the blood-brain barrier prevents hydrophobic molecules from diffusing into the brain. T or F
Excitable cells are incapable of maintaining a constant resting membrane potential. T or F
The membrane of resting nerve cells is more permeable to______ions than _________ions.
a.sodium, potassium
b. calcium, potassium
c.potassium, sodium
d.chloride, potassium
Nerve cells depolarize due to the influx of K+ True or False
I reallllllllly need this for a test
For the first question, the blood-brain barrier does indeed prevent hydrophobic molecules from freely diffusing into the brain. This is typically true, so the answer is "True."
Regarding the second question, excitable cells are actually capable of maintaining a constant resting membrane potential. This is due to the existence of ion channels and ion pumps that help maintain the balance of ions inside and outside the cell. So the answer is "False."
The third question involves the membrane permeability of resting nerve cells. The correct answer is option (c): potassium ions are more permeable than sodium ions. When a nerve cell is at rest, the permeability of its membrane is higher to potassium ions compared to sodium ions. So the answer is option (c).
Regarding the fourth question, nerve cells depolarize due to the influx of sodium ions (Na+), not potassium ions (K+). During an action potential, the membrane potential becomes more positive due to the activation of sodium channels and the subsequent influx of sodium ions. So the statement is "False."
I hope this clarifies the concepts for your test preparation. Good luck!