Cytology Flashcards

1
Q

cell classification

A

polarity

functional

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2
Q

polarity classifications

A

number of poles:

1: multipolar
2: bipolar
3: pseudo-unipolar

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3
Q

bi-polar

A

specialized- seen in sensory systems

smell, sight, vestibular

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4
Q

multi-polar

A

most common

predominant kind of neuron in CNS and PNS

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5
Q

pseudo-unipolar

A

evolves for speed/faster conduction- bypasses cell body so it doesn’t have to travel through

seen for pain/pressure
self propagating

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6
Q

golgi I

A

LONG axon which projects from one subsystem to another (brain–>SC, SC–>foot)

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7
Q

Golgi II

A

(interneurons)
SHORT axons
make connections with other neurons in the same subsystem
most numerous; short or no axon;
neurons that integrate things (connect dorsal horn to ventral horn of C5 on the same side)

1: segmental
2: propriospinal

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8
Q

segmental golgi II

A

project only to the same segment

associative: same side (ipsilateral fiber)
commissural: opposite side (contralateral fiber)

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9
Q

Propriospinal golgi II

A

project to other SC segments

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10
Q

tract cells

A

similar to golgi I but reside only in the CNS
forms tracts- collections of axons carrying the same kind of information (project to higher or lower levels of communication; fasiculus)

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11
Q

Functional classifications

A

1: directional
2: action on other neurons
3: discharge patterns
4: neurotransmitter release

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12
Q

directional classifications

A

afferent

efferent

interneurons

point of reference is usually the CNS; when it is, then you can refer to them as sensory or motor neurons

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13
Q

afferent=

A

coming to the point of reference (CNS)

usually “sensory”

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14
Q

efferent=

A

leaves the point of reference (CNS)

usually “motor” in the sense that it innervates muscles

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15
Q

actions on other neurons

A

excitatory:

inhibitory:

modulatory:

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16
Q

modulatory=

A

changes how the system reacts to the next time the stimulus is introduced

endorphins- modulate system to feel less pain to same painful stimulus

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17
Q

discharge patterns

A

tonic or regular spiking

phasic or bursting

fast spiking

thin spike

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18
Q

tonic (or regular spiking) discharge pattern

A

firing- always firing at a rhythmic rate and changed by increasing or decreasing firing rate; slow adapting

stimulate a neuron, continue to fire for a long time

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19
Q

phasic (or bursting) discharge pattern

A

“dynamic”
only on when they are stimulated and go off quickly; quick adapting

stimulate a neuron, fires, stops when stimulus is removed

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20
Q

fast spiking discharge pattern

A

fast firing rates

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21
Q

neurotransmitter release

A

cholinergic neurons

GABAergic neurons

glutamatergic neurons

dopaminergic neurons

serotonin

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22
Q

cholinergic neurons

A

excitatory to muscle
inhibitory to PNS

acetylcholine- usually always excitatory, used to contract muscle and inhibit the heart

