Lesson 1: Cell Biology of the Nervous System Flashcards
1
Q
Describe the dendrite
A
Receive input signals from other neurons
2
Q
Describe the soma
A
Contain nucleus, organelles
3
Q
What is another name for the soma?
A
Cell Body
4
Q
Describe the axon (2)
A
Often myelinated
Rapidly conduct electrical signals
5
Q
Describe the axon terminal
A
Transfer signals to other neurons
6
Q
What are the parts of neurons? (8)
A
Dendrite Nucleus Cell body Axon Node of Ranvier Myelin sheath Schwann cell Axon terminal
7
Q
What is the function of neurons?
A
Process neural signals in the nervous system
8
Q
______________ information flow occurs from ________ through _____
A
Unidirectional
Dendrite
Axons
9
Q
Large number of amount of dendrites permit…
A
The integration of a wide range of inputs
10
Q
True or False:
The structure of glial cells are largely dependent on their function
A
True
11
Q
What does the four prevalent populations of Glia include? (4)
A
Astrocytes
Microglia
Oligodendrocytes
Schwann Cells
12
Q
What is the function of astrocytes?
A
Cellular metabolism
13
Q
What is the function of microglia?
A
Waste clearance
14
Q
What is the function of oligodendrocytes?
A
Myelinating
15
Q
What is the function of Schwann Cells?
A
Myelinating
16
Q
Glial cells form the _____ _____ _______ to regulate movement of molecules
A
Blood Brain Barrier
17
Q
Specific types of glia ___________ cell debris to clear _____
A
Phagocytose
Waste
18
Q
What does phagocytose mean?
A
Eat
19
Q
Astrocytes interact with ____ _________ and _________ to form __________ _______
A
Axon terminals
Dendrites
Tripartite synapse
20
Q
Glia ________ neuronal communication and clear _____ __________
A
Modulate
Toxic substances
21
Q
The soma contains the nucleus of the neuron, which holds what?
A
Genetic information of the cell
22
Q
The soma also houses organelles such as what? (3)
A
Rough endoplasmic reticulum (ER)
Mitochondria
Golgi Apparatus
23
Q
Where are proteins synthesized?
A
On the Rough ER
24
Q
Where are the proteins taken after synthesized?
A
Golgi, packaged into vesicles
25
What happens when the protein enters the Golgi?
Buds off of the Golgi and transports to final destination (e.g. plasma membrane)
26
The cytoskeleton provides _________ to neurons
Structure
27
Cytoskeletal elements are ___________ regulated
Dynamically
28
What are the main components of the cytoskeleton? (3)
Microtubules
Intermediate filaments
Microfilaments
29
Describe microtubules
Large longitudinal structures that give neurites their structure
30
Describe intermediate filaments
Medium sized structures that are strong and consist of long protein molecules wound together
31
Describe microfilaments and their function
Thin structures that are important for mobility
32
Describe neurites and their function
Projections which branch off the soma of neurons
33
Describe the function of axons
Important for transmitting information
34
Describe the function of dendrites
Collect information and bring it to the soma
35
True or False:
| Neurons only have on dendrite
False, neurons can have many dendrites
36
Axons are only found in _______
Neurons
37
True or False:
| Axons have rough ER and ribosomes
False, no rough ER or ribosomes exist in axons (no protein synthesis)
38
True or False:
| Protein composition of axonal membrane differs from soma membrane
True
39
Axons branch to form ____ ___________
Axon collaterals
40
Where do axons begin and end?
Begin at the axon hillock
| End at the axon terminal
41
In between axon hillock and axon terminal, what is it known as?
Axon proper
42
What does not exist in axon terminals?
Microtubules
43
What are axon terminals filled with?
Synaptic vesicles
44
The portion of the axon terminal facing the synapse is called the:
Active zone
45
True or False:
| The active zone isn't protein rich
False, the active zone is protein rich
46
The axon terminal is densely filled with ____________
Mitochondria
47
What is the axonal diameter of human axons?
Anywhere from 1-25 micrometers
48
Does the axonal diameter correlate with the speed the impulse travel?
Yes, the thicker diameter means faster information transfer
49
What are all the dendrites of a neurons collectively called?
Dendritic tree
50
What is each individual dendrite on the dendritic tree known as?
Dendritic branch
51
Dendrites are covered with _________ of synapses
Thousands
52
Many ________ occur on specific protrusions of dendrites know as what?
Synapses
| Dendritic spines
53
What are neurons that have no dendrites known as?
Unipolar neuron
54
What are neurons that have one dendrite known as?
