Nervous System Flashcards
1
Q
cns includes
A
brain & spinal cord
2
Q
pns
A
all nerves except brain & spinal cord
3
Q
two basic structure of nervous system
A
neurons & glial cells
4
Q
gray matter made of
A
many cell bodies & dendrites; actually pinkish
5
Q
white matter contains
A
many axons; axons are insulated by lipid-rich substance called myelin
6
Q
ganglion
A
cluster of neuron cell bodies; in PNS
7
Q
tract
A
bundle of axons, fibers found in CNS
8
Q
nerve
A
bundle of axons, fibers in PNS
9
Q
insulation for axons in nervous system is provided by
A
glial cells, oligodendrocytes in CNS, schwann cells in PNS
10
Q
myelin
A
lipid-rich sheath that surrounds the axon & creates a myelin sheath that facilitates transmission of electrical along the axon
11
Q
demyelination
A
myelin insulation of axons is compromised making electrical signaling slower; diseases like MS & Guillain-Barre syndrome
12
Q
which of the following shows the correct order of nervous transmission
A
dendrite - soma - axon
13
Q
cells of the nervous system are termed
A
neurons
14
Q
neurons
A
highly specialized cells that conduct electrical impulses to communicate w/different cells; produce movement in response to stimuli
15
Q
glial cells
A
considered supporting cells to the neurons
16
Q
what are the four different types of glial cells CNS
A
astrocytes, oligodendrocytes, micorglial cells, ependrymal cells
17
Q
two different glial cells in PNS
A
satellite cells, schwann cells
18
Q
astrocytes
A
most common type have numerous processes that support neurons & connect them to nutrient-rich capillaries; support by maintaining concentration of chemicals in extracellular space, removing excess signaling molecules, reacting to tissue damage, contributing to blood brain barrier
19
Q
oligodendroctyes
A
form myelin sheaths that protect neurons and increase conduction speed in CNS; provide myelin for multiple axon segments for same or different axons
20
Q
ependymal cells
A
line central cavities of brain & spinal cord & ventricles, help produce & circulate cerebrospinal fluid;
21
Q
microglia
A
provide immune system by using phagocytosis to remove pathogens that pass blood-brain barrier or are introduced directly into brain; originate as white blood cells macrophages; aka CNS resident macrophages
22
Q
axon
A
fiber that emerges from cell body & projects to target cells
23
Q
dendrites
A
receive information from other neurons at specialized areas of contact called synapses
24
Q
what does is it mean when a neuron has polarity
A
information flows in this one direction
25
axon hillock
where axon emerges from cell body; tapering of cell body toward axon fiber
26
axoplasm
w/in axon hillock, cytoplasm changes to solution of limited components
27
initial segment of axon
axon hillock
28
node of ranvier
gap in myelin covering
29
axon segment
length of the axon between each gap, wrapped in myelin
30
axon terminal
end of axon; several branches extending toward the target cell ends in enlargement called synaptic end bulb
31
unipolar cells
one process emerging from the cell; found in invertebrate animals; cell bodies always found in ganglia
32
bipolar
2 processes; extend from each end of the cell body opposite to each other; one axon and one dendrite; not common; found in olfactory epithelium & retina
33
multipolar neurons
one axon and two or more dendrites;
34
blood brain barrier
keeps many substances that circulate in rest of body from getting into central nervous system; restricting what can cross from blood in CNS
35
satellite cell
found in sensory & autonomic ganglia; surround cell bodies of neurons; provide support, performing similar functions in periphery as astrocytes do in CNS
36
schwann cell
insulates axons w/myelin in periphery; wraps around portion of only one axon segment & no others; oligodendrocytes have processes that reach out to multiple axon segments whereas entire schwann cell surrounds just one axon segment
37
what is the extension of the cell membrane of neurons called
processes
38
what are the three primary vesicles developed
prosencephalon (front), mesencephalon (middle), rhombencephalon (hindbrain)
39
secondary vesicles developed
prosencephalon turns into telencephalon & diencephalon, telencephalon will become cerebrum & diencephalon turns into thalamus & hypothalamus
40
the part of the brain that acts as a relay for sensory information
thalamus
41
threshold
amount of stimulus needed to generate an action potential
42
conscious perception of a sensory stimulus is accomplished by which part of the brain
cerebral cortex
43
movement of an action potential along an axon
propagation
44
size exclusion
ion channels can specified by diameter of pore; distance between amino acid will be specific for diameter of ion; large pores are not ideal for smaller ions because water molecules will interact
45
nonspecific channel
ion channels are selective for charge but not size; allow cations (Na+, K+, Ca2+) to cross membrane but not anions
46
