MCQs Flashcards
What is the speed of arterial pulse?
4-8m/s at aorta
16 m/s at small arteries
What is the structure of desflurane?
fluorinated ethyl methyl ether
What is the strength of contraction of smooth muscle compared to skeletal muscle?
Smooth muscle has potentially greater contractile force due to extended period of contraction and the presence of connexin
What is the metabolism of lignocaine
Hepatic
N-dealkylation to acetaldehyde M1, 80% activity of parent, longer T1/2B
What is the treatment of paracetamol toxicity?
NAC or glutathione synthesis enhancer like methionine.
These are sulphydryl-group donors.
How is iron absorbed?
passively in Fe2+ state by divalent metal transporter
How does vitamin C enhance iron absorption?
chelator, or decrease gastric pH to enhance reduction of Fe3+ to Fe2+
What is a Clark electrode?
measure partial pressure of oxygen
silver anode, platinum cathode in KCL solution
Anode silver reacts with KCL to produce electrons.
Electrons travel to cathode and reacts with oxygen to greater hydroxide ions
More O2 = more electrons taken up = greater current flow in circuit
What is the muscle content of soleus muscle?
slow fatigue resistance fibres, type I
strong, sustained contractions
High mitochondria and Mb content -> relies on aerobic metabolism
What is the muscle AP duration and refractory period?
duration 2-4 msec (100x faster than cardiac AP)
absolute RP - 1-3 msc
How is N2O made?
thermal decomposition of ammonium nitrate, occurs between 170 to 240 degrees
What ion is required for Na/K ATPase?
Magnesium is a cofactor
What are the factors affecting blood viscosity?
HCT
temperature -> low temp -> increase viscosity (2% for every degree drop)
flow rate -> low flow rate -> increased viscosity
smaller radius -> higher viscosity
Incidence of EaEa varian for PChE?
1:3200
Which volatile agent does not affect SVR?
Halothane
