Nerve Tissue & Nervous System Flashcards
(188 cards)
1
Q
Los pares craneales se consideran
A
Del sistema nervioso periférico
2
Q
Intracelularmente la neurona es rica en…, sirven a la neurona para transportar los neurotransmisores
A
Neurofilamento
3
Q
Los neurofilamentos abundan en
A
Pericarion y dan cuerpo a las neuritas
4
Q
El conjunto de prolongaciones neuronales y de las células acompañantes se llama
A
Neropilo
5
Q
El nucleo es
A
Eucromatico
6
Q
El nucleolo en microscopio es evidente
A
Ojo de búho
7
Q
El neuroplasma es
A
Basofilo por riqueza de ergastoplasma
8
Q
El RER de la neurona se denomina
A
Cuerpo de Nissl
9
Q
El número de células nerviosas dentro del sistema nervioso central es sobre pasado por la Glia aproximadamente
A
5 veces mas
10
Q
Las células que se consideran neuroglia periférica
A
Células satélites o capsulares
Células de Shwann
11
Q
Tres tipos de células neuroglia
A
Astrocitos
Oligodendrocitos
Microglia
12
Q
Son llamados colectivamente macroglia
A
Astrocitos
Oligodendrocitos
13
Q
Macroglia es de origen
A
Ectodermico como las células nerviosas
14
Q
La microglia es de origen
A
Mesodermico
15
Q
Son los mas grandes de las células gliales
A
Astrocitos
16
Q
Tiene un nucleo mas grande que el oligodendrocitos,abundante citoplasma granular presentes en la sustancia gris
A
Astrocitos protoplasmáticos
17
Q
Largas expansiones relativamente delgadas regulares y ramificadas presente en la sustancia blanca
A
Astrocitos fibrosos
18
Q
Son las células de defensa del SNC funcionan como los macrofagos aunque con una mayor capacidad migratoria
A
Microglia
19
Q
Tres etapas de diferenciación son
A
La célula precursora totipotencial (glioblasto)
Células son inducidas a expresar los genes para lípidos y proteinas especializadas.
Diferenciación terminal
20
Q
Comienzan a aparecer hacia el tercer día después del nacimiento , tienen división celular, su citoplasma)
A
Los oligodendrocitos jóvenes
21
Q
Antes que inicie la formación de mielina aparece
A
La Glia de mielinizacion ( la oligodendroglia)
22
Q
Migran en sentido proximo distal a lo largo de los axones en crecimiento
A
Células de schwann
23
Q
Las células de Schwann en contacto con axones de gran tamaño producen una vaina de mielina asociándose a un solo axon cual es el diámetro
A
1.0 micrometro
24
Q
Células de Schwann que envuelven a diámetro inferior a 1.0 micrometro los
A
Envuelven sin producir mielina
25
Algunos componentes fosfolipidicos de la mielina es de origen axonal ya que existe una transferencia de
Fosfatidilcolina
26
Las células de Schwann son capaces de fabricar colagena de tipo
I, III, IV
27
Es el axon de una neurona
Fibra nerviosa
28
Es la prolongación celular particularmente especializada en transmitir información
Axon
29
Marcan la interrupción de la vaina de mielina a intervalos regulares (segmentos internodales) la principal función es en la conducción saltatoria del impulso nervioso
Nodos de Ranvier
30
En los cortes trnasversales consiste de una banda densa dispuesta en espirales multilamelares alrededor del axon
mielina internodal
31
El extremo exterior de la espiral deriva del estrechamiento de las partes adyacentes de la membrana citoplasmatica de una pequeña lengüeta del citoplasma del oligodendrocito llamado
Mesaxon externo
32
Consta de la fusión de las hojas internas de la membrana plasmatica de la célula mielinizante
Mielina compacta
33
Las hojas externas yuxtapuestas y frecuentemente fusionadas en apariencia forman la línea intraperiodica, el espacio entre los dos componentes membranales es de
1 nm
34
La periodicidad de las lamelas es de
11 nm
35
El oligodendrocitos está separado de la membrana axonal por una delgada hendidura extracelular el
Espacio periaxonal
36
Es una región de la vaina de mielina donde terminan las lamelas
Nodo de Ranvier
37
% de lípidos que contiene la mielina
70%
38
% de proteinas de mielina
30%
39
La mielina contiene
Colesterol
Fósfolipidos
Galactolipidos
40
Las proteínas de mielina
Po, P1 y P2
41
