Oxford SBA book Flashcards
Which cells are essential to wound forming
Monocytes/macrophages
PML not required for first stages
Collagen constitution and distriubution
Triple helix
Type I: bone, skin, tendon, uterus, arteries Type II: hyaline cartilage, eye tissues
Type III: skin, arteries, uterus, and bowel wall Type IV: basement membrane
Type V: basement membrane and other tissues
The normal ratio of type I to type III collagen in the skin is approximately 4:1.
Example of physiological metaplasia
squamous metaplasia occurring in the endocervix in response to hormonal surges during puberty
Columnar to squamous at transitional zone
Signs of pancreatitis
Relief sitting forward
Tachy and fever
Cullens and Grey turner
BP and CO after infrarenal cross clamping in AAA repair
Hypertension and increased CO
Unless severe aorta-iliac disease- in which collaterals would form
BP and SVR drop after unclamping
What to give during aortic clamping in AAA repiar and cardiac disease
Vasodilators
Patient with long haul flight, young, now presenting with weakness Ix?
TOE- patent foreamen ovale
What nerve could be damaged from nail in medial calcaneus
Medial plantar
How to calculate osmolality
2 (Na+k) + urea +glucose
What does portal hypertension cause in rectus
Varices not haemorrhoids
Most common place for Ependymomas
Fourth ventricle
Differentiating between haemophilia and VWD
Excessive bleeding in VWD
Bleeding in joints in haemophillia
Urethral injury ix
Retrograde urography
Artery of Adamkiewicz
Greater radicular artery
Usually arises from a left intercos- tal branch of the aorta between T8 and T12, and supplies the anterior spinal artery and distal spinal cord.
Where does the anterior spinal artery arise from
Vertebral arteries
Unite below foreamen magnum to form ASA
Unpaired
What does anterior spinal artery supply
Supplies the pia mater and anterior two-thirds of the spinal cord, including the anterior and lateral columns
Where do anterior and posterior spinal arteries anastomose
Conus medullaris- L1
Posterior vertebral arteries formation and supply
The posterior spinal arteries arise from the vertebral arteries. They pass down the spinal cord individually and supply the posterior one-third of the spinal cord (i.e. including the major sensory tracts).
CSF pathway
Made by choroid plexus in lateral and third
From lateral to third by foremen of Monroe
To fourth by aqueduct of Sylvius
Then to SA by lateral Luschka and middle Magendie
Law of Laplace
Aneurysmal expansion is governed by the law of Laplace
This states that the wall tension is proportional to the pressure multiplied by the radius.
As radius increases angle decreases therefore lateral tension increases
With increasing diameter, there is further increase in wall tension leading to an increased risk of rupture.
T = PR
When are diabetic meds taken before surgery
Night before
When should sliding scale be started for type 1
6am of day of surgery
Which thyroid cancer is FNA useful and unuseful for
Papillary - rueful
Follicular cells found with adenoma and carcinoma
Colloid and macrophages on thyroid FNA
highly suggestive of benign disease.
What are the 2 lobes of parotid separated by
Retromandibular vein
Frey Syndrome
Misdirected roflcopters auriculotemproal to sweat glands after super- ficial parotidectomy leads to Frey’s syndrome.
This typically develops about 6 months after sur- gery and mainly features sweating and vasodilatation of the skin supplied by the auriculotemporal nerve.
Where the majority of airway resistance occurs
Approximately 30% of airway resist- ance is located in the nose, pharynx, and larynx, and the remaining 70% of airway resistance is gen- erated by the trachea and subsequent airway division
When is lung compliance greatest
Lung compliance is greater during the expiration phase compared with the inspiration phase
Relationship between laminar vs turbulent flow with pressure
The relationship between laminar flow and pressure is one of direct proportionality.
However, during conditions of turbulent flow, pressure is indeed proportional to the square of the flow rate.
Risk of complication of direct vs indirect hernia
Indirect higher 2-5%
Direct- 0.5 %
Cardiorespiratory dysfunction within 72 hours of surgery in diabetic with no chest pain
Silent MI
Disorders increasing incidence of cerebral aneurysm
Adult polycystic kidney disease, Ehlers–Danlos type IV, neurofibroma- tosis type 1 and Marfan’s syndrome.
