General physiology of the excitable tissues

Август 2, 2022

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Биология
General physiology of the excitable tissues

Содержание

2. THE RESTING CELL HIGH POTASSIUM LOW SODIUM NA/K ATPASE PUMP RESTING POTENTIAL ABOUT 90 - 120
4. BIOELECTRICITY THE ORIGIN OF THE MEMBRANE POTENTIAL
5. MOBILITY OF IONS DEPENDS ON HYDRATED SIZE IONS WITH SMALLER CRYSTAL RADIUS HAVE A HIGHER CHARGE
6. IONS MOVE WITH THEIR HYDRATION SHELLS - + - + Hydration Shells - + - +
7. ELECTRONEUTRAL DIFFUSSION HIGH SALT CONCEMTRATION LOW SALT CONCEMTRATION BARRIER SEPARATES THE TWO SOLUTIONS
8. ELECTRONEUTRAL DIFFUSSION + - CHARGE SEPARATION = ELECTRICAL POTENTIAL
9. ELECTRICAL POTENTIAL=CHARGE SEPARATION In water, without a membrane hydrated Chloride is smaller than hydrated Sodium, therefore
10. THE MEMBRANE POTENTIAL M E M B R A N E Extracellular Fluid Intracellular Fluid Na+
11. THE ORIGIN OF BIOELECTRICITY POTASSIUM CHANNELS ALLOW HIGH MOBILITY SODIUM CHANNELS LESS OPEN CHARGE SEPARATION OCCURS
12. THE RESTING CELL HIGH POTASSIUM LOW SODIUM NA/K ATPASE PUMP RESTING POTENTIAL ABOUT 90 - 120
14. ACTIVE TRANSPORT ADP ATP
15. ACTIVE TRANSPORT REQUIRES AN INPUT OF ENERGY USUALLY IN THE FORM OF ATP ATPase IS INVOLVED
16. EXCITABLE TISSUES NERVE AND MUSCLE VOLTAGE GATED CHANNELS DEPOLARIZATION LESS THAN THRESHOLD IS GRADED DEPOLARIZATION BEYOND
17. THE NERVE CELL CELL BODY DENDRITES AXON AXON HILLOCK AXON TERMINALS
18. EXCITABLE TISSUES:THE ACTION POTENTIAL THE MEMBRANE USES VOLTAGE GATED CHANNELS TO SWITCH FROM A POTASSIUM DOMINATED
19. FOR EACH CONCENTRATION DIFFERENCE ACROSS THE MEMBRANE THERE IS AN ELECTRIC POTENTIAL DIFFERENCE WHICH WILL PRODUCE
20. THE EQUILIBRIUM MEMBRANE POTENTIAL FOR POTASSIUM IS -90 mV + - CONCENTRATION POTENTIAL K+ K+ IN
21. THE EQUILIBRIUM MEMBRANE POTENTIAL FOR SODIUM IS + 60 mV Na+ Na+ + - CONCENTRATION POTENTIAL
22. THE RESTING POTENTIAL IS NEAR THE POTASSIUM EQUILIBRIUM POTENTIAL AT REST THE POTASSIUM CHANNELS ARE MORE
23. EVENTS DURING EXCITATION DEPOLARIZATION EXCEEDS THRESHOLD SODIUM CHANNELS OPEN MEMBRANE POTENTIAL SHIFTS FROM POTASSIUM CONTROLLED (-90
24. OPENING THE SODIUM CHANNELS ALLOWS SODIUM TO RUSH IN THE MEMBRANE DEPOLARIZES AND THEN THE MEMBRANE
25. GRADED VS ALL OR NONE A RECEPTOR’S RESPONSE TO A STIMULUS IS GRADED IF THRESHOLD IS
28. PROPAGATION OF THE ACTION POTENTIAL +++++ -------- --------------------- +++++++++++++ AXON MEMBRANE INSIDE OUTSIDE ACTION POTENTIAL DEPOLARIZING
29. PROPAGATION OF THE ACTION POTENTIAL +++++ -------- --------------------- +++++++++++++ AXON MEMBRANE INSIDE OUTSIDE ACTION POTENTIAL DEPOLARIZING
30. PROPAGATION OF THE ACTION POTENTIAL --+++ ++------ +++------------------ ---++++++++++ AXON MEMBRANE INSIDE OUTSIDE ACTION POTENTIAL DEPOLARIZING
31. PROPAGATION OF THE ACTION POTENTIAL -------- +++++ ++++++------- -----------++++ AXON MEMBRANE INSIDE OUTSIDE ACTION POTENTIAL DEPOLARIZING
32. SALTATORY CONDUCTION +++++ -------- -------- +++++ AXON MEMBRANE INSIDE OUTSIDE ACTION POTENTIAL DEPOLARIZING CURRENT MYELIN NODE
33. NORMALLY A NERVE IS EXCITED BY A SYNAPSE OR BY A RECEPTOR MANY NERVES SYNAPSE ON
35. THE SYNAPSE JUNCTION BETWEEN TWO NEURONS CHEMICAL TRANSMITTER MAY BE 100,000 ON A SINGLE CNS NEURON
36. THE SYNAPSE SYNAPTIC VESSICLES ••• ••• ••• ••• ••• ••• ••• ••• ••• INCOMING ACTION POTENTIAL
37. THE SYNAPSE SYNAPTIC VESSICLES ••• ••• ••• ••• ••• ••• ••• ••• ••• INCOMING ACTION POTENTIAL
38. THE SYNAPSE SYNAPTIC VESSICLES ••• ••• ••• ••• ••• ••• ••• ••• ••• INCOMING ACTION POTENTIAL
39. THE SYNAPSE SYNAPTIC VESSICLES ••• ••• ••• ••• ••• ••• ••• ••• ••• CALCIUM CHANNEL ION
40. THE SYNAPSE SYNAPTIC VESSICLES ••• ••• ••• ••• ••• ••• ••• ••• ••• CALCIUM CHANNEL ION
41. THE SYNAPSE SYNAPTIC VESSICLES ••• ••• ••• ••• ••• ••• ••• ••• ••• CALCIUM CHANNEL ION
42. THE SYNAPSE SYNAPTIC VESSICLES ••• ••• ••• ••• ••• ••• ••• ••• ••• CALCIUM CHANNEL ION
43. POSTSYNAPTIC POTENTIALS RESTING POTENTIAL EPSP TIME
44. TEMPORAL SUMMATION TIME TOO FAR APART IN TIME: NO SUMMATION
45. TEMPORAL SUMMATION TIME CLOSER IN TIME: SUMMATION BUT BELOW THRESHOLD THRESHOLD
46. TEMPORAL SUMMATION TIME STILL CLOSER IN TIME: ABOVE THRESHOLD THRESHOLD
47. SPATIAL SUMMATION TIME SIMULTANEOUS INPUT FROM TWO SYNAPSES: ABOVE THRESHOLD THRESHOLD
48. EPSP-IPSP CANCELLATION
50. Скачать презентацию

Слайд 2

THE RESTING CELL
HIGH POTASSIUM
LOW SODIUM
NA/K ATPASE PUMP
RESTING POTENTIAL ABOUT 90

- 120 MV
OSMOTICALLY BALANCED (CONSTANT VOLUME)

Слайд 3

Слайд 4

BIOELECTRICITY
THE ORIGIN OF THE MEMBRANE POTENTIAL

Слайд 5

MOBILITY OF IONS DEPENDS ON HYDRATED SIZE
IONS WITH SMALLER CRYSTAL RADIUS

HAVE A HIGHER CHARGE DENSITY
THE HIGHER CHARGE DENSITY ATTRACTS MORE WATER OF HYDRATION
THUS THE SMALLER THE CRYSTAL RADIUS, THE LOWER THE MOBILITY IN WATER

Слайд 6

IONS MOVE WITH THEIR HYDRATION SHELLS
- +
- +
Hydration Shells
- +
- +
-

- +

Слайд 7

ELECTRONEUTRAL DIFFUSSION
HIGH SALT
CONCEMTRATION
LOW SALT
CONCEMTRATION
BARRIER SEPARATES THE
TWO SOLUTIONS

Слайд 8

ELECTRONEUTRAL DIFFUSSION
+
-
CHARGE SEPARATION = ELECTRICAL POTENTIAL

Слайд 9

ELECTRICAL POTENTIAL=CHARGE SEPARATION
In water, without a membrane hydrated
Chloride is smaller

than hydrated Sodium,
therefore faster:

