Lecture 1 - Cell Membranes And Excitation Flashcards
(23 cards)
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
