Key concepts: Ion channel physiology

Question 1

conditions

Answer 1

epilepsy
alzheimers

Question 2

membrane potential

Answer 2

charge difference inside and outside neuron

Question 3

what is the charge difference caused. by

Answer 3

ions on either side

Question 4

important ions

Answer 4

Na+
Cl-
K+
organic anions

Question 5

neuron at rest

Answer 5

ions more prevalent outside cell are Na+ and Cl-
ions more prevalent inside are K+ and organic anions
inside is more negatively charged than outside
causes the resting membrane potential to be around -70mV
this potential needs maintaining

Question 6

how is the membrane potential maintained

Answer 6

uses ATP
3 sodium out and 2 potassium in
more positive out than in
keeps the membrane potential negative
K+ travels easily through ion channels, will pass out of the neuron until equilibrium is reached

Question 7

anatomy of the neuron

Answer 7

Question 8

components of an electrochemical gradient

Answer 8

electrical gradient
chemical gradient

Question 9

electrical gradient definition

Answer 9

build up of charge on one side will repel more ions of the same charge

Question 10

chemical gradient definition

Answer 10

ions moving high concentration to low

Question 11

depolarisation

Answer 11

voltage increases from the RMP
excitatory event

Question 12

hyperpolarisation

Answer 12

outage decreases from RMP
inhibitory event

Question 13

different types of membrane channels

Answer 13

voltage gated
ligand gated
leaky channels

Question 14

voltage gated channels

Answer 14

change in the intracellular charge
will open the channel
found in the axon and axon terminals

Question 15

ligad gated channels

Answer 15

molecule binds to a specific site on the channel causing it to open
mainly found in dendrites

Question 16

leaky channels

Answer 16

channel that facilitates passive diffusion of a specific ion/molecule
found throughout an axon

Question 17

types of neurotransmitters in dendrites

Answer 17

excitatory post synaptic potential (EPSP)= glutamate
inhibitory post synaptic potential (IPSP)= GABA

Question 18

when will action potentials occur

Answer 18

all or nothing principle
must meet the threshold

Question 19

axon terminals

Answer 19

action potential arrives
calcium ion influx through the voltage gated calcium channels
exocytosis of neurotransmitter- containing vesicles through the synaptic cleft
binding of neurotransmitters to post synaptic membrane channel
influx of Na+
action potential occurs