurons synapse with?
1. neurons
2. muscle
3. glands
72
what is the function of the brain ?
the brain receives and processes sensory info , initiates responses , stores memories , generates thoughts and emotions
73
what is the function of the spinal cord?
the spinal cord conducts signals to and from the brain , controls reflex activities
74
what is the function of motor neurons?
transmits responses from the CNS to the effectors : muscles and glands
75
what is the function of sensory neurons?
sensory neurons send stimuli to the sensory organs and from there the info is transmitted to the CNS
76
what is the function of the somatic nervous system?
the somatic nervous system controls voluntary movements
77
what is the function of the autonomic nervous system?
the autonomic nervous system controls involuntary responses
78
what is the sympathetic division of the ANS responsible for?
fight or flight
79
what is the parasympathetic division of the ANS responsible for?
rest or digest
80
WHAT DOES A NEURON CONSIST OF?
a cell body + an axon + dendrites
81
CNS GREY MATTER: WHAT does nuclei consist of?
collections of cell bodies and dendrites within the CNS
82
CNS GREY MATTER: what does ganglia consist of?
collections of cell bodies outside the CNS
83
how are cell body collections the same?
cell body collections are functionally the same
84
CNS "WHITE" MATTER: what are axons enclosed in?
myelin
85
what do fibre tracts/white matter form?
bundles of parallel axons - called "tracts" or "fibre tracts" [also fasciculi , funiculus, lemnisci, etc.]
86
what is a nerve tract ?
a bundle of nerve fibers[axons] connecting the nuclei of the CNS
87
what do 2 - part names of tracts indicate?
origin and destination[e.g. cortico - spinal tract]
88
PNS GREY MATTER: GANGLIA. what are ganglia ?
ganglia are collections of nerve cell bodies outside of the CNS (but connected to it)
89
PNS GREY MATTER: GANGLIA. where is a cell body identifiable?
in a ganglion
90
cell bodies in clumps are...
ganglia
91
PNS WHITE MATTER: PERIPHERAL NERVES. what does the axon make up?
the actual "nerve"
92
Where is grey and white matter found in the BRAIN
| (i.e. pattern)?
CNS GREY MATTER:
Forms outer layer (cortex)
CNS WHITE MATTER:
Found deeper
93
in which areas does cerebral white matter provide extensive communication?
→Areas of cortex with each other
| →Areas of cortex with brain stem & spinal cord
94
Via which (mostly) myelinated axon fibres is the cerebral white matter bundled into tracts?
– Commissural fibres
– Association fibres
– Projection fibres
95
Where is grey & white matter found in the SPINAL
| CORD (i.e. pattern)?
CNS GREYMATTER:
Found deeper
CNS WHITE MATTER:
Forms outer layer
96
In the spinal cord grey and white matter are easily separated:
```
“H” shaped grey matter consists of:
sensory neurons (dorsal)
interneurons
motor neurons (ventral)
```
White columns have:
ascending tracts
descending tracts
97
in the brain , white & gray matter aren't...
absolutely separate
98
what sometimes passes through or
| between the areas of grey matter on its ascent or descent?
a tract of "white" ascending or descending fibres
99
Grey matter & white matter in the spinal cord.the hollow central cavity is the..
"central canal"
100
Grey matter & white matter in the spinal cord.what surrounds the cavity?
Gray matter
101
Grey matter & white matter in the spinal cord. what surrounds the gray matter?
white matter
102
Grey matter & white matter in the spinal cord. what is gray matter?
ascending & descending tracts of axons
103
Grey matter & white matter in the spinal cord. what shape is seen in a cross section?
“H” shape
104
Grey matter & white matter in the spinal cord. The Dorsal half of “H” consists of:
cell bodies of
| interneurons
105
Grey matter & white matter in the spinal cord. The Ventral half of “H” consists of:
cell bodies of motor
| neurons
106
Grey matter & white matter in the spinal cord. what is the difference between the brain and spinal cord?
the brain has a number of cortex
the spinal cord has no cortex
107
White matter of the spinal cord include :
myelinated & unmyelinated axons
108
White matter of the spinal cord - what is the function of the ascending fibres?
the ascending fibres send Sensory information from the sensory neurons up to brain
109
what are the functions of the descending fibres ?
Descending fibres send motor instructions from brain to spinal cord
▪ Stimulates contraction of body’s muscles
▪ Stimulates secretion from body’s glands
110
what are Commissural fibres?
white-matter fibres crossing from one side of the spinal cord to the other
111
what do most pathways do?
Most pathways cross (or decussate) at some point
112
how many times do most synapse switch along the way[in the brain stem , thalamus or other parts of the brain]?
2 or 3 times
113
damage to the motor areas causes :
paralysis
114
damage to the sensory areas causes :
paresthesia
115
what are ventricles?
expanded central cavities
116
what are the ventricles filled with ?
CSF [cerebrospinal fluid]
117
what are the ventricles lined by?
ependymal cells. ependymal cells also line the choroid plexus and produce CSF]
118
WHAT are the ventricles continuous with?
ventricles are Continuous with each other and central canal of the
spinal cord
119
describe the lateral ventricles.
lateral ventricles are paired , horseshoe - shaped
120
where are the lateral ventricles found?
In the cerebral hemispheres
121
the anterior of the lateral ventricles are closed. what are they separated by?
thin Septum pellucidum
122
where is the 3rd ventricle located ?
In the diencephalon
123
what are the connections of the 3rd ventricle?
Interventricular foramen
| ▪ Cerebral aqueduct
124
where is the 4th ventricle found?
in the brainstem
125
describe the shape of the 4th ventricle.
the 4th ventricle is diamond shaped
126
what is the 4th ventricle dorsal to and superior to?
the 4th ventricle is :
dorsal to the pons
superior to the medulla
127
what connects the 4th ventricle to the subarachnoid space?
holes
128
where is the subarachnoid space found?
under the thick coverings of the brain[dura and arachnoid mater]
129
List the lobes of the brain
frontal , parietal , occipital and temporal lobes
130
name the gyrus that 'hug' the corpus callosum.
the cingulate gyrus
131
what are the 2 hemispheres of the cerebrum separated by?
a median cleft called longitudinal fissure
132
what are the right and left hemispheres connected[to each other] by?
a large commissure called the corpus callosum
133
what does each hemisphere contain?
an irregular cavity containing CSF - lateral ventricle
134
what is the cerebrum composed of ?
grey matter [cortex - externally] ; white matter[internally]
135
what is the cerebral cortex?
the outermost layer of gray matter making up the superficial aspect of the cerebrum
136
where is the cortex the thickest and the thinnest?
the cortex is the thickest at the motor area and the thinnest at the occipital pole
137
what increases the cortical area ?
the numerous convolutions called gyri and the gyri is separated by fissures called sulci [the depths of these vary]
138
the Cerebrum - what does the white matter consist of?
nerve fibres which
transmit impulses to and from the cortical
nerve cells and from one cortical area to
another
139
what does the cerebrum enclose?
the cerebrum encloses some larger and smaller masses
of grey matter such as corpus striatum,
claustrum, amygdaloid body
140
name the 3 surfaces of the cerebrum
Supero-lateral
Medial
Inferior
141
what is supero - lateral surface divided into?
the frontal, parietal, occipital and temporal parts by central , parieto-occipital
(extension from medial surface) and lateral sulci
142
FRONTAL LOBE
| Anteriorly - what does the superior and inferior frontal sulcus divide the frontal lobe into?
the superior and inferior frontal sulcus dividing the frontal lobe into the superior ,middle and inferior
frontal gyri
143
FRONTAL LOBE
| Posteriorly it consists of the:
The Pre – central sulcus and Pre- central gyrus (the motor area)
144
PARIETAL LOBE - what is the parietal lobe divided into?
the superior and inferior parietal lobule by intra-parietal sulcus
145
PARIETAL LOBE - what is the sensory area called?
the post central gyrus
146
OCCIPITAL LOBE - what is it divided by and what does the occipital lobe consist of ?
the occipital lobe is divided by transverse occipital sulcus and consists of superior and inferior Occipital gyri
147
what divides the temporal lobe into superior , middle and inferior temporal gyri?
the superior & inferior temporal sulci
148
Medial Surface FRONTAL LOBE. what is the beneath the corpus callosum?
the Cingulate Sulcus and Cingulate gyrus
149
what does the medial frontal gyrus extend above ?
above the cingulate gyrus to the superior border
150
what is the central sulcus and where is it located ?
the central sulcus is a continuation from the supero-lateral surface and it is located on the medial surface
151
what is the central sulcus surrounded by?
Paracentral Lobule
152
what divides the parietal and frontal lobes?
central sulcus
153
MEDIAL SURFACE - parietal lobe where is part of the paracentral lobule located ?
behind the central sulcus
154
what is the pre -cuneus?
the area before the
| parieto-occipital sulcus
155
MEDIAL SURFACE - occipital lobe. what is the occipital lobe bounded by superiorly and inferiorly?
superiorly - the parieto-occipital sulcus
inferiorly - the calcarine sulcus
156
MEDIAL SURFACE - occipital lobe. where does the lingual gyrus lie?
the lingual gyrus lies between the calcarine and the collateral sulcus
157
what does the interior surface of the cerebrum consist of?
smaller anterior and larger posterior
| parts
158
what area is the anterior part of the inferior surface[of the cerebrum]?
the orbital area
