Brainscape's Knowledge GenomeTM

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


See full index

Module 8 > Cellular Anatomy of CNS > Flashcards

Cellular Anatomy of CNS Flashcards

1
Q

what are the cells of nervous tissue

A
  1. neurons (nerve cells)
  2. neuroglia (astrocytes, oligodendrocytes, microglia)
  3. ependymal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are neurons

A

comminication network

excitable

receptive to stimuli

conduct impulses

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

what are neuroglia

A

supportive cells

regulate environment

help neurons function

immune function

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

what are ependymal cells

A

specialized epithelial cells

involved in CSF production

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

what are the parts of the neuron

A
  1. cell body
  2. dendrite
  3. axon
  4. axon terminal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the features of the neuron cell body

A

supply centre of neurons

contain nucleus and cytoplasmic organelles

nissi body has concentration of ribosomes for protein synthesis

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

what are the features of dendrites

A

processes that ramify from the other cell body

provide large surface area for contact with other neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

wgat are axons

A

a prominent dendrite extends from the cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the axon terminals

A

point of synapse

contact with other neurons

communicate by chemicals

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

what are the morphological variations of neurons

A
  1. multipolar
  2. bipolar
  3. unipolar
  4. pseudounipolar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are mutlipolar neurons

A

several dendrites

most dominate type

throughout the brain and spinal cord

single axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are bipolar neurons

A

one main dendrite receiving stimuli

one axon delivering impulse to target site

olfactory, inner ear and retinal

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

what are unipolar neurons

A

sensory neurons

short extension from cell body

one dendrite and one axon

fused together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are pseudounipolar neurons

A

begin as bipolar and fuse with development to give the unipolar neuron

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

what are the functional classification of neurons

A
  1. sensory or afferent neurons
  2. motor or efferent
  3. interneurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are sensory or afferent neurons

A

receive sensory input directly (dendrites) or from adjacent cells

conveys sensory stimuli as impulse (action potential) to the CNS via cranial or spinal nerves

mostly unipolar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are motor or efferent neurons

A

convey impulse from CNS to target (muscle, glands) via cranial or spinal nerves

mostly multipolar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are interneurons

A

located with CNS

connection between sensory and motor

mostly multipolar

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

what are olfactory cells

A

detect odour on chemical receptors on bipolar neurons

chemoreceptors are located on cilia that project from dendrites

cilia covered by mucs from supporting cells and olfactory glands

required to solubilize the odour for receptor association

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

what are the types of sensory neurons

A
  1. meissners corpuscles: touch receptor, mass of dendrite ending
  2. merkel: touch, free nerve endings
  3. pacinian: pressure, laminated capsules
  4. nociceptor: pain, free nerve endings
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the most abundant neuron in the CNS

A

multipolar neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the types of multipolar neurons

A
  1. dendritic tree
  2. purkinje neuron
  3. pyramidal neuron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are dendritic tree neurons

A

pattern can vary

greatly enhances number of synapses

dendritic spine can alter and gives a level of plasticity

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

what are the features of purkinje neurons

A

found in cerebellum

controls gait

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

what are the features of pyramidal neuron

A

found in cortex

thought processing

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

what is a depolarizing graded potential

A

makes the membrane less polarized

inside is less negative

reduced potential difference between the inside and outside of the membrane

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

what is hyperpolarized graded potential

A

makes the membrane potential more polarized

inside is more negative

greater potential difference between inside and outside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what are the effects of myelin

A
  1. insulates segments of the axons (internodes) –> nodes of ranvier is gap between internodes, has high concentration of ion channels
  2. action potential jumps (saltatory conduction)
  3. greatly enhances speed of conductance
  4. reduced the need for large diameter axons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what are the variable arrangements of neuron connections

A
  1. simple series circuit
  2. divergent series
  3. convergent series
  4. reverberating
  5. parallel after discharge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what are simple series circuit

A

single presynaptic (before synapse) stimulates a single postsynaptic (after synapse)

ex. reflex arc

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

what are divergent series

A

single presynaptic stimulates several post synaptic

ex. nerve impulse from a single neuron can influence many spinal neurons for complex movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what are convergent series

A

several neurons stimulate single neuron

ex. a neuron that connects to a specific neuromuscular junction recieves input from many cells in the brain

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

what are reverberating circuit

A

feedbacks to stimulate neurons at early points in cascade

thought to be involved in memory formation

34
Q

what are parallel after discharge circuits

A

different number of neurons in a cascade that converge on a common neuron

ex. complex cognitive processing such as math

35
Q

what does the gray matter in the brain contain

A

neuronal cell bodies

dendrites

astrocytes

neurons arranged in specific layers and form complex networks

36
Q

what does the white matter contain

A

myelinated axons

oligodendrocytes

microglia

37
Q

what is the spinal cord composed of

A

gray and white matter

38
Q

how is the organization of the spinal cord different from the brain

A

white matter on outside with gray matter forming a horn

39
Q

what does gray matter in the spinal cord contain

A

cell bodies and dendrites

sensory neuron input (cell body in ganglion) in dorsal nerve root

interneuron mediator

motor output from ventral nerve root

connects to ascending (sensory) and descending (motor) white matter tracks

40
Q

how is white matter organized in the spinal cord

A

tracks of myelinated axons

arranged into specific bundles called tracts

41
Q

how is the PNS organized

A

arranged in bundles of nerve fibres

nerves enclosed in 3 layers

42
Q

what are the 3 layers that enclose nerves in the PNS

A
  1. epineurium
  2. perineurium
  3. endonurium

schawnn cells myelinate axons in the PNS

43
Q

what is the epineurium

A

thick, tough connective tissue

44
Q

what is the perineurium

A

tough CT surrounding bundle

45
Q

what is the endonurium

A

loose delicate CT

surrounds each axon

46
Q

how many schawnn cells per axon

A

1 cell per axon

47
Q

what are the labels

A
48
Q

what are the cells that support the cells of the CNS

A
  1. astrocytes
  2. oligodendrocytes
  3. microglia
49
Q

what are astrocytes and their function

A

star shaped

protoplasmic (gray) and fibrous (white)

involved in blood brain matter and remove neurotransmitters from synaptic cleft

50
Q

what are oligodendrocytes and their function

A

found mainly in white matter

smaller than astrocytes

produce myelin around axons

51
Q

what are microglia

A

ovoid shape

change morphology on activation

resident immune cells, remove debris + bacteria (lipid laden macrophages gitter cells)