Calot triangle borders, contents and variation
Inferior border of liver- superiorly
Cystic duct inferiorly
Common hepatic duct medially
The triangle contains the cystic artery and a lymph node (Lund’s node or Mascagni’s lymph node).
An aberrant right hepatic artery running medial to
the common hepatic duct and arising from the superior mesenteric artery is seen in approxi- mately 15% of patients.
Differentials for hyponatraemia
Reduced ECF: dehydrated patients with urinary sodium >20 mmol/L suggests renal loss of sodium (e.g. Addison’s, renal failure, diuretics). Sodium <20 mmol/L suggests losses else- where (sweating, gastrointestinal (GI) tract).
Normal ECF: syndrome of inappropriate antidiuretic hormone (ADH) secretion or hypothyroidism.
Increased ECF: excessive water administration, heart failure, renal failure.
Urinary Na in SIADH
> 20 as water reabsorbed but not Na
Leading to concentrated urine
Bile produced per day
5L by liver
gallbladder concentrates this 5 L into 500 mL per day
SE of cholecystectomy
Absence of a gallbladder to concentrate bile, large volumes of it will flow into the duodenum and may cause biliary reflux
Fat intolerance and malabsorption of fat may result in colicky abdominal pain and
diarrhoea after fatty meals in post-cholecystectomy patients.
Stages of cell cycle
The cell cycle is divided into the M (mitosis) phase and interphases G1 (gap 1), S (synthesis) and G2 (gap 2) phases. G0 is a resting phase of variable duration and is permanent for terminally dif- ferentiated cells like neurons.
G1 has a high rate of biosynthetic activity.
At the restriction point (R) the cell decides whether to complete the cycle within G1.
DNA synthesis occurs in the S phase.
Further cell growth and differentiation occurs in G2 followed by cell division (both nuclear and cytoplas- mic) in the M (Mitosis) phase.
G1 phase is under the influence of p53
Muscles cut through in posterolateral approach to hip replacement
Gluteus medius and minimus
Short external rotators of the hip
Where does sympathetic trunk enter the skull
Carotid canal
Forms a plexus on the internal carotid arter
How IAP is measured
laparoscopically or via pressure transducers placed in the femoral vein, stomach, rectum, or bladder, the last being the most popular method
Presentation of prolapsed disc
Pain and neurological deficit in a single nerve root.
Usually Lumbosacral
Pterion formation
Between frontal, parietal, temporal, and sphenoidal bones.
Presentation of appendicitis in pregnancy, risks and when can you lap
Can present with pain in right hypochondrial
Higher chances of perf
Can lap before 26w
Bacterial peritonitis in children sx
Abdominal pain, pyrexia, nausea, vomiting, tachycardia, hypotension, and decreased urine output.
Abdominal examination may reveal board-like rigidity, rebound tenderness, and absent bowel sounds
Pathophysiology of pyloric stenosis
Hypertrophy and hyperplasia of the circular and longitudinal muscular layers of the pylorus, leading to a narrowing of the gastric antrum
Physiological effects of surgery on metabolism
Raised basal metabolic rate, which in the absence of adequate calorific intake, will result in proteolysis
Diabetic state- insulin resistance and high insulin
Glucose remain normal unless in shock or sepsis- hypoglycaemia
Ketones normal
In the proteolytic state, the action of glucocorticoids results in muscle breakdown and a negative nitrogen balance.
Sodium retention
Goodsall rule
If the external opening of a fistula lies behind a line drawn transversely across the anus the track should curve towards an internal opening in the midline posteriorly (i.e. at 6 o’clock).
However, if the external opening lies in front of the transverse anal line, the track is likely to pass radially in a straight line towards the internal open- ing.
Unless its is more than 3cm then it goes to the posterior midline
When to treat carotid stenosis
Symptomatic and stenosis >70%
When is elective cholecystectomy considered
Symptomatic gallstones failing conservative management (dietary manipulation) or by patient choice
Episodes of septic gallbladder complications to prevent recurrence (in patients who are fit for surgery)
Episodes of complications (e.g. pancreatitis) or to prevent recurrence of complications.