Bipolar neuron
55
What are neurons that have many dendrites known as?
Multipolar
56
Dendritic Tree arrangements:
| What are pyramid shaped structures known as?
Pyramidal cells
57
Dendritic Tree arrangements:
| What are star shaped structures known as?
Stellate cells
58
What are microtubules composed of? (2)
Alpha tubulin dimers
| Beta tubulin dimers
59
Microtubules exhibit _________
Polarity
60
Dimers are continuously added to the ________ end of the microtubule (_) end
Growing
| +
61
Proteins must be transported to axon terminals by what?
Axoplasmic transport
62
Proteins are transported down the axon through:
Anterograde transport
63
How do we locate direction of axon terminal?
Through polarity of microtubules
64
Other molecules have __________ residing at the axon terminal
Precursors
65
Precursors are synthesized into _________________ on-site
Neurotransmitters
66
________ bud off of Golgi containing proteins to be transported
Vesicles
67
What are vesicles transported by?
Kinesin
68
Kinesin walks down microtubules in an ___ dependent manner
ATP
69
What is cargo transported from the terminal to the soma (up the axon) known as?
Retrograde transport
70
During retrograde transport ______ carries cargo down microtubules
Dynein
71
How are microtubules in axons organized?
(-) to (+) end
72
How are microtubules in dendrites organized?
Orientated randomly (no net polarity)
73
Kinesin travels:
| Dynein travels:
(-) to (+)
| +) to (-
74
Brain is _% body mass, to __% oxygen, and __% glucose
2
20
25
75
What is the single largest contributor to the brain's energy demand?
Na+/K+ ATPase
76
Without consistent supply of ___, neurons quickly die
ATP
77
What is the most common type of glia in the CNS?
Astrocytes
78
What are the two main types of astrocytes?
Fibrous
| Protoplasmic
79
Describe fibrous astrocytes
Found among myelinated nerve fibres in white matter of CNS
80
Describe protoplasmic astrocytes
Found in gray matter of CNS
81
What are the functions of astrocytes? (2)
Support of the blood-brain barrier
| Provide nutrients to neurons
82
Function of Astrocytes:
| How does astrocytes support the blood-brain barrier? (2)
Regulates which molecules enter the brain
| Dynamically regulate blood flow in response to neuronal activity
83
Function of Astrocytes:
| What do the nutrients the astrocytes provide do?
Provide metabolic support to neurons
84
Define reactive astrogliosis
A complex inflammatory state induced in response to disease
85
Describe reactive astrogliosis (2)
Proliferate rapidly and expand in size
| Form glial scar surrounding sites of injury
86
What are the beneficial and harmful effects of reactive astrogliosis? (2)
Limits spread of injury to healthy tissue
| If inflammation persists, can prevent neuronal or even kill neurons
87
What glial cells myelinates axons in the CNS? (2)
Oligodendrocytes
| Schwann Cells
88
What is the function of oligodendrocytes? (2)
Acts as insulator to speed up information flow
| Provides metabolic support to axons
89
1 oligodendrocyte can contact up to __ axons
50
90
What is the function of Schwann Cells? (2)
Acts as insulator to speed up information flow
| Provides metabolic support to axons
91
Schwann cells only forms one _________
Internode
92
What is an internode?
Myelinated segment between two Nodes of Ranvier
93
What are the populations of perivascular glia known as?
Pericytes
94
Define perivascular
Next to blood vessels
95
What is the function of Pericytes? (2)
Regulate blood flow in response to neuronal activity and other cues
Maintain blood-brain barrier
96
True or False:
| Pericytes can respond directly to neurotrasmitters
True
97
___________ can disrupt blood flow to critical brain regions
Dysfunction
98
What are the resident immune cells of the CNS known as?
Microglia
99
What is the function of microglia? (2)
Clearance of cellular debris
Extracellular signalling
Synaptic pruning
100
Describe the clearance of cellular debris by microglia
Cleaning up any waste material (foreign material, damaged cells, plaques, etc.) through phagocytosis
101
Describe the extracellular signalling by microglia
Release inflammatory mediators in response to infection or danger
102
Describe the synaptic pruning of microglia
Eliminate excessive synaptic terminals during development
103
Define reactive microgliosis
A complex inflammatory state induced in response to disease and injury
104
Describe reactive microgliosis (2)
Develop amoeboid shape
| Upregulate secretion of proinflammatory signals
105
What are the beneficial and harmful effects of reactive microgliosis? (2)
Sequester toxic molecules and fight infections
| Can induce aberrant synaptic pruning and neuronal death