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23
Q

GABAergic neurons

A

primary inhibitors

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24
Q

glutamatergic neurons

A

excitatory

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25
dopaminergic neurons
excitatory and inhibitory
26
serotonin
excitatory
27
nucleus
contains genetic material (chromosomes) including information for cell development and synthesis of proteins necessary for cell maintenance and survival. covered by a membrane
28
nucleolus
produces ribosomes necessary for translation of genetic information into proteins
29
nissl bodies
groups of ribosomes used for protein synthesis
30
endoplasmic reticulum (ER)
system of tubes for transport of materials within cytoplasm Rough ER: have ribosomes- important for protein synthesis Smooth ER: no ribosomes
31
golgi apparatus
membrane-bound struction important in packaging peptides and proteins (including neurotransmitters) into vesicles
32
microfilaments/neurotubules
system of transport for materials within a neuron and may be used for structural support passes nutrients/proteins up and down axon anterograde retrograde
33
mitochondria
produce energy to fuel cellular activities
34
anterograde
produced in cell, going down to synapse away from home
35
retrograde
coming back towards nucleus or cell body of neuron
36
cell hillock
where AP is generated because it has the lowest threshold
37
function of the intracellular matrix
1: gives the cell its shape and stiffness 2: provides the mechanisms for cell growth and motility 3: provides the internal network over which molecules and organelles are transported
38
elements of the intracellular matrix
structural- keep axon together 1: actin filaments 2: neurofilament 3: microtubules
39
actin filaments (don't memorize)
STRUCTURAL INTEGRITY- gives membranes structure - closely associated with the cell membrane- forms a dense network - responsible for developing and maintaining surface irregularities of cells (i.e. dendritic spines) and growing axons - 3-5 nM in diameter - key role in the dynamic function of the cell's periphery (ie motility or growth cones during developmental, formation or pre- and post morphologic specializations
40
intermediate filaments (neurofilaments (neurons)) (don't memorize)
(railroad track for structures to move and and down the axon) gives cells mechanical integrity- bones of the cytoskeleton give high tensile strength most numerous aligned in orderly parallel arrays 10nm in diameter forms the neurofibrillary tangles of Alzheimer's
41
microtubules (don't memorize)
largest intracellular protein abundant in all cells in neurons, provide rigidity by x-linking with neurofilaments essential in the transport of macromolecules and membrane bound structures long scaffolds- extend the full length of the neuron responsible for maintaining the neuron's processes
42
axons
not only transports AP but moves fluids if you take an axon off a muscle the muscle will atrophy can be up to a meter long!
43
neuroglia cells
non-neural cells of CNS & PNS outnumber neurons 5-50x & comprise 40% of the total CNS (most numerous cell in the NS) determine what goes in/out of BBB
44
main functions of neuroglia cells
1: developmental- radial astrocyytes (scaffold, release GFs) 2: support 3: nurture 4: maintenance of a relative constant environment -nutritive -impulse conduction (can control the environment - absorb K or Na to modulate impulse conduction )
45
spongioblast
precursers to glia cells | they continue to grow and divide after birth
46
neuroglia classification (CNS)
ASTROCYTES - fibrous - protoplasmic - perivascular glia OLIGODRODENDROGLIA MICROGLIA EPENDYMAL
47
astrocytes
neuroglia located everywhere. look like neurons help make blood brain barrier (BBB); controls diffusion; most predominant FIBROUS: maintain the integrity of the axons in the white matter PROTOPLASMIC: touching the cells-gray matter PERIVASCULAR GLIA:
48
oligodrodendroglia
neuroglia myelin producing cells in the CNS (in PNS myelin producing cells= Scwann cells)
49
microglia
neuroglia mesodermic come in when the blood comes in, cleans up debris
50
myelin
fatty substance that insulates the nerve fiber doesn't heal well; chemical doesn't allow neuron regeneration to occur
51
Ependymal
glia cells remnants of neuroepithelial cell lining that becomes more CT like lines the ventricle system; single layer
52
choroid plexus
multiple layers of ependymal that produce CSF
53
zomula occlusions=
tight junctions between glial cells in BBB
54
Glia cells in the periphery
SCHWANN- myelin SATELLITE GLIA- astroglia like functions PERINEURAL GLIA- structure
55
Scwann cells
produce myelin in the periphery and support axon in environment
56
satellite glia cells
astrocyte in ganglia in PNS similar function in CNS; ganglion is a collection of neurons in periphery
57
perineural glia cells
protective covering of nerve fiber for structure
58
what is glia reaction to injury?
GLIOSIS= proliferates of astrocytes to form plaques or scars primarily astrocytes start to multiply, take form of a plaque, grow processes, take place of injury. Not a good thing bc it forms a barrier and new growth can't get by. major problem with regeneration in CNS
59
what are the 7 types of synapses?
``` 1- axospinous 2- axodendritic 3-axosomatic 4-axoaxonic 5-chain 6-en passant 7- electrical ```
60
axospinous synapse
axon synapses with spine of dendritic tree (spine is a bulbous extension of the dendrite to increase surface area) spines are extensions on dendrite
61
axodendritic synapse
axon synapses with dendrite without use of spine
62
axosomatic synapse
axon synapses with cell body (soma)
63
axoaxonic synapse
axon synapses with axon
64
chain synapse
goes to 2 different things
65
en passant synapse
goes to >2 places
66
electrical synapse
doesn't use chemicals | usually gap junctions
67
neuromuscular junction
l
68
iontotropic
most common
69
metabotropic
k
70
axon branches can divide into...
collateral branches axon is not 1 string/fiber, gives off collaterals or branches (can give off as many as it wants)
71
what are the meningeal layers surrounding the CNS?
pia mater: like skin arachnoid: like spandex; goes over bumps and dents dura mater: like overcoat; extends into the peripheral nerve and is renamed Epineurium dura mater attaches to periosteum of bone