Cl-

Na+

The resulting separation of charge is called an
ELECTRICAL POTENTIAL

Слайд 10

THE MEMBRANE POTENTIAL
M
E
M
B
R
A
N
E
Extracellular
Fluid
Intracellular
Fluid
Na+
K+
Sodium channel is less open causing sodium to be

slower

Potassium channel is more open causing potassium to be faster

MEMRANE POTENTIAL
(ABOUT 90 -120 mv)

Слайд 11

THE ORIGIN OF BIOELECTRICITY
POTASSIUM CHANNELS ALLOW HIGH MOBILITY
SODIUM CHANNELS LESS OPEN
CHARGE

SEPARATION OCCURS UNTIL BOTH MOVE AT SAME SPEED
STEADY STEADY IS ACHIEVED WITH A CONSTANT MEMBRANE POTENTIAL

Слайд 12

THE RESTING CELL
HIGH POTASSIUM
LOW SODIUM
NA/K ATPASE PUMP
RESTING POTENTIAL ABOUT 90

- 120 MV
OSMOTICALLY BALANCED (CONSTANT VOLUME)

Слайд 13

Слайд 14

ACTIVE TRANSPORT
ADP
ATP

Слайд 15

ACTIVE TRANSPORT REQUIRES AN INPUT OF ENERGY
USUALLY IN THE FORM OF

ATP
ATPase IS INVOLVED
SOME ASYMMETRY IS NECESSARY
CAN PUMP UPHILL

Слайд 16

EXCITABLE TISSUES
NERVE AND MUSCLE
VOLTAGE GATED CHANNELS
DEPOLARIZATION LESS THAN THRESHOLD IS GRADED
DEPOLARIZATION

BEYOND THRESHOLD LEADS TO ACTION POTENTIAL
ACTION POTENTIAL IS ALL OR NONE

Слайд 17

THE NERVE CELL
CELL
BODY
DENDRITES
AXON
AXON
HILLOCK
AXON
TERMINALS

Слайд 18

EXCITABLE TISSUES:THE ACTION POTENTIAL
THE MEMBRANE USES VOLTAGE GATED CHANNELS TO SWITCH

FROM A POTASSIUM DOMINATED TO A SODIUM DOMINATED POTENTIAL
IT THEN INACTIVATES AND RETURNS TO THE RESTING STATE
THE RESPONSE IS “ALL OR NONE”

Слайд 19

FOR EACH CONCENTRATION
DIFFERENCE ACROSS THE
MEMBRANE THERE IS AN ELECTRIC

POTENTIAL DIFFERENCE WHICH
WILL PRODUCE EQUILIBRIUM.
AT EQUILIBRIUM NO
NET ION FLOW OCCURS

EQUILIBRIUM POTENTIALS FOR IONS

Слайд 20

THE EQUILIBRIUM MEMBRANE POTENTIAL FOR POTASSIUM IS -90 mV
+
-
CONCENTRATION
POTENTIAL
K+
K+
IN

Слайд 21

THE EQUILIBRIUM MEMBRANE POTENTIAL FOR SODIUM IS + 60 mV
Na+
Na+
+
-
CONCENTRATION
POTENTIAL
IN
OUT

Слайд 22

THE RESTING POTENTIAL IS NEAR THE POTASSIUM EQUILIBRIUM POTENTIAL
AT REST THE

POTASSIUM CHANNELS ARE MORE OPEN AND THE POTASSIUM IONS MAKE THE INSIDE OF THE CELL NEGATIVE
THE SODIUM CHANNELS ARE MORE CLOSED AND THE SODIUM MOVES SLOWER

Слайд 23

EVENTS DURING EXCITATION
DEPOLARIZATION EXCEEDS THRESHOLD
SODIUM CHANNELS OPEN
MEMBRANE POTENTIAL SHIFTS FROM

POTASSIUM CONTROLLED (-90 MV) TO SODIUM CONTROLLED (+60 MV)
AS MEMBRANE POTENTIAL REACHES THE SODIUM POTENTIAL, THE SODIUM CHANNELS CLOSE AND ARE INACTIVATED
POTASSIUM CHANNELS OPEN TO REPOLARIZE THE MEMBRANE