52
Q

what are the structures

A
53
Q

what are the important roles astrocytes play

A

associates with blood vessel to form barrier –> association with pericytes to regulate gene expression

reactive in many neurodegenerative disorders and extend processes

produce trophic substances and can upatake glutamate and potassium

can form scar tissue to block formation of neuronal tracks (spinal cord injury)

54
Q

what is the blood brain barrier and the blood CSF barrier

A

CNS needs a consistent environment

cannot be subjected to gross fluctuations of ionic chemical and hormonal levels

energy source needs replenished and waste needs to be removed

55
Q

what is the function of the choroid plexus

A

produces CSF

lateral, third and 4th ventricle

CSF enters subarachnoid space –> between pia and arachnoid meninges

then enters spinal canal –> circulates around the CNS

56
Q

what are ependymal cells of the choroid plexus

A

cuboidal or columnar epithelial cells

line the vesicles of the brain and spinal cord

ciliated to regulate CSF movement and turnover

57
Q

what is the funciton of ependymal cells of the choroid plexus

A

ependymal tight junction

act to filter blood

CSF is clear solution

58
Q
A
59
Q

how is CSF absorbed

A

in arachnoidal villus into venous sinus

60
Q

what are arachnoid villi

A

project into the sinus through the dura matter (grouped arachnoid villi termed arachnoid granulations)

61
Q

what are arachnoid villi covered in

A

thin layer of epithelium from sinus

62
Q

what occurs when pressure in subarachnoid space is higher than sinus

A

CSF moves into sinus

higher pressure closes the tubules of the arachnoid villa

63
Q

what can abnormality of arachnoid villi lead to

A

abnormality in regulation can lead to hydrocephalus

64
Q

how does communication via neurotransmitters (NT) occur

A

synaptic cleft –> gap between presynaptic and postsynaptic membranes

APs can’t jump the cleft –> NT cause either excitatory or inhibitory gradient on postsynaptic sites

65
Q

what are excitatory NTs

A

depolarizes post synaptic membranes so resting potential nearer the threshold for AP

excitatory postsynaptic potential (EPSP)

ex. glutamate, aspartate

stimulate influx of +ve ions or efflux of -ve ions

66
Q

what are inhibitory NTs

A

hyperpolarization of post synaptic membrane so resting potential further from threshold

inhibitory postsynaptic potential (IPSP)

GABA, glycine

stimulates influx of -ve ions or efflux of +ve ions

67
Q

what are the events at the synapse (7)

A
  1. nerve impulse travels along axon to the presynaptic terminal
  2. impulse causes depolarization that activates and opens calcium channels
  3. calcium activates a series of protein events on synaptic vesicles (proteolytic and phosphorylation events)
  4. synaptic vesicles fuse with membrane and release the NTs into synaptic cleft
  5. Nts bind to receptors on postsynaptic membrane ion channels (dendrites)
  6. initates post synaptic depolarization
  7. clearance of NTs from the synaptic cleft occurs by various methods (diffusion, enzymatic breakdown, reabsorption)
68
Q

what are ionotropic receptors

A

ligand binding site

ligand modulates opening

probablity and ion flux

GABA

69
Q

what are metabotropic receptors

A

has a ligand binding site

couples to a G protein site

production of 2nd messenger modulates ion channels

alters opening probability

ex. acetylcholine

70
Q

what are the classes of neurotransmitters

A
  1. amino acids
  2. monoamines
  3. soluble gases
  4. acetylcholine

(excitatory, inhibitory, both)

71
Q

what are the features of glutamate

A

simple amino acid

excitatory transmitter in CNS

72
Q

what is NMDA

A

a subtype of glutamate receptor

73
Q

what is a feature of NMDA

A

has a pore containing a Mg2+ binding site –> binding block the channel and is removed following depolarization

74
Q

what is GABA

A

g-aminobutyric acid

inhibitory NT

75
Q

how is GABA generated

A

by conversion of glutamate by GAD

76
Q

what are the two types of receptors

A
  1. GABA A: ionotropic, located post synaptically and permeable to Cl- ions
  2. GABA B: metabotropic, located pre and post synaptically and modulated calcium and potassium channels
77
Q

what are biogenic amines

A

removal of carboxy groups of certain amino acids generate biogenic amines

most act via metabotropic receptors

78
Q

what is a class of biogenic amines

A

catecholamines

norepinephrine, epinephrine, dopamine

79
Q

what are the receptors of acetylcholine

A

ionotropic (nicotine) and metabotropic (muscarinic)

mainly excitatory

80
Q

what are purines

A

ATP and adenosines

ATP acts on P2 ionotropic receptors and can be excitatory

adenosines: A1-3 receptors

81
Q

what is nitric oxide

A

lipid soluble free radical

no receptor, passes membrane by diffusions

influences blood pressure

82
Q

what are neuropeptides

A

G-protein coupled receptors

powerful analgesics

Module 8 (43 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions