3.8 nervous system

Question 1

label spinal cord

Question 2

label neurone

Question 3

resting potential
words to remember

Answer 3

-sodium potassium pump
-70mV (more positive outside than inside) 3Na out/ 2K in
-Diffusion/closed channel
-K+ diffuse x20 faster
-more positive inside than outside

Question 4

action potential
words to remember

Answer 4

-70mV to +40mV
-depolarisation
-stimulus
-Na sodium channels open
-Na flood in to the axon

Question 5

40 mV peak
words to remember

Answer 5

-more positive out than in
- maximum Na in the axon
-sodium gates close

Question 6

repolarisation
words to remember

Answer 6

• K gates open
  -K+ flood out the axon
• less positive in the axon, more positive out the axon
  -return to rp
• sodium potassium pump

Question 7

hyperpolarisation
words to remember

Answer 7

• below -70mV
• delay in closing gates
• return to rp
• NA/K pump