human anatomy and physiology
posted by Kristen .
cells are the basic unit of life based on the original cell theory. name and define the function of at least nine organelles of animal cells.
You will find a list of 14 cell organelles and their functions (what they do) at:
Why is it important that digestive enzymes are inactive in the pancreas?
What four elements make up the bulk of all living matter?
I am a little confused about the action potential concept (see nervous system)
I have 3 multiple-choice questions that I need help with:
Which is the correct sequence of events that follows a threshold potential:
1.the membrane becomes depolarized
2.sodium channels open and sodium ions diffuse inward
3.the membrane becomes repolarized
4.potassium channels open and potassium ions diffuse outward while sodium is actively transported out of the cell
My answer is C, but not sure because the questions refers to the sequence of events THAT FOLLOWS A THRESHOLD POTENTIAL. The correct answer could be D?
Second questions is:
An action potential:
A)is essential for impulse propagation
B)involves the influx of negative ions to depolarize the membrane
C)involves the outflux of negative ions to depolarize the membrane
D)involves the outflux of positive
ions to depolarize the membrane
E)is initiated by potassium ion movements
My answer is A
Match the following:
1.Period when the interior of the cell becomes less negative due to an influx of sodium ions
2.Term a nerve impulse when transmitted
My answer is 1.D and 2.A
Thank you for your help.