Слайд 24

OPENING THE SODIUM CHANNELS ALLOWS SODIUM TO RUSH IN
THE MEMBRANE DEPOLARIZES

AND THEN THE MEMBRANE POTENTIAL APPROACHES THE SODIUM EQUILIBRIUM POTENTIAL
THIS RADICAL CHANGE IN MEMBRANE POTENTIAL CAUSES THE SODIUM CHANNELS TO CLOSE (INACTIVATION) AND THE POTASSIUM CHANNELS TO OPEN REPOLARIZING THE MEMBRANE
THERE IS A SLIGHT OVERSHOOT (HYPERPOLARIZATION) DUE TO THE POTASSIUM CHANNELS BEING MORE OPEN

Слайд 25

GRADED VS ALL OR NONE
A RECEPTOR’S RESPONSE TO A STIMULUS

IS GRADED
IF THRESHOLD IS EXCEEDED, THE ACTION POTENTIAL RESULTING IS ALL OR NONE

Слайд 26

Слайд 27

Слайд 28

PROPAGATION OF THE ACTION POTENTIAL
+++++
--------
---------------------
+++++++++++++
AXON MEMBRANE
INSIDE
OUTSIDE
ACTION
POTENTIAL
DEPOLARIZING
CURRENT

Слайд 29

PROPAGATION OF THE ACTION POTENTIAL
+++++
--------
---------------------
+++++++++++++
AXON MEMBRANE
INSIDE
OUTSIDE
ACTION
POTENTIAL
DEPOLARIZING
CURRENT

Слайд 30

PROPAGATION OF THE ACTION POTENTIAL
--+++
++------
+++------------------
---++++++++++
AXON MEMBRANE
INSIDE
OUTSIDE
ACTION
POTENTIAL
DEPOLARIZING
CURRENT

Слайд 31

PROPAGATION OF THE ACTION POTENTIAL
--------
+++++
++++++-------
-----------++++
AXON MEMBRANE
INSIDE
OUTSIDE
ACTION
POTENTIAL
DEPOLARIZING
CURRENT

Слайд 32

SALTATORY CONDUCTION
+++++
--------
--------
+++++
AXON MEMBRANE
INSIDE
OUTSIDE
ACTION
POTENTIAL
DEPOLARIZING
CURRENT
MYELIN
NODE OF
RANVIER
NODE OF
RANVIER

Слайд 33

NORMALLY A NERVE IS EXCITED BY A SYNAPSE OR BY A

RECEPTOR

MANY NERVES SYNAPSE ON ANY GIVEN NERVE
RECEPTORS HAVE GENERATOR POTENTIALS WHICH ARE GRADED
IN EITHER CASE WHEN THE NERVE IS DEPOLARIZED BEYOND THRESHOLD IT FIRE AN ALL-OR-NONE ACTION POTENTIAL AT THE FIRST NODE OF RANVIER

