nervous systems part 3 ra # 4.3. what is a synapse? gaps between neurons or between neurons and...
DESCRIPTION
Nerve Impulse is approaching the axon terminal by Saltatory Conduction Cell body Schwann cell Depolarized region (node of Ranvier) Myelin sheath AxonTRANSCRIPT
Nervous SystemsPart 3
RA # 4.3
What is a synapse?
Gaps between neurons or between neurons
and effectors
Nerve Impulse is approaching the axon terminal by
Saltatory Conduction
Cell body
Schwann cell
Depolarized region(node of Ranvier)
Myelinsheath
Axon
Explain the steps of nerve impulse conversion
Postsynaptic cellPresynaptic cell
Synaptic vesiclescontainingneurotransmitter
Presynaptic membrane
Voltage-gatedCa2+ channel
Ca2+Postsynaptic membrane
Postsynaptic membrane
Neuro-transmitter
Ligand-gatedion channel
Na+
K+
Ligand-gatedion channels
Synaptic cleft
Post synaptic membrane
Resting potential
Threshold
Mem
bran
e po
tent
ial
(mV)
Actionpotential
Time–100
–50
+50
0
Potassiumchannel
Extracellular fluid
Plasma membrane
Na+
Resting state
Inactivationgate
Activationgates
Sodiumchannel K+
Cytosol
Na+
Depolarization
K+
Na+
Na+
Rising phase of the action potential
K+
Na+
Na+
Falling phase of the action potential
K+
Na+
Na+
Undershoot
K+
Na+
The ability of the postsynaptic membrane to either turn on (EPSP) or turn off (IPSP) a nerve impulse.
COMPARE EPSP’s TO IPSP’s.
Explain the purpose of summation
Motorunit 1
Motorunit 2
Nerve
Synaptic terminals
Motor neuroncell body
Spinal cord
Motor neuronaxon
Muscle
Tendon
Muscle fibers
To reach threshold more quickly
What is the most common neurotransmitter in the human body?Acetylcholine
What is the “sleep” neurotransmitter?Serotonin
What neurotransmitter relays pain?Substance P
Which gas is AKA “laughing gas?”Nitric oxide
What do GABA’s do?Inhibit transmission
Which neurotransmitters create the “fight or flight” response?Epinephrine and norepinephrine
Which neurotransmitter is the “happy” neurotransmitter?Dopamine
What affect does carbon monoxide have on nerve transmission?Inhibits
What do endorphins do?Block Substance P