Lecture 1 - Cell Membranes And Excitation Flashcards
Contracts when information is sent (excitable cell)
Muscle cell
Conveys electrical signals over long distances
Nerve excitable cell
Contains DNA within the cell body in a neuron
Nucleus
Contains the neuron cells nucleus
Cell body soma
Received input from other neurones to convey the message
5-7 dendrites
Nerve fibres (found within the middle of neuron)
Axon - short and long
Contact region for other cells
Terminal bouton synapse
The 1st terminal of the synapse
Pre anterior synapse
Protective covering of neurone
Myelin (schwann cell - PNS)
What is the transmembrane testing potential?
-70mV
The inside of the cell is ….. vly charged
Negatively
The outside of a cell is …..ively charged
Positively
Uses facilitated (passive) diffusion
Voltage gated Na+ channel
Uses active transport
Na+K+ATPase pump
Uses rapid kinetics
Na+ channel
Uses slow kinetics
ATPase pump
What does electrogenic pump mean?
Net loss of one positive charge from the cytoplasm helps to maintain an electric gradient within a cell and extra cellular environment
Enters the cell via ATPase pump
2xK+
Exits cell via ATPase pump
3x Na+ ions, therefore causing there to be a positive charge outside of the cell because only 2X K+ ions are entering
Synaptic/graded response
Local - non propagated
Response found usually at the dendrites and cell body (EPSP & IPSP)
Local - non propograted
Relies on AP
Propogated disturbance
Features of propagated
- does not diminish
- all or none response (not graded)
- constant
- over large distances
- threshold is -55mV
