Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Histology > Histology - Nervous Tissue > Flashcards

Histology - Nervous Tissue Flashcards

0
Q

End bulbs (terminal boutons)

A

Axon terminal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Perikaryon

A

Cell body of a neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Nissles bodies

A

= RER + polyribosomes

Basophilic material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Axon hillock

A
  • RER is absent
  • Highest concentration of sodium (Na+) gates/ channels
  • Pyramidal-shaped region of the soma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Hypolemma cisterna

A
  • SER extending from the axons to the dendrites

- Continous with RER of the cell body and weave between nissls bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Golgi complex

A

Responsible for the packaging of neurotransmitter substances or enzymes essential for their production in the axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Mitochondria

A
  • Most abundant at the axon terminals

- More slender in neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Centriole

A
  • Most adult neuron display one centriole associated with a basal body of a cilium
  • Possesses the 9+0 arrangement in microtubules
  • Believed to be vestigial structures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Melanin granules

A 
- CNS:
    > Substantia nigra
    > Locus ceruleus
    > Dorsal motor nucelus of the vagus and the spinal cord
 - PNS:
    > Sympathetic ganglia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the precusor of the melanin granules?

A

Dihydroxyphenylalanine (DOPA)/methyldopa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Inclucions

A
  • Melanin
  • Lipofuscin pigments
  • Lipid droplets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Lipofuscin

A
  • Irregulary shaped, yellowish brown pigment granule
  • Remant of lysosomal activity
  • Increase in number with age
  • May crowd the organelles and the nucleus to one side, possibly affecting cellular funtion
  • Purkinjie cellsof the cerebellar cortex do not accumulate lipofuscin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Give an example of a cell that does not accumulate lipofuscin?

A

Purkinjie cells of cerebellar cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Lipid droplets

A
  • Observed in neuronal cytoplasm
  • May be the result of faulty metanolism or from energy reserves
  • Secretory granules are observed in neurosecretory cells; many of them containing signaling molecules.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Secretory granules

A

Observed in neurosecretory cells; many of them containing signaling molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Neuronal cytoskeletal components;

A
  • Exhibit neurofibrils
  • 3 filamentous structures:
    1. Microtubules (MAP-2 and MAP-3)
    2. Neurofilaments (clumped bundles of neurofilaments)
    3. Microfilaments (actin filaments)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Dendrites

A
  • Do not contain golgi complex
  • Neurofilaments are reduced to small bundles or single filaments, which may be cross-linked to microtubules.
  • Mitochondria is abundant
  • Some dendrites have spines which permit them to form synapses with other neurons
  • Sometimes the dendrites contain vesicles and transmit impulses to other dendrites.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Spines

A
  • Located on the surface of some dendrites
  • Permit them to form synapses with other neurons
  • Diminish woth age and poor nutrition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Collateral branches

A

Arise at right angles from the axon trunk.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Terminal arbor

A

Small branches of the axon terminals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Initial segment =

A

Spine trigger zone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Axolemma

A
  • Plasmalemma of the axon
  • Lacks RER
  • Houses abundant microtubules and neurofilaments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Myelin sheath

A

Surround some axons in poth CNS and PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the precusor of the neurotransmitters dopamine and noradrenaline?

A

Dihydroxyphenylalanine (DOPA)/methyldopa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Unmyelinated axon

A

Axons lacking myelin sheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Myelinated axon

A

Axons surroundednby myelin sheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Axonal transport

A

Transport of materials between the soma and the axon terminals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Anterograde transport

A
  • Transport of materials from the cell body to the axon terminals.
  • Translocation of organelles and vesicles as well as macromolecules such as:
    > Actin
    > Myosin
    > Clathrin
    > Some enzymes necessary for neurotransmitter synthesis at the axon terminals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Retrograde transport

A
  • Transport of materials from the axon terminals to the cell body
  • include;
    > Protein building blocks of neurofilaments
    > Subunits of microtubules
    > Soluble enzymes
    > Materials taken by endocytosis (e.g. viruses, toxins)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Horseradish peroxidase

A

Enzyme used for axonal retrograde transport.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Tubulin dimers

A
  • Reaches the axoplasm via anterograde transport

- Are assembled onto the microtubules at their plus end and depolarized at their minus end.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Kinesin

A
  • Involve in the anterograde mechanism because one end attaches to a vesicle and the other end interact in a cyclical fashion with a microtubule, thus permitting the kinesin to transport the vesicle.
  • A microtubule-associated protein.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Dynein

A
  • Microtubule associated protein

- Responsible for moving vesicles along microtubules in retrograde transport.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Where is the bipolar neurons located?

