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33 terms

Nervous 1

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charge
Neurons have a ___ (AKA electrical potential) made by the difference in charged particles across that membrane.
volts
charge is measured in ___
-70, -90
RMP is ___mV in neurons and ___mV in muscle cells
F
[T,F] the extracellular charge is more negative than intracellular charge
proteins
inside the cell are large anions, specifically ____, which contribute to the ICF negativity
K+
The main IC ion in neurons
Na+
The main EC ion in neurons
K+
Most important ion in maintaining RMP.
T
[T,F] K+ is more permeable than Na+, making it the most important ion in maintaining RMP.
3, 2
ratio of Na-K pump: _ Na+ to _ K+
active (1 ATP for every 3Na:2K movement)
the Na-K pump uses ___ transport
ATP
___ is made from glucose and O2 during aerobic respiration.
F (stimuli may depolarize and generate local potentials w/o generating APs)
[T,F] If a stimuli is strong enough to open Na-gated channels, it is strong enough to become an AP rather than just a local potential
local
short distance current: ___ potential
local
___ potentials (action or local) occur at the junctions of neurons
dendrites
the parts of the nerve cell where information is received
local, action
___ potentials are achieved through gated channels, while ___ are achieved through voltage gated channels
-55
___mV is the threshold level of depolarization needed to reach an AP from a local potential
trigger zone
If enough local potentials spread to the ___ ___ (the axon hillock area), it activates voltage gated channels and an AP fires
35
peek voltage during an AP is ___mV. This is when the cell is very depolarized and Na+ channels finally close.
hyperpolarization
Occurs b/c K+ channels are slow to close, allowing K+ to flow out for a bit longer down its concentration gradient (making ICF super negative)
refractory
during the ___ period, it's difficult to re-stimulate an AP immediately after "firing"
absolute, relative
The refractory period is broken into the ____ refractory period and the ___ refractory period
absolute refractory
during the ___ ___ period, it's impossible to generate another AP b/c Na+ channels are still open and the former AP is still going.
relative refractory
during the ___ ___ period, it takes a very intense stimulus to generate another AP since the K+ channels are still open
Na+
during the absolute refractory period, it's impossible to generate another AP since the ___ channels are still open
K+
during the relative refractory period, it takes a very intense stimulus to generate another AP since the ___ channels are still open
schwann cells
form myelin sheaths on axons of nerves located in the peripheral nervous system
oligodendrocytes
form myelin sheaths on axons of nerves located in the central nervous system.
myelinated
signal conduction is much faster in ___ fibers.
nodes of Ranvier
where Na+ flows into the axon in myelinated fibers
nodes of Ranvier
where APs are generated in myelinated fibers
Saltatory Conduction
the name for signal conduction through myelinated fibers. Quick, relies on Na+ entering through the nodes and powering the AP through the internodes