Card Set Information
synapses, NTs, cicruitry
What is the purpose of the nervous system? (2)
Do we have direct connectiong between control and target organ?
no, we have multiple neurons that synapse AP all along
broad descripton of AP
-communcation in form of ion flow
where does continuous conduciton occur?
where are the voltage gated channels located on unmyelinated cells?
all along the length of membrane
broad description of myelin (2)
-lipid coating on enrve axons
What type of conduction occurs for myelinated nerves?
What are the nodes of ranvier ?
-areas of no myelin
what do nodes of ranvier contain?
voltage gated channels
*are only found here
where are APs generated at in saltatory conduction?
at the nodes of ranvier
*they regeenerate at each of the nodes
Where do graded potentals start?
where do AP start?
where do AP travel through/
what is a synpase?
junction between nerve and effector cell
*permits and preserves communication
what is the synapse called in skeletal muscles?
what is a presynaptic neuron?
submits action potential to the synapse
what is the postsynaptic neuron?
receives action potential from synapse
what are the 4 types of anatomical arrangements?
- axo-dendritic synapse
description of axo-dendritic synapse
what is axo-axonal synapse
description of dendro-dendritic synapse?
description of dendro-somatic synapse
What structure can modify communcation between neurons?
surrounding glial cells, Astrocytes
How do astrocytes modify communication between neurons? (3)
-absorb K ions from neurons
*so there wont be too many out on the extracell space
-recapture and recycle NTs
-connected to each other by gap junctions
*communicate by calcium
what are the 2 types of functional arrangmenets of synapse?
what is electrical synapse?
they are gap junctions (connexons) that are used to communicate between cells
*ion flow from one cell to another
**the pre and post membrane are fused by the gap jucntions
is there physical contact between cells in chemical synapse?
is there ion flow between cells in chemical synapse?
in chemical synapses, what is used to interact with receptors?
in chemical synapses, what doesthe membrane of terminal bouton in pre synaptic cell contain?
-calcum voltage gated channels
in chemical synapses, what happens when AP arrives at the terminal bouton?
the calcium voltage gated channels open, allowing calcium to flow in
in chemical synapses, what does the calcium flowing into the terminal bouton cause?
synaptic vesicles to migrate and fuse with the membrane to release NTs into synaptic cleft
in chemical synapses, when NTs are relased what do they do?
bind with receptors in post-synaptic neuron
in chemical synapses, after the NTs bind with receptors, what happens?
in chemical synapses, after the graded potential is initiated, what event can occur ?
Why do we degrade or remove the NTs from a cell?
to prevent inappropriate graded/action potential initiation
what are the 3 mechanisms for removal of NTs?
-pre-synaptic neuron reuptake
-uptake by surrounding glial cells
-enzymatic degradation and diffusion of components
Where can acetylcholine be found? (4)
-skeletal neuromuscular junction
*involved in memory
what are the 3 NTs that are in the group of catecholamines that derive from biogenic amines
what is dopamine involved in? (2)
-coordination of body movements
*assocaited with love
In what disease is dopamine deficient in?
in what disease is dopamine in excess?
for what functions is norepinephrine involved in? (4)
What fucntions is epinephrine involved in?
****SAME AS NOREPINEPHRINE
which are the 2 NTs that are from the Indolamines deriving from biogenic amines?
what is serotonin involved in? (3)
*deficient in depression
what is histmaine involved in? (3)
-learning and memory
IN general what do biogenic amines do? (2)
-regulate bio clock
How does LSD cause hallucinations?
binds to biogenic amine receptors
what are the 3 amino acids that participate in synapse?
what fucntion does GABA do?
what fucntions does glycine do?
what function does glutamate do?
which 2 peptides are involved in synapse?
what is substance P involved in?
-important mediator of pain transmission in PNS
what are endorphins involved in? (2)
-block pain by inhibiting substance P