A

In the vestibular and the cochlear ganglia and in the olfactory epithelium of the nasal cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does the unipolar neurons develop from?

A

The unipolar neurons develop from the bipolar neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Which neurons are the most common?

A

Mutlipolar neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What kinds of neurons are the purkinji cells?

A

Multipolar neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What kind of neurons are the pyramidal cells?

A

Multipolar neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Motor (efferent) neurons and interneirons are….?

A

Multipolar neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Which cells undergo mitosis?

A 
- Neuroglia;
    > Astrocyte
    > Oligodendrocyte
    > Microglia
    > Ependymal cells
    > Schwann cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Which neuroglial cells are in the CNS?

A

> Astrocyte
> Oligodendrocyte
> Microglia
> Ependymal cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Which neuroglial cells are in the PNS?

A

Scwann cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Gray matter in the CNS

A

Protoplasmic astrocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

White matter in the CNS

A

Fibrous astrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Unique to astrocytes

A

Glial fibrillar acidic protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Protoplasmic astrocyte

A
  • Stellate cells
  • Have pedicles (vascular) feet that come in contact with blood vessles
  • ## Other protoplasmic astrocyte near the brain or surface of the spinal cord exhibit pedicletipped process that contact the pia mater, forming the pia-glial membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Fibrous astrocyte

A
  • Possess a euchromatic cytoplasm
  • Few organelles, free ribosomes, and glycogen
  • long and mostøy unbranched processes. These processes are closely associated with the pia mater and blood vessles but are separated by these structures by their own basal lamina.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Astrocyte functions

A
  • function in scavenging(remove) ions, neurotransmitters, and remants of neuronal metabolism
  • Assist in the maintaining the blood-brain barrier
  • Are recruited to damaged areas of the CNS, where they form cellular scar tissue.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Which cells forms the cellular scar tissue?

A

Astrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Which cell does the oligodendrocye resemble?

A

Astrocytes

50
Q

Oligodendrocytes

A
  • Resemble astrocyte
  • Darkest-staining neuroglial cell
  • Located in both gray matter and white matter of the CNS
  • Microtubules are present
51
Q

Which two types of oligodendrocytes do we have?

A
  1. Interfascicular oligodendrocytes

2. Satellite oligodendrocyte

52
Q

CNS: white matter and gray matter

A

In the fresh state the myelin sheath imprats a wite appearance to the axon.

53
Q

Interfascicular oligodendrocytes

A
  • Located in budles beside the axons
  • Responisible for manufacturing and maintaining myelin about the axon of the CNS
  • A single oligodendrocyte wraps around ceveral axons
  • Particapate in myelination of nerve fibers in the brain
54
Q

Satellite oligodendrocytes

A
  • Closely applied to cell bodies of large neurons

- Function: not clear

55
Q

Microglial cells

A
  • Resemble oligodendrocyte
  • Oval to triangular nuclus
  • Spines
  • Protect the nervous system from viruses, microorganisms, and tumour formation.
  • They act like antigen-presenting cells and secrete cytokinese
  • Derive from the bone marrow and are part of the mononucelarphagocytotic cell population.
56
Q

Where do the neuroglial cells dervie from?

A

The neuroglial cells derive from the neural tube, exept for the microglial cells which derive from the bone maroow

57
Q

Ependymal cells

A

=> Ependymocytes

  • low columnar to cuboidal cells linind the ventricles of the brain and the central cana of the spinal cord.
  • Derived from embryonic neuroepithelium of the developing nervous.
  • Cytoplasm: abundant mitochondria, intermediate fillaments
  • Can be ciliated -> to facilitate the movement of the cerebrospinal fluid
  • Forms the internal limiting memebrane lining the ventricles.
  • Froms the external limiting membrane beneath the pia mater. Both formed by fused pedicles.
  • Participate in the fomration of the choroid plexus
  • Tanycytes
58
Q

Internal limiting membrane

A

Lines the ventricles

59
Q

External limiting membran

A
  • Beneath the pia mater

- Formed by fused pedicles

60
Q

Pia mater and the external limiting membrane is formed by…?