Слайд 34

Слайд 35

THE SYNAPSE
JUNCTION BETWEEN TWO NEURONS
CHEMICAL TRANSMITTER
MAY BE 100,000 ON A SINGLE

CNS NEURON
SPATIAL AND TEMPORAL SUMMATION
CAN BE EXCITATORY OR INHIBITORY

Слайд 36

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
INCOMING
ACTION

POTENTIAL

CALCIUM
CHANNEL

ION
CHANNEL

RECEPTOR

ENZYME

Слайд 37

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
INCOMING
ACTION

POTENTIAL

CALCIUM
CHANNEL

ION
CHANNEL

RECEPTOR

ENZYME

Слайд 38

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
INCOMING
ACTION

POTENTIAL

CALCIUM
CHANNEL

ION
CHANNEL

RECEPTOR

ENZYME

Слайд 39

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
CALCIUM

CHANNEL

ION
CHANNEL

RECEPTOR

ENZYME

Слайд 40

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
CALCIUM

CHANNEL

ION
CHANNEL

RECEPTOR

ENZYME

•••

Слайд 41

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
CALCIUM

CHANNEL

ION
CHANNEL

RECEPTOR

ENZYME

Слайд 42

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
CALCIUM

CHANNEL

ION
CHANNEL

RECEPTOR

ENZYME

Слайд 43

POSTSYNAPTIC POTENTIALS
RESTING
POTENTIAL
EPSP
TIME

Слайд 44

TEMPORAL SUMMATION
TIME
TOO FAR APART IN TIME:
NO SUMMATION

Слайд 45

TEMPORAL SUMMATION
TIME
CLOSER IN TIME:
SUMMATION BUT
BELOW THRESHOLD
THRESHOLD

Слайд 46

TEMPORAL SUMMATION
TIME
STILL CLOSER IN
TIME: ABOVE
THRESHOLD
THRESHOLD

Слайд 47

SPATIAL SUMMATION
TIME
SIMULTANEOUS
INPUT FROM TWO
SYNAPSES: ABOVE
THRESHOLD
THRESHOLD

Слайд 48

General physiology of the excitable tissues

Содержание

THE RESTING CELLHIGH POTASSIUMLOW SODIUMNA/K ATPASE PUMP RESTING POTENTIAL ABOUT 90

BIOELECTRICITYTHE ORIGIN OF THE MEMBRANE POTENTIAL

MOBILITY OF IONS DEPENDS ON HYDRATED SIZEIONS WITH SMALLER CRYSTAL RADIUS

IONS MOVE WITH THEIR HYDRATION SHELLS- +- +Hydration Shells- +- +-

ELECTRONEUTRAL DIFFUSSIONHIGH SALT CONCEMTRATIONLOW SALT CONCEMTRATIONBARRIER SEPARATES THE TWO SOLUTIONS

ELECTRONEUTRAL DIFFUSSION+-CHARGE SEPARATION = ELECTRICAL POTENTIAL

ELECTRICAL POTENTIAL=CHARGE SEPARATIONIn water, without a membrane hydrated Chloride is smaller

THE MEMBRANE POTENTIALMEMBRANEExtracellularFluidIntracellularFluidNa+K+Sodium channel is less open causing sodium to be

THE ORIGIN OF BIOELECTRICITYPOTASSIUM CHANNELS ALLOW HIGH MOBILITYSODIUM CHANNELS LESS OPENCHARGE

THE RESTING CELLHIGH POTASSIUMLOW SODIUMNA/K ATPASE PUMP RESTING POTENTIAL ABOUT 90

ACTIVE TRANSPORTADP ATP

ACTIVE TRANSPORT REQUIRES AN INPUT OF ENERGYUSUALLY IN THE FORM OF

EXCITABLE TISSUESNERVE AND MUSCLEVOLTAGE GATED CHANNELSDEPOLARIZATION LESS THAN THRESHOLD IS GRADEDDEPOLARIZATION

THE NERVE CELLCELLBODYDENDRITESAXONAXONHILLOCKAXONTERMINALS

EXCITABLE TISSUES:THE ACTION POTENTIALTHE MEMBRANE USES VOLTAGE GATED CHANNELS TO SWITCH

FOR EACH CONCENTRATION DIFFERENCE ACROSS THE MEMBRANE THERE IS AN ELECTRIC

THE EQUILIBRIUM MEMBRANE POTENTIAL FOR POTASSIUM IS -90 mV+-CONCENTRATIONPOTENTIALK+K+IN

THE EQUILIBRIUM MEMBRANE POTENTIAL FOR SODIUM IS + 60 mVNa+Na++-CONCENTRATIONPOTENTIALINOUT

THE RESTING POTENTIAL IS NEAR THE POTASSIUM EQUILIBRIUM POTENTIALAT REST THE

EVENTS DURING EXCITATION DEPOLARIZATION EXCEEDS THRESHOLDSODIUM CHANNELS OPENMEMBRANE POTENTIAL SHIFTS FROM

OPENING THE SODIUM CHANNELS ALLOWS SODIUM TO RUSH INTHE MEMBRANE DEPOLARIZES

GRADED VS ALL OR NONE A RECEPTOR’S RESPONSE TO A STIMULUS

PROPAGATION OF THE ACTION POTENTIAL+++++-----------------------------+++++++++++++AXON MEMBRANEINSIDEOUTSIDEACTION POTENTIALDEPOLARIZINGCURRENT

