chap 3 transmission Flashcards
resting membrane potential
difference in charge between inside and outside of neuron at rest
Electrical value of RMP
-70mv
Why is RMP -70mv
difference in concentration of sodium and potassium ions across the membrane
Is sodium or potassium more permeable to the membrane
potassium
Types of pressure on NA to enter the cell
electrostatic and concentration gradient
Why does NA not succumb to pressure and enter the cell
1) At rest K channels are open and NA are closed
2) more K channels than NA channels
3) Na-K pump , 3 Na out, 2 K in
This maintains -70mv
What is an action potential
brief reversal in membrane potential caused by Na rushing into cell making it positive
Action potentials travel ____ through nodes of Ranvier (gaps in myelin), and ____ in myelinated areas
Actively, passively
Action potentials are not graded , T/F
T- Action potentials are all or nothing
What does it mean to say that an action potential is non decremental
it does not lose strength as it travels
What causes hyperpolarization
K ions rushing out of cell, membrane goes below resting potential
What is a postsynaptic potential
Pulse that occurs within cell body as result of activity in neighboring cells
What are the two types of PSP
Excitatory and inhibitory
What happens when sum of PSP’s reach threshold
action potential
Batrachotoxin is a toxin, secreted by poison arrow frogs, that selectively interferes with _______ channels.
sodium
A brief period of complete insensitivity to stimuli
absolute refractory period
When the interior of the neuron becomes less negative, it is said to be
depolarized
When the interior of the neuron becomes even more negative, it is said to be
hyperpolarized
A receptor protein that includes an ion channel that is opened when the correct neurotransmitter attaches to the receptor
Ionotropic
When a NT binds to this type of receptor, a G protein is activated and this alters the functioning of the postsynaptic cell
metabotrophic
most prevalent excitatory NT in mammals
glutamate
contributing to un equal dist of ions on either side of resting neural mem
na k pump
what is correct seq of NT release
synthesis storage exocytosis reiptake
compared to metab receptors, ionotropic produce effects that are
less diffuse and develop rapidly
plays a role in reducing excess nt release
autoreceptors
