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344; exam 2

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zelanaga's version from 2017-09-29 13:30

Section 1

Question Answer
True or false, Endorphins are a type of neuropeptideTrue
True or false, Metabotrophic receptors allow the amplifications of a responseFalse
The most common structure of a synapse receptor is _.axodendritic
____ is not a criteria for a NTAgonists block the effect
The ____ is the place where an action potential beginsaxon hillock
An active force that contributes to resting potential is Na/K pump
At rest, the neuronal membrane has a high concentration of both ___ and ___ ions on the outside of the membrane, while K and negative anions are at high concentration on the inside of the membraneNa and Cl
What is the phase of a neuron that occurs before an AP is initiated?Resting phase
True of False. charged molecules called anions and K ions are found in highest concentration outside the resting neuronal membraneFalse
What would cause an EPSP?influx of Na
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Section 2

Question Answer
What is potential?The difference in electrical charge on the outside versus the inside of the membrane.
What does the spinal reflex do?It coordinates the physical response of pulling back that part of the body from the dangerous object. Involves excitation of those muscles.
Where in this neural communication circuit does the impulse get changed from a chemical impulse to an electric impulse?At the level of pain receptor, there is a chemical excitation of that neuron.
Whose research identified which side the dorsal, ventral this sensory information comes in?Bell and Megendy
What is Bell and Megendy Law? Where the receptor information comes in the dorsal side of the spinal cord and motor information goes out of the ventral side of the spinal cord.
What is Action potential (AP)?It is the change in voltage across the central membrane that carries that electrical impulse. It is where stored energy is released and neuronal impulses are conducted.
What is membrane potential?It is where stored energy can be released rapidly.
What happens when the neuronal membrane is at rest?the inside of the neuron is negative and the outside is positive; Resting potential is about 70mV; membrane is polarized so it carries a charge.
Why does the polarized membrane carry a charge?Because of the charge difference, more positive ions on outside and more negative ions on the inside.
What are the 4 forces that contribute to Resting potential?1. differential membrane permiability 2. concentration forces (diffusion forces or random motion) 3. voltage forces (electrostatic pressure) 4. Na - K pump
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Section 3

Question Answer
Which of the 4 resting potential forces are passive?differential membrane permiability, concentratioin forces, and voltage forces
Which of the 4 resting potential forces are active?Na-K pump, it requires ATP
What is a polarizing force?it is an increasing positive charge on the outside or increasing negative charge on the inside of the membrane.
Are concentration forces polarizing or homogenizing?Homogenizing because they tend to equalize across the membrane.
Are voltage forces polarizing or homogenizing? Homogenizing because they equalize charge across the membrane.
What is water the main ingredient of?intracellular and extracellular fluids. is also a polar solvent.
What is a key feature of water?its uneven charge. it is an unstable fluid and moves all the time.
What are ions?charged particles.
What is a solvent?it is something that provides a matrix for something else to dissolve into it.
What does the phospholipid membrane contain?hydrophilic, hydrophobic, phosphate, and a bilayer
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Section 4

Question Answer
What are the ions that contribute to resting potential?Na, Cl, K, negatively charged proteins (A)
What is diffusion?dissolved ions that distribute evenly; ions flow down concentration gradient; channels permeable to specific ions; concentration gradient across membrane.
What is electric charge the property of?Sub atomic particles and it determines their electromagnetic interactions.
What is electric current?is the movement or flow of electrically charged particles.
What is electric field?is an influence produced by a charge on other charges in the vacinity.
What is electric potential?is the capacity of that electric field to do work or inact change.
What are voltage forces?ions with opposite charge attract and ions with a like charge repel.
What are concentration forces?the movement of ions from areas of high concentration to areas of low concentration.
What are ion pumps?membrane spanning proteins and they use energy from ATP.
Are Na-K pumps polarizing?yes
Homogenizing forces?random motion, electrostatic pressure
Polarizing forces?selective permiability, Na-K pump
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Section 5

