ICPP S6 Changing The Membrane Potential Flashcards
What process can changes in the membrane potential control?
Action potentials in nerve / muscle cells.
Control of muscle contraction
Control of NT/ hormone secretion.
Give 3 types of gating channel activity.
Ligand gating.
Voltage gating
Mechanical gating.
How do hair cells in the ear detect sound?
Vibration of eardrum
Vibration pass to fluid in the inner ear compressing it
Compressions - closes K+ channels in cuticular plate of hair cells.
Membrane depolarises.
Ca2+ channels open.
Vesicles containing NT
NT binds to receptor on post-synaptic plate blah blah blah
What are the 4 types of synaptic connection?
Nerve cell - nerve cell
Nerve cell - muscle cell
Nerve cell - gland cell
Sensory cell - nerve cell.
What do excitatory transmitters do?
What are post-synaptic membranes of such synapses permeable to?
Open ligand-gated channels that cause membrane depolarisation.
Na+ ca2+ cations in general.
What do inhibitor transmitters do?
What are the post-synaptic membranes of such synapses permeable to?
Bind to ligand gated ion channels that cause hyperpolarisation.
K+ Cl- etc
The resulting change in membrane potential after a excitatory transmitter has been released is called a what?
What is the role of these?
EPSP
excitatory post-synaptic potential
Add up to generate a voltage that can reach threshold potential.
What are 2 basic patterns for slow synaptic transmission?
Which one is faster and why?
Direct G-Protein gating
Gating via intracellular messenger.
G protein gating because no signalling cascade is involved.
Describe control of insulin release from B cell in islets of Langerhans.
Extracellular [glucose] increases Glucose diffuses into cell Enter glycolysis ATP generation ATP sensitive K+ channel close Membrane depolarisation Ca2+ channels open Exocytosis of insulin vesicles.
