PPE Questions Flashcards
Give 2 changes in lipid levels produced by statins
reduced LDL/VLDL/triglycerides
increased HDL
State 2 ADRs of simvastatin
rased transaminases
myalgia/myopathy
diarrhoea
Give 4 secondary benefits of statins.
anti-inflammatory, plaque reduction, improved endothelial function, antithrombotic
Give the preferred 2nd line lipid lowering drug used if statins alone are ineffective
ezetimibe: Ch absorption inhibitor
Give 2 effects of giving pre-medication during anaesthesia
sedation, anxiolysis
Name the one physiochemical property of inhalational agents that best predicts its potency
? lipophhilicity
MAC of 0.5 for 60% N2O.
1MAC = 1.2% for isoflurance.
If give both N20 and isoflurane in combination what % isoflurane would you have to give.
0.6
Name 2 inhibitory ligand gated ion channels involved in MOA of inhalational agents
GABA, glycine
Explain GABA and glycine MOA in terms of their pharmacodynamic effect, resulting ion transfer and action
potential generation.
Positive allosteric modulation: increased potency and efficacy of GABA
and glycine cl- entry into cell hyperpolarizes cell depresses CNS)
Give a respiratory ADR for N2O and one agent given to alleviate this.
Respiratory depression
Describe phase 2 metabolism of paracetamol in liver.
conjugation to sulphate and glucuronide
What crucial changes happen in metabolism of paracetamol in overdose.
saturation of phase
2 metabolism, glutathione depletion, build up of NAPQI
What class of drugs do fluoxetine and paroxetine belong to?
SSRIs
Ki for paroxetine is lower than fluoxetine.
Using this determine which drug is more potent
Explain why
Paroxetine
lower Ki in paroxetine = a lower concentration of the drug required to
achieve 50% occupancy
so has a greater affinity and therefore potency (potency = affinity
+ efficacy))
Patient presents with right sided hemiparesis, slurred speech, visual disturbances.
What is the most likely diagnosis?
Which side of the brain is affected
Which tract is most likely to be affected to cause muscle weakness in the body
Where do most fibres of this tract decussate
Stroke
Left
left lateral corticospinal tract
Medulla
Between which layers of the meninges is a subdural haematoma contained?
What is nature of the vessel affected?
which local circulation does it contribute
to?
meningeal layer of dura matter, arachnoid matter
venous
Dural venous sinus
Patient initially collapse at home. He was later brought to the hospital and regain consciousness. The level GSC score was 15/15. A few hours later, he started to deterioriate and GSC started to drop. What is the clinical term used to describe the short period of full
consciousness?
Lucid interval
Explain why elderly more prone to subdural haematomas
cortical atrophy increases
stretching of the bridging veins so more vunerable to tear when the brain moves inside the
cranium, weaker vessel walls
Suggest how would you treat a patient with subdural haematoma to save his life?
craniotomy + drain the
haematoma)
results of Weber’s and Rhinne’s test:
Right ear Left Ear
Weber’s test Quiet Loud
Rhinne’s test AC>BC BC>AC
State the type of hearing loss found in this patient and in which ear. Explain your reasons.
conductive hearing loss in the left ear.
(No lateralisation on Weber’s test + AC>BC in both
ears on Rhinne’s test are normal findings)
Lateralisation to the left ear suggests conductive in
left or SN in the right. BC>AC in the left confirms conductive loss in the left ear.
20 year old presents with fever, neck stiffness, rash photophobia
A blood test is performed. Name the principle marker of inflammation in the blood
What other test would you need to perform?
Give 4 changes in CSF seen in a patient with bacterial meningitis
What is the most likely pathogen involved
C reactive protein
Lumbar puncture
raised WCC/PMNs,
increased protein, decreased glucose, increased tubidity, increased pressure
N.meningitides in 5-30 year olds
Another bacterial cause of meningitis (S. pneumoniae, H. influenza type B)
Where do the dorsal columns decussate
Medulla
Patient has muscle wasting. What can you infer about the type of neuron involved
LMN
Patient has breast cancer. Xray shows microcalcification.
