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NERVOUS COORDINATION AND MUSCLES
NERVE IMPULSE
SPEED
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Created by
Jasmine Singh
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Cards (5)
WHAT IS A NERVE IMPULSE?
transmission
of an
action potential
along an
axon
(
0.5
to
120
ms^-1
)
WHAT ARE THE FACTORS AFFECTING THE SPEED OF A NERVE IMPULSE?
Myelin sheath
Axon diameter
Temperature
HOW DOES THE MYELIN SHEATH ALTER THE SPEED OF A NERVE IMPULSE?
acts as an
electrical insulator
causes
saltatory conduction
increase speed
of
nerve impulse
conductance
as
less membrane area
is
depolarised
HOW DOES AXON DIAMETER AFFECT THE SPEED OF ACTION POTENTIAL?
greater diameter
=
faster conductance
less leakage
of
ions
increases
SA
increases number
of
channel
/
carrier proteins
HOW DOES TEMPERATURE AFFECT SPEED OF NERVE IMPULSE?
ACTIVE TRANSPORT
(
Na+/K+ pump
)
requires
ATP
from
respiration
relies on
enzymes
temperature
affects
enzyme action
DIFFUSION
increases
temperature
increases
KE
of
particles
increases rate
of
diffusion
