Membane Potential Flashcards
What is membrane potential
The magnitude of an electrical charge across a plasma membrane expressed at the potential inside the cell relative to the outside
Membrane potential of cardiac myocytes
-80mv
Membrane potential of neurones
-70mv
Membrane potential f skeletal myocyes and smooth muscle myocyes
- 90mv
- 50mv
What is depolarisation
Cell interior becomes less negative
What is hyperpolarisation
Cell becomes more negative
What does increasing the membrane permeability to a particular ion do
Moves the membrane potential towards the equilibrium potential for that ion
What ions cause hyperpolarisation
Potassium
Chloride
What ions calls depolarisation
Sodium
Calcium
What is fast transmission in a synapses
Involves ligand - gated ion channels which open i response to neurotransmitters binding
What is slow synaptic transmission
Involves g-protein coupled receptors which activate channels via direct and indirect signalling pathway
What are excitatory synapses
Cause membrane depolarisation
Glutamate dopamine and acetylcholine
What are inhibitory synapses
Caus hyperpolarisation
GABA and glycine
