Neurophysiology Revision Lecture Flashcards Preview

Y3S1 NEURO > Neurophysiology Revision Lecture > Flashcards

Flashcards in Neurophysiology Revision Lecture Deck (18)
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1
Q

how are APs graded

A

the frequency (more or less rapid - like bullets from a machine gun or a vibration)

2
Q

where do APs occur

A

mainly in axons are start at the axon hillock near the cell body

3
Q

Schwann cell

A

found in the peripheral nervous system and act as the myelin sheath

4
Q

Oligodendrocytes

A

provide myelination in the CNS

5
Q

Saltatory Jumping conduction

A

jumps along nodes in sections and resumes a fresh at each one

6
Q

unmyelinated nerve fibres trend for the speed of conduction

A

larger the diameter the faster the conduction

7
Q

if there is any slowing in the speed of conduction this would be consistent with

A

demyelination

8
Q

When neurotransmitters are released they are inactivated, why?

A
  • diffusion
  • re-uptake
  • enzymes inactivation
9
Q

what’s the difference between inotropic and metabotropic receptors

A

inotropic - directly gate ion flow

metabotropic - indirectly gate ion flow or activate other pathways

10
Q

Post-synpatic (PSPs) are caused by

A

the passage of ions through ion channels which have been opened following receptor/neurotransmitter interactions

11
Q

after a PSP what happens

A

a NET flow of positive ions into he cell depolarises the membrane (bringing it closer to the threshold) and is thus termed EXCITORY EPSP. single EPSP rarely result in an action potential

12
Q

summation

A

if multiple EPSPs summate together they can cause an action potential

13
Q

This means stronger external signals result in a

A

higher frequency of APs in the axon

14
Q

SNAP

A

sensory nerve action potential

15
Q

CMAP =

A

compound muscle action potential

16
Q

Autoimmune channelopathies

A

Myasthenia gravis
Lambert-Eaton myasthenic syndrome (associated with small cell lung Ca) Limbic encephalitis (memory loss; associated with underlying neoplasm)

17
Q

Compression syndromes include

A

carpal tunnel syndrome, ulnar nerve compression at elbow

18
Q

Less axons means

A

reduced size of compound action potential