chapter 2 Flashcards
What was sherringtons discovery about reflexes
He studied how neurons communicate with each other in reflexes in a process known as reflex arc
describe the pathway involved in the reflex arc
sensory neuron gets information from sensory system, becomes exited and propagates to intrinsic neuron that becomes exited and excites motor neuron which travels along and excites a muscle..all happens at spinal cord
what did the reflex arc provide support of and why
the idea of a synapse, because it was slower than action potential accounting for the time for communication between neurons
what is the speed of conduction alone an axon? how slower in reflex arc?
40m/s …15m/s
compare temporal summation and spatial summation
temporal: multiple stimuli shortly after one another and can have a cumulative effect
spatial: synaptic input from several locations can have cumulative effect and trigger a nerve impulse
what does epsp stand for
excitatory postsynaptic potential
EPSP is associated with the opening of
sodium channels
what is the IPSP served to act as
break that surpasses excitation
IPSP is associated with the opening of
potassium channels or the opening of chloride channels
where do the EPSPS AND IPSPS get summated?
axon hillock
neurons have a spontanoues firing rate, what decreasing these action potentials?
IPSPS
explain the frog experiment and what it proved
he stimulated the heart of one frog and then took the water and transferred to it to the water of another frog which also affected the vagus nerve causing heart rate to slow….this proved that he was transferring chemicals not electricity…the chemical involved was acetylcholine
explain diving radicardia and what causes it
the heart beat slows to almost stopping caused by acetylcholine
the heart beat slows to almost stopping caused by acetylcholine while diving this is called
radicardia
in the frog experiment he also discovered the chemical to speedup heart rate? which chemical and what processes are involved
epinephrine (adrenaline) fight or flight, heart rate increase, pupils dilate,..used for allergic reactions
describe the 6 steps of neurotransmission
- neurotransmitter synthesized inside the neuron. they’re built there and they are stored in vessicl
- released to the presynaptic membrane. this happens when an action potential occurs and calcium channels open and they bind to a protein that moves the vesicles and empties them into the synapse
- bind and activate receptor. they have to go a specific they have a preference. diffused across synaptic fab. they may depolarize or hyper polarize
- the neurotransmitter seperates
- its degraded or removed. so may simply diffuse or it may be degraded by enzymes or it may be rep uptake… astrocytes night take them up
- some cells have retrograde transmission.. release a chemical go back to presynaptic cell and say e don’t need this much
describes retrograde transmission
some cells release a chemical that goes back and say woah we don’t need as much neurotransmitter. so it send information back
neuropeptides are ___..examples
chains of amino acids .. endorphins, substance P, neuropeptide Y
monoamines are ____ they include
modified from amino acids…serotonin, dopamine, norepinephrine, epinephirine
what are the 4 amino acids
glutamate, GABA, glycine, aspirate
what is the one modified amino acid
acetylcholine
what are the three catecholamines
dopamine, norepinephrine, epinephrine
what are the purines
ATP, adenosine
what are the 6 classifications of neurotransmitters
amino acids, monoamines, modified amino acids, neuropeptides (chains of amino acids), purines, gases
what are the three substances provided by diet involved in creating neurotransmitters
choline (found milk eggs nuts) to make acetylcholine, phenylanin, tryptophan
describe chemical process of making dopamine..what foods
phenylanine, tryosine dopa, dopamine…proteins, hard cheeses, bananas
people can be prescribed _____ to treat Parkinson’s which increase amount of dopamine transmitters
al dopa
the term for when action potential comes down and causes the release of neurotransmitters
exocytosis
describe MAO
some neurotransmitters have them, they break down excess levels of neurotransmitters so they don’t become toxic
what are MAO inhibiters used for
they inhibit the MAO enzyme leaving more of the neurotranmitter in the cleft…people who are severely depressed, social phobias etc.
describe the steps in an ionotropic receptor..what are the most common two …what are these receptors generally used for
its a binding site for neuron to come and bind to and then a pore opens that regulates ion flow to directly and rapidly change membrane voltage, so sodium potassium and calcium can cross the membrane…glutamate (excitatory) and gaba.
things for survival that you need immediately such as vision and auction
describe the metabotropic receptor…what is is used for
it bends receptor protein that gores through the membrane of the cell. this bending is what allowed portion of protein to react with other moleculae. it indirectly produces changes in nearby ion channels or in the cells metabolic activity…behaviors such as taste, smell, pain
neuropeptides..how do they differ from neurotranmitters …6 ways
synthesized in the cell body opposed to presypnaptic terminal, they are released from dendrites opposed to axon terminal, they are released by repeated depolarization opposed to single action potential, they release the nuropeptite of neighbouring cells instead of no affect, they diffuse to to wide areas instead o just receptors of adjacent postsynaptic cell, and their duration of effects last minutes compared to seconds/milliseconds
compare agonist vs antagonist
agonist enhances function of a synapse, antagonist is a substance that blocks or decreases the function of a synapse
describe how LSD works
resembles serotonin so it can bind to receptors and stimulate at inappropriate times and longer duration…causes subjective high and distortions
describe how nicotine works
stimulates acetylchlone,,,in turn increase dopamine in certain areas that are responsible for reward
Explain endorphins are and how opiates work
endoprhins are neuropeptides important for pain management…opiates such as morphine heroin work by binding to same receptors as endorphins and producing over amount
what is the difference between coke and ritalin
they both block reuptake but ritalin does it in a more gradual way..so there’s more dopamine in the synapse
what are two ways that the post synaptic cell communicates that it has enough neurotransmitters
- autoreceptors that detect the amount of a transmitter releases and inhibit synthesis and release
- post synaptic neurons test respond to stimulation by releasing chemicals that travel back to presynaptic terminal where they inhibit further release. such as anandamide
describe how cannibindoids work
bind to anandamide which signals presynaptic cell to stop sending neurotransmitter. they decrease both excitatory and inhibitory messages from many neurons. also bind to gaba
describe electrical synapses and what they’re important for
they need to move faster, its the direct contact of the membrane of one neuron with the membrane of another, depolarization will occur in both cells and they will act as if they’re one…..importance for specialized behaviro such as rhythmic breathing
hormones are produced by the ______
endocrine glands
hormones are chemicals secreted by a gland that is transported to ______ by the ____, where it then ____
organs by the blood where it alters activity
where does nitric oxide come from
local neurones release it
all neurotransmitters are synthensized by neurons from _____ which the body obtains from ____
amino acids, proteins in the diet
where are most neurotransmitters synthensized
presynaptic terminal
when do neurons release nitric oxide
as soon as they form it
most excitatory ionotropic synapses use _____
glutamate
most inhibitory ionotropic synapses use ____
GABA
during meyabotopic effects what happens to the protein
it releases GTP, increases concentration of a second messenger AMP which communicates to areas within the cell,,,it may open or close ion channels or activate portion of a chromosome
what receptor mediates nausea
serotoninin receptor type 3
how does reuptake occur?
through special membrane proteins called transporters
what enzyme breaks down neurotransmitters
COMT
why do people get depressed after taking a stimulant
COMT breaks down before the presynaptic cell can replace it and the stimulant has inhibiting the transporters responsible for the reuptake
what are three reverse transmitters
nitric oxide, anandamide, 2AG
describe the telephone radio analogy between hormones and neurotransmitters
neurotransmitters send a signal like a telephone, only to the intended receiver…hormones send a signal like a radio, going to anyone tuned to the right station
what are the two types of hormone? what do they activate?
protein, peptide….attatch to membrane receptors and activate a second messenger
the _____ gland is attached to the hypothalamus and has two parts
pituitary…anterior and posterior