Question Answer
In each phospholipic bilayer, what does each membrane have?hydrophilic head and hydrophilic tail. they align together and make fatty lipid soluble substances.
What is outside the membrane?the hydrophilic head, which forms ion channels.
diffusion and electrical forces =no net movement of ions.
What would happen if the membrane's permeability to Na were increased?Since it is highly concentrated on the outside, it would move to the inside of the cell. The diffusion force would lower concentration and the electrical force says opposites repel each other.
What would happen tot the membrane's permeability to K were increased?It would move to the outside since it is highly concentrated on the inside. It doesn't have two forces acting on it like Na, but it has a concentration force.
What is it called when K channels open?IPSP, the membrane becomes hyperpolarized.
Fluctuations toward 0mV are:depolarizing and excitatory
Fluctuations away from 0mV are:hyperpolarizing and inhibitory
EPSP's are:closer to 0, depolarizing, hypopolarizing
IPSP's are:farther from 0, hyperpolarizing, have a likelihood of firing
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Section 6

Question Answer
GRADEDbigger stimulation= higher level of response
DECREMENTALfather they get from point of origination, they weaker they get
PASSIVEdoes not require energy to be propagated, passively travels from the site of origin.
RAPIDinstantaneous travel
Molecular basis for EPSP and IPSPa) influx of Na causes EPSP b) influx of K causes IPSP c) influx of Cl causes IPSP
AP is divided up in 6 phases:1) resting phase 2) rising phase 3) overshoot phase 4) falling phase 5) undershoot phase 6) recovery phase
What must happen for an AP to fire?A threshold voltage must occur
How many mV have to occur after being integrated by PSP's in order to generate AP's?about 65mV
temporal summationintegration over time
spatial summationintegration over place
What is summation?combining of individual signals into one overall signal; at part of the cell body where axon leaves.
What type of summation occurs when one neuron fires rapidly?temporal
What type of summation occurs when multiple neurons fire at the same time?spatial
What type of summation occurs when several neurons fire repeatedly>both temporal and spatial
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Section 7

Question Answer
Properties of generating AP by integrating PSP's?1) artificially (inject current into a neuron using a microelectrode. 2) firing frequently reflects the magnitude of the depolarizing current.
What happens during the rising phase?1) summation --> depolarization, Na channels open as voltage rises. 2) Threshold is reached, many voltage gated Na channels open and Na rushes in.
What happens during the overshoot phase?1) Threshold exceeded, progressively more Na channels open. 2) Na conductance starts to decline when interior of cell is at its most positive state. 3) Voltage gated K channels open, K rapidly flows out.
What happens during the falling phase?1) Membrane is repolarized, then hyperpolarized, more Na channels close
What happens during the undershoot recovery phase?1) Resting potential established.
Does the "all or none" law apply to AP?yes
Rate lawstimulus intensity is signaled by the rate (frequency) or firing
What do the refactory periods do?
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Section 8

Question Answer
chemical communication between neurons is faster than electrical communications within neuronsfalse
What is one major cause for the resting potential of a neuron's membranes?the refractory period of the membrane.
The neuron excretes neurotransmitter through its membrane by a process called ___exocytosis
Presynaptic inhibition is mediated by _________axoaxonic synapses
Action potentials begin by the___opening of voltage activated Na channels
A neuron fires when ___the degree of depolarization on the axon adjacent to the hillock exceeds the threshold of activation
The anterior pituitary is composed of ____ and the posterior pituitary is composed of ___glandular tissue, neural tissue
Saltatory conduction occurs only across gap junctions
True or false, local neurons have short dendrites and axonstrue
Where do secondary messengers cary their messages?areas within the postsynaptic cell.
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Section 9

Question Answer
conduction of action potentials in myelinated axonsgraded
the concentration gradient refers tothe difference in distribution for various ions between the inside and outside of the membrane
the difference in voltage in a resting neuron is called the resting potentialtrue
What happens when a NT is released by a postsynaptic cell?the NT passively spreads across the synaptic cleft.
in the normal course of an AP ____Na remains much more concentrated outside than inside the neuron.
Metabotropic receptors are linked toG-proteins
"Telencephalon" refers to thecerebral hemispheres
unlike studies in animals, MDMA in humans is harmless to serotonin neuronsfalse
_____ refers to the difference in electrical charge between the inside and the outside of a resting neuronresting membrane potential
What is the difference in voltage called that typically exists between the inside and outside of a neuron?resting potential
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Section 10

Question Answer
which effect is consistently associated with a second messenger?metabotropic
additional stimulation beyond the threshold of excitation will result in a greater depolarization of the membrane during an action potentialtrue
what is not governed by the all or nothing law?local neurons
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