Pastest Past papers Flashcards
Which pancreatic enzyme should be tested for in a pateint C/O pale greasy stools?
Faecal elastase
Elastase required for fat digestion
Low levels seen in chronic pancreatitis and pancreas exocrine insufficiency
Serum lipase and amylase raised in acute pancreatitis, not chronic
What is the most appropriate landmark for injection site for pudendal nerve block?
Ischial spine
Pudendal nerve passes close to ischial spine as it reenters pelvis through lesser sciatic foramen
How can positive pressure ventilation affect venous return?
PPV increases intrathoracic pressure, which reduces venous return to the R side of heart
This leads to reduction in cardiac output
What fissure does the chorda typmani pass through to exit the middle ear?
What nerve does it then go on to join?
Chorda tympani exits middle ear via petrotympanic fissure
Joins the lingual verve (branch of mandibular branch of trigeminal nerve)
This allows the chorda tympani to carry sensation to ant 2/3 of tongue
Name the structure that lies deepest in popliteal fossa and the structure that lies most superfical (most posterior)?
Deepest/most anterior = popliteal artery
Most superficial/posterior = tibial nerve
The common peroneal (fibular) nerve travels along lateral aspect of popliteal fossa and is not located within central region
Compare what the ascending and descending loops of henele are permeable/impermeable to?
What is the role of the collecting duct?
Descending loop - permeable to water, impermeable to Na and Cl
Ascending Loop - permeable to Na, Cl, K, Impermeable to water
Collecting duct- under control of ADH, allows resorption of water and concentrates urine
Is the metaplasia seen in Barretts oesophagus irreversible or reversible?
Reversible metaplasia
If reflux is managed early on, the columnar epithelium may revert back to the original squamous epithelium
In the stress state, how does cortisol raise BMs?
Gluconeogenesis
Occurs mostly in liver
Cortisol also encourages lipolysis
Which muscle moves thumb away from hand at right angle?
Abductor pollicis brevis
Responsible for thumb abduction
Part of the thenar eminance, innervated by median nerve
Compare the relationship of the right and left vagus nerves to the oesophagus in the oesophageal hiatus?
Right vagus passes posterior to oesophagus in oesophageal hiatus
Left vagus passes anterior to the oesophagus in oesophageal hiatus
Occurs at T10
What is the position of the DJ flexure in a healthy infant?
Left side, transpyloric plane (L1)
Which structure most likely to be injured in emergency splenectomy?
Tail of pancreas
Hilum of spleen is at level of transpyloric plane, L1
Which nerve is assessed in froments sign?
Which muscle is this?
Ulnar nerve tested
Testing adductor pollicis
Patient will bend their thumb in a positive froments sign - this means the adductor pollicis is non functional, and they are relying on flexor pollicis longus, which is innervated by the anterior interosseous nerve (branch of median nerve)
Which baroreceptors have the highest sensitivity to changes in BP?
Carotid sinus baroreceptors
They transmit sensory innervation via the glossopharyngeal nerve to brainstems nucleus tractus solitarius
Aortic arch baroreceptors are less sensitive and responsive - mainly modulate BP via the vagus nerve, so slower than carotid sinus
Which nerve innervates extensor pollicis longus?
How will damage to this nerve present?
Posterior interosseous nerve - a branch of the radial nerve. Innervates extensor muscles
Damage will result in loss of thumb extension
Will be unable to lift the thumb off the table
What is a key feature on XR to identify jejunal dilatation?
Valvulae Conniventes
If them plus multiple air bubbles present on XR, suggestive of jejunal dilatation
Where is lymph from a lesion located laterally on the ant 2/3 of tongue most likely to drain initially?
Will drain to submandibular nodes
Lesions on tip of tongue will drain to submental nodes
Theyll both then drain to deep cervical nodes
What structure is a posterior relation to the adrenal glands?
The right and left crus of diaphragm
The Quadratus lumborum is located in the posterio abdominal wall and is a posterior relation to the lower 2/3 of the left kidney
Where does the radial nerve traverse from the posterior to anterior compartment of the arm?
The lateral intermuscular septum
A fascial plane seperating the anterior and posterior comaprtments of the arm
Which muscle of the thumb allows it to make a 90 degree angle with the palm?
Opponens pollicis muscle
Innervated by median nerve
Which nerve root is affected if patellar reflex is diminished?
L4
Dorsiflexion is L5
Ankle reflex is S1
Defects to which embryonic structure can result in VSDs?
Bulbus cordis
It forms the interventricular septum
Septum primum and secundum defects cause ASDs
Does kidney lie posterior or anterior to spleen?
Kidney lies posterior and slightly inferior to spleen
What is the most appropriote site for a tracheostomy?
Between second and third tracheal rings
Incision made below cricoid cartilage
Which ligament is clamped in pringle’s manoeuvre?
Hepatoduodenal ligament
It contains the portal triad - hepatic artery, portal vein and CBD
Lesion to which CN results in patients adopting a head tilt to the opposite side of the affected eye to alleviate symptoms?
Trochlear nerve
Dysfunction results in vertical diplopia, worse on looking down
Inflammation of what structure can occur secondary to oesophageal perforation?
Mediastinitis
Inflammation of the mediastinum
Presents with high grade fever, chest pain and creps in the neck and chest wall (secondary to perforation)
What is the first line imaging study for women >35y/o with breast symptoms?
Mammogram
If <35y/o, do US
Describe presentation of GORD in infants?
Commonly vomiting after feeds, non bilious
Normal biochemisty and continue to gain weight
Occurs due to immaturity of the LOS
Normally benign and self limiting
What is the most appropriote scan to diagnose Meckel’s Diverticulum?
Technetium-99m pertechnetate scan
Ectopic gastric mucosa in diverticulum causes GI pain and PR bleeding
Compare symptoms seen in intermittent claudication and critical limb ischaemia?
Intermittent claudication - pain on exertion, improves with rest. Diminished peripheral pulses
Critical limb ischemia - pain occurs at rest, is extreme and worst at night (“rest pain”). Weak/absent pulses
Which renal condition presents with oliguria, haematuria and slough in urine?
Which condition can it be a complication in?
Renal papillary necrosis
Slough is necrotic tissue from renal papillae being passed in the urine
Seen in diabetes, secondary to microvascular disease
What is seen in the urine in diabetic nephropathy?
Albuminuria
Initially microalbumuria, progressing to macroalbuminuria
Also causes gradual hypertension
Describe Hodgkins lymphoma on histology?
Large cells with large nuclei and prominent nucleoli
This is the definition of reed steenberg cells - they have an “Owls eye appearance”
Abundant cytoplasm with large bilobed nuclei
Which inflammatory mediatior causes hypotension and flushing when the tourniquet is released?
Histamine
Acts on H1 receptors to cause vasodilation and increased permeability of blood vessels - causes hypotension and flushing
Which arterial supply determines dominance of the coronary circulation?
Dominance of the LCA is determined by the artery that supplies the Posterior descending artery
In L dominant system, the PDA arises from left circumflex artery
In R dominant system, PDA originates from RCA (80% of cases)
The coronary that gives rise to the PDA determines the dominance of the coronary circulation
What is the substrate for the action of renin?
Angiotensinogen
An inactive precursor produced by liver and released into bloodstream
Renin acts on angiotensinogen to produce angiotensin I
Compare the anatomical landmarks used to guide pudendal nerve blocks and Lumbar puncture?
Pudendal nerve block = ischial spine
LP = Highest point of iliac crests (L4)
Compare pre and post ganglionic neurotransmitters in the sympathetic nervous system?
Preganglionic = ACh
Postganglionic = norepinephrine
In parasymp system, it is ACh in pre and post ganglionic
Name the 3 contents of Calots triangle?
Right hepatic artery
Cystic artery
Cystic LNs (Lund’s node)
Which part of the male urethra is particularly prone to stricture formation or trauma (in pelvic injuries)?
Membranous urethra
It is the narrowest part of the urethra, passing through urogenital diaphragm
Can be damaged in pelvic injuries or traumatic catheter removals
Which electrolyte abnormality cayses prolonged QT interval and TWI?
Hypocalcemia
Seen in pancreatitis, with muscle cramps and parasthesia
What is Rigler’s sign suggestive of on XR?
Pneumoperitoneum
Also known as a double wall sign
Seen in perforated peptic ulcer on CXR
Compare the types of inflammation that neutrophils and macrophages are seen in?
Neutrophils - acute inflammation. Phagocytose bacteria and release inflammatory mediators
Macrophages - chronic inflammation. Engulf and diggest pathogens. Contribute to the formation of granulomas
Which nerve is most superficial nerve in posteriomedial knee?
Saphenous nerve
Most susceptible to damage in baker’s cyst removal
Susceptible during posterior approaches to the knee
Common peroneal nerve travels laterally in popliteal fossa and is more susceptible in surgical approaches from lateral aspect
What is the mechanism of transport of potassium?
Primary active transport
Uses energy to drive ions across cell membrane
In Na/K pump, 2 K molecules are driven intracellularly and 3 Na molecules extracellularly for every ATP molecule consumed
Which artery supplies Meckel’s diverticulum?
Ileocolic artery
Supplies terminal ileum, caecum and appendix
Middle colic artery supplies the transverse colon
Which breast cancer is most commonly associated with mircocalcifications?
DCIS
What is the most likely site of lines of Zahn?
Thrombus
Alternating layers of pale platelet rich material and darker red fibrin
In comparison, emboli typically lack this structured layering
Describe findings on biopsy in C.Diff?
Ulcers covered by fibrin and deposits
This is pseudomembranous colitis due to C.Diff infection
Pseudomonas are composed of fibrin, neutrophils and necrotic tissue and reflect severe mucosal inflammation
Which testicular cancer can cause gynecomastia?
Leydig cell tumours
They can produce oestrogen, leading to gynaecomastia
Which nerve gives sensation to lower set of teeth?
Inferior alveolar nerve
Branch of V3
Gives off mental nerve, which supplies chin, lower lip and anterior gum
Which receptors have the most vital role in regulating respiratory drive?
Central chemoreceptors
Located in medulla oblongata and v sensitive to changes in pH of CSF, which reflects CO2 levels in blood - may become desensitised in COPD
Baroreceptors are located in aortic arch and carotid sinus, and are responsible for maintaining BP
Name the first site cervical cancer may spread to?
Internal iliac lymph nodes
External iliac LNs drain membranous urethra, bladder and upper part of vagina in women and prostate in men
Name the collagen type most commonly involved in keloid scarring?
Type 3
Excessive and perisistent deposition of type 3 collagen in keloid scarring
Where is the primary site of action of ADH?
Collecting duct
Responsible for final urine concentration and volume adjustments
ADH acts on aquaporin channels to allow water resorption
Which type of hepatitis can be transmitted through blood transfusions?
Hepatitis B
Incubation period is typically 6 weeks to 6 months, causes deranged transaminases
What embryological defect results in Bochdalek’s hernia in neonates?
Defects of the pleuroperitoneal membrane
What do the 2 medial umbilical ligaments carry during the fetal period?
Deoxygenated blood from fetus to placenta
During fetal development, 2 umbilical arteries emerge from internal iliac arteries and carry deoxyg blood from fetus to the placenta, where it is oxygenated anad returned to fetus
These arteries then regress post natally into the medial umbilical ligaments (fibrous remnants)
During fetal development, what carries oxygenated blood from placenta to fetus?
Postnatally, what does this structure regress to?
Umbilical vein
Regresses to ligamentum teres hepatis
Damage to which muscles in the hand directly lead to claw hand deformity?
Lumbricals
They flex the MCP joints and extend the IP joints
3rd and 4th lumbricals innervated by ulnar nerve - damage to the nerve results in claw hand deformity
(1st and 2nd innervated by median nerve)
Which embryological defect results in hypospadias?
Failure of urethral folds to fuse properly
Also have downward curvature during erection
What electrolyte derangement can excessive amounts of 0.9%NaCl administration cause?
Hyperchloremic (metabolic) acidosis
High chloride content displaces displaces the bicarbonate in blood
What is the best option for bypassing an occluded iliac artery in a co-morbid patient with poor cardiac function?
Axillo-bifemoral bypass
Unlike aortobifemoral bypass, it avoids the need for a laparotomy, which is desirable in high risk patients
Aortoifemoral bypass is considered gold standard in fit patients tho
Describe the calcium biochemical profile seen in osteoporosis?
Normocalcemia
Bone quality is good, but issue is lack of quantity
How should a life threatening tension pneumothorax causing v low sats in an adult be managed immediately?
Where should be targeted in children with this condition?
Adults - Needle thoracocentesis in 5th ICS, anterior to mid axillary line
Children - Needle thoracocentesis in 2nd ICS, mid- clavicular line
Chest tube insertion is definitive treatment but not appropriate in the acute environment initially
Name the 2 medications that should be administered in thyroid storm prior to surgery?
Beta blockers
Thionamides
eg-propylthiouracil - inhibit thyroid hormone synthesis
Compare branchial cysts and thyroglossal cysts?
Thyroglossal cysts - occur in midline and move up with tongue protrusion
Branchial cysts - occur in lateral neck and do not move on tongue protrusion
What is the normal accepted rate of urine output, at ml/kg/hr?
0.5ml/kg/hr
ie - 35ml/hr in a 70kg man
Describe the 68-95-99.7 rule for normal distributions?
68% of data falls within 1SD of the mean
95% of data falls within 2SD of the mean
99.7% of data falls within 3SD of the mean
Which testicular tumour causes significantly elevated AFP levels?
Yolk sac tumour
Typically a hetrogeneous mass in testicle in young boys- most common tumour in young children
What is the most appropriate anaesthetic agent for rapid sequence intubation?
Ketamine
Good in haemodynamically unstable patients as it increases HR and BP due to sympathomimetic effects
Advantageous in RSI as it preserves airway reflexes and respiratory drive
Describe the electrolyte abnormality seen in TURP syndrome?
Hyponatremia
Can lead to confusion, seizures
Tx - fluid restrict and salt
What is the most likely electrolyte abnormality to occur in massive blood transfusion?
Hypocalcemia
Citrate is used to prevent clotting of stored blood but also sequesters calcium
Present with muscle cramps, tetany or arrhythmias
Which XR view is essential to evaluate carpal bone alignment and positioning?
True lateral view
PA view with lateral deviation is good to evaluate scaphoid but not as effective for diagnosing lunate dislocation
What can be used to rapidly correct severe hyponatremia?
What can hyponatremia cause in head trauma?
50ml of 3% hypertonic saline
Hyponatremia in head trauma can exacerbate brain oedema and increase ICP
In hyponatremia with head injury, diuretics are contraindicated - they further reduce Na
Mannitol is used to reduce ICP in brain oedema, but does not address hyponatremia
Which paediatric condition presents with an olive shaped mass in RUQ and non-billious vomiting?
Pyloric stenosis - hypokalemic hypochloremic metabolic alkalosis
Pyloromyotomy is definitive treatment but patient must be stabilised first
What is the mechanism of action of Atrial Natriuretic Peptide, esp in heart failure?
A vasodilatory hormone produced by atria in response to increased atrial pressure and vol
Causes relaxation of vasc smooth muscle cells and vasodilation and promotes diuresis to reduce blood volume and BP
What is best management of highly comminuted patellar fractures?
Circumfrential cerclage wiring
For larger, re-constructible fragments, tension band wire fixation is used
Definative management of orbital compartment syndrome?
Canthotomy
Involves making an incision at the lateral canthus to relieve pressure
Which nerve carries sympathetic fibres to the lacrimal gland?
Greater petrosal nerve
A branch of the facial nerve
Damage to it results in reduced lacrimation
Name the formula used to calculate the number needed to treat?
NNT = 1/absolute risk reduction
Rate of initial fluid resuscitation in children?
20ml/kg
Which part of the stomach does the short gastric artery supply?
Gastric fundus
Just below the diaphragm
Short gastric arteries branch from splenic artery
What artery supplies the lesser curvature of the stomach?
Left and right gastric artery
Right gastric is branch of common hepatic
Left gastric is branch of splenic artery
What arteries supply the greater curvature of the stomach?
Right and left gastroepiplpoic arteries
Left gastroepiploic - branch of splenic artery
Right gastroepiploic - branch of gastroduodenal (branch of common hepatic in coeliac trunk)
Describe the histological finding in arterial walls due to CTD like Marfan’s?
Medial necrosis with cystic wall degeneration
Involves degeneration of the elastic fibres in the aortic wall
Makes them prone to aneurysm formation and rupture
Compare the radiological appearances of Ewings sarcoma and osteosarcoma?
Both affect young children in the diaphysis and metaphysis of long bones
Ewings sarcoma = destructive “onion skin” appearance due to layered new bone formation
Osteosarcoma = mixed sclerotic and lytic lesion with aggressive sunburst pattern of periosteal reaction