A

Fused pedicles

61
Q

Tanycytes

A
  • Specialized ependymal cells
  • Extend processes into the hypothalamus, where they terminate near blood vessles and neurosecretory cells.
  • Tanycytes transport CSF to these neurosecretory cells, and possibly under the control from the anterior lobe of the pituitary, may respond to changes in hormone levels in the CSF by discharging secretory products in the capillaries.
62
Q

Schwann cells

A
  • In the PNS

- Form either myelinated or unmyelinated coverings

63
Q

Myelinated nerves

A

Axons that have myelin wrapped around it

64
Q

Nodes of ranvier

A

Interruptions on the myelin sheath at regular intervals along the axon, exposing the axon.

65
Q

What is covered by a basal lamina?

A

Nodes of ranvier and the Schwann cells

66
Q

Internodal segments

A

Areas of the axon covered in concentretic lamellae of myelin and the single Schwann cell that produced the myelin.

67
Q

Clefts (incisures) of Schmidt-Lanterman

A

Oblique clefts in the myelin sheath of each internodal segment

68
Q

Major dense line

A

Represent the fused cytoplasmic surfaces of the Schwann cell plasma membrane

69
Q

Intraperiod line

A

Represent the apposing outer leaflets of the Schwann cell plasma membrane

70
Q

Intraperiod gaps

A
  • Small gaps within the period line.

- Provide access for small molecules to reach the axon

71
Q

Internal mesaxon

A

The region of the intaperiod line that is in intimate contact with the axon

72
Q

Extrenal mesaxon

A

The outermost aspect of the intraperiod line, which is in contact with the bidy if the Schwann cells

73
Q

Myelination

A

Process whereby the Scwanncells(in PNS) or the Oligodendrocyte (CNS) concentrically wraps around the axon to form the myelin sheath

74
Q

How many axons can a Schwann cell myelinate?

A

Myelinate one internode of a single axon and only in the PNS

75
Q

How many axons can an oligodendrocyte myelinate?

A

Can myelinate an internode of several axons and only in the CNS

76
Q

When are the motor almost muelinated completely?

A

At birth

77
Q

When are sensory roots myelinated?

A

Several months after birth

78
Q

How many unmyelinated axons may be envelpoed by a single Schwann cell?

A

Several

79
Q

Resting potential

A
  • It is about -90 mV

- The inside of a cell is less positive thatn the outside

80
Q

Refractory period

A

When the Na+ channles are inactive

81
Q

Read 198-200

A

About the “generation and conduction of nerve impulses”

82
Q

Electrical synapses

A
  • Uncommon in mammals
  • Present in the retina and cerebral cortex
  • Presented by gap junctions that permit free movements of ions from one cell to another
  • Faster than chemical synapses
83
Q

Chemical synapses

A
  • Gated ion-channel rceptors

- Slower than electrical synapses

84
Q

Neurotransmitter

A
  • Signaling molecules that act as “first messenger systems”
  • Diffuse across the synaptic cleft to gated ions-channel receptors.
  • They only activate the response. They do not accomplish the reaction events at the postsynaptic membrane.
85
Q

Excitatory postsynaptic potential

A
  • Action potential
86
Q

Inhibitory postsynaptic potential

A
  • Maintainance of a membrane potential or increasing its hyperpolarization.
87
Q

Axodendric synapse

A

Synapse between an axon and a dendrite

Synapse between an axon and a spine(which is from a dendrite)

88
Q

Axosomatic synapse

A

Synapse between an axon and a soma

89
Q

Axoaxonic synapse

A

Synapse between two axons

90
Q

Dendrodendric synapse

A

Synapse between two dendrites

91
Q

Synapsin-I

A
  • Small protein that forms a complex with the vesicle surface.
  • Appearsnto assistin the clustering of synaptic vesicles held in reserve
92
Q

What happens when synapsin-I is phosphorylated?

A

The synaptic vesicles become free to move to the active zone in prepraration for release of the neurotransmitter.

93
Q

What happens when the synapsin-I is dephosphorylated?

A

The results of the phosphorylation will be reversed

94
Q

Synaptotagmin and synaptophysin

A
  • Synaptic vesicle proteins that control the docking of the synaptic vesicles with the presynaptic membrane
95
Q

What causes the synaptic vesicles to fuse with the presynatpic membrane, emptrying neurotransmitter into the synaptic cleft via exocytosis?