Proteina específica del SNP
Po
42
Marca la principal diferencia entre los componentes químicas del SNC y SNP
Po
43
Se produce como consecuencia de una sección del axon o de una afección local que le es equivalente
Degradación walleriana
44
En la degeneración walleriana las células de Schwann se multiplican en el segmento distal y se organizan linealmente en bandas de
Bunger en el interior del tubo formado por la lamina basal preexistente
45
En la degradación walleriana esta actividad de proliferación continua durante
25 días y luego disminuye
46
En la degradación walleriana la regeneración axonal comienza
Desde las primeras horas
47
Los muñones en la regeneración axonal se incrustan en los tubos de lámina basal progresan a una velocidad aproximada de
2.0 a 3 mm por día
48
Es debida a una destrucción primaria de la mielina y se acompaña también de una proliferación de las células de Schwann , alrededor de un eje constituido por el axon intacto
Desmielinizacion segmentaria
49
El cerebro y la médula espinal contienen vasos sanguíneos derivados de
Mesenquima
50
Las tres túnicas que envuelven al SNC están compuestas por
Tejido conectivo
51
La mas externa también conocida como paquimeninge es densa y firme
Duramadre
52
Constituyen las leptomeninges
Aracnoides y piamadre
53
Transparente , inodoro e incoloro de aspecto cristalino llamado "agua de roca"
LCR
54
Se encuentra dentro del encéfalo y del canal medular, amortigua traumatismos cráneo encefálico, aporta metabolitos por difusión e interviene en la compensación de cambios en el volumen de la masa encefálica
Sistema nervioso central
55
La cantidad de líquido producida en un día es aproximadamente
un promedio de 0.35 ml/min (500ml/dia)
56
El volumen de recambio de LCR
De cuatro a cinco veces en el transcurso del día, para mantener un volumen promedio de 130ml durante el día
57
% de LCR que se encuentra en el espacio subaracnoideo
75%
58
% de LCR que se encuentra en los ventrículos
25%
59
LCR es producido principalmente en
```
Plexo coroides
Espacio subaracnoideo
Ependimo
Superficie cerebral glial
Espacios extracelulares cerebrales
```
60
Se encuentran en los ventrículos III y IV en su suelo del cuerpo, atrio y cuernos inferiores, ventrículos laterales, superficie basal del tallo cerebral
Plexo coroides
61
Consisten en invaginaciones de la piamadre cubiertas por epitelio cúbico simple o cilíndrico bajo con presencia de capilares fe estrados y dilatados
Plexo coroides
62
De los ventrículos laterales al tercer ventrículo se comunica por medio de
Agujero de monroe
63
El tercer ventrículo con el cuarto se comunica por
Acueducto de Silvio
64
El cuarto ventrículo se comunica con el espacio subaracnoideo por
El agujero medias de Luschka y dos agujeros laterales de Magendie
65
LCR es absorbido por medio de
Velocidades aracnoideas
66
Ubicadas en la cara superolateral y medial de los hemisferios cerebrales con predominio en el seno sagital superior
Velocidades aracnoideas
67
Se hipertrofia las vellocidades subaracnoideo y sufren acumulos de colagena para ser llamados
Granulaciones de Paccioni
68
Entre los componentes de LCR encontramos
```
Densidad especifica. 1.004-1.008
pH 7.35
Cloruros 720 mg/dl
Glucosa 65 mg/dl
Base total 157 mEq/l
Proteína total
Lumbar 15-45mg/dl
Cisternal 10-25mg/dl
Ventrícular 5-15mg/dl
```
69
Regula las concentraciones de iones, hormonas, y sustancias en contacto con cerebro y médula espinal
Barrera hematoencefalica
70
Los vasos se encuentran rodeados por
As trocitos
71
Las áreas que carecen de barrera hematoencefalica son conocidas como
Órganos cirunventriculares
72
Órganos cirunventriculares incluyen
```
Área postrema de la médula oblongada
Neurohipofisis
Glándula pineal
Lamina terminal (órgano vascular)
Hipotalamo (tubérculo intercolumnar)
Órgano subfornical (tubérculo intercolumnar )
Órgano subcomisural
```
73
The nervoous system develops from and beginning
Ectoderm and third week
74
The NS develops with signals from
Notochord
75
