The neurotransmitter _______ is used in the production of inhibitory post synaptic potentials.
The neurotransmitter _______ is used on the production of excitatory postsynaptic potentials.
Define the term membrane potential
The charges intracellularly and the charge extracellularly on the membrane.
Ion channels in cell membranes
Which of the following statements is false concerning myelinated nerves?
When the initial segments of an axon is stimulated to threshold the voltage gated...
In general, polar molecules diffuse more easily through the lipid bilayer part of cell membranes than do nonpolar molecules. This statement is...
B) false. Nonpolar molecules diffuse through more easily because much of the bilayer is hydrophobic
C. false. Polar molecules diffuse through less easily because the bilayer is completely hydrophilic
D. false. Polar molecules diffuse through less easily because the bilayer is completely hydrophobic.
Explain how the neuron's membrane potential is able to go from the undershoot value back to the resting membrane potential value. Be specific
Recovers from the undershoot by using Na+/K+ active transport pump until it reaches the RMP of -70 mv AND...
List 2 ways graded potentials are different from action potentials.
Graded potentials get weaker as it's going away from its source. They also fade with time so they are only good for short distances. They don't regenerate a new graded current like a action potential and just starts a new AP
All the following are true of graded potentials except they...
Which of the following statements about the refractory period of a membrane is true?
You place a cell into a unknown solution and the cell shrinks. What can be concluded about the unknown solution?
In a presynaptic facilitation that neurotransmitter called ________ leads to an increased flow of what ion? _____
Serotonin and Ca+
In presynaptic inhibition the neurotransmitter called _____ leads to an decrease flow of what ion? _____
GABA and Ca+
Describe 2 things you know when K+ is at its electrochemical equilibrium?
When K+ at its chemical and electrical equilibiurm the forces are opposite in direction but equal in force. The chemical force wants to flow out of the cell because there is a higher concentration of K+ in the cell then out; while the electrical force wants to go into the cell since the K+ is positive and the cell is a overall negative.
How do we know that K+ ions compared to Na+ ions are more influential in establishing the value of a neuron cell's resting membrane potential value- what is your evidence for this?
The regular resting equilibrium for a cell is -70 mv. You can tell the K+ has more influence because it's equilibrium is -90 mv only a 20 mv difference while Na+ equilibrium is a +60 mv which is a 130 mv difference not even close to the RMP.
Which of the following best explains the repolarization phase of the action potential?
The process of transporting neurotransmitters from the telodendria to the soma is specifically known as ______ movement and is one of 2 types of _______.
Retrograde and axoplasmic transport
Explain the terms temporal summation and spatial summation.
Spatial summation- 2 or more axon terminals simultaneously releasing a stimulus (like a NT) onto a single neuron.
Temporal summation- 1 axon terminal rapidly and repeatedly releasing a stimulus onto a single neuron.
Which of the following statements about a nerve cell with a resting membrane potential is true?
Explain what the letters MAOI stand for and what this does
MonoAmine Oxidase Inhibitor
It means that it inhibits the enzyme oxidase from breaking down a neurotransmitter so that more NT is in the synaptic cleft making the probability that will attach to a chemical gated channel more likely.
What affect does Black Widow venom have the function of a neuron, what does it cause to happen?
the black widow venom continuously release ACh so that it keeps going preforming exocytosis until it simply can't do it anymore.
A "threshold level od stimulus" applied to an excitable membrane is one that is just enough to...
EPSP involves ______ NT, the ions and flows across cell membrane is ________ and how has the membrane potential changed?
ACh, K+ out, Na+ in and the membrane potential is more positive or excitable.
IPSP involves ___NT and the ions and the flow across the membrane is? and how has the membrane potential changed?
GABA, K+ out Cl- in, the membrane becomes more negative.
Explain why the strength of a stimulus needs to change in order to initiate a 2nd action potential if that part of the membrane is still in the refractory period.
If it's in the absolute refractory period then no amount of stimulus no matter how big will ever create another AP.
If a strong stimulus happens during the relative refractory period then it has to overcome the "undershoot" or the extra negativity of the membrane potential so it needs a even bigger stimulus to bring it up from lets say -80 mv back to the -55 mv to start another AP.
Action potentials travel only in one direction in the body due to
What does the term half life refer too?
How long a substance takes to degrade or metabolize so that only 50% of it is still there
List 2 ways that the effect of NT can be reduced after the NT has been released.
Reuptake- the presynaptic neuron sucks the neurotransmitter back into the cell (endocytosis)
Degradation- enzymes come and break down the NT that always end in -ase
The electrochemical equilibrium of K+ ions in nerve cells is about -90 mV. The membrane potential of typical nerve cells at rest is slightly more positive. therefore
A. increasing the membrane potential of a nerve cell would slow the diffusion of K+ ions out of it.
B. increasing the permeability of a resting neurons membrane to K+ ions will increase the membrane potential (that is, make it more negative, inside with respect to outside)
C. in nerve cells at rest, there is a net diffusion of K+ ions out of the cell.
C and 1 other one??
When a solute X is placed in compartment A of a 2 compartment container and allowed to diffuse into compartment B and reach a chemical equilibrium then
Assume that all neurons are the same. Neurons have a resting membrane potential of ______(give a value in correct units) and would therefore typically have a threshold value of ____ (give units)
-70 mV and -55 mV
The axons which conduct action potentials the slowesr are known as "type ___ " axons
When the membrane potential changes in a nerve cell it can result in the formation of...
Compartments A and B are seperated by a membrane that is permeavle to K+ but not to Cl-. At the start of the expermiment, a solution of KCL is poured intp compartment A and pure H2O s poured into compartment B. when the electrochemical equilibrium reached which answer/s below is/are true.
A. concentration of K+ in A will be lower than it was at hte start of the experiment.
B. diffusion of K+ from A to B will be equal to the diffusion of K+ from B to A
C. There will be a potential difference across the membrane with side A negative relative to side B
D. the electrical and chemical potentials for K+ will be equal in strength and opposite in direction.
All of them are true
What classification of medication discussed in lecture is designed to prevent the reuptake of a specific neurotransmitter and not several different NTs at the same time?
SSRI- selective serotonin reuptake inhibitor, it only inhibits the reuptake of one NT called serotonin.
the period of time that a neuron could respond to another stimulus before the membrane has been returned to its resting membrane potential is known as the...
When the membrane potential changes in a nerve cell it can produce...
Which of the following statements regarding the structure and function of cell membranes is the most accurate (the most complete)?
Name the different types of glucose transporters
Facilitated diffusion/ glucose transporters just physically moves glucose following concentration gradient
Na+/Glu transporter- glucose piggy backs by indirectly using the Na+/K+ pump
At the peak of the action potential in a neuron,
Which of the following statements about the refractory period of a membrane is true?
If you were to place a blood cell into a solution which caused that cell to swell and explode, that would indicate that the solution was...
Draw diagrams to show how an EPSP and an IPSP changes the membrane potential. diagrams must be properly done for full credit.
can't draw but IPSP GABA, K+ out Cl- in hyperpolarization
EPSP ACh K+ out Na+ in and hypopolarization
If yo changed the membrane potential of a neuron which of the following are possible?
A. A graded current
B. an action potential
E. A and B
F. all of the above
I THINK F but I dont know
What affect does serotonin have on the release of a neurotransmitter?
Increases the ca+ that gets into the cell when the voltage gated Ca+ open so that more vesicles can leave and the postsynaptic can get more neurotransmitter and be more excitable