Lec 2 Nervous System Flashcards
Myelin is produced by what?
- Oligodendrocyte glia in CNS
- Schwann cells in PNS
What role does micro glia play?
- structural support for neurons
- cleans up debris from damaged cells
What is the neuronal membrane?
Bilipid layer containing ion channels
What is the resting membrane potential?
-70mV. Voltage at which the neuron is resting
What does “Neurons are exitable” mean?
State at which a neuron can not depolarize
What is the neuronal membrane more permeable to?
K+ potassium ions because it contributes to the resting membrane potential
What is meant by Electrical gradient?
A force that pushes ions to an area with the opposite charge.
What is electrochemical equilibrium?
Balance between chemical and electrical driving forces: resting membrane potential
Concentration gradient?
Uneven distribution of ions in a cell membrane
What is decremental conduction/ electrotonic conduction?
Passive current conduction, a small electrical current create by ESPS conducted through cytoplasm of dendrites, soma and axon
What is the Hodgkin-Huxley cycle?
When AP threshold is met, Na+ flows in, depolarises cell, open voltage gated Na+ channels, more Na+
What is EPSP?
Excitatory Post-Synaptic Potential
What is the necessary excitation threshold needed for an AP?
-55mV
What causes Ca+ channels to open?
Depolarization of the axon terminal (AP)
What happens at a synapse?
Calcium influx, vesicles bind to axon terminal button, release NT, binds to PSC, (reuptake, diffusion or enzymatic breakdown)
