Diversity of Form and Function of Voltage- Gated Potassium Channels
CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE...
-
Upload
alice-dixon -
Category
Documents
-
view
220 -
download
0
Transcript of CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE...
![Page 1: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/1.jpg)
Cardiac ActionPotential
Presenter: Parichay S R
![Page 2: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/2.jpg)
CONTENTS
• INTRODUCTION• RESTING MEMBRANE POTENTIAL• ACTION POTENTIAL• ION DISTRIBUTION• CHARGE DISTRIGUTION• VOLTAGE GATED CHANNELS• SPECIFIC CHANNELS INVOLVED• CARDIAC ACTION POTENTIAL• SUMMARY• REFERENCES
![Page 3: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/3.jpg)
INTRODUCTION
What is membrane potential?
Resting membrane potential
Action potential
![Page 4: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/4.jpg)
ION DISTRIBUTION
![Page 5: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/5.jpg)
CHARGE DISRIBUTION
++++++++
++++++++
+ + + + + + + + + +
+ + + + + + + + + +
Vm= -70mv
![Page 6: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/6.jpg)
VOLTAGE GATED CHANNELSIt is an opening so that ions move inwards and outwards
-70 mv -55 mv
+++
+++
![Page 7: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/7.jpg)
SPECIFIC CHANNELS INVOLVEDType of channel
Na+
weakFast Ca2++ Autoryh
ThmicK+
Voltage Dependent Na+
Slow Ca2+
+
opened continously
Opens @-40mv
Opens@ 0mv
Opens @-55mv
Opens @+30mv
Result on ions
Na+ entersin
Ca2++
Enters inK+ out Na+
enters inCa2++ out
Effect onVm
Raise in Vm
Raise inVm
Lower inVm
Raise in Vm
Raise in Vm
CardiacMuscle K+
Opens @+30mv
Lets K+
out
Lower in Vm
![Page 8: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/8.jpg)
CARDIAC ACTION POTENTIAL
SA (Sinoatrial) node
AV(Atrioventricular)node
Autorhythmic cells
![Page 9: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/9.jpg)
Explaination
Time
Vm
Time
Vm
-By these two graphs
![Page 10: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/10.jpg)
IN AUTORHYTHMIC CELLS
Na+ weakFastCa2+ AR k+
Vm
Time-60-40
o
![Page 11: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/11.jpg)
PHASE I Na+ enters through leak channel and raises Vm.
PHASE II When Vm reaches -40mv, Fast ca2+ channels open and ca2+ enters, this raises Vm further.
PHASE III At 0mv k+ channel opens, k+ excite cell and returns Vm to rest (-60mv).
PHASE IV Start over.
![Page 12: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/12.jpg)
IN CARDIAC MUSCLE
Time
Vm
Time
Vm
-70-55
30
VD Na+SlowCa2+
CMK+
Intercalated disc
----------------------------------------------------------
Gap junctions
![Page 13: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/13.jpg)
PHASE I Na+ and Ca2+ leaks from neighbouring cells and raise Vm from -70mv to -55mv.
PHASE II At –55mv voltage dependent Na+ channel opens enters to raise Vm.
PHASE III At +30mv both slow Ca2+ and k+ opens and k+ exits, while Vm remains the same.
PHASE IV Calcium causes muscle contraction
PHASE V Ca2+ closes, K+ remains open, K+ exits and Vm returns to rest and continues for next set
![Page 14: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/14.jpg)
SUMMARY
![Page 15: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/15.jpg)
REFERENCES
Textbook of cell and molecular biology- 2nd ed– Ajoy Paul
Textbook of Medical physiology- Tenth edition – Arthur C.Guyton, M.D & John E.Hall, Ph.D.
![Page 16: CONTENTS INTRODUCTION RESTING MEMBRANE POTENTIAL ACTION POTENTIAL ION DISTRIBUTION CHARGE DISTRIGUTION VOLTAGE GATED CHANNELS SPECIFIC CHANNELS INVOLVED.](https://reader038.fdocuments.in/reader038/viewer/2022102818/56649ec85503460f94bd5ae0/html5/thumbnails/16.jpg)