When the calcium was removed from the extracellular solution |
no neurotransmitter was released |
When magnesium was added to the extracellular solution, |
the amount of neurotransmitter released decreased |
Calcium and magnesium are both |
divalent cations |
The receptor potential is generated at the |
receiving region |
Sensory transduction is defined as |
the conversion of a stimulus to a change in membrane potential |
For the receptor potential |
amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be graded with a stimulus intensity |
What describes depolarization? |
The membrane becomes less polarized |
Why does the threshold increase when the internal between the stimuli decreases? |
Some sodium channels have been inactivated and cannot be reopened immediately |
During the relative refractory period, |
another action potential can be generated provided the stimulus is large enough |
When the interval between the stimuli decreases, |
a second action potential is generated until the interval reaches the absolute refractory period |
When the stimulus voltage is increased, |
a greater-than-threshold depolarization results and sodium permeability into the cell increases to overcome the potassium exiting |
Which fibers generate the smallest value for conduction velocity? |
C fibers |
The time interval for conduction would be shortest with, |
the largest and most heavily myelinated axons |
Increasing the amount of myelination |
decreases the time between action potentials |
In this activity, the stimulus voltage used was |
the same for all of the axons and suprathreshold for all of the axons |
What occurred in the presence of tetrodotoxin? |
The number of action potentials decreased, and an action potential was always seen at R1 |
In the presence of lidocaine, the action potential was NOT affected at R1 because |
lidocaine was applied downstream of R1 |
The effects of lidocaine and tetrodotoxin were |
similar, but tetrodotoxin had a greater effect |
The minimum voltage that is required to generate and action potential is called the |
threshold voltage |
Increasing the voltage resulted in |
no change to the action potential |
An axon that is more negative than the resting membrane potential is said to be |
hyperpolarized |
If an increase in extracellular potassium hyper polarizes a neuron, |
it would change the membrane potential to a more negative value |
Which of the following statements about receptor potentials is FALSE? |
The receptor potential is carries by neuroglia |
Which of the following is NOT a functional region of a neuron? |
medullary region |
The conducting region of the neuron is the |
axon |
The typical concentration of sodium is |
lower than potassium intracellularly |
Which of the following describes a change from the resting membrane potential? |
a receptor potential, a synaptic potential, or an action potential |
The time interval between the action potential is called the |
interspike interval |
Increase in stimulus intensity |
increases the frequency of action potentials |
The frequency of action potentials is |
the reciprocal of the interspike interval, and measured in Herz |
During the relative refractory period |
the stimulus must be above threshold to generate action potential |
At a chemical synapse, the intensity of the stimulus is coded by |
the amount of neurotransmitter released and the amount of calcium that enters the axon terminal |
Anatomy Practical 3
Share This
Unfinished tasks keep piling up?
Let us complete them for you. Quickly and professionally.
Check Price