Biology Doubt: Nervous System!

[XPFMember]

Assalamoalaikum!!


I'm tooo confused about action potential and that transmission across a synapse and all that. :/

Anybody with some good notes or anything?!

JazakAllah Khair!

 

[aquariangurl]

W/s
You know right, that the action potential passes in a sequence of events?
Here's how it goes:

Resting Potential

• There are30 times more Na+ ions on the outside of an axon during a resting potential
  If any Na+ ions diffuse in, they are expelled by the Sodium-Potassium pump
  The Sodium Potassium pump is an active transport mechanism by which a carrier protein, with ATP, expels Na+ ions against a concentration gradient & allows K+ ions into the axon.
  This creates a Polarisation, i.e. there is a +ive charge on the outside of the membrane & a -ive charge on the inside.
  The potential difference is called the resting potential & can be measured at around -70 MV.

Action Potential - Depolarisation

• During an action potential, sodium channel protiens open to allow Na+ ions into the axon.
  There is now a -ive charge on the outside & a +ive charge on the inside known as depolarisation.
  The potential difference changes to around +50 MV
  The profile of the action potential, shown by an oscilloscope, is always the same.

Action Potential - Repolarisation

• A K+ channel opens so K+ ions leave the axon
  This results in the membrane becoming polarised again.
  Any Na+ ions that have entered during the action potential will be removed by the Sodium Potassium pump.

Err..I hope this was helpful =/

 

[XPFMember]

Aoa!

Yup it surely did, I've to complete this topic today, InshaAllah. If I've any further doubts, I'll clear it again...hope you don't mind!

And Jazakumullah Khairen!!

 

[hassam]

budd y wach khan acdemy video ....

 

[mrpaudel]

yeah...as hassam suggested...www.khanacademy.org go to this site..and watch videos.!!