Ectoderm on the mid dorsal side of the embryo thickens to form the epithelial
Neural plate
76
The lateral sides of this plate fold upward bend and grow toward each other medially and fuse forming
Neural tube
77
Are the numerous enlongated processes extending from the perikaryon and specialized to receive stimuli from other neurons at synapses
Dendrites
78
Measure of the cell body
150 micrometer in diameter
79
Body's smallest cells
Cerebellar granule
80
Have one axon and two or more dendrites
Multipolar neurons
81
Have one dendrite and one axon
Bipolar neurons
82
Sigle Process that biffurcates with one longer branch extending to a peripheral ending and the other toward the CNS
Unipolar o pseudounipolar
83
Many dendrites but no true axon regulate electrical changes of adjacent neurons
Anaxonic neurons
84
Most neurons are
Multipolar
85
Bipolar neurons are found in
Retina
Olfatory mucosa
(Inner ear) cochlear and vestibular ganglia
86
Pseudounipolar neurons are found in the
```
Spinal ganglia (sensory ganglia)
Craneal ganglia
```
87
Establish relationships among other neurons forming complex funtion al network or circuits
Interneurons
88
In PNS cell bodies are found in
Ganglia
89
Neurulation take place at
Fourth week
90
Slowly progressing disorder affecting muscular activity characterized by tremors, reduced activity of facial muscle , loss of balance and postural stiffness, caused by gradual loss by apoptosis of dopamine-producing neurons
Parkinson disease
91
The end of axones have many small branches called
Telodendria
92
Concentrated RER and other polysomes appear as clumps of Basophilic material called chromatophilic substance or
Nissl bodies
93
Abundant of Nissl substance or bodies in particulary
Large nerve cells such as motor neurons
94
Intermediate filaments are abundant both in perikarya and processes and in this cell are often called
Neurofilaments
95
Neurofilaments forms neurofibrils visible with certain fixatives like
Silver stains
96
Inclusions of pigmented material that nerve cell contains
Lipofuscin
97
Consist of residual bodies left from lysosomal digestion
Lipofuscin
98
Number of axonal ending Make functional contact with the dendrites of a single large Purkinje cell
200,000 axonal ending
99
Short blunt structures projecting at point along dendrites and most synapses impinging on neurons
Dendritic spines
100
Dendritic spines occur in vast Numbers for cells of the human cerebral cortex and serve as the initial processing sites for synaptic signals
10^14
101
Dendritic spines are of key importance in the constant changes of the neutral plasticity for
Underlying adaptation
Learning
Memory
102
Length of a motor neuron of the spinal cord that innervate the foot muscle
100 cm
103
Axons originate from a pyramid shaped region of the perikaryon called the
Axon hillock
104
The plasma membrane of the axon is often called
Axolemma
105
Citoplasm of An axon
Axoplasm
106
Site where various excitatory and inhibitory stimuli impinging on the neuron are algebraically summed
Initial segment
107
The distal end of An axon forms a
Terminal arborization
108
Axons of interneurons and some motor neurons have branches called..., that end at synapses influencing the activity of many other neurons
Collateral
109
Each branch ends with dilation called
Terminal bouton
110
Axoplasm contains
```
Mitocondria
Microtubules
Neurofilaments
Cisternae of smooth ER
No polyribosomes or RER
```
111
Organelles and macromolecules synthesized in cell body moves by
Anterograde transport along the axon from perikaryon to the synaptic terminals
112
Opposite direction carries macromolecules such material Taken by endocytosis
Retrograde transport
113
Mediate anterograde vesicular transport,a microtubule activated ATPase
Kinesin
114
Microtubule activated ATPase , provides retrograde transport
Dynein
115
Anterograde and retrograde transport a rate of
50 - 400 mm/d
116
The action potential is propagated along the axon as a wave of membrane depolarization produce by
