2nd yr rev

Question 1

in a lineweaver-Burk plot, which type of enzyme inhibition is occuring when both the lines cross the Y axis?

Answer 1

competitive
–> Vmax = same, Km = varies

(opposite for non-competitive)

Question 2

which cranial nerves have afferent sensory fibres only?

Answer 2

CN I - olfactory

CN II - optic

CN VIII - vestibulocochlear

Question 3

which Ig is actively transported across placenta from mother to baby + responsible for foetal immune protection?

Answer 3

IgG

–> most abundant Ig, only one that can cross placenta

Question 4

which of these processes does NOT occur in phase 1 of drug metabolism: oxidation, conjugation, reduction, hydrolysis

Answer 4

conjugation
–> phase 2 - add endogenous compound, increasing polarity

transferases

Question 5

what happens in phase 1 drug metabolism?

Answer 5

oxidation, reduction, hydrolysis

–> adds a chemically reactive group, cytochrome p450

Question 6

how to calculate the negative predictive value?

Answer 6

true negative / (false neg + true neg)

ratio of those truly negative to those who had neg results

Question 7

how does group A streptococcus stain on blood agar?

Answer 7

complete haemolysis (beta) - golden

Question 8

how does strep pneumoniae stain on blood agar?

Answer 8

alpha haemolysis = partial = greenish

Question 9

how does staph epidermis stain on blood agar?

Answer 9

gamma haemolysis = no haemolysis

Question 10

mutation most assoc with breast cancer?

Answer 10

BRAC1 (also BRAC2)

Question 11

which of the following is NOT included in the 4 Cs antibiotics most likely to cause Cdiff?
co-amoxiclav, clindamycin, ciprofloxacin, clarithromycin, cefuroxime

Answer 11

clarithromycin

co-amoxiclav
clindamycin
ciprofloxin
cefuroxime = cephalosporin

Question 12

type of hypersensitivity is anaphylaxis

Answer 12

type 1 immediate

–> IgE most abundant

Question 13

which cells secrete insulating material in the CNS?

Answer 13

ooligodendrocytes

schwann = PNS

Question 14

length of TB treatment

Answer 14

2 months RIPE

4 months RI

Question 15

side effects of TB meds

Answer 15

rifampicin = orange fluids
isoniazid = neuropathy

pyrazinamide = joint pains
ethambutamol = colour blindness

Question 16

vichows triad

Answer 16

stagnant blood
hypercoaguable state (eg pregnancy)
endothelial damage

Question 17

CURB 65 score of 3 + penicillin allergy, most appropriate antibiotic therapy?

Answer 17

IV levofloxacin

Question 18

HIV positive with pneumonia, most likely causative organisim?

Answer 18

pneumocystitis jivrovecii

non-productive cough due to significantly increased mucous viscosity

Question 19

3.5cm mass in left midzone of lung, non-smoker, found to be malignant, diagnosis?

Answer 19

adenocarcinoma
(midzone = peripheral)

(small cell - central + mestastasis early)

Question 20

A 24 year old female asthmatic becomes increasingly breathless and wheezy and requires her reliever 4 times on most days and on at least 3 nights a week with coughing. She is taking salbutamol only. Serial peak flow measurement shows 30% diurnal variability.​

What regular treatment would you consider starting?​

Answer 20

inhaled corticosteroid alone

-> stepwise, add this then reasses before starting LABA

Question 21

A 53yo woman has a cough. She has a history of central weight gain, easy bruising, abdominal striae and hyperpigmentation.
She undergoes investigation for suspected lung cancer.
What is the most likely histological diagnosis?

Answer 21

small cell

ectopic ACTH causing bilateral adrenal hyperplasia -> cushings

Question 22

ST elevation in V1-V4

Answer 22

anteroseptal = left anterior descending (LAD)

Question 23

ST elevation in II, III, aVF

Answer 23

inferior = right coronary artery

Question 24

ST elevation in V4-6, I, aVL

Answer 24

anterolateral = left anterior descending or left circumflex

Question 25

ST elevation in I, aVL +/- V5-V6

Answer 25

lateral = left circum flex

Question 26

40 year old man presents with increased dyspnoea on exertion. On auscultation a mid-diastolic murmur is heard in the apex region when the patient lies in the left lateral position. What is the most likely diagnosis?

Answer 26

mitral stenosis

Question 27

MRS ASS

Answer 27

mitral regurg = systolic Aortic stenosis = systolic

Question 28

tetralogy of fallot

Answer 28

puulmonary stenosis overriding aorta VSD right ventricular hypertrophy

Question 29

A 52 year old Caucaisan woman has just been diagnosed with hypertension with no past medical history of note. Which of the following is the most appropriate first-line treatment?

Answer 29

lisinopril - ACEi

Question 30

``` Which of the following is not a direct branch of the aorta? Right coronary artery Left common carotid artery Brachiocephalic artery Left coronary artery Right common carotid artery ```

Answer 30

right common carotid brachiocephalic splits into right subclavian + right common carotid

Question 31

first degree heart block

Answer 31

prolonged PR interval (>0.2s/5small square)

Question 32

second degree heart block, mobitz 1 vs mobitz 2

Answer 32

mobitz 1 = progressive prolongation of PR intergal until eventually QRS is dropped mobitz 2 = consistent PR interval duration with intermittently dropped QRS complex

Question 33

heart condition assoc with Ehlers-Danlos

Answer 33

aortic dissection

Question 34

aortic dissection vs ruptured AAA

Answer 34

aortic dissection = tear in aortic intima creating false lumen with ortic media, tearing chest pain, aortic regurg (diastolic murmur), hypertension AAA = hypotensive, pain lower down

Question 35

septal, anterior and lateral ECG leads

Answer 35

``` V1 = septal V2 = septal V3 = anterior V4 = anterior V5 = lateral V6 = lateral ```

Question 36

scoring system for infective endocarditis

Answer 36

duke criteria - diagnosis of infect endocard) | *dukes staging = severity of colorectal cancer

Question 37

DVT risk calculation

Answer 37

Wells score

Question 38

drug to stop oesophageal varice bleeding?

Answer 38

terlipressin - causes vasoconstriction --> secondary prevention = propanolol

Question 39

skip lesions on endoscopy

Answer 39

crohns

Question 40

what do G cells secrete

Answer 40

gastrin

Question 41

what do enterochromaffin like cells secrete

Answer 41

histamine

Question 42

what do chief cells secrete

Answer 42

pepsinogen | pepsin formed by pepsinogen secreted by the chief cells

Question 43

which cells secrete hydrochloric acid?

Answer 43

parietal

Question 44

which cells secrete somatostatin

Answer 44

D cells

Question 45

A 47 year-old lady presents with RUQ pain. She appears is confused and systemically unwell with a high fever and low blood pressure. Physical examination reveals jaundice. She is known to have gallstones. most likely diagnosis?

Answer 45

cholangitis - > charcots triad = RUQpain, jaundice, fever - history of gallstones

Question 46

Mx of cholangitis

Answer 46

IV antibiotics + ERCP to relieve obstruction

Question 47

acute cholecystitis vs cholangitis

Answer 47

cholangitis = RUQ pain, jaundice, fever acute cholecystitis = positive murphys sign, no jaundice or hypotension

Question 48

murphys sign positive

Answer 48

acute cholecystits

Question 49

unresponsive peptic ulcer disease + urea breath test positive, management?

Answer 49

omeprazole + amoxicillin + metronidazole/clarithromycin pen allergy = omeprazole + clarithromycin + metronidazole

Question 50

coeliac findings on biopsy

Answer 50

villous atrophy

Question 51

crypt abscesses on biopsy

Answer 51

UC

Question 52

difference between wilsons + haemochromatosis?

Answer 52

wilsons = copper, kayser-fleischer rings haemochromatosis = iron, ferritin, bronzed diabetic

Question 53

A 27 year old woman presents to her GP with a unilateral hand tremor. She is also concerned because she feels that she has been experiencing mood changes. On examination, greenish-brown discolouration is seen around her eyes. The patient reports that her uncle died of liver cirrhosis at the age of 40 years. What is the most likely diagnosis?

Answer 53

Wilsons | -> copper accumulation, tx = copper binding drugs (penicillamine)

Question 54

COPD vibes in non-smoker

Answer 54

alpha1 anti-trypsin deficiency -> emphysema + cirrhosis due to excessive breadown of elastin

Question 55

gastroenteritis 24hr history after cruise ship holiday

Answer 55

norovirus

Question 56

tumour marker of hepatocellular carcinoma

Answer 56

alpha-fetoprotein

Question 57

CEA tumour marker

Answer 57

colorectal cancer