Brainscape's Knowledge GenomeTM

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


See full index

PHYS - NEURO > 2. NEURONS & GLIA > Flashcards

2. NEURONS & GLIA Flashcards

1
Q

What is the human brain comprised of?

A
  • The human brain is comprised of neurones & glial cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the reticular theory?

A
  • Reticular theory suggests that neurones fuse together & form a continuous network
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the neurone doctrine theory?

A
  • The neurone doctrine theory suggests that neurones are individual units which communicate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the process of fixation & sectioning of neural tissue?

A
  • Brain tissue can be fixated & sectioned for visualisation
  • Fixation = freezing the tissue or embedding it in paraffin wax
  • The tissue can then be sectioned with a microtome
  • Different orientations e.g horizontal, coronal, saggital
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the Nissl stain & what can it show?

A
  • Nissl stain can differentiate between glial cells & neurones
  • Cresyl violet
  • Stains nuclei & Nissl bodies (cell bodies)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

** What is the Golgi stain & what can it show?

A
  • Golgi stain can differentiate between structures better than the nissl stain
  • Silver chromate solution
  • Stains neurones & their projections (neurites)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How did discovery of the electron microscope provide insight about neurones?

A
  • The space between neurones is 0.02um but light microscopes only had a resolution of 0.1 um so there was a lot of disagreement about whether neurones were connected
  • Electron microscope -. resolution was small enough to see between neurones
  • Conclusion = Neurone doctrine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are neurones?

A
  • Neurones are specialised cells in the nervous system involved in the transmission & conduction of electrical & chemical signals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the three parts to a neurone?

A
  1. CELL BODY
  2. AXON
  3. DENDRITES
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the properties of the cell body of a neurone?

A
  • The cell body of a neurone contains the same organelles as those in other cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define the neuronal cytoskeleton

A
  • The neuronal cytoskeleton is the internal scaffold which provides the neurone with shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What three structures make up the neuronal cytoskeleton?

A
  1. MICROFILAMENTS
  2. NEUROFILAMENTS
  3. MICROTUBULES
    - Ordered smallest -> largest
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

*What are the properties of neuronal microfilaments?

A
  • MICROFILAMENTS - Smallest fibre
  • Length = 5nm
  • What? Polymer of the protein ACTIN
  • Where? axons & dendrites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the properties of neuronal neurofilaments?

A
  • NEUROFILAMENTS = intermediate fibre
  • Length = 10nm
  • What? Bound together in a rope like structure to provide strength
  • Where? Axons - regulating axonal shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the properties of neuronal microtubules?

A
  • MICROTUBULES = 20 nm
  • Length = 20nm
  • What? Polymer of the protein TUBULIN. Involved in axoplasmic transport
  • Where? Axons & dendrites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define axons & the three parts of axons

A
  • Axons are highly specialised neuronal projections that are involved in transporting nerve impulses over long distances
    1. AXON HILLOCK
    2. AXON PROPER
    3. AXON TERMINAL
17
Q

What is the axon hillcock?

A
  • Initial segment of an axon
18
Q

What are axon collaterals & recurrent collaterals?

A
  • Axon collaterals are branches of the axon proper
  • These axon collaterals will branch out to different areas but if they return to the same cell, they are known as recurrent collaterals
19
Q

Define dendrites

A
  • Dendrites are highly specialised neuronal projections that receive synaptic input from otehr neurones
  • dendrites form dendritic trees with dendritic branches
20
Q

What are the two main types of neuron classification?

A
  1. NEURONAL STRUCTURE
  2. GENE EXPRESSION
    - But these two broad categories can be subdivided
21
Q

What are the four types of neuronal classification by structure?

A
  • Neurones can be classified by structure:
    1. NUMBER OF PROJECTIONS
    2. DENDRITES
    3. CONNECTIONS
    4. AXON LENGTH
22
Q

How can neurones be classified by the number of projections?

