SAQs

Question 1

What is complementary

Answer 1

when drugs are used together, the shortcomings are covered

Question 2

What drugs do CYP2E1 metabolise?

Answer 2

volatile agents - sevo

panadol

Question 3

What is pKa of midazolam

Answer 3

6.5

Question 4

How is midazlolam excreted?

Answer 4

Metabolites - a-OH-midazolam, oxazepam

Metabolites further glucuronised then excreted in urine

Question 5

What structures are lateral to the vocal cords?

Answer 5

quadrangular membrane then aryepiglottic folds

Question 6

What is Volume of distribution

Answer 6

the apparent volume for which a drug is dispersed into evenly to provide the observed plasma concentration

Question 7

How does metformin cause lactic acidosis?

Answer 7

Inhibition of complex 1 electron transport chain.

increase anaerobic metabolism -> lactate production

Question 8

Describe the pharmaceutical disadvantage of xenon

Answer 8

expensive
high density and viscosity may increase airway resistance
inefficient storage in gas phase at room temp

Question 9

What is the MAC of isoflurane and enflurane?

Answer 9

iso 1.2
enf 1.6

iso more potent

Question 10

For optical isomers with absolute atomic number nomenclature, how are the atoms oriented?

Answer 10

lowest number pointing to back. 
Define sinister (anti-clockwise), or rectus (clockwise) in descending atomic number

Question 11

What is an example of geometric isomer?

Answer 11

mivacurium, with 3 isomers

cis-cis, cis-tran, tran-tran

Question 12

Define enantiomer

Answer 12

stereoisomers that mirror image of each other

Question 13

What are the cough receptors sensitive to and where are they located?

Answer 13

chemical or mechanical stimuli

Mainly on the posterior wall of trachea, pharynx and carina. Receptors less abundant in distal airway

Question 14

What are the sites of efferent neural innervation for cough reflex?

Answer 14

NTS -> dorsal vagal nucleus, nucleus ambiguous

Question 15

which vocal muscles cause vocal cord adduction with cough reflex

Answer 15

interarytenoids

lateral cricoarytenoids

Question 16

Which vocal muscle cause vocal cord abduction and release of air with cough reflex?

Answer 16

posterior cricoarytenoids

Question 17

What are the three complement cascades?

Answer 17

classic (C1QRS -> C3 convertase)
alternative
lectin

Question 18

Why does a neonatal rib cage collapse in on expiration?

Answer 18

Cartilagenous rib cage, decrease outward recoil

almost all diaphragm breathing -> exhale -> reduce intrathoracic pressure -> atmospheric pressure pushes inward

Question 19

Describe the chest wall compliance of neonates

Answer 19

lower static compliance mainly due to increased alveolar resistance from lack of surfactant

Chest wall has very high compliance, 3x more than lung. Not sufficiently rigid to sustain high inspiratory pressure
- Neonatal chest wall can collapse in on deep inspiration

Question 20

Why do neonates take very small tidal volumes?

Answer 20

High resistance of alveoli, low static compliance

Cartilagenous chest wall which collapses in on deep inspiration

Question 21

How is neonatal gas exchange capacity different to adults

Answer 21

High physiological shunt up to 25% from patent ductus arteriosus

High Hb concentration up to 190g/L

Foetal Hb has greater affinity, left shift

Question 22

What are the complications of oxygen therapy in neonates

Answer 22

retinopathy

bronchopulmonary dysplasia

Question 23

How is control of ventilation different in neonates?

Answer 23

Immature resp centres - frequent periodic apnoea

PCO2 ventilatory response less steep.
In the presence of hypoxia, PCO2 response is blunted further -> can cause low MV

Question 24

How does Henry’s law relate temperature and solubility

Answer 24

Henry’s Law: solubility proportional to partial pressure

Amount dissolved = solubility coefficient x partial pressure

solubility is inversely proportional to temperature
- Lower the temp, higher the solubility, higher the amount dissolved, and lower the partial pressure

Question 25

How much does CO2 reduce per degree of temperature drop?

Answer 25

2mmHg per degree

Question 26

What is the rationale of alpha stat?

Answer 26

intracellular protein buffer alters the intracellular p neutrality with pH change across range of temperature. Setting the temp at 37 ensures normal enzymic function, as introduction of respiratory alkalosis may cause a change

Question 27

Important structures of mitochondria?

Answer 27

2 membranes - outer with pores - inner without pores 2 compartments - Intermembrane space or outer compartment - Matrix space or inner compartment

Question 28

How is the inner membrane organised (?increase surface area)

Answer 28

cristae | ATP synthase molecules on the inner surface

Question 29

Characteristics of the outer membrane

Answer 29

Permits relatively unobstructed movement of molecules in either direction via voltage-gated anion channels

Question 30

Why is the inter membranous space much more acidic than matrix?

Answer 30

H+ pumped out -> gradient inward to generate ATP

Question 31

What energy sources are imported into mitochondrial matrix?

Answer 31

pyruvate and fatty acids

Question 32

How much energy (in ATP) does 1 unit glucose generate?

Answer 32

36 ATPs Glycolysis - 2 ATP, 2 NADH Pyruvate -> acetylCoa -> 2 NADH (+2CO2) Kreb - 2 ATP, 6NADH, 2 FADH2 (+4CO2) ETC - 10 NADH, 2 FADH2 -> 34 ATPs

Question 33

What are some of the non-metabolic roles of mitochondria?

Answer 33

1. cellular apoptosis, release of cytochrome upon apoptotic trigger 2. Sequestration of calcium to maintain homeostasis 3. Haem synthesis 4. Urea cycle: convert product of ammonia to L-citrulline 5. Immune responses, reactive O2 species

Question 34

What is Novoseven?

Answer 34

activated factor 7a | given in addition to prothrombinex only if persistent haemorrhage despite all other efforts

Question 35

Define tolerance

Answer 35

decreased response to a drug with repeated long term use.

Question 36

Respiratory effects of opioid?

Answer 36

1. Effect on pre-Botzinger complex, direct depression and disrupts resp pattern -> prolonged pauses between breaths 2. Right shift of PaCO2 curve 3. Depression of airway reflex 4. Bronchospasm via histamine release

Question 37

CNS effects of opioid

Answer 37

1. reduced in neurotransmitter release in reticular activating system -> sedation -> delirium 2. Seizures from metabolites of pethidine 3. Miosis -> excitatory action at Edinger-Westphal nucleus 4. N/V -> opioid receptors at vomiting centre and CTZ

Question 38

Theophylline MoA?

Answer 38

inhibitor of adenosine receptor and facilitates release of endogenous catecholamine from adrenal medulla inhibitor phosphodiesterase -> increase cGMP and cAMP

Question 39

What kind of GCPRs are muscarinic receptors?

Answer 39

M1, 3, 5, -> Gq | M2 ,4 -> Gi

Question 40

What is the definition of an exponential function?

Answer 40

any function that takes the form f(x) = a^x where a is the base, greater than zero and not 1 When the base is Euler's number ,the function is said to be a natural exponential function