Chapter 2: neurophysiology Flashcards
define:
Ions
electically charged molecules
define:
anions
negatively charged ions
define:
Cations
positively charged ions
Answer:
what is the majority of ions in a neuron
anions
True or False:
The inside of a neuron is more positively charged than the fluid around it
false
the neuron is more negatively charged
define:
resting potential
electrical difference across the membrane
Answer:
What is the resting potential of a neuron
-50 to -80 millivolts (mV)
define:
ion channel
tubelike pore that allows ions of a specific type to pass through the membrane.
Define:
selective permeability
membrane allows some things to pass through and not others
define:
diffusion
tendency for molecules of a substance to spread from regions of high concentration to regions of low concentration.
define
electrostatic pressure
the distribution of electrical charges
Answer:
What are positively charged K+ particles to?
the negatively charged interior of the cell
Answer:
Anions are repelled by the cell interior so they tend to do what?
exit into the extracellular fluid
Answer:
Where is sodium found
in relation to the cell
more outside cell
Answer:
where is chloride (Cl-) found
in relation to the cell
more outside cell
Answer:
where is potassium (K+) found
in relation to the cell
more inside the cell
Answer:
where are negatively charged protiens (A-) synthesized
within the neuron
Answer:
where are negatively chanrged particles (A-) found?
within the neuron
Answer:
What particles do Ion channels allow to pass through?
K+ (potassium)
Answer:
What particles aren’t passed through ion channels?
Na+ (sodium)
List:
factors influencing ion distribution
4 points
- semipermeable membrane
- sodium-potassium pump
- Homogenization/ diffusion
- Electrostatic pressure
Define
phospholipid bilayer
head is hydrophillic
tail is hydrophobic
Describe:
Sodium potassium pump
Actively forces Na+ out of the neuron and brings in K+
Answer:
- how many Na+ particles are pumped out in the sodium potassium pump
- how many K+ particles enter?
- 3
- 2
Answer:
What is the source of energy for the sodium potassium pump?
ATP