How are ion gradients (high concentrations of Na+ and K+) maintained between cell regions?
Active transporters via Na+/K+ ATPase
what are the 4 main functions/goals of the nervous system?
- Collect information
- Process and integrate information
- Transmit information
- Response
during resting membrane potentials, what are [Na+] and [K+] inside the cell? (ICF)
high [K+] and low [Na+] levels
during resting membrane potentials, what are [Na+] and [K+] outside the cell? (ECF)
low [K+] and high [Na+] levels
Na+/K+ ATPase and leak channels create:
electrochemical gradient
Resting membrane potential must remain at:
-70 mV
Na+/K+ ATPase pumps:
3 [Na+] out, 2 [K+ in]
which channel operates via a chemical gradient?
leak channels
which channel generates an electrical gradient?
Na+/K+ pump
During RMP, the cell is in: depolarized, hyper polarized, or polarized state?
Polarized state (unequal distribution of ions between cell regions)
Depolarizing means to become + or -
More positive inside
Hyperpolarizing means to become more + or -
More negative inside
Electrotonic potentials
- small changes in membrane potentials (-70 to -60)
- used to initiate APs in the axon hillock
- currents travel short distance along membrane
- currents decrease exponentially with distance
- can hyperpolarize and depolarize cell
sympathetic nervous system
- fight or flight
- more active when body needs to be used
- e.g. stimulates heart, inhibits digestion in stomach
parasympathetic nervous system
- rest and digest
- more active when body energy stores are being conserved/restored
- e.g. inhibits heart, stimulates digestion in stomach
parasympathetic nervous system is more active when body energy stores:
conserved/restored
sympathetic nervous system is more active when body energy stores:
need to be used
