Nerves Flashcards
Full Nernst equation?
RT/zF x ln(C ref/C test)
Short Nernst equation?
58log(C ref/C test)
Goldman equation?
RT/F x ln (Pk x [K0])/(Pk x [K1]) etc.
Threshold potential?
-55mV
Equilibrium potential of Ca?
150
Equilibrium potential of Na?
58
Equilibrium potential of H?
-12
Equilibrium potential of Cl?
-64
Equilibrium potential of K?
-90
How many coulombs is one mole of electrons - the Faraday constant?
96500
The two types of muscle fibres?
Extrafusal generates force, spindle/stretch send info back to spinal cord
Capacitance=?
charge/voltage
Capacitance of biomembranes?
1 micro Farad
Time to diffuse xcm?
x^2/2D (where D=diffusion constant)
What is the time constant?
Rm x Cm, time to change voltage by 63%
If Na conc increases x10, what’s the equilibrium potential change?
58mV
Iion?
Gion x (Vm - Eion)
What is the length constant?
63% change or sqrt(Rm/Ri)
What is the critical diameter?
Below 1 micron
What do F type primary active transporters do?
ATP synthase in mitochondria, mechanism involves rotation
What do V type primary active transporters do?
Transports H+ > vesicles e.g. lysosomes, golgi
What do P type primary active transporters do?
Na+ and Ca2+ pumps, both have low conc inside cell
What are ABC transporters?
Have motif in structure, either uses ATP or has it as cofactor
What are SLC transporters?
No role for ATP, get energy from electrochemical gradient, can be cotransporter, antiporter or Na-dependent glutamate uptake transporter (removed excess glutamate in glial cells)
How is intracellular K+ regulated?
Blood K+, controlled blood osmolarity, Na+ pump
Another word for exchanger?
Antiporter
Another word for cotransporter?
Symporter
Which muscle cell types are electrical synapses found between?
Smooth and cardiac
Where is the end plate?
Presynaptic terminal
Other names for the post-synaptic potential?
End plate potential or excitatory junctional potential
What are connections between electrical synapses called?
Connexons
What is an excitatory integratory synpase compared to a relay synapse?
Depolarises motoneurone but not always creating an action potential WHEREAS relay synapses always fire an action potential
What initiates muscle action in striated muscle?
EPP
Which channels do inhibitory transmitters open?
Cl-
What kind of synapse is an end plate?
Relay - always excites muscle
What kind of an end plate is a sensory synapse?
Integratory - only causes small excitation
What are ionotropic receptors?
Where receptor itself is an ion channel
What are metabotropic receptors?
Where the receptor starts a cascade to open an ion channel
What is the most potent inhibitor?
GABA
Is glutamate excitatory or inhibtory?
Excitatory almost everywhere
What kind of an ion channel is nAchR?
Fast excitatory ionotropic
What kind of an ion channel is mAchR?
SLow ex/in metabotropic?
What are the three gases in neurotransmission?
CO, NO, H2S
What/where are NA synapses?
Slow synaptic transmitter in CNS and smooth and cardiac muscle
What/where are serotonin synapses?
Slow, in CNS and smooth muscle. Many different receptors, only one is ionotropic
What/where are dopamine receptors?
SLow synaptic transmission in central and periphery NS
