(b) Table 2.1 shows some processes that occur in a kidney. In Table 2.1, write the letter of the part shown in Fig. 2.1 where each process occurs.
You must put one letter in each box. You may use the same letter more than once.
Table 2.1
process
letter
filtration of blood
reabsorption of most of the solutes from the filtrate
water is absorbed by osmosis to determine the
concentration of urine
unfiltered blood returns to the renal vein

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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