What is responsible for ESTABLISHING the RESTING membrane potential of a cell?
faster leaking (greater permeability) to K
What term describes the cell membrane potential of a neuron at rest?
polarized
T or F: A graded potential may be depolarizing or hyperpolarizing.
True
In the process of generating an action potential, which occurs first?
Think about the ENTIRE process of an action potential,
including what precedes threshold.
ligand-gated Na channels open
the channels most directly responsible for the voltage change recorded in a PHASE 1 of an action potential graph.
voltage-gated Na channels
The type of channel most likely to be open during the repolarization phase
voltage-gated K+ channels
T or F: A strong stimulus produces a strong action potential.
False
During the relative refractory period, a second action potentialSelect an answer and submit.
a) cannot be elicited
b) can be elicited by a threshold stimulus
c) can be elicited by a subthreshold stimulus
d) can be elicited by a suprathreshold stimulus
e) Either B or D
e) Either B or D
Saltatory conduction refers to which of the following?
a) The conduction of a graded potential along a myelinated axon.
b) The conduction of an action potential along a myelinated axon.
c) The conduction of an action potential along an unmyelinated axon.
d) The conduction of a graded potential along an unmyelinated axon.
b) The conduction of an action potential along a myelinated axon.
As the axon hillock depolarizes, voltage-gated Na+ channels open and Na+ moves (into or out of) ______________ the cell causing further (depolarization or repolarization) ______________.
into; depolarization
What is the primary difference between graded potentials versus actions potentials?
In neurons, action potentials occur in axons, while graded potentials occur in the dendrites and cell bodies
Absolute and relative refractory periods are important aspects of which of the following?
a) Action potentials
b) Resting potentials
c) Hyperpolarizing graded potentials
d) Graded potentials
a) Action potentials
What will Hypokalemia (low extracellular K+ concentration), if sustained, cause?
hyperpolarization and difficulty achieving action potentials