Give two conditions in which microcalcification is a feature.
Often benign:
Fibroadenoma
Breast cyst
Can be sign of first stages of breast cancer
tests to find out predisposition to breast cancer
BRCA1/2
mutation leading to breast/ovarian cancer syndromes)
Patient attend antenatal assessment and undergo ultrasound assessment.
In this assessment, what measurements used to determine the gestational age of fetus in
a) first trimester
b) second trimester
a) crown-rump length
b) biparietal diameter, abdominal circumference, femur length
Which palpable structures used to measure symphysis-fundal height?
Pubic symphysis
Fundus of uterus
Explain how amniotic fluid is a)produced b)reabsorbed in third trimester.
produced by fetal
metanephric kidney producing urine, reabsorbed by fetal swallowing
clinical term for excessive amniotic fluid.
Pilyhydraminos
Baby born and projectile vomits when fed. duodenal atresia is diagnosed.
2 other fetal causes for excessive amniotic fluid other than duodenal atresia.
Bartter syndrome causing increased urine production, anencephaly impairing the swallowing reflex
and causing reduced reabsorption)
Where along the GI tract atresia can occur and what may have caused the defect
embryologically?
bile duct, oesophagus- caused by recanalisation failure
A lady reported chest pain relieved by rest. A diagnosis of angina was made.
What test to investigation the cause of her chest pain?
What would be the findings from the investigation?
ECG stress test
ST depression
Patient is given nitroglycerin spray. What is the active substance?
How does it relieve symptoms
NO
venodilation reduced preload on the heart, 2.
vasodilation of collateral coronary vessels improved blood/O2 delivery to heart
Patient has aortic stenosis due to myocardial infarction. Which phase in the cardiac cycle is
the murmur heard?
Systolic
Explain the normal mechanism of aortic valve closure.
Which heart sound is heard when the aortic valve closes?
aortic pressure > ventricular pressure
towards the end of systole brief backflow of flood pushes valve leaflets closed)
s2
Explain the reasons for dizziness, angina and SOB in aortic stenosis
dizziness: reduced brain perfusion
angina: ventricular hypertrophy causing increased O2 demand, SOB: backflow of flood into pulmonary circulation affecting gas exchange
Patient presents with moon face and central obesity. Diagnosis of Cushing’s made.
Give 3 other signs seen in this patient and give a metabolic reason for each
buffalo hump in
the neck/area around collar bone as abnormally high cortisol switches action from lipolysis to
lipogenesis, muscle wasting/skin striae due to increased proteolysis in skin/muscle,
hyperglycaemia due to increased glycogenolysis and gluconeogenesis in liver
What detects changes in osmolarity and where are they located?
What detects changes in blood plasma [Na+] and where exactly are they located?
Hypothalmic osmoreceptors
Macula densa: DCT of kidney
State 2 main mechanisms used to control plasma osmolarity
Explain how these 2 mechanisms utilise a negative feedback mechanism to control plasma osmolarity
ADH, thirst
- raised osmolarity ADH secretion by p.pituary production of small amounts
of hyperosmotic urine decreases osmolarity back to normal. - raised osmolarity
initiates thirst mechanism consumption of hypoosmotic fluid decreases osmolarity back
to normal).
What is the plasma volume in 70kg man
What is the total body volume in 70kg man
Approx
2.8L
42L
how cells prevent dehydration and how ICF is affected during
changes to plasma osmolarity
? Movement of osmotically active ions such Na , H
Patient with persistent vomiting.
Name the 3 most important ions lost in vomit.
Name the acid base disturbance vomiting can lead to.
Explain the mechanism leading to this AB disturbance.
H+, Na+, K+, (NOT cl-)
metabolic alkalosis
loss of protons in vomitus body
produces more to replace those lost, in the process also produces HCO3- which goes into
ECF raised HCO3-:pCO2 ratio raised plasma pH)
If plasma sodium increased, what changes in plasma osmolarity?
no change as water follows
by osmosis
Why is the thirst mechanism not stimulated as seen in simple dehydration?