PROPAGATION OF THE ACTION POTENTIAL+++++-----------------------------+++++++++++++AXON MEMBRANEINSIDEOUTSIDEACTION POTENTIALDEPOLARIZINGCURRENT

PROPAGATION OF THE ACTION POTENTIAL--+++++------+++---------------------++++++++++AXON MEMBRANEINSIDEOUTSIDEACTION POTENTIALDEPOLARIZINGCURRENT

PROPAGATION OF THE ACTION POTENTIAL--------+++++++++++------------------++++AXON MEMBRANEINSIDEOUTSIDEACTION POTENTIALDEPOLARIZINGCURRENT

SALTATORY CONDUCTION+++++----------------+++++AXON MEMBRANEINSIDEOUTSIDEACTION POTENTIALDEPOLARIZINGCURRENTMYELINNODE OFRANVIERNODE OFRANVIER

NORMALLY A NERVE IS EXCITED BY A SYNAPSE OR BY A

THE SYNAPSEJUNCTION BETWEEN TWO NEURONSCHEMICAL TRANSMITTERMAY BE 100,000 ON A SINGLE

THE SYNAPSESYNAPTICVESSICLES ••• ••• ••• ••• ••• ••• ••• ••• •••INCOMINGACTION

THE SYNAPSESYNAPTICVESSICLES ••• ••• ••• ••• ••• ••• ••• ••• •••INCOMINGACTION

THE SYNAPSESYNAPTICVESSICLES ••• ••• ••• ••• ••• ••• ••• ••• •••INCOMINGACTION

THE SYNAPSESYNAPTICVESSICLES ••• ••• ••• ••• ••• ••• ••• ••• •••CALCIUM

THE SYNAPSESYNAPTICVESSICLES ••• ••• ••• ••• ••• ••• ••• ••• •••CALCIUM

THE SYNAPSESYNAPTICVESSICLES ••• ••• ••• ••• ••• ••• ••• ••• •••CALCIUM

THE SYNAPSESYNAPTICVESSICLES ••• ••• ••• ••• ••• ••• ••• ••• •••CALCIUM

POSTSYNAPTIC POTENTIALSRESTINGPOTENTIALEPSPTIME

TEMPORAL SUMMATIONTIMETOO FAR APART IN TIME:NO SUMMATION

TEMPORAL SUMMATIONTIMECLOSER IN TIME: SUMMATION BUT BELOW THRESHOLDTHRESHOLD

TEMPORAL SUMMATIONTIMESTILL CLOSER IN TIME: ABOVETHRESHOLDTHRESHOLD

SPATIAL SUMMATIONTIMESIMULTANEOUSINPUT FROM TWOSYNAPSES: ABOVETHRESHOLDTHRESHOLD

EPSP-IPSP CANCELLATION

Похожие презентации

THE RESTING CELL
HIGH POTASSIUM
LOW SODIUM
NA/K ATPASE PUMP
RESTING POTENTIAL ABOUT 90

BIOELECTRICITY
THE ORIGIN OF THE MEMBRANE POTENTIAL

MOBILITY OF IONS DEPENDS ON HYDRATED SIZE
IONS WITH SMALLER CRYSTAL RADIUS

IONS MOVE WITH THEIR HYDRATION SHELLS
- +
- +
Hydration Shells
- +
- +
-

ELECTRONEUTRAL DIFFUSSION
HIGH SALT
CONCEMTRATION
LOW SALT
CONCEMTRATION
BARRIER SEPARATES THE
TWO SOLUTIONS

ELECTRONEUTRAL DIFFUSSION
+
-
CHARGE SEPARATION = ELECTRICAL POTENTIAL

ELECTRICAL POTENTIAL=CHARGE SEPARATION
In water, without a membrane hydrated
Chloride is smaller

THE MEMBRANE POTENTIAL
M
E
M
B
R
A
N
E
Extracellular
Fluid
Intracellular
Fluid
Na+
K+
Sodium channel is less open causing sodium to be

