ICPP 4 Changing Membrane Potential Flashcards
What is depolarisation?
A decrease in the size of the membrane potential
Inside cell becomes less negative
What is hyperpolarisation?
An increase in the size of the membrane potential from its normal value
Inside cell becomes more negative than RMP
What is repolarisation?
Membrane potential returning to resting membrane potential
What are changes in membrane potential caused by?
Changes in the activity of ion channels
Where do chemical synapses occur between?
Nerve cell - nerve cell
Nerve cell - muscle cell
Nerve cell - gland cell
Sensory cell - nerve cell
What type of receptors cause depolarisation?
What does this result in?
Excitatory receptors
Excitatory post-synaptic potential
What type of receptors cause hyperpolarisation?
What does this result in?
Inhibitory receptors
Inhibitory post synaptic potential
What are inhibitory receptors permeable to?
K+
Cl-
What are excitatory receptors permeable to?
Na+
Ca2+
Two patterns of slow synaptic transmission
G-protein coupled receptors
Gating via an intracellular messenger
What are the three type of gating?
Ligand gating
Voltage gating
Mechanical gating
What equation outlines the imperfect selectivity of cell membranes?
Goldman-Hodgkin-Katz equation
What are the 2 classes of synaptic transmission?
Fast + slow
Describe fast synaptic transmission
Receptor protein is also ion channel
Transmitter binding causes channel to open
Can be excitatory or inhibitory
What are the 2 different classes of fast synaptic transmission?
Excitatory»_space; depolarisation
Inhibitory»_space; hyperpolarisation
