Electrical Potential/ Action Potential Exam1 Flashcards
Definition of electrical current
The movement of electrical charges as they do work.
Current is created when selected positive and negative charges come back together
Definition of electrical potential
Potential to do electrical work (measured in volts)
Definition of charge rules
Opposite charge ions attract each other like charge ions repel each other
Definition of channels or pores
Protein structure in the cell membrane that allow ions or water life’s into or out of the cell
Definition of gated channels
Protein channels through the membrane which can open and close are called “gated channels”
Some channels open and close with chemical stimulus or electrical stimulus or physical stimulus
Definition of separation of charges
Separation of positive and negative charges form each other by the cell membrane to create an electrical potential
Definition of resting potential
Electrical potential in all cells during rest ( always negative inside relative to outside)
Definition of depolarization
Inside of cell become more positive relative to outside
Definition of hyper polarization
Inside of cell become more negative relative to outside
Definition of repolarization
The cell returns to its original resting potential
Definition of action potential
A self propagating, positive "spike" of current through the membrane followed by a re-setting to the resting potential. Action potentials only occur in excitable cells such as: Nerve cells Muscle cells Fertilized ovum Secretory cells
Definition of threshold
Minimum cell potential above the resting potential to start an action potential
Definition of “runaway depolarization” or “sodium cycle “
Self propagating in rush of sodium Ions during AP
“All or none” definition
Use to describe the action potential, which, once started, cannot be stopped or changed in size
Definition of repolarization
The process of resetting of membrane potential to resting potential after runway depolarization
Definition of propagation
Movement of action potentials along the cell membrane from one part of cell to another
Definition of Salvatory propagation
The movement of action potentials in a myelinated nerve from one node to the node down.
What is r first concept of electrical potential
Electrical potential is created In living cells by ions and can be used to create electrical current
What is the second concept of electrical potential
Cell membranes create electrical potential by separating positive And negative charges
The third concept of electrical potential is
The separation of charges occurs as the result of A) an imbalance in passive transport of ions from high to low concentration B) the rules of electrical charges [likes repel opposites attract]
