Membrane Potential Flashcards
What are the 2 cell types that have specialized use of membrane potentials?
Muscle cells
Neurons
In general, what is the function of dendrites? What is the function of axons?

Dendrites receive sensory information and carry it to the cell body
Axons carry information away from the cell body
What are the 2 subdivisions of the CNS?
Brain and spinal cord
What is the function of the CNS?
Receive, modify and transmit information
What is the function of the PNS?
Connect the brain and spinal cord to the limbs and organs
The […] is a layer of connective tissue that surrounds each individual axon.
Endoneurium
Label this diagram.


Axons are bundled together into groups called […]
Fasicles
Each fasicle is wrapped in a layer of connective tissue called the […]
Perineurium
The entire nerve is warpped in a layer of connective tissue called the […]
Epineurium
Only select cells in the body display membrane potential.
True/False
False - all cells do
What is membrane potential?
A separatin of positive and negative charges across the cell membrane
[…] transmit a particular kind of signal, the nerve impulse or action potential.
Axons
Cells capable of generating and conducting action potentials have an […] membrane.
Excitable
What is resting membrane potential?
When an excitable cell is at rest, there is a difference in electrical charge across the membrane
What are the 3 major factors that generate the resting membrane potential?
- Charge carriers (water and ions)
- Membrane is an impermeable barrier
- Ion channels
It would take years for charged particles to spontaneously diffuse across a plasma membrane. How then do they cross?
Through ion channels
What 2 things define the selectivity of ion channels?
- Diameter
- Inner surface properties
What are the 3 subtypes of ion channels?
- Ligand gated
- Voltage gated
- Leak channels (always open)
What is the difference between an ion channel and an ion pump?
When open, an ion channel lets molecules move freely according to their concentration gradients (diffusion and EMF). An ion pump uses energy (ATP) to actively transport ions across a membrane against a concentration gradient.
What makes ions pass through ion channels?
- Diffusion
- Electromotive Force (EMF)
What is the EMF?
In an electrical field, charged particles will move. The separation of charge on the inside vs. outside of the membrane creates an electrical field due to a difference in potential.
[…] = rate of flow of charge carriers
Current
[…] = electrical pressure
Voltage






















