Other Things Learnt - Reveal / Viva Flashcards
Why does N20 cause expansion of gas filled spaces ?
Diffuses into gas filled cavities much quicker than N2 can diffuse out so cause expansion
Due to higher blood solubility
Can cause pneumothorax , dilated bowel loops, increased middle ear pressure, can leak into ET tube cuff and pressure needs to be monitored
Describe the concept of saturated vapour pressure ..
In a closed container , some molecules within the liquid will evaporate and become a vapour within the container, they will bounce of the walls of the containers exerting a pressure. Some molecules also dissolve back into solution and eventually an equilibrium will be reached where those coming out is equal to those coming in .
The saturated vapour pressure is the pressure exerted at this equilibrium. This varies with temp and the molecule in question
why is phenylephrenine used in maternity vs metaraminol
metaraminol found to cause uterine contractions
what is the parkland formula?
The Parkland formula is a method used to calculate the initial fluid resuscitation needs for patients with burn injuries
= 4 x % BSA burnt x weight in kg
half in first 8 hrs
half in next 16 hrs
how does nitrous oxide cause pain releif?
NMDA receptor anatagonist - invovled in pain transmission
also has actions on opioid receptors for a short time
how does nitrous oxide cause megaloblastic anaemia/ acute degen of spinal cord?
oxidation of colbalt ion in B12
B12 cant work as a co-factor for methionine synthase which makes methionine
methionine is needed for myelination and methylation of DNA in DNA synthesis
hence megaloblastic anaemia and subacute degeneration of the cord.
draw basic structure of a protein
previously asked.
then draw chain of aa
2nd, tertiary and quart structure.
name some essential aa
phenylalanine
tryptophan
alanine
methionine