Voltage-gated Na and K channel
117
Axoplasmic concentration
K
118
Potential electrical difference across the axolemma of about
-65 mV
119
Low-molecular weight molecules that bind to the voltage-Gated sodium channel of the axolemma
Local anesthetic
120
Depolarization resting the potential from negative to positive at
+30 mV
121
Immediately after the membrane depolarization the
Voltage gated Na channels close and those for K open
122
Terminal bouton from which neurotransmitters is released by exocitosis from
Synaptic vesicles
123
Synaptic cleft are separated by
20 to 30 nm
124
At the presynaptic region the nerve impulse briefly opens
Calcium channel influx that trigger neurotransmitters release by exocytosis or similar mechanism
125
Neurotransmitters are removed quickly by
enzymatic breakdown diffusion or endocytosis
126
The chemical transmitter used at neuromuscular junctions is
Acetylcholine
127
A widely used class of drugs for treatment of depression An axiety disorder
Selective serotonin reuptake inhibitors
128
The predominant glial cells in CNS
Oligodendrocito
129
Most common neurotransmitter in the brain, opens Na channels, excites activity in neurons to promote cognitive function in the brain (learning and memory)
Glutamate
130
Synthesized from glutamate, primary inhibitory neurotransmitter, also influences muscle tone, opens or closes various ions channels
gamma -aminobutyric acid GABA
131
Inhibits activity between neurons in the CNS including retina , opens Cl channels
Glycine
132
Functions in the brain related to sleep, appetite, cognition and mood, modulates actions of other neurotransmitters
Serotonin or 5 hydroxytryptamine
133
A distinct group of monoamines
Catecolamines
134
Produces inhibitory activity in the brain, important roles in cognition, motivation, behaviors and mood, open K channels , close Ca channel
Dopamine
135
Neurotransmitter of PNS (sympathetic division of autonomic nervous system) and specific CNS regions
Norepinephrine
136
Has various effects in CNS , especially the spinal cord , thalamus, and hypothalamus
Epinephrine
137
Helps regulate response to noxious and potentially harmful stimuli
Enkephalin
138
Involved in memory regulation and energy balance (increase food in take and decreased physical activity)
Neuropeptide Y
139
Inhibits activities of neurons in specific brain areas
Somatostatin
140
Assists with pain information transmission into the brain
Substance P
141
Stimulates neurons in the brain to help mediate satiation (fullness) and repress hunger
Cholecystokinin
142
Prevents release of pain signals from neurons and fosters a feeling of well being
Beta endorphin
143
Helps control and moderate the effects of dopamine
Neurotensin
144
Inhibits activities in certain CNS neurons
Adenosine
145
Involved in learning and memory relaxes muscle in the digestive tract important for relaxation of smooth muscle in blood vessels (vasodilatation)
Nitric oxide
146
Have a large number of radiating processes
Astrocytes
147
Typical in white matter, with few long processes
Fibrous astrocytes
148
Many shorter branched processes are called..., predominant in gray matter
Protoplasmatic astrocytes
149
The larger processes of all astrocytes are reinforced with bundles of intermediate filaments made of ..., which serves as a unique marker for astrocytes, the most common source of brain tumors
Glial fibrillary acid protein (GFAP)
150
Derived from those glial cells and characterized pathologically by their expression of GFAP
Astrocytomas
151
Astrocytes Forming a barrier layer of expanded processes called ...,lining the meninges at the external CNS surface
Glial limiting membrane
152
Astrocytic processes are seen with
Gold staining
153
Astrocytes extending processes that cover capillary endothelial cells and contribute to the BBB
Perivascular feet
154
Common type of dementria in elderly, affect both neuronal perikarya and synapses within the cerebrum
Alzheimer disease