A

Ca2+ influx undr the influence of SNARE (SNAP receprot) proteins.
Including synaptobrevin, syntaxin, and soluble N-ethylmaleimide-sensetive fusion protein attachment protein-25 [SNAP-25]

96
Q

Interactions between synaptotagmin and vesicle coat protein AP-2

A

Involves in recyclin of synaptic vesicles

97
Q

Synaptobrevin

A

The synapstic vesicle protein

98
Q

Asymmetric synapse

A

Is usually the site of exitatory responses

99
Q

Symmetric synapse

A

Usually the site of inhibitory responses

100
Q

Neuromodulators or neurohormones

A

Signaling molecules thatn invoke “second messenger system”

101
Q

Neurotransmitters

A

Signaling molecules that act as “first messenger systems”

102
Q

Neurotransmitters (and neuromodulators) are represented by the following 3 groups;

A
  1. Small-molecule transmitters
  2. Neuropeptides
  3. Gases
103
Q

Small-molecule transmitters are of 3 major types:

A
  1. Acetylcholine
  2. The aminoacids
  3. Biogenic amines
104
Q

Acetylcholine

A
  • Not an aminoacid derivate

- Small-molecule transmitter

105
Q

Aminoacids

A
  • Glutamate
  • Aspartate
  • Glycine
  • “Gamma”-aminobutyric acid (GABA)
  • Small-molecule transmitter
106
Q

Biogenic amines

A
  • Monoamines
  • Serotonin
  • 3 catecholamines;
    1. Dopamine
    2. Norepinephrine (noradrenaline)
    3. Epinephrine (adrenaline)
  • Small-molecule transmitter
107
Q

Neuropeptides

A
  • Neuromodulators
  • Include:
    1. Opioid peptides
    2. Gastrointestinal peptides
    3. Hypothalamic releasing hormones
    4. Hormones
108
Q

Opioid peptides

A
  • Enkephalins

- Endorphins

109
Q

Gastrointestinal peptides

A
  • Produced by cells of the diffuse neuroendocrine system.
    > Substance P
    > Neurotestin
    > Vasoactive intestinal peptides
110
Q

Hypothalamic-releasing factor

A

E.g:
> Thyrotrompin releasing hormone
> Somatostatin

111
Q

Hormones

A

Stored in and released from the neurohypophysis (antiduretic hormone and oxytocin)

112
Q

Gases

A

May act as neuromodulators. The ones that do are:

  • Nitric oxid (NO)
  • Carbon monoxide (CO)
113
Q

Epineurium

A
  • The outermost layer of the connective tissue investment covering nerves.
  • Composed of: dense, irregular, collagenous connecitve tissue containing thick elastic fibers.
114
Q

Perineurium

A
  • The middle layer of connective tissue investmen.
  • Cover each bundle of nerve fibers.
  • Composed of dense connective tissue but is thinner than epineurium.
  • It inner suraface is covered byseveral layers of epitheloid cells joined by zonulae occuludentes and surrounded by basal lamina that isolates the neuronal enviroment.
  • There are sparse collagen fibers between the layers of epitheloid cells adn interwined with a few elastic fibers
115
Q

Where can we find epitheloid cells?

A

Perineurium

116
Q

Endoneurium

A
  • Innermost layer of the three connective tissue investememt of a nerve
  • Surrounds individualnerve fibers (axons)
  • A loose connective tissue composed of a thin layer of reticular fibers (produced by undrlyibg Schwann cells), scattered fibroblasts, fixed macrophages, capillaries, and perivascular mast cells in extracellular fluid.
  • The endoneurium is in contact with the basal lamina of the Schwann cells
  • Isolated from the perineurium and Schwann cells
117
Q

Mixed peripheral nerves

A

=> spinal nerves

- Carry both sensory and motor fibers

118
Q

Salatory conduction

A
  • Is when the action potential jumps from node to node.

- Occure in myelinated fibers

119
Q

Continous conduction

A
  • Is slower and requires more energy than the salatory conduction
  • Occure in unmyelinated fibers
120
Q

Which cranial nerves contains somatic efferent components?

A
  • III
  • IV
  • VI
  • XII

Excluding those nerves supplying muscles of brachiomeric origin

121
Q

What nerves provide the motor innervation for the skeletal muscles?

A

The somatic nerves

122
Q

What nerve provide motor innervation for smooth muscle and cardiac muscle and supply secretomotor innervation to glands?

A

Autonomic nerves

123
Q

MORE

A

PAGES

Histology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions