Cells and Structures of Nervous System Flashcards
(144 cards)
1
Q
Where is Sylvian fissure?
A
Between Temporal lobe and Frontal and Parietal lobes
2
Q
Where is Central sulcus?
A
Between Parietal lobe and frontal lobe
3
Q
Where is precentral gyrus?
A
Frontal lobe, on border with central sulcus
4
Q
Where is post central gyrus?
A
On Parietal lobe, bordering central sulcus
5
Q
glial cells
A
provide support for information processing neurons
6
Q
What is neuron doctrine?
A
The brain is composed of independent cells and information is transmitted from cell to cell across synapses
7
Q
neuron structure:
what is input zone?
A
Dendrites are cellular extensions that receive information
8
Q
What are dendrites?
A
Dendrites are the input zone.
Dendrites are cellular extensions that receive information from environment or other cells
9
Q
Neuron Structure:
What is the integration zone?
A
The cell body integrates information
10
Q
What does the cell body of a neuron do?
A
Cell body integrates the information
It is the Integration zone
Where decision to produce a neural signal is made
11
Q
Neuron Structure:
What is the conduction zone?
A
Conduction zone: axons carry information away from the cell body
12
Q
Where axons carry information away from the cell body is called…
A
conduction zone
where information can be electrically transmitted over great distances
13
Q
Neuron structure: What is the output zone?
A
The output zone are the axon terminals–
signals are transmitted across synapses
14
Q
What are axon terminals?
A
Axon terminals are the output zone.
Where signals are transmitted across synapses
15
Q
Where is the decision to produce a neural signal made?
A
In the integration zone (seems like area where cell body meets axon)
16
Q
How are neurons classified?
A
neurons are classified by shape, size or function
17
Q
multipolar neuron
A
one axon, many dendrites.
most common type of neuron
18
Q
Bipolar neuron
A
One axon, one dendrite
19
Q
unipolar neuron
A
a single extension branches in two directions, forming a receptive pole and an output zone.
20
Q
Motor neurons
A
stimulate muscles or glands
21
Q
sensory neurons
A
respond to environmental stimuli, such as light, odor or touch
22
Q
Interneurons
A
receive input from and send input to other neurons
23
Q
arborization
A
branching of dendrites
degree of arborization reflects the complexity of the neuron’s information processing function
24
Q
information is transmitted…how?
A
information is transmitted across synapses from the presynaptic neuron to the post synaptic neuron
25
synaptic cleft
synaptic cleft is the gap that separates the pre and post synaptic membranes
26
synaptic vesicles
synaptic vesicles in presynaptic axon terminals contain a chemical neurotransmitter
27
What is released in response to electrical activity in the axon?
neurotransmitters
28
What are receptors in the postsynaptic membrane?
Receptors in the postsynaptic membrane are specialized proteins that react when a neurotransmitter molecule binds to them.
29
neural plasticity
Neural plasticity: configuration of synapses on dendrites and cell body is constantly changing in response to experience and environment
30
dendritic spines
Dendritic spines, which increase surface area for synapses, can be rapidly altered, facilitating the continual remodeling of neural connections
31
axon hillock
Axon hillock: cone-shaped area of the cell body that gives rise to the axon; site of integration.
Axons often divide into axon collaterals, allowing a neuron to innervate more than one postsynaptic cell.
32
Axonal transport
Axonal transport: The movement of materials within an axon via motor proteins
Axons often divide into axon collaterals, allowing a neuron to innervate more than one postsynaptic cell.
33
4 types of glial cells which support and enhance neurons.
astrocytes
microglial cells
oligodendrocytes
Schwann cells
34
Astrocytes
Astrocytes: many processes receive neuronal input and monitor activity.
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microglial cells
Microglial cells are small cells that remove debris from injured cells
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Oligodendrocytes
Oligodendrocytes form myelin sheath in brain and spinal cord
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Schwann Cells
Schwann cells form myelin sheath for cells outside the brain and spinal cord.
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myelination
glial cells wrap axons with a fatty sheath, myelin, to insulate and speed conduction.
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nodes of Ranvier
Nodes of Ranvier are gaps between sections of myelin where the axon is exposed
40
Glial cells (when things go wrong)
Glial cells respond to injury by edema and are also susceptible to tumors.
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Astrocytes (when things go wrong)
Astrocytes influence brain chemistry and have been implicated in epilepsy.
42
Microglia (when things go wrong)
Microglia have been implicated in degenerative diseases, such as Alzheimer's.
43
Name a demyelinating disease
multiple sclerosis
44
CNS
Central nervous system: the brain and spinal cord
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PNS
Peripheral nervous system: all parts of the nervous system found outside the skull and spinal column
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4 aspects of PNS
Motor nerves
Sensory nerves
Somatic nervous system
Autonomic nervous system
47
motor nerves
motor nerves transmit information from the CNS to muscles, organs, and glands
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sensory nerves
sensory nerves convey information from the body to the CNS
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Somatic nervous system
sometime nervous system connects brain and major muscles and sensory systems
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autonomic nervous system
autonomic nervous system are nerves that primarily control the viscera
51
What does the somatic nervous system consist of?
The somatic nervous system consists of cranial nerves and spinal nerves
52
Cranial nerves
12 pairs of cranial nerves
some are sensory, some motor, some have both functions--separate axons in the nerve carry the sensory and motor signals
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List the 12 Cranial Nerves
```
Olfactory (s)
Optic (s)
Oculomotor (m)
Trochlear (m)
Abducens (m)
Trigeminal (s, m)
Facial (s, m)
Vestibulocochlear (s)
Glossopharyngeal (s, m)
Vagus (s, m)
Spinal Accessory (m)
Hypoglossal (m)
```
54
How many spinal nerves?
31 pairs
55
Each spinal nerve is...
Each spinal nerve is the fusion of two distinct branches, or roots: dorsal root and ventral root
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Dorsal root
Dorsal root of spinal nerve carries sensory information from the body to the spinal cord
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Ventral root
Ventral root of a spinal nerve carries motor information from the spinal cord to the muscles
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Autonomic Nervous System
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Autonomic ganglia
autonomic ganglia are groups of neurons located outside the CNS
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Preganglionic neurons
preganglionic neurons run from the CNS to the autonomic ganglia
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Postganglionic neurons
Postganglionic neurons run from the autonomic ganglia to targets in the body
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3 major divisions of the ANS
Sympathetic nervous system
Parasympathetic nervous system
Enteric nervous system
63
What does sympathetic nervous system do?
Sympathetic nervous system prepares body for action (fight or flight)
64
What neurotransmitter is sent when sympathetic nervous system is activated
Norepinephrine is neurotransmitter that is sent when sympathetic nervous system is activated
65
Parasympathetic nervous system
Parasympathetic nervous system: activation is often in opposition to sympathetic activity (rest and digest)
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What neurotransmitter is sent when parasympathetic nervous system is activated?
acetylcholine is the neurotransmitter that is sent when the parasympathetic nervous system is activated
67
Symptoms of Sympathetic response
```
dilates pupil
inhibits salivation
relaxes airways
accelerates heartbeat
stimulates glucose and production and release
inhibits digestion
stimulates secretion of epinephrine and norepinephrine
relaxes bladder
stimulates ejaculation
stimulates blood vessels in skin
stimulates secretion by sweat glands
```
68
Symptoms of Parasympathetic response
```
Constricts pupils
stimulates salivation
constricts airways
slows heartbeat
stimulates digestion
stimulates gallbladder to release bile
dilates blood vessels in intestines
dilates blood vessels in skin
contracts bladder
stimulates sex organ engorgement
```
69
enteric nervous system
enteric nervous system is a local network of neurons that governs function of gut
--is controlled by CNS
--Plays a key role in maintaining fluid and nutrient balance
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cerebral hemispheres
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cerebral cortex
folded outermost layer of the cerebral hemispheres, comprised mostly of neuron cell bodies, dendrites and axons
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gyri and sulci
gyri and sulci are folds that increase amount of context that can fit into the skull and are grouped together into lobes
73
4 lobes of cortex
frontal
parietal
occipital
temporal
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frontal lobe of cortex
movement and high level cognition
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parietal lobe
spatial cognition
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occipital lobe
visual processing
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temporal lobe
auditory processing, sense of smell, aspects of learning
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sagittal plane
bisects body into right and left halves
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coronal plane
divides body into front and back regions
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horizontal plane
divides into upper and lower parts
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postcentral gyrus
strip of cortex behind the central context that is important for touch
82
precentral gyrus
in the frontal lobe, important for motor control
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corpus callosum
a bundle of axons that connects the two cerebral hemispheres
84
gray matter
contains more cell bodies and dendrites, which lack myelin
85
white matter
consists mostly of axons with white myelin sheaths
86
The CNS develops from the neural tube; at the head end, three subdivisions arise:
Forebrain (prosencephalon)
Midbrain (mesencephalon)
Hindbrain (rhombencephalon)
Forebrain later develops into the telencephalon (cerebral hemispheres) and the diencephalon (thalamus and hypothalamus).