A
  • Neurones can be classified according to teh number of projections or neurites
  • UNIPOLAR = one neurite
  • BIPOLAR = 2
  • MULTIPOLAR = many
23
Q

What two ways can neurones be classified by their dendrite structure?

A
  1. Denditic tree structure (pyramidal/stellate)

2. Dendritic spines

24
Q

How can neurons be classified according to the structure of their dendritic trees?

A
  1. PYRAMIDAL = Pyramidal cells

2. STELLATE = Stellate cells

25
Q

How can neurones be classified according to the structure of their dendritic spines?

A
  • Neurones can be classified based on the absence or presence of dendrites
  • SPINY = presence of dendrites
  • ASPINY = absence of dendrites
26
Q

How can neurones be classified according to their connections?

A
  • Neurones can be classified according to their connections as: SENSORY, MOTOR, INTERNEURONE etc
  • SENSORY = skin to CNS
  • INTERNEURONE = neurones synapsing with each other in the CNS
  • MOTOR - CNS to gland/effector
27
Q

How can neurones be classiifed according to axonal length?

A
  • neurones can be classified into two types based on axonal length
  • GOLGI TYPE 1 - axons extend from one region of brain to another (Pyramidal)
  • GOLGI TYPE 2 - axons don’t extend to other regions (Stellate)
28
Q

How can neurones be classified according to gene expression?

A
  • Classified based on neurotransmitter produced

- E.g glutamatergic, serotonergic

29
Q

What are glial cells & the 4 types of glial cell?

A
  • Glial cells = support cells of the nervous sytem
    1. ASTROCYTES
    2. MICROGLIA
    3. EPENDYMAL
    4. OLIGODENDROCYTES/ SCHWANN CELLS
30
Q

What are astrocytes?

A
  • Astrocytes are star shaped glial cells
  • Most numerous in the human brain
  • Found in extracellular space between neurones
31
Q

What are the functions of astrocytes?

A
  • Regulate the extracellular environment in the brain by:
    1. Actively removing neurotransmitter in the cleft
    2. Covering & enclosing the synaptic junction
32
Q

What are microglia cells?

A
  • Microglia cells are found in the spinal cord
  • They phagocytose neuronal & glial cell debris
  • Ramified & ameboid
33
Q

What are the two types of microglia cells?

A
  1. RAMIFIED (inactive)
  2. AMEBOID
    - The ramified microglia contract their processes becoming ameboid
    - Ramified microglia don’t phagocytose but identify threats
    - Ameboid microglia are active & carry out phagocytosis
34
Q

What are 3 functions of microglia cells?

A
  1. Phagocytose neuronal & glial debris
  2. Synaptic remodelling - microglia scavenge & remove unnecessary synaptic connections
  3. Direct neuronal migration during devlopment
35
Q

What are ependymal cells?

A
  • Ependymal cells are glial cells that line the ventricular system of the brain
  • They act as a physical barrier between the tissue & CSF
36
Q

What are 3 functions of ependymal cells?

A
  1. Osmotic regulation of CSF - controls osmolality by taking up ions & water
  2. Flow of CSF - ependymal cells beat to contribute to flow of CSF through ventricles
  3. Direct cell migration during brain development
37
Q

What is a hydrocephalus & why does it occur?

A
  • A hydrocephalus is when there’s severe pressure in the brain characterized by the accumulation of CSF in the ventricular system leading to enlarged lateral. 3rd & 4th ventricles
  • Hydrocephalus occurs as a result of deficits in differentiation, maturation & function of ependymal cells
38
Q

What are oligodendrocytes & schwann cells & what do they do?

A
  • Oligodendrocytes & schwann cells are a type of glial cell that myelinate neurones
  • OLIGODENDRICYTES = CNS, myelinate MANY neurones
  • SCHWANN CELLS = PNS, myelinate SINGLE neurone

PHYS - NEURO (18 decks)

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