Biolistrik Kedokteran Kesehatan Medis.pdf

Physics

1. Biolistrik
Irfiansyah Irwadi

2. Outline
Bioelectricity
•Action potential
@. Electrolyte@. depolarization
@. RMP @. repolarization
•Electric signal recording
@. Electrocardiograph (EKG)
@. Electroencephalograph (EEG)
@. Electromiograph (EMG)

3. Action potential
- 70 mV
+30 mV
- 55 mV
- 0 mV
Firing level
depolarization
repolarization
Action potential
Overshoot

4. Membran plasma
Lipid bilayer
Sifat : Semipermeabel
Fungsi :
1. Pemisah cairan ekstrasel dan intrasel
2. Perlindungan bagian dalam sel terhadap lingkungannya
3. Sarana transpor bahan-bahan yang akan masuk ke dalam sel atau dikeluarkan oleh sel

5. Membran plasma
Composition :
1.Protein (55%)
2.Lemak
–Fosfolipid (25%)
–Kolesterol (13%)
–Lipid lain (4%)
3.Karbohidrat (3%)
–Glikoprotein
–Glikoloipid

6. Membran Sel

7. Electrolyte ECF vs ICF
Ion PlasmaInterstisialIntracellularDirection
Na
+ 142 139 14 In
Ca
++ 1,3 1,2 <<< In
K
+ 4,2 4 140 Out
CL
- 108 108 <<< / 4 In
ICF : intra cellular fluid (cytoplasm)
ECF : extra cellular fluid (plasma + interstitial)

8. RMP (resting membrane potential)
•The difference of ion concentration
between ECF & ICF  electrial membrane
gradient
•RMP = ± -70 till - 90 mv depend on cell

9. RMP : ICF is more negative than ECF
-70 till -90 mv
+ + + +
-- --
++
--

10. Stimulation
•Stimulation (electric or chemical)  open
voltage or ligand gated channel
•ECF & ICF is conected  ion move influx or
eflux  increase or decrease membran potential
•Stimulation must be adequate, more than firing
level
•Firing level : minimum intensity to stimulate
depolarization

11. Copyright © Allyn & Bacon 2004
Membrane Potentials
1.
Resting
Potential
(just
describe
d)
2.
Excitato
ry
Post-
synaptic
potential
threshold
4.
Inhibitory
Post-
synaptic
potential
3.
Action
Potential

12. Excitatory Post-synaptic Potential (EPSP)
Post-synaptic neuron
Pre-synaptic neuron

13. 1.The pre-synaptic neuron releases a
neurotransmitter.
2.Neurotransmitter diffuses across
extra-cellular space - synaptic cleft.
3.Neurotransmitter binds to post-
synaptic receptor.
4.Binding of neurotransmitter causes
Na+ channels in post-synaptic
membrane to open.
5.Depolarization occurs (excitatory
potential)
Post-synaptic neuron
Pre-synaptic neuron
Excitatory Post-synaptic Potential (EPSP)

14. 14
OUTSIDE
INSIDE
K
+ = Potassium; Na
+ = Sodium; Cl
- = Chloride; Pr
- = proteins
Na
+
Na
+
K
+
K
+
Force of Diffusion
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - -
Cl
-
Force of Diffusion
Cl
-
Pr
-
Closed
channel
open
channel
open
channel
no
channel
OPEN Na+
CHANNEL
+ + +
- 65 mV- 50 mV
1. Resting Membrane PotentialExcitatory Post-Synaptic Potential (EPSP)

15. EPSP
•EPSP is a “graded” potential
•Multiple EPSPs are integrated across
space and time.
Excitatory
Post-synaptic
potential
Integration
•Once the threshold is
reached, voltage-
dependent sodium
channels are opened
•The cell is depolarized
(action potential)

16. Electric
stimulation
Na
+
channel
opened
Na
+
Na
+
channel
closed
Membrane
Cell
Fast response channel : fast opened and closed, ex : Na
Voltage gated ion channel
Electric sensor