Loss of isoosmotic fluid so no change in osmolarity.
How does the body compensate for metabolic alkalosis (as seen in persistent vomiting)
partially compensates by reducing ventilation rate raising
pCO2 decreasing HCO3-:pCO2 ratio decreasing pH back to normal
Patient with acute cholecystitis.
Explain why pain is felt 1 hour after a meal
cholecystokinin release and contraction of the
inflamed gall bladder to release bile occurs after food leaves stomach and enters duodenum
Patient with liver disease gets ascites.
Define acites
Explain how liver disease leads to ascites.
Explain one other cause of abdominal distention and how it would present
abnormal presence of fluid in peritoneal cavity
cirrhosis fibrosis compresses portal vein PH
increased hydrostatic pressure in capillaries increased tissue fluid leaving capillary)
bowel obstruction
with vomiting and constipation
Patient is diagnosed with bronchial adenocarcinoma
What is the Epithelium of the main bronchus
Is this benign or malignant?
2 histological types of bronchial carcinoma
pseuodostratified ciliated columnar with goblet cells
Malignant
adenocarcinoma, squamous carcinoma, large
cell, small cell
Give two neurones that are damaged if there is bronchial carcinoma around
left hilar region of the lung and give the symptoms that would result.
left recurrent laryngeal
nerve hoarse voice, phrenic nerve dyspnoea
2 narrowest parts of the oesophagus
as it crosses left main bronchus, LOS
FVC : 3.2 litre (predicted is 3 litre), FEV1: 2.5 litre. Comment on these results.
normal as
FEV1:FVC>0.7, FVC as predicted
give two investigation/tests to differentiate between obstructive or restrictive deficit in this
patient
Spirometry
Peak flow
Give two reasons for reduced pO2 in PE
impaired gas exchange in some alveoli
leading to VQ mismatch
Name 2 regional lymph nodes
Name the terminal group that drains these
Give important fibrous structure that encircle the terminal lymph node
submental, submandibular, buccal, pre/post auricular, occipital, ant/post cervical
Jugulo-digastric
Investing layer of deep
cervical fascia
2 neurovascular structures that can be found on posterior triangle of neck
One cranial nerve in posterior triangle that can be affected and its innervations
Give two MAJOR groups of nerves that may also be disrupted in the posterior triangle.
Subclavian artery, spinal accessory nerve
spinal accessory- SCM, trapezius
Cervical and brachial plexus
A 9 year old boy is diagnosed with DMD. His older brother and sister are asymptomatic. Older brother is expecting a baby.
why boys more likely to get the disease than girls
prevelance of the mutant dystrophin gene (~1/1100). use this to calculate the probability of the asymptomatic older brother having a child who has the disease if they are
a) male
b) female
x-linked recessive condition/ dystrophin gene located on x chromosome so males only carry one
copy of the gene so having the mutant gene means they have the disease, women carry two copies the gene so require 2 copies of the mutant gene to have the disease
a) 1/1100
b) 0
(The probability of him having a partner who is a
carrier, XDXd, is 1/1100 and his genetype must be XDY- so a baby boy would have 1/1100
chance of being XdY- and having the disease and a baby girl would have a zero chance of
being XdXd as would have at least 1 normal gene from her father)
Back pain radiates to the back of the leg. Patient is diagnosed with sciatica
Name ligament that runs anteriorly to the vertebra
Give another ligament or any processes of the vertebra
Anterior longitudinal ligament
Posterior longitudinal ligament
Which structure of the intervertebral disc a) that is ruptured b) herniated
What imaging technique is best to investigate this injury?
a) annulus fibrosis
b) nucleus propulsus
MRI
Compression of the L5 nerve. Explain dermatomal distribution of L5.
lateral leg + middle 3
digits of the foot + lateral half of the great toe + medial half of small toe
Give two muscles involved in dorsiflexion of the ankle
tibialis anterior, extensor hallucis
longus, extensor digitorum longus, fibularis tertius)