lecture 5 - neurons & nerves Flashcards

1
Q

What are the components of a neuron?

A

Dendrites, soma/cell body, axon, synapses

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2
Q

What is the name for the cell body of a neuron?

A

Soma

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3
Q

What is the function of neuron dendrites?

A

Receive signals from other neurons via synapses

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4
Q

What are axons?

A

Processes that leave a neuron’s soma to propagate an action potential for signalling to other neurons via synpases

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5
Q

What are the 4 morphological types of neuron?

A

multipolar, bipolar, unipolar, anaxonic

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6
Q

What is the structure of a multipolar neuron?

A

Multiple processes emanate from the cell body

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7
Q

What is the structure of a bipolar neuron?

A

2 processes emanate from the cell body

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8
Q

What is the structure of a unipolar neuron?

A

One process emanating from the cell body that branches into the dendrite and axon

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9
Q

What is the structure of an anaxonic neuron?

A

No distinct axon because all processes look alike

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10
Q

What are glia?

A

Non-neuronal support cells of the CNS or PNS

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11
Q

What are the 4 key glia types of the CNS?

A

oligodendrocytes, astrocytes, microglia, ependymal cells

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12
Q

What are the 2 key types of glia in the PNS?

A

Schwann cells, satellite cells

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13
Q

What is the function of oligodendrocytes?

A

Form the myelin sheath around neurons in the CNS

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14
Q

What is the function of astrocytes?

A

Provide nutrients, maintain extracellular environment and structural support to neurons in the CNS

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15
Q

What is the function of microglia?

A

Mount the immune response within the CNS

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16
Q

What is the function of Ependymal cells?

A

Circulate and produce cerebrospinal fluid in the CNS

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17
Q

Which cells produce CSF in the CNS?

A

Ependymal cells

18
Q

What is the function of Schwann Cells?

A

Form the myelin sheath around neurons in the PNS

19
Q

What is the function of Satellite Cells?

A

Provide nutrients and structural support to neurons in the PNS

20
Q

What is the name for a unit of neurons with a nerve that is surrounded by perineurium?

A

Fascicle

21
Q

Where does sensory information enter the spinal cord?

A

Dorsal root

22
Q

Where does motor information leave the spinal cord?

A

Ventral root

23
Q

What type of peripheral nerve has the fastest relative conduction velocity?

A

Motor neurons

24
Q

What type of peripheral nerve has the slowest relative conduction velocity?

A

Sensory - pain/temperature, etc.

25
Q

What are the characteristics of motor neurons?

A

Large diameter, heavily myelinated = fast conduction velocity

26
Q

Which 2 factors influence the relative conduction velocity of a nerve?

A

Diameter, myelination

27
Q

What happens to the conduction velocity of a nerve as its diameter increases?

A

Increases

28
Q

What is the resting membrane potential inside of neurons?

A

~-70mV

29
Q

Which factors contribute to the resting membrane potential?

A

Concentration gradient of ions across membrane, differential permeability of membrane to K+ vs Na+

30
Q

Are cell membranes more permeable to K+ or Na+?

A

K+

31
Q

Which ion has the greatest influence on resting membrane potential?

A

K+

32
Q

What creates the electrochemical gradient across a cell membrane?

A

The difference on the concentration of ions on either side of the membrane, and the permeability of the membrane to these ions

33
Q

What ion channel maintains the electrochemical gradient across a cell membrane?

A

Na+,K+ - ATPase

34
Q

What does Na+,K+-ATPase pump, and in what directions?

A

3Na+ out of cell, 2K+ into it

35
Q

Which equation calculates the equilibrium potential for an ion?

A

Nernst equation

36
Q

How does the ratio of ions in/outside a cell influence the voltage across the membrane?

A

The greater the concentration difference between outside and inside, the greater the voltage

37
Q

Which equation calculates the resting membrane potential of a cell?

A

Goldman-Hodgkin-Katz

38
Q

What are voltage-gated ion channels?

A

Ion channels that provide selective permeability to certain ions due to changes in membrane potential

39
Q

What are mechanically gated ions channels?

A

Ion channels that open when a physical stimulus causes membrane deformation

40
Q

What are chemically gated channels?

A

Ion channels that open when a ligand binds