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WorksheetsUNIT 2: Neurotransmitters and Synapses
Total questions: 77
Worksheet time: 1hrs 6mins
the purpose of the action potential is to quickly transmit a signal along the axon of a neuron until it reaches the axon terminal
true
false
one neuron sends signals to another neuron
(a)
the (a) includes the axon terminal of the presynaptic cell and the part of the postsynaptic cell that receives the message, as well as any space between
neurons send signals to thousands of other neurons, integrating these signals together
true
false
what are the 2 types of synapses?
cultural
electrical
chemical
rural
2 cells directly touch and electrical signals are directly passed between the cells
(a)
a small gap (synaptic cleft) between the cells and neurotransmitters is released from the presynaptic neuron into the cleft
(a)
gap junctions from pores that allow ions to flow directly between the neurons, so action potentials move directly from 1 neuron to another
(a)
2 cells linked by special structures
(a)
allow signals to be passed in both directions through the gap junctions
true
false
gap junctions are rare in the body, typically only round in the developing nervous system, and regions of the brain that need tight coordination
-like those that control breathing
true
false
only allow signals to travel in 1 direction and there is a short delay in the signal as chemicals are released
(a)
the gap between the pre and post synaptic neurons
(a)
(a) are stored in the vesicles in the axon terminal
when an action potential arrives at the axon terminal, causes vesicles to fuse with the membrane, dumping neurotransmitters in the synaptic cleft
(a)
neurotransmitter crosses the synaptic cleft and then binds to (a) on the postsynaptic cell
synthesizes directly in the axon terminal by enzymes (chemical factories) from nutrients in our diet
(a)
small molecule neurotransmitters are packaged into vesicles by special pumps (transporters)
true
false
(neuropeptides) small proteins made from amino acids using DNA/RNA instructions
(a)
peptide neurotransmitters are synthesized in the cell body of the neuron by ribosomes
true
false
packaged into vesicles in the endoplasmic reticulum > sent to the Golgi apparatus> shipped down the axon to the axon terminal
(a)
when materials travel from the cell body towards the axon terminal
(a)
materials travel from the axon terminal towards the cell body
(a)
when the action potential arrives at the axon terminal, the entry of sodium causes (a) -causes voltage-gated calcium channels to open> calcium enters the axon terminal
special regions of the axon terminal that contain calcium channels
(a)
docked vesicles are held in place by a complex of 3 proteins
(a)
a nearby protein
(a)
(a) enters the axon terminal> attaches to synaptotagmin> change shape> synaptotagmin interacts with SNARE proteins> SNARE proteins change shape> vesicle fuses with the membrane (exocytosis)> releasing neurotransmitter> synaptic cleft> neurotransmitter crosses the synaptic cleft> to the postsynaptic cell.
receptors contain a pocket that the neurotransmitter attaches to
true
false
ion channels that open when a neurotransmitter binds to them
-also called ligand-gated ion channels
(a)
initiate signals within the neuron
-sometimes open other ion channels delay
(a)
a chemical that binds to a protein> changes shape
(a)
when neurotransmitters bind to these receptors they...
(a)
neurotransmitters will only open the receptors that they can attach to
true
false
receptors allow different ions to cross the membrane when they close
true
false
when receptors open and allow ions to cross the membrane, membrane potential in that region of the cell will change slightly
true
false
change begins in the reion where the channels open, ripples out from that location, affecting other nearby regions, getting weaker with distance
(a)
channels that allow ______ and _______ across the membrane will cause a small depolarization-both
sodium
chloride
potassium
calcium
channels that allow chloride or potassium across the membrane will cause a small hyperpolarization -moving further away from threshold
(a)
presynaptic neurons send messages that are excitatory, helping the presynaptic neuron to get closer to the threshold, while other presynaptic neurons are sending messages that are inhibitory moving postsynaptic further from the threshold
true
false
if enough excitatory messages are received, then an action potential is generated
true
false
inputs closer to the ____ _______ are going to be more powerful than those far away
(a)
excitatory synapses are on the (a)
inhibitory synapses are on the ____ ____
(a)
to generate an action potential, the membrane potential at the axon hillock must reach (a)
a single EPSP is strong enough to bring the axon hillock, to threshold
true
false
multiple EPSPs are generated at the same time and they add on top of each other
(a)
the membrane potential at the axon hillock can reach threshold and generate an action potential
true
false
how many types of summation are there?
(a)
multiple EPSP's come from the same synapse in quick succession and add on top of each other (time)
(a)
EPSPs from different synapses all arrive at the same time and add on top of each other
(a)
if an IPSP and EPSP overlap, they might cancel each other out of the overall depolarization might be reduced
true
false
excitatory neurons help keep things under control
true
false
caused by abnormal electrical activity in the brain, leading to seizures
(a)
many (a) all fire action potentials at the same time. overwhelms the normal pathways in the brain. excessive excitation that overwhelms the inhibitory signals
neurotransmitters can be removed in _ ways
(a)
what are the 3 ways neurotransmitters can be removed?
degradation
diffusion and absorption
reuptake
adaptation
some neurotransmitters simply diffuse away and are eventually taken up by astrocytes and destroyed or returned to the presynaptic neuron
(a)
some neurotransmitters are broken down by enzymes in the synapse. sometimes remaining parts are recycled
(a)
some neurotransmitters are pumped back into the presynaptic neurons to be reused and repackaged
(a)
special synapses between a motor neuron and a muscle cell
(a)
1 neurotransmitter is used in every NMJ in your body
(a)
when acetylcholine binds to acetylcholine receptors on the muscle cell, this causes an ______ _________ in the muscle, leading to muscle contraction
(a)
1 signal from a single motor neuron is enough to cause muscle contraction
true
false
acetylcholine is removed by (a) by an enzyme called acetylcholinesterase that breaks down into smaller peices
a single muscle cell receives messages from a single motor neuron which sends messages to multiple cells because its axon branches multiple times
true
false
a single motor neuron and all of the muscle cells that it sends messages to
(a)
motor neurons and interneurons send messages to other neurons through synapses neurotransmitters
true
false
sensory neurons have ion channels, and open in response to the sensory stimulus, not neurotransmitters
true
false
if the sensory stimulus is (a) enough, the sensory neuron reaches threshold and generates an action potential
open when they are all pushed on, stretch, vibrated, etc
(a)
when the stretch-gated ion channels (a) it leads to change in membrane potential that eventually causes the sensory neuron to reach threshold and send an action potential to your brain
sensory neurons in your tongue and nose have (a) - activated channels
activated by the molecule that you are smelling or tasting and use metabotropic receptors
(a)
open in response to temperature changes
(a)
exist in nature
(a)
light-gated channels in specific neurons, they can activate or inhibit these neurons simply by shining certain colors of light on them
(a)
