L1 - L3 Introduction - 9 IRL flashcards

Question 1

List 3 differences between NMJ and CNS synapse

Answer 1

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

Question 2

The m gate is ___cellular, h gate is ____cellular

Answer 2

Mextra, Hintra

Question 3

Drugs that block Na+ (e.g. local anaesthetics) bind extra or intracellularly?

Answer 3

Intracellularly (TM Domain - S6 in domain IV)

Question 4

Toxins bind extra or intracellularly?

Answer 4

Extracellularly

Question 5

Intracellular environment is basic or acidic?

Answer 5

Acidic

Question 6

Mechanism of action of local anaesthetics?

Answer 6

Stabilize axon membrane -> they reversibly decrease the rate of depolarization and repolarization of excitable membranes (like nociceptors) -> no AP

Question 7

Local anesthetics have more pronounced effect in acidic or basic medium?

Answer 7

Basic (uncharged species, more active)

Question 8

Route of admin. for anesthetics? What is the exception?

Answer 8

Topically usually BUT exception to admin systemically is when ventricular tachyarrhythmia occurs

Question 9

IRL Generic NT exocytosis does not occur for?

Answer 9

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.

Question 10

Adrenal glands react to what type of NT?

Answer 10

Nic ACh

Question 11

Sweat glands react to what type of NT?

Answer 11

Musc ACh

Question 12

Which receptor antag (a1/2, b1/2) has no clinical application?

Answer 12

B2

Question 13

Name one area there is symp innerv but not para

Answer 13

Blood vessels

Question 14

Clonidine selectively inhibits symp nerve mediated responses in the heart pre or postjunctionally?

Answer 14

Pre - inhibits NA release -> no change is seen when used in conjunction with NA as there was sufficient NA to initiate a response

Question 15

!Heteroreceptor

Answer 15

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

Question 16

!Autoreceptor

Answer 16

Receptor of their own NTs

Sensitive only to NT/hormones released by the cell in whose wall they are embedd

Question 17

!2 types of NA vesicles - which one is more common and what do they contain?

Answer 17

Both contain NA, ATP, Dop-B-hydroxylase, chromogranins (proteins that balance the positive charge on NA)
Small (more common)
Large - NPY!!!

Question 18

!Pre or/and post-junctional receptors and response time:

• NA
• Clonidine
• ATP
• NPY

Answer 18

• NA: Both, slow (GPCR)
• Clonidine: Pre, a2, slow (GPCR)
• ATP: Post, P2X, fast
• NPY: Both, slow (GPCR)

Question 19

!alpha, Beta-methyl ATP inhibits ___ and has the effect of___

Answer 19

P2X purinergic (ATP) receptors, abolishing vasoconstriction
*It is used in combination with prasozin (a1 antag)

Question 20

Which fibre is more sensitive - Motor, sensory, ANS

Answer 20

Sensory > ANS > Motor

*Smaller fibres more sensitive