Question

question 30 (1 point)
for the action potential to be reached,
a) the membrane must be out of the relative refractory period.
b) the na+ entering the cell must exceed the k+ leaving the cell
c) the stimulus must reach or exceed the threshold.
d) all of the above
question 31 (1 point)
which stucture in the brain connects the two cerebral hemispheres?
pons
corpus callosum
medulla oblongata
cerebellum

Explanation:

Question 30

• Option A: During the relative refractory period, a neuron can fire an action potential if the stimulus is strong enough. So, being out of it is a condition for action potential.
• Option B: When \(Na^+\) entering (depolarization) exceeds \(K^+\) leaving (repolarization), the membrane potential becomes more positive, which is part of action - potential generation.
• Option C: The stimulus must reach or exceed the threshold to trigger an action potential. Since all A, B, and C are correct.

• Pons: It is involved in functions like sleep, respiration regulation, etc., not connecting cerebral hemispheres.
• Corpus callosum: It is a thick band of nerve fibers that connects the two cerebral hemispheres, allowing communication between them.
• Medulla oblongata: Controls vital functions like heart rate, breathing, not hemisphere connection.
• Cerebellum: Coordinates movement, balance, not for connecting hemispheres.

Answer:

D. all of the above

Question 31