Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
27 Cards in this Set
- Front
- Back
|
What type of neuroeffector junctions are found in s.muscle, cardiac muscle and exocrine glands?
|
postganglionic neuroeffector junctions
|
|
|
What is the major CNS excitatory NT?
|
Glutamic acid
|
|
|
What are the major CNS inhibitory NTs?
|
glycine and GABA
|
|
|
Where are non-peptide transmitters (ACh and NE) made and stored?
|
presynaptic terminals
|
|
|
What causes the release of Ca++ in the presynaptic vessicle?
|
depolarization-->voltage gated Ca++ channels open
|
|
|
What does Ca++ do in the presynaptic vessicle?
|
mobilization and fusion of NT vessicles on the inner membrane surface near dense bodies, which leads to the docking and formation of a fusion pore
|
|
|
Do NT release spontaneously in the absence of APs?
|
yes, at active site (dense bodies). They are called spontaneous miniature potentials
|
|
|
What is an ionotropic receptor?
|
ligand gated ion channel
|
|
|
What is a metabatropic receptor
|
G-protein coupled receptor
|
|
|
What type of receptors (ligand gated or G-protein couple) do you find in the PNS and the CNS?
|
PNS: G-protein coupled (metabatropic)… CNS: both Ligand gated (ionotropic) and metabatropic
|
|
|
About how many molecules of ACh are found in on quantum (vessicle)?
|
~10,000
|
|
|
What type of receptors are found on the post-synaptic vessicles?
|
Ligand-gated
|
|
|
Is the binding of NT to ligand-gated ion channels reversible?
|
Yes
|
|
|
What type of receptors do you find at autonomic neuroeffector junctions?
|
G-protein receptors
|
|
|
What types of receptors do you find at CNS synapses?
|
Ligand-gated and G-protein receptors
|
|
|
Are Ligand-gated ion channels selective? Give an example of one? How many ACh channels must bind for activation of the channel?
|
a) no, they allow Na, K and Ca, b) ACh nicotinic receptor allows Na, K and Ca ion, c) two
|
|
|
What type of Potential is produced at ligand-gated receptors that allow a flow of Na, K, and Ca down their electrochemical gradient?
|
excitatory postsynaptic potential (EPSP), but at neuromuscular junction end-plates it's usually called an end-plate potential (EPP)
|
|
|
What type of Potential is produced at ligand-gated receptors that allows the diffusion of Cl ?
|
Inhibitory postsynaptic potential (IPSP)
|
|
|
Detail the G-protein cascade that leads to the opening of an G-protein ion channel.
|
As an example the G-protein second messenger system: binding of NT --> GDP --> GTP (active form) --> activation of adenylyl cyclase --> ATP --> cAMP (second messenger)--> activation of protein kinase (PK) --> phosphorylation of channel P --> ionic flow
|
|
|
What type of receptors are muscarinic receptors? How does it function in cardiac pacemaker cells?
|
G-protein receptor… NO SECOND MESSENGER, instead the directly acts on K+ membrane channels causing them to open and slow the HR
|
|
|
What type of receptors are ß-adrenergic receptors? How does it function in myocardial cells?
|
G-protein coupled… In myocardial cells when the ß-adrenoceptor is bound by the sympathetic transmitter, NE --> causes the influx of Ca++ (through L-type Ca++ channels) --> causing an increase in HR
|
|
|
What occurs as a result of ACh binding to muscarinic, (G-protein second messenger system) cholinoceptor?
|
K+ channel pore opens and allows the efflux of K down its electrochemical gradient.
|
|
|
Where are ACh muscarinic, (G-protein second messenger system) cholinoceptor found?
|
Vagus nerve, parasympathetic, innervation of the heart, which slows the heart.
|
|
|
What is another name for and EPSP at a neuromuscular junction?
|
EPP
|
|
|
Which are longer in duration, ligand-gated or G-protein coupled receptors?
|
G-protein coupled receptors, which can also produce significant amplification
|
|
|
What 5 things determines the time that it takes for a membrane potential to return to its pre-AP membrane potential?
|
1) number of NT release, 2) NT receptors, 3) rate of NT removal, and 4) G-protein (longer, amplified) process, 5) membrane capacitance (passive property)
|
|
|
Give 3 ways NTs are removed and/or inactivated?
|
diffusion from cleft, enzymatic b/d, re-uptake
|
