GCU BIO 201 Exam 2 Test Questions and Answers Graded A+
Neuron Structure dendrites, cell body, axon
short, highly branched signal receptive regions of the
dendrites
nerve cell. Convey incoming message toward cell bodies
each nerve cell (neuron) has only one axon
axon impulse generating and conducting region of neuron
Whitish fatty protein layer that protects and electrically
myelin sheath insulates the axon. Increases the speed of transmission of
nerve impulses
myelin sheath is only associated with axons, not dendrites
what determines resting membrane potential balance of K+ and Na+
k+ leak permeability out of the cell
Na+ leak permeability into the cell
3 types of ion channels chemically gated, voltage gated, mechanically gated
channel-linked receptors that open to let a specific ion
chemically gated ion channels
pass in response to a ligand
Channels that open or close in response to a change in the
voltage-gated ion channels
membrane potential.
membrane ion channels that are opened or closed by
mechanically gated ion channels
deformation or stretch of the plasma membrane
action potentials are also known as nerve impulses
self-regenerating wave of electrochemical activity that al-
action potential lows neurons to carry a signal over a distance. All or non
phenomenon
resting membrane potential -70mV
"Depolarization to Threshold"
step one of action potential
, GCU BIO 201 Exam 2 Test Questions and Answers Graded A+
A graded depolarization brings an area of excitable me-
brane to threshold (-60mV)
"Activation of Sodium Channels and Rapid Depolariza-
tion"
1. The voltage-regulated sodium channels open (sodium
step two of action potential channel activation)
2. Sodium ions, driven by electrical attraction and the
chemical gradient, flood into the cell.
3. The transmembrane potential goes from -60 mV, the
threshold level, toward +30 mV.
"Inactivation of Sodium Channels and Activation of Potas-
sium Channels"
1. the voltage-regulated sodium channels close (sodium
Step Three of Action Potential
channel inactivation occurs) at +30 mV.
2. The voltage-regulated potassium channels are now
open, and the potassium ions dittuse out of the cell.
3. Repolarization begins.
"Return to Normal Permeability"
1. The voltage regulated sodium channels regain their
normal properties in 0.4-1.0 msec. The membrane is now
capable of generating another action potential if a larger
than normal stimulus is provided.
step four of action potential
2. The voltage regulated potassium channels begin clos-
ing at -70 mV. Because they do not all close at the same
time, potassium loss continues and a temporary hyperpo-
larization to approximately -90 mV occurs.
3. At the end of the relative refractory period, all volt-
Neuron Structure dendrites, cell body, axon
short, highly branched signal receptive regions of the
dendrites
nerve cell. Convey incoming message toward cell bodies
each nerve cell (neuron) has only one axon
axon impulse generating and conducting region of neuron
Whitish fatty protein layer that protects and electrically
myelin sheath insulates the axon. Increases the speed of transmission of
nerve impulses
myelin sheath is only associated with axons, not dendrites
what determines resting membrane potential balance of K+ and Na+
k+ leak permeability out of the cell
Na+ leak permeability into the cell
3 types of ion channels chemically gated, voltage gated, mechanically gated
channel-linked receptors that open to let a specific ion
chemically gated ion channels
pass in response to a ligand
Channels that open or close in response to a change in the
voltage-gated ion channels
membrane potential.
membrane ion channels that are opened or closed by
mechanically gated ion channels
deformation or stretch of the plasma membrane
action potentials are also known as nerve impulses
self-regenerating wave of electrochemical activity that al-
action potential lows neurons to carry a signal over a distance. All or non
phenomenon
resting membrane potential -70mV
"Depolarization to Threshold"
step one of action potential
, GCU BIO 201 Exam 2 Test Questions and Answers Graded A+
A graded depolarization brings an area of excitable me-
brane to threshold (-60mV)
"Activation of Sodium Channels and Rapid Depolariza-
tion"
1. The voltage-regulated sodium channels open (sodium
step two of action potential channel activation)
2. Sodium ions, driven by electrical attraction and the
chemical gradient, flood into the cell.
3. The transmembrane potential goes from -60 mV, the
threshold level, toward +30 mV.
"Inactivation of Sodium Channels and Activation of Potas-
sium Channels"
1. the voltage-regulated sodium channels close (sodium
Step Three of Action Potential
channel inactivation occurs) at +30 mV.
2. The voltage-regulated potassium channels are now
open, and the potassium ions dittuse out of the cell.
3. Repolarization begins.
"Return to Normal Permeability"
1. The voltage regulated sodium channels regain their
normal properties in 0.4-1.0 msec. The membrane is now
capable of generating another action potential if a larger
than normal stimulus is provided.
step four of action potential
2. The voltage regulated potassium channels begin clos-
ing at -70 mV. Because they do not all close at the same
time, potassium loss continues and a temporary hyperpo-
larization to approximately -90 mV occurs.
3. At the end of the relative refractory period, all volt-