THE ORIGIN OF BIOELECTRICITY
POTASSIUM CHANNELS ALLOW HIGH MOBILITY
SODIUM CHANNELS LESS OPEN
CHARGE

THE RESTING CELL
HIGH POTASSIUM
LOW SODIUM
NA/K ATPASE PUMP
RESTING POTENTIAL ABOUT 90

ACTIVE TRANSPORT
ADP
ATP

ACTIVE TRANSPORT REQUIRES AN INPUT OF ENERGY
USUALLY IN THE FORM OF

EXCITABLE TISSUES
NERVE AND MUSCLE
VOLTAGE GATED CHANNELS
DEPOLARIZATION LESS THAN THRESHOLD IS GRADED
DEPOLARIZATION

THE NERVE CELL
CELL
BODY
DENDRITES
AXON
AXON
HILLOCK
AXON
TERMINALS

EXCITABLE TISSUES:THE ACTION POTENTIAL
THE MEMBRANE USES VOLTAGE GATED CHANNELS TO SWITCH

FOR EACH CONCENTRATION
DIFFERENCE ACROSS THE
MEMBRANE THERE IS AN ELECTRIC

THE EQUILIBRIUM MEMBRANE POTENTIAL FOR POTASSIUM IS -90 mV
+
-
CONCENTRATION
POTENTIAL
K+
K+
IN

THE EQUILIBRIUM MEMBRANE POTENTIAL FOR SODIUM IS + 60 mV
Na+
Na+
+
-
CONCENTRATION
POTENTIAL
IN
OUT

THE RESTING POTENTIAL IS NEAR THE POTASSIUM EQUILIBRIUM POTENTIAL
AT REST THE

EVENTS DURING EXCITATION
DEPOLARIZATION EXCEEDS THRESHOLD
SODIUM CHANNELS OPEN
MEMBRANE POTENTIAL SHIFTS FROM

OPENING THE SODIUM CHANNELS ALLOWS SODIUM TO RUSH IN
THE MEMBRANE DEPOLARIZES

GRADED VS ALL OR NONE
A RECEPTOR’S RESPONSE TO A STIMULUS

PROPAGATION OF THE ACTION POTENTIAL
+++++
--------
---------------------
+++++++++++++
AXON MEMBRANE
INSIDE
OUTSIDE
ACTION
POTENTIAL
DEPOLARIZING
CURRENT

PROPAGATION OF THE ACTION POTENTIAL
+++++
--------
---------------------
+++++++++++++
AXON MEMBRANE
INSIDE
OUTSIDE
ACTION
POTENTIAL
DEPOLARIZING
CURRENT

PROPAGATION OF THE ACTION POTENTIAL
--+++
++------
+++------------------
---++++++++++
AXON MEMBRANE
INSIDE
OUTSIDE
ACTION
POTENTIAL
DEPOLARIZING
CURRENT

PROPAGATION OF THE ACTION POTENTIAL
--------
+++++
++++++-------
-----------++++
AXON MEMBRANE
INSIDE
OUTSIDE
ACTION
POTENTIAL
DEPOLARIZING
CURRENT

SALTATORY CONDUCTION
+++++
--------
--------
+++++
AXON MEMBRANE
INSIDE
OUTSIDE
ACTION
POTENTIAL
DEPOLARIZING
CURRENT
MYELIN
NODE OF
RANVIER
NODE OF
RANVIER

THE SYNAPSE
JUNCTION BETWEEN TWO NEURONS
CHEMICAL TRANSMITTER
MAY BE 100,000 ON A SINGLE

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
INCOMING
ACTION

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
INCOMING
ACTION

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
INCOMING
ACTION

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
CALCIUM

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
CALCIUM

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
CALCIUM

THE SYNAPSE
SYNAPTIC
VESSICLES
•••
•••
•••
•••
•••
•••
•••
•••
•••
CALCIUM

POSTSYNAPTIC POTENTIALS
RESTING
POTENTIAL
EPSP
TIME

TEMPORAL SUMMATION
TIME
TOO FAR APART IN TIME:
NO SUMMATION

TEMPORAL SUMMATION
TIME
CLOSER IN TIME:
SUMMATION BUT
BELOW THRESHOLD
THRESHOLD

TEMPORAL SUMMATION
TIME
STILL CLOSER IN
TIME: ABOVE
THRESHOLD
THRESHOLD

SPATIAL SUMMATION
TIME
SIMULTANEOUS
INPUT FROM TWO
SYNAPSES: ABOVE
THRESHOLD
THRESHOLD