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‫فیزیولوژی تکمیلی‬
Advanced Physiology
(part 1, Neuronal system)
By: A. Riasi
(PhD in Animal Nutrition & Physiology)
Introduction
All cells in animal body have membrane potential.
Neurons and muscles are excitable.
Adapted from: Akers M. & Denbow M., Anatomy and Physiology of Domestic Animal.
The voltage clamp uses a negative feedback mechanism. The membrane potential amplifier
measures membrane voltage and sends output to the feedback amplifier. The feedback
amplifier subtracts the membrane voltage from the command voltage, which it receives
from the signal generator. This signal is amplified and returned into the cell via the
recording electrode
Adapted from: https://en.wikipedia.org/wiki/Electrophysiology
The cell-attached patch clamp uses a micropipette attached to the cell membrane to
allow recording from a single ion channel
Adapted from: https://en.wikipedia.org/wiki/Electrophysiology
Adapted from: Akers M. & Denbow M., Anatomy and Physiology of Domestic Animal.
The water-soluble ion have to penetrate the
plasma membrane using the specific channels.
Leak channels (non-gated channels)
Gated channels
Voltage-gated channels
Chemically gated channels (ligand channels)
Mechanically channels
Two basic forms of electrical signals
Graded potential
Action potential
Graded potential
Graded potential
Graded potential
Adapted from: Sherwood et al., Animal Physiology
Graded potential
The graded potentials are critically important to
neurnal functions:
Postsynaptic potentials
Receptor potentials
End-plate potentials
Pacemaker potentials
Slow-wave potential
Graded potential
Adapted from: Akers M. & Denbow M., Anatomy and Physiology of Domestic Animal.
Action potential
Action potential
Action potential
Action potential
Action potential
Action potential