155
Are columnar or cuboidal cells that line the ventricules of the brain and central canal of the spinal cord , in some CNS locations the apical ends of ependymal cells have cilia,facilitates movement of CSF and long microvilli for absorption
Ependymal cells
156
Ependymal cells are joined apically by... , but lack a basal lamina
Juntional complexes
157
Major mechanism of inmune defense in CNS
Microglia
158
The myelin sheaths surrounding axons are damaged by an autoimmune mechanism
Multiple sclerosis
159
Funtion of satellite cells
Form An intimate covering layer over the large neuronal cell bodies in the ganglia of the PNS
160
The main components of white matter are myelinated axons often group together as
Tracts
161
Deep regions of the CNS have darker aggregates consist of large number of neuronal cell bodies
Nuclei
162
Number of layers in cerebral cortex
Six layers
163
Diameter of granular layer cells
4-5micrometers
164
White matter is peripheral and gray matter is internal
Spinal cord
165
Consist of dense , fibroelastic connective tissue that is continuous with the periosteum of the skull
Dura mater
166
Around the spinal cord the dura mater is separated from the periosteum of the vertebrae by
Epidural space which contains a plexus of thin-walled veins and areolar connective tissue
167
The dura mater is always separated from the arachnoid by the thin
Subdural space
168
The internal surface of all dura mater as well as the external surface in the spinal cord is covered by
Squamous epithelium of mesenchymal origin
169
Two components of the arachnoid
A Sheet of connective tissue in contact with dura mater
| System of trabeculae composed of collagen and fibroblast
170
Surrounding the trabeculae is a large sponge like cavity the..., filled with CSF
Subarachnoid space
171
The connective tissue of the arachnoid is said to be
Avascular
172
Consists of flattened,mesenchymally derived cells closely applied to the entire surface of the CNS tissue
Pía mater
173
The pia does not directly contact nerve cells or fibers being separated from the neural elements by the very thin superficial layer of
Astrocytic processes the glia limitans
174
Blood vessels penetrate the CNS through long
Perivascular spaces covered by pia mater
175
Is a functional barrier that allows much tighter control than in most tissue over the passage of substances moving from blood into the CNS tissue
Blood brain barrier
176
Completely envelops the basal lamina of the capillaries in most CNS regions forms another BBB component and further regulates passage of molecules and ions from blood to brain
Limiting layer of perivascular astrocytic feet
177
Function of the choroid plexus
Is to remove water from blood and release it as the CSF
178
Provide the main pathways for absorption of CSF back into the venous circulation
Arachnoid villi
179
Also called neurolemmocytes
Schwann cells
180
The length of axon ensheathed by one Schwann cell the
Internodal segment
181
Axonal diameter ranges
300 to 1500 micrometers
182
Consist of reticular fibers scattered fibroblast and capillaries , immediatedly around the external laminae of the Shwann cells
Endoneurium
183
Schwann cells and endoneurium are bundled together as fascicles by a sleeve of
Perineurium
184
Autonomic ganglia are small bulbous dilations in autonomic nerves usually with
Multipolar neurons
185
Sensory ganglia are associated to
Cranial nerves
| Dorsal roots
186
The chemical mediator present in the synaptic vesicles of all preganglionic axons is
Acetylcholine
187
Proteins produced by both neurons and glial cells the neural plasticity
Neurotrophins
188
is the dissolution of the Nissl bodies in the cell body of a neuron. It is an induced response of the cell usually triggered by axotomy, ischemia, toxicity to the cell, cell exhaustion, virus infections, and hibernation in lower vertebrates. Neuronal recovery through regeneration , but most often it is a precursor of apoptosis.
Chromatolysis