The CNS develops from the neural tube; at the head end, three subdivisions arise:
Forebrain (prosencephalon)
Midbrain (mesencephalon)
Hindbrain (rhombencephalon)
Forebrain later develops into the telencephalon (cerebral hemispheres) and the diencephalon (thalamus and hypothalamus).
87
The hindbrain develops into:
Metencephalon—becomes the cerebellum and pons
Myelencephalon, also called the medulla
Brainstem: the cerebellum, pons, and medulla
The hindbrain develops into:
Metencephalon—becomes the cerebellum and pons
Myelencephalon, also called the medulla
Brainstem: the cerebellum, pons, and medulla
88
brainstem
cerebellum
pons
medulla
89
Within the CNS:
- the nucleus is...
- the tract is...
Within the PNS
- neurons form...
- bundles of axons are...
Within the CNS:
- the nucleus is a collection of neurons
- the tract is a bundle of axons
Within the PNS
- neurons form ganglia
- bundles of axons are nerves
90
Neurons of the cortex are arranged in six layers based on type of neuron and pattern of dendrites or axons.
Pyramidal cells are most prominent:
Pyramid-shaped cell body in layer III or V
Apical dendrite extends to outermost cortex
Basal dendrites spread horizontally from cell body
Neurons of the cortex are arranged in six layers based on type of neuron and pattern of dendrites or axons.
Pyramidal cells are most prominent:
Pyramid-shaped cell body in layer III or V
Apical dendrite extends to outermost cortex
Basal dendrites spread horizontally from cell body
91
Neurons in the cortex are organized into cortical columns.
Each column is perpendicular to the cortical layers and serves as a unit to process information.
Within each column, most synaptic interconnections are vertical, although some are horizontal.
Neurons in the cortex are organized into cortical columns.
Each column is perpendicular to the cortical layers and serves as a unit to process information.
Within each column, most synaptic interconnections are vertical, although some are horizontal.
92
Basal ganglia (nuclei)
are important in motor control; reciprocally connected to the cortex
93
are important in motor control; reciprocally connected to the cortex
Basal ganglia (nuclei)
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Limbic system
includes structures important for learning and memory, cognitive functions, emotional regulation, sense of smell
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includes structures important for learning and memory, cognitive functions, emotional regulation, sense of smell
Limbic system
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2 main components of the diencephalon
Thalamus
| Hypothalamus
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thalamus
- a cluster of nuclei that relay sensory information
| - a component of the diencephalon
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- a cluster of nuclei that relay sensory information
| - a component of the diencephalon
Thalamus
99
Hypothalamus
- contains nuclei with many vital functions (hunger, thirst, temperature regulation, sex, and more); also controls the pituitary
- a component of the diencephalon
100
- contains nuclei with many vital functions (hunger, thirst, temperature regulation, sex, and more); also controls the pituitary
- a component of the diencephalon
hypothalamus
101
thalamus and hypothalamus
2 main components of the diencephalon
102
Midbrain sensory systems:
-Tectum--2regions process visual and auditory information
103
-Tectum--2regions process visual and auditory information
midbrain sensory systems
104
midbrain motor centers
substantia nigra--has neurons that release dopamine
red nucleus--communicates with motor neurons in the spinal cord
105
substantia nigra
--one of the midbrain motor centers
--has neurons that release dopamine
106
red nucleus
--a midbrain motor center
--communicates with motor neurons in the spinal cord
107
tectum
2 regions process visual and auditory information
midbrain sensory system
108
Other midbrain system
reticular formation--involved with sleep and arousal, temperature control and motor control
-the midbrain also gives rise to several cranial nerves
109
cerebellum
- -convoluted, involved in motor coordination and learning
- Purkinje cell layer- middle layer; large cells form a single row
- Granule cell layer-small neurons whose axons form the third layer
- Parallel fibers make up the third, outermost layer
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- Purkinje cell layer- middle layer; large cells form a single row
- Granule cell layer-small neurons whose axons form the third layer
- Parallel fibers make up the third, outermost layer
cerebellum
111
pons
- below cerebellum
- contains motor control and sensory nuclei
- gives rise to cranial nerves
112
- below cerebellum
- contains motor control and sensory nuclei
- gives rise to cranial nerves
pons
113
medulla
- contains cranial nerve nuclei and nuclei that regulate breathing and heart rate
- all axons from the brain to the spinal cord pass through the medulla
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- contains cranial nerve nuclei and nuclei that regulate breathing and heart rate
- all axons from the brain to the spinal cord pass through this
medulla
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cortical regions communicate via tracts of axons:
- short-nearby
- longer-other parts of cortex
- connections between hemispheres via the corpus callosum
- long, multisynaptic chains through subcortical regions
"connectome"
116
brain and spinal cord are surrounded by 3 protective membranes
the meninges:
- Dura mater--tough outermost sheet
- Pia mater-delicate innermost layer
- Arachnoid--substance between the dura mater and pia mater that cushions the brain in cerebrospinal fluid (CSF)
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ventricular system
series of chambers filled with CSF
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series of chambers filled with CSF
Ventricular system
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2 main functions of CSF
act as shock absorber
provide an exchange medium between blood and brain
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carotid arteries
major arteries to the brain
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what are the major arteries to the brain called?
Carotid arteries
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stroke
caused by rupture or blockage of blood vessels, leading to insufficient blood supply
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blood brain barrier
higher resistance in brain capillaries restricts passage of large molecules from the blood into the brain tissue
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circle of Willis
circle of carotid arteries at base of brain
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hemorrhagic stroke occurs when...
ischemic stroke occurs when....
hemorrhagic stroke occurs when rupture in artery leaks blood into brain
ischemic stroke occurs when clots or other debris prevent blood from reaching a region of the brain
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glymphatic system
newly discovered lymphatic system in brain; provide flow of CSF through the interior of the brain that helps clear cellular debris, proteins and other wastes
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angiography
x-ray of head with dye present in cerebral blood vessels
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CAT or CT
| computerized axial tomography
a measure of x-ray absorption at several positions around the head; maps tissue density
129
MRI
| magnetic resonance imaging
produces high-resolution images using radio frequency energy
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DTI
| Diffusion tensor imaging
uses MRI technology to study white matter tracts; based on fractional anisotropy (FA)
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DTI tractography
uses mathematical manipulations to produce structural images of axonal fiber pathways
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PET
| positron emission tomography
produces images of brain activity; identifies brain regions that contribute to specific functions
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color coded "difference image" can show
areas of brain most active during experimental condition
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mean difference image
using brain scans of difference images from several participants can be added together and averaged to arrive at a "mean difference image" that shows the most active brain areas across participants in an experiment
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fMRI
| Functional MRI
detects small changes in brain metabolism, such as oxygen use, in active brain areas
fMRI can show how networks of brain structures collaborate
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optical imaging
uses near-infrared light passed through the skull to reveal brain activity
137
TMS
| transcranial magnetic stimulation
briefly stimulates discrete cortical regions with magnets
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MEG
| Magnetoencephalography
measures the tiny magnetic fields given off by active neurons
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MEG more info
Using measurements of the minuscule magnetic fields given off by ensembles of cortical cells during specific behavioral functions, magnetoencephalography (MEG) provides a real-time map of brain activity. In these images, MEG data have been superimposed on structural MRIs of a participant’s brain, creating maps of brain activity associated with viewing faces (A) versus nonface objects (B).
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speed-accuracy trade off
some imaging techniques like fMRI, have high spatial resolution (show structural detail) but are relatively slow in making images so these techniques have low temporal resolution and do not track dynamic changes in brain activity well.
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what imaging techniques have high temporal resolution but low spatial resolution
MEG and EEG
142
social neuroscience
aims to understand brain activity as it relates to our interactions with others
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dfMRI
| Dyadic functional MRI
uses MRI scanner that is fitted with specially designed dual head coils (encircling the head to produce brain images)
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dfMRI can reveal
dfMRI can reveal subtle collaboration of brain activity in two people involved in the same behavioral situation
