2 - neural signaling, electrical Flashcards
ions
molecules that carry electrical charge
important function of neuron
communication
bewteen:
- neurons
- neuron and organs
- sensory receptors and neurons
cellmembrane of a neuron, closes the cell and …
seperates intra and extra cellurare space
- is impearable (water dissolves molecules can flow trough)
sodium
NA+
potassium
k+
chloride
cl-
diffusion, causes
molecules to move from high to low concentration
sodium/potassium pump, can
EXCHANGES SODIUM FOR POTASSIUM
transport ions across membrane
(3 NA+ out, 2 KA+ in)
non-gated potassium channel
- needs to be added to membrane, is - selective for potassium, only lets it trough.
- Always open
- Passive process, costs no energy
equilibrum potential for an ion at a given concentration gradien
when pulling and pushing forces are equally strong
when concentration gradient across membrane in stable
can be calculated with nernst equation
3 reasons why KA+ is dominant at rest
- most permeability
- lots of channels
- reaches equilibrium the best
multiple schlerosis
disease, where own immune system attacks myelin, this will slow down AP speed and makes brain malfunction
In a typical neuron, which ion has a large concentration inside?
K+ (think about banana)
Which ion can move trough membrane freely due to non-gated ion channels
K+
At membrane resting potential, which ion is close to equilibrum
K+
What forces act upon NA+ when NA+ channels open up?
diffusion & electrostatic
In which direction does NA+ flow when NA+ channels open up at rest
in (bc there is a lot outside and it wants to be in equilibrium)
what is a depolarization of a neuron at rest?
when charge inside cell becomes less negative / more positive)
Which electrical signal of neurons is all or nothing?
action potentials
Which part of electrical signaling is directly linked to energy use?
Maintaining membrane resting potential
Input side of neuron?
dendrites
Output side of neuron?
axons(terminal)
Most important mechanism underlying refractory phase?
NA+ channel inactivation
Function of myelin
Increase AP speed
How does myelin speed up AP propagation?
Increase distance of electronic conduction in axon
Primary visual cortex in is
Occipital lobe (onder achterin hoofd)