How much does atrial contraction lead to ventricular filling
10% at rest
40% during exercise
Bones affected and sign in basal skull fracture
Rof of the orbits, the sphenoid bone, and parts of the temporal bone
Periorbital haematoma
Subconjunctival haemorrhage
rhinorrhoea or otorrhoea- damage to cribriform plate
Battle sign- retromastoid bruising- last to develop
Duodenum in transpyloric plane and what lies behind it
Second part
Hilum of right kidney
Nerves arising form posterior cord
the upper sub- scapular nerve (C5 and C6),
middle subscapular nerve (i.e. the thoracodorsal nerve, supplying latissimus dorsi; C6, C7, C8)
lower subscapular nerve (C5 and C6)
axillary nerve (C5 and C6)
radial nerve (C5, C6, C7, C8, T1
Nerves arising from roots of brachial plexus
Dorsal scapular
Muscles to scalene
Long thoracic
Damage to internal laryngeal nerve risk
This nerve supplies sensa- tion to the laryngeal mucosa above the vocal folds. Damage to this nerve may therefore result in insensitivity of the mucous membrane of the superior part of the larynx to food, resulting in a loss of cough impulse and increased risk of aspiration.
Where is a fish bone likely to get stuck in laryngopharynx
Piriform recess
Boundaries of piriform recess
aryepiglottic folds medially
Thyroidcartilage laterally
Complications of colles fracture
EPL rupture
Median nerve damage
Sudeck’s atrophy: reflex sympathetic dystrophy, which leaves the hand painful, stiff, and hypersensitive
Commonest presentation of hyperparathyroid
Renal stones
Types of transplant rejection and cells involved
Hyperacute- minutrd- pre exisitng- HLA or ABO
Accelerated- 2-4d- cellular infiltrate (macrophages and T-lymphocytes)
Acute- 7–21 days post transplantation- T cells
Chronci- insidious - associated with fibrosis of the internal blood vessels
Use of case control over cohort
Can be used to investigate rarer diseases
Define oliguria
<0.5ml/kg/hour
Oliguria in the postoperative period is defined as a urine output of less than 30 mL/hour for 4 consecutive hours
Histological changes in dysplasia
Increased mitosis
z Abnormal mitosis (tripolar, tetrapolar, sunburst, or bizarre)
z An increase in the nuclear:cytoplasmic ratio
z Pleomorphism (variance of size and shape of tumour cells)
z Hyperchromatism (increased amounts of DNA leading to dark-stained nuclei).
In addition, there may be focal or extensive areas of haemorrhage and necrosis due to the abnormal vascularity associated with malignant changes.
Bone cyst presentation
Benign fluid collection in metaphysic
Can cause pathological fractures
X ray
well-defined radiolucent area with sclerotic edges
Nerves from trunk of brachial plexus
Suprascapular nerve
Nerve to subclavius
Actions of insulin
It increases tissue uptake of glucose, amino acids, and lipids.
It stimulates glycogenesis, protein synthesis, and lipid oxidation.
Insulin also inhibits gluconeogenesis and promotes intracellular uptake of potassium and phosphate.
Features of Horners
Ptosis
Miosis
Enophthalmos
Decreased sweating of the affected side of the face, and loss of the ciliospinal reflex.
The ciliospinal reflex refers to pupillary dilatation caused by a painful stimulus to the head, neck or upper trunk.
Causes of Horners
Pancoast tumour
Carotid body tumours, carotid artery dissections or aneurysms, and syringomyelia.
Pancreatic resection- problems with absorption ?
ADEK
Loss of iron, ca, p absorption due to loss of alkalinization- OP
Formation of urinary system in embryo
pronephric duct, which is a duct that extends from the cervical region to the cloaca
Which forms mesonephric duct (Wollfain)- initially function as filtration and drainage in utero which sprouts ureteric bud
Ureteric bud forms metanephric blastema
Collecting system – derived from the ureteric bud.
Excretory system – derived from the metanephric blastema.
Kidneys formed from metanephros- ascending
And mesonephros descend and become the ejaculatory ducts.
Origin of bladder tissue
the cloaca and mesonephric ducts
Cloaca forms urogenital sinus
The bladder develops mostly from the vesicular part of the urogenital sinus, and the bladder trigone is formed from the mesonephric ducts being drawn into the bladder floor.
The transitional epithelium of the bladder is derived