72
what is the subarachnoid space?
space between the pia and arachnoid matter that is filled with CSF there is where a spinal tap is done
73
what is the subdural space?
potential space between dura and arachnoid mater | no adhesions
74
what are the 3 sheaths around a peripheral nerve?
Endoneurium Perineurium Epineurium
75
what is the endoneurium?
the layer around an axon of a peripheral nerve between axons is a loose CT of type I & II collagen longitudinally oriented
76
what is the perineurium?
the layer around a bundle of axons (fascicle) acts as the BBB of the peripheral nerve tight junctions provides mechanical strength primary load bearing portion small arterioles and venules located longitudinally in this area
77
what is the epineurium?
the layer around a whole nerve bundle originally known in the CNS as the dura mater then attaches to the periosteum of bone * only meninge to continue
78
what are the 2 subtypes of epineurium?
1: Epifasicular 2: Interfasicular
79
what does the epifasicular epineurium do?
surrounds and infiltrates the entire nerve bundle externally
80
what does the interfasicular epineurium do?
it is loosely attached to the epifasicular allowing for sliding of 1 fasicle independently on another large amount of interfasicular epineurium helps facilitate the dispersion of compressive forces
81
the perineurium is composed of:
type I and II collagen oriented in oblique, longitudinal and circumferential directions up to 15 cell layers thick
82
what is the primary load bearing portion of the peripheral nerve?
the perineurium
83
basal lamina is type ? collagen
type IV collage
84
blood supply of the peripheral nerves
blood vessels enter the epineurium periodically along the length of the nerve divides into arterioles that form anatomatic network in epineurium and perineurium vessels in endoneurium turn into capillaries and travel longitudinally 3 parallel arteries: regional nutrient, epinutrient and perinutrient
85
what are the characteristics of an unmyelinated nerve?
unmyelinated cells usually travel together multiple neurons for 1 schwann cell usually very thin and slow conducting all have a schwann cell membrane surrounding
86
what are the characteristics of a myelinated nerve?
1:1 relationship with schwann cell 1 schwann to 1 axon schwann cell wraps its plasma membrane around the axon and forms the myelin sheath (pushes into cell and wraps around and around)
87
what does myelin do?
acts as an insulater speeds up AP AP jumps from node to node (node of Ranvier) "saltatory conduction"
88
myelin in the CNS
in CNS, no plasma membrane around anything unmyelinated- nothing around it myelinated- just myelin, no membrane this is bc oligodendrogliocytes are not in 1:1 ratio oligo shoots of processes to wrap around neighboring cells. one can produce myelin for many axons at segment. still have slatatory conduction bc you still have nodes of Ranvier. This is why there is no functional regenerationg bc there is no plasma membrane around nerve forming a tube to show the nerve to to go/grow. Tube also provides nutrition in PNS. since nerve can't figure out where to grow in CNS, it becomes a neuroma tube is neurolemma sheath PNS schwann cells create a tube around all the axons so regeneration is possible. tube tells nerve where to go
89
what are the 3 nerve fiber classifications?
general (G) or special (S) visceral (V) or Somatic (S) Afferent (A) or Efferent (E)
90
general vs. special nerve fiber classification:
general: distributed throughout the body spinal nerves and CNs special: restricted area of the body only in some CNs hearing, taste, smell; special motor in CNs
91
visceral or somatic nerve fiber classification:
visceral: autonomic/brachial arches ANS, origin is from gill region of developing embryo, organs somatic: somites, body, skin, muscle joints
92
afferent or efferent nerve fiber classification
afferent: sensory efferent: motor
93
what are the anatomic functional components of general nerve fibers?
General somatic afferent (GSA) General somatic efferent (GVA) General visceral afferent (GVA) General visceral efferent (GVE)
94
what do GSA nerve fibers control?
conscious sensation (pain, temperature, touch, proprioception)
95
what do GVA nerve fibers control?
visceral sensation (mainly pain from ischemia, blood pressure, etc)
96
what do GSE nerve fibers control?
voluntary motor to skeletal muscle (derived from myotomes)
97
what do GVE nerve fibers control?
autonomic motor to smooth and cardiac muscle and glands (parasympathetic, sympathetic- preganglionic and postganglionic fibers)
98
what are the anatomic functional components of special nerve fibers?
special visceral afferent (SVA) special visceral efferent (SVE) special somatic afferent (SSA) special somatic efferent (SSE)
99
what do SVA nerve fibers control?
visceral sensations of taste and smell
100
what do SVE nerve fibers control?
?
101
what do SSA nerve fibers control?
somatic sensations of vision, heading and equilibrium
102
what do SSE nerve fibers control?
? voluntary motor to skeletal muscle (derived from branchiomeres)??
103
Erlanger size classification of fibers
A fibers: largest with lots of myelin, very fast conduction B fibers: small with a little myelin; ANS C fibers: unmyelinated (small in diameter, slow conducting); ANS
104
ventral root classification:
``` ventral root: motor greek letters (alpha, beta, gamma, delta) efferents don't conduct as fast as afferents ``` dorsal root: sensory roman numerals
105
sensory root nerve classification by Lloyd:
sensory neurons classified based on diameter --> speed of conduction Ia: from muscle spindle, proprioceptors Ib: from GTO (touch and pressure receptors) II: secondary from ms spindles, touch and pressure receptors and pacinian corpuscles (vibration) III: small lightly myelinated fibers; touch & pressure, pain & temp IV: pain & temp (different from III only in speed (fast pain vs slow pain)
106
erlanger size classification of fibers are further subdivided into:
fibers are further subdivided by mean conduction velocity: alpha: large diameter fibers, innervate extrafusal muscle (straited skeletal muscle outside the muscle spindles) gamma: small diameter fibers; innervate intrafusal muscle fibers (within muscle spindles) beta: intermediate fibers: innervate both intrafusal and extrafusal fibers delta: