Basics Of LA

Question 1

Sensations lost in which order after LA ADMINISTRATION?

Answer 1

1 Pain…

Then… Temperature…
Touch…
Proprioception…
Skeletal muscle tone - lost LAST!!

Pn -1st Pain…. Obvly!!!! That’s what we want to be lost first….

Then Temp… It’s also close to PAIN… as it causes pain!!

Next two… Touch n proprioception…. Here only it’s Ulta!

N finally… Muscle!! We’re least concerned with it… So lost LAST!!

Question 2

LA is not effective in the area INFECTION because of increase in?

Answer 2

Cations….

Question 3

What’s depolarization? N how does an LA actually act?

Answer 3

When the nerve is at REST… K+ ions r concentrated inside the nerve… N NA+ n Cl- r on the exterior…

As the nerve is stimulated (DEPOLARIZED)… there is passage of Na+ into the cell.. n Ka+ out of the cell…!

Thus LA does nothing much but decreases the PERMEABILITY of nerve memb to Na+ n in a way blocks the entry of Na+ into the Nerve.. n thus prevents DEPOLARIZATION…!

Question 4

Role of Sodium metasulfite in LA?

Answer 4

Acts as an anti oxidant or reducing agent…

It prevents the oxidation of VASOCONSTRICTOR in LA…

HOW??

It competes with Vasoconstrictor for the available OXYGEN

Question 5

In INDIA… Which preservative is MCly used in LA?

Answer 5

Methyl Paraben (Methyl Hydroxyl Benzoate)…

Question 6

Methyl Paraben function?

Answer 6

Bacteriostatic n fungistatic..

Question 7

Excretion of LA takes place in?

Answer 7

Kidney…

Question 8

Basics of LA?

Answer 8

– LA is ACIDIC salts of weak base

– Sensitivity of LA highest in case of C fibres…