Exam 2 Lecture - Synapse Flashcards
What is an axodendritic synapse?
a synapse that is connecting to the dendrites
What is an axosomatic synapse?
synapse that is connecting to the soma
What is an axoaxonic synapse?
a synapse that is connecting to the axon
What are the presynaptic structures of a synapse?
synaptic vesicles with a neurotransmitter and a presynaptic membrane
Where is the synaptic cleft located?
in between the presynaptic structures and postsynaptic structures
What are the postsynaptic structures of a synapse?
postynaptic membrane and a ligand-gated receptor
What are the excitatory neurotransmitters of the CNS?
glutamate and acetylcholine
What is glutamates receptor?
GluR
What is acetylcholines receptor?
AChR
What are the excitatory neurotransmitters of the PNS?
acetylocholine
What are the inhibitory neurotransmitters of the CNS?
Glycine and GABA
Where are synapses located?
Where the terminal branches meet either the cell body, dendrites, or axon
True or False: a neuron gets a signal from only one other neuron
False
How do tetanus and strychnine interfere with motor function?
they prevent the release of glycine and GABA from inhibitory neurons and Renshaw cells
What are the clinical signs of strychnine?
over activity of extensor muscles
How long does the tetanus toxin stay bound?
for over 4 weeks
What are the clinical signs of teanus toxin?
over activity of extensor muscles
How does the excitatory synapse generate membrane depolarization?
- releases excitatory neurotransmitters
- neurotransmitters bind to their receptors
- receptors open ligand-gated ion channels for Na
- Na inflow
- generation of depolarizing excitatory postsynaptic membrane potential (ESPS)
How does the inhibatory synapse generate membrane hyperpolarization?
- releases inhibitory neurotransmitter
- neurotransmitters binds to their receptors
- receptors open ligand-gated ion channels for Cl
- Cl influx
- generates hyperpolarizing inhibitory postsynaptic membrane potential (IPSP)
What is the difference between a graded potential and an action potential?
Action potentials are either all or nothing
Graded potentials vary in size, they aren’t either all or nothing
Where is the axon hillock located in a neuron?
between the cell body and the axon
What roll does the axon hillock play in generating action potential?
generates AP when sum of ESPS and IPSP goes over the threshold membrane potential
What are the two mechanisms that determine membrane potential at the axon hillock?
spatial and temporal summation
What is spatial summation?
the summation of multiple separate signals arriving at different synaptic sites simultaneously
What is temporal summation?
the summation of multiple signals arriving at a single synaptic site