ionotropic receptor
ligand binds to protein ions across membrane changing its charge
47
mechanically gated channel
opens because of a physical distortion of the cell membrane; associated w/sense of touch
48
voltage-gated channel
responds to changes in electrical properties of membrane which is embedded; inner portion of membrane is negative voltage; less negative means channel allows ions to cross membrane
49
leakage channel
randomly gated; opens & closes at random; leakage channels contribute to resting transmembrane voltage of excitable membrane
50
membrane potential measures ____ charge relative to charge outside the cell
intracellular
51
depolarization of a cell
starting voltage is -70 mV; sodium cation entering cell will cause it to become more positive; membrane potential moves toward zero
52
repolarization of the cell
K+ leaves the cell and takes its positive charge w/ it; eventually the cell will reach a threshold and move back toward resting voltage of -70mV
53
what are the 2 types of voltage-gated Na+ Channels
activation gate; opens when membrane potential crosses -55 mV; inactivation gate- closes after a specific period of time
54
voltage-gated K+ channel
sensitive to -50 mV; doesn't open as fast as Na+ channel; when Na+ flow peaks voltage-gated K+ channels open
55
continuous conduction
propagation along unmyelinated axon; slow; Na+ rushing into cell
56
saltatory conduction
propagation along myelinated axon
57
resistance in terms of electrical propagation along a neuron is due to
speed of depolarization is dependent on the width of the axon
58
action potentials are initiated by a release of ___ in the membrane through ion channels
sodium
59
generator potential
graded potentials develop in dendrites that influence generation of an action potential in axon of same cell; unipolar cells of sensory neurons
60
receptor potential
photoreceptors of retina, sensory receptor cells; graded membranes result in release of neurotransmitters at synapses
61
excitatory postsynaptic potential (EPSP)
causes membrane potential to move toward threshold
62
Postsynaptic potential (PSP)
graded potential in dendrites of neuron that is receiving synapses from other cells; depolarizing or hyperpolarizing
63
inhibitory postsynaptic potential (IPSP)
hyperpolarization in a postsynaptic potential; causes membrane potential to move away from threshold
64
summation
takes place in axon hillock; can be spatial & temporal, result of multiple graded potentials at different locations of the neuron or all at the same place but separated in time
65
spatial summation
associating activity of multiple inputs to a neuron w/each other
66
temporal summation
relationship of multiple action potentials from a single cell resulting in significant change in membrane potential
67
electrical synapse
direct connection between two cells so that ions pass directly from one cell to the next; if one cell is depolarized than the other does as well
68
chemical synapses
involve transmission of chemical info from one cell to the next; ex. NMJ; contain neurotransmitter, presynaptic element, synaptic cleft, receptor proteins, postsynaptic element, neurotransmitter elimination or re-uptake
69
what are the two receptors in cholinergic system
nicotinic receptor & muscarinic receptor
70
amino acids
group of neurotransmitters; includes glutamate, GABA, glycine
71
biogenic amine
group of transmitters enzymatically made from amino acids; serotonin, dopamine, norepinephrine, epinephrine
72
neuropeptides
neurotransmitter molecule made up of chains of amino acids connected by peptide bonds
73
summation of graded potentials refers to
cumulative changes in membrane potential across a neuron
74
amount of electrical voltage change in a membrane due to a stimulus is determined most significantly by
size of the stimulus
75
graded potential is associated w/which part of the neuron
dendrites
76
what happens to amino acid neurotransmitters after they are active in a stimulus transmission
recycled & used again
77
aorta
carries recently oxygenated blood away from heart; first branch supply heart w/nutrients & O2; next branches lead into common carotid arteries & internal carotid arteries
78
internal carotid artery enters the cranium in temporal lobe through which canal
carotid canal
79
which arteries pass through foramen magnum of occipital bone
vertebral arteries; supply CNS
80
after passing through CNS, blood returns to circulation through what
dural sinuses & veins
81
ventricles
open spaces w/in brain where CSF circulates
82
CSF function
circulates to remove metabolic wastes from interstitial fluids of nervous tissues & return them to bloodstream
83
the four ventricles w/in brain
within central canal; lateral ventricles (2), space between L & R sides of diencephalon; space between cerebellum & pons & upper medulla
84
where is cerebrospinal fluid produced
w/in ventricles by choroid plexus; fluid is clear & made of water, small molecules & electrolytes
85
perfusion to the brain is maintained by
circle of willis
86
Dura Mater
covers brain; entire CNS & major blood vessels that enter cranium
87
arachnoid mater
middle layer of meninges; sac like enclosure around CNS; circulates CSF;
88
Pia Mater
outer surface of CNS covered in thin fibrous membrane; continuous layer of cells providing a fluid-impermeable membrane
89
corpus callosum
provides pathway for communication between two hemispheres of the cerebral cortex
90
basal nuclei
responsible for cognitive processing
91
basal forebrain
contains nuclei that are important in learning & memory
92
limbic cortex
part of limbic system; collection of structures involved in emotion, memory, behavior
93
temporal lobe
auditory sensation, memory
94
parietal lobe
somatosensation; general sensations associated w/body; postcentral gyrus (primary somatosensation) tactile senses
95
frontal lobe
motor functions; precentral gyrus (primary motor cortex); premotor area (thinking of movement to be made); frontal eye fields (eliciting eye movements); broca's area (production of language, speech); prefrontal lobe (personality, short-term memory, consciousness)
96
hippocampus & amygdala
long term memory formation & emotional responses
97
direct pathway
projection of axons from striatum to globus pallidus internal segment & substantia nigra pars reticulata
98
indirect pathway
projection of axons from striatum to globus pallidus external segment to subthalamic nucleus and then to GPi/SNr
99
disinhibition
inhibition of one cell on a target cell that then inhibits first cell
100
substantia nigra pars compacta
switch between two pathways; projects into striatum & releases neurotransmitter dopamine
101
cerebral cortex
outer portion of cerebrum composed of grey matter
102
diencephalon
brain, spinal cord, PNS send info to cerebrum through here except olfaction; any region w/ "thalamus" in name;
103
thalamus
relay info between cerebral cortex & periphery, spinal cord, brain stem
104
cerebellum
"little brain";
105
axons entering dorsal nerve root of the vertebral column transmit signals from
sensory input
106
main connection between cerebellum & brain stem is
pons
107
ganglion
group of neuron cell bodies in the periphery; sensory or autonomic ganglia
108
dorsal (posterior) root ganglion
in skin; extend into CNS through dorsal nerve root
109
autonomic ganglia
divided into sympathetic & parasympathetic nervous systemsq
110
acronym for remembering cranial nerves (12)
on old olympus towering tops/a finn and german viewed some hops ; olfactory nerve I, Optic nerve II, oculomotor nerve III, trochlear nerve IV, trigeminal nerve V, abducens nerve VI, Facial nerve VII, Glossopharyngeal nerve IX, Vagus Nerve X, accessory nerve XI, hypoglossal nerve XII
111
olfactory/optic nerve
sense of smell & vision
112
oculomotor nerve
eye movements; upper eyelid & pupillary constriction
113
trochlear nerve & abducens nerve
responsible eye movement by controlling extraocular muscles
114
trigeminal nerve
cutaneous sensations of face & controlling muscles of mastication
115
facial nerve
muscles in facial expressions; taste & production of saliva
116
vestibulocochlear nerve
sense of hearing & balance
117
glossopharyngeal nerve
controlling muscles in oral cavity & upper throat
118
vagus nerve
contributing to homeostatic control of organs of thoracic & upper abdominal cavities
119
spinal accessory nerve
controlling muscles of neck, along cervical spinal nerves
120
hypoglossal nerve
controlling muscles of lower throat & tongue
121
how many spinal nerves are there
31; 8 pairs of cervical nerves, 12 thoracic nerves, 5 pairs of lumbar nerves, five pairs of sacral nerves; 1 coccxygal nerves
122
cervical plexus
composed of axons from spinal nerves C1 through C5 & branches into nerves in the posterior neck & head
123
lumbar plexus
arises from lumbar spinal nerves & enervates to pelvic region & anterior leg
124
femoral nerve
major nerve from lumbar plexus; gives rise to saphenous nerve as branch that extends through anterior lower leg
125
sacral plexus
lower lumbar & sacral nerves; sciatic nerve comes form here
126
anosmia
loss of sense of smell; olfactory nerve being severed
127
association of spinal nerves C4 through T1 known as
brachial plexus
128
functions of the nervous system
sensation, integration, response
129
somatic nervous system
responsible for conscious perception & voluntary motor responses (contraction of skeletal muscle)
130
autonomic nervous system
responsible for involuntary control of body (for sake of homeostasis)
131
enteric nervous system
describes functional responses (controlling nervous system) & smooth muscle & glandular tissue in digestive system; not dependent on CNS; large part of PNS
132
integration & association areas of the nervous system function to
combine sensory perceptions w/ higher cognitive functions in order to produce a response
133
central processing of sensory stimuli into a meaningful pattern is termed
perception
134