17. Electric
stimulation
K
+
channel
opened
K
+
K
+
channel
closed
Membrane
Cell
Slow response channel : late in opened and closed, ex : Ca & K
Voltage gated ion channel
Electric sensor

18. Action potential
- 70 mV
+30 mV
- 55 mV
- 0 mV
Firing level
depolarization
repolarization
Action potential
Overshoot

19. Chemical
stimulation
Cl- channel
opened
Cl
-
K
+
channel
closed
Membrane
Cell
Ligand gated channel, slow in response ex : Cl
Chemical substance : GABA, benzodiazepine
receptor
Ligand

20. Stimmulation
↓
Fast natrium channel is opened
↓
Natrium influx
↓
membrane potential decrease
↓
Depolarization
↓
Fast natrium channel closed &
Slow kalium channel opened
↓
Kalium eflux
↓
membran potential back increase
↓
repolarization

21. Cl
-
ligand gated
Channel complex
Cl
-

22. Electrical stimulation :
stimulate at the same time but in the different quick response
Fast response Slow response
Na channel
open
depolarization
Ca channel
open
Cl channel
open
K channel
open
repolarization

23. Depolarization Vs Repolarization
•Depolarization : decrease in membrane
potential, approaching zero (0 mv)
•Depolarization  natrium influx
•Repolarization : increase in membrane
potential, back to the RMP
•Repolarization  kalium eflux

24. After potential
Inwarding Na & outwarding K
are trapped
↓
Positif after potensial
↓
Danger
↓
Stimulate Na/K ATP ase pump
↓
Active Transport
↓
Decrease in Membrane
potential ~ RMP
RMP
FL
0
PRAPRR

25. Refracted Periods
•Periods when cell
become insensitive
even stimulate again
•Refracted periods :
@. Absolute :
when depolarization
@. Relatif :
when repolarization,
need higher intensity 
RMP
FL
0
PRAPRR

26. Hipopolarisasi
mvolt
- 55
- 70
Firing level
RMP
Hiperpolarisasi

27. Propagation
•Conducting action
potential through the
membrane
•By stimulation on
electric sensor of fast
natrium channel
•So there is electrical
conduction

28. Plateau in action potential
Plateau delay on repolarization, which sign as steady state after depolarization
Because of 2 factors :
@ Delay on kalium channel opening or
@ Slow natrium-calcium channel open (it only in cardiac and smooth muscle

29. Action potential
•Spike
•Neuron, skeletal
muscle
•Plateau
•Cardiac muscle,
smooth muscle

30. Cardiac muscle
Stimulation
Na–Ca channel
complex
Fast Na
Channel
open first
Slow Ca
Channel
Open later
Quick
depolarization
Plateau

31. Electrical signal recording
EMG, EEG, EKG

32. Electromiogram (EMG)
•record electrical signal from peripheral
neuron and skeleltal muscle
•EMG consist of a protrude which
administered to the muscle & completed
by electrical stimulator
•EMG is used to measure function &
diagnose neuron & muscle disturbaces,
ex : myasthenia gravis, polio & paralysis

33. Electroencefalogram (EEG)
•Record electrical signal from brain or CNS
•EEG consist of some electrodes which putted in
head
•EEG is used to evaluate brain function &
diagnose in brain disturbances, ex : sleep
disorder & epilepsy

34. Electrocardiogram (ECG)
•ECG record in cardiac
electricity, depolarization
& repolarization
•The recording is a result
of electrical vector which
in one direction
•These show cardiac axis
and cardiac apex location

35. Depend on electrode location ?
Depolarization/ repolarization
ventrikel
Deflect +
Deflect -
Bifasic

36. Elektrodes
•Unipolar
@. Augmented : aVR, aVL, aVF
@. Chest : V1-6
•Bipolar
Lead I
Lead II
Lead III

39. Lead II recording
P wave
atrium depol
qrs complex
ventrikel depol
t wave
Ventrikel repol
Question :
atrium Repol..?
Why t wave (Ventr
repol)  defleksi + ?