L1 - L3 Introduction - 9 IRL flashcards
List 3 differences between NMJ and CNS synapse
NMJ
- 1 neuron: few muscle fibres
- AP in motor nerve -> AP in muscle
- Excit NT ONLY
CNS
- 1 neuron: many neurons
- AP in presynaptic neuron -> small change in membrane potential of many neurons
- Excit or Inhib NT
The m gate is ___cellular, h gate is ____cellular
Mextra, Hintra
Drugs that block Na+ (e.g. local anaesthetics) bind extra or intracellularly?
Intracellularly (TM Domain - S6 in domain IV)
Toxins bind extra or intracellularly?
Extracellularly
Intracellular environment is basic or acidic?
Acidic
Mechanism of action of local anaesthetics?
Stabilize axon membrane -> they reversibly decrease the rate of depolarization and repolarization of excitable membranes (like nociceptors) -> no AP
Local anesthetics have more pronounced effect in acidic or basic medium?
Basic (uncharged species, more active)
Route of admin. for anesthetics? What is the exception?
Topically usually BUT exception to admin systemically is when ventricular tachyarrhythmia occurs
IRL Generic NT exocytosis does not occur for?
NO (It is a gas - releaxes vascular smooth muscle) - it is transported as eNOS and nNOS in nitrergic nerves innervating the cerebral artery and brain neurons
Nitregic nerves synthesize and release nitric oxide from arginine in response to nerve stimulation.
Adrenal glands react to what type of NT?
Nic ACh
Sweat glands react to what type of NT?
Musc ACh
Which receptor antag (a1/2, b1/2) has no clinical application?
B2
Name one area there is symp innerv but not para
Blood vessels
Clonidine selectively inhibits symp nerve mediated responses in the heart pre or postjunctionally?
Pre - inhibits NA release -> no change is seen when used in conjunction with NA as there was sufficient NA to initiate a response
!Heteroreceptor
Receptor of other NTs
A receptor regulating the synthesis and/or release of mediators other than its own ligand e.g. a nerve type talking to another nerve type
!Autoreceptor
Receptor of their own NTs
Sensitive only to NT/hormones released by the cell in whose wall they are embedd
!2 types of NA vesicles - which one is more common and what do they contain?
Both contain NA, ATP, Dop-B-hydroxylase, chromogranins (proteins that balance the positive charge on NA)
Small (more common)
Large - NPY!!!
!Pre or/and post-junctional receptors and response time:
- NA
- Clonidine
- ATP
- NPY
- NA: Both, slow (GPCR)
- Clonidine: Pre, a2, slow (GPCR)
- ATP: Post, P2X, fast
- NPY: Both, slow (GPCR)
!alpha, Beta-methyl ATP inhibits ___ and has the effect of___
P2X purinergic (ATP) receptors, abolishing vasoconstriction *It is used in combination with prasozin (a1 antag)
Which fibre is more sensitive - Motor, sensory, ANS
Sensory > ANS > Motor
*Smaller fibres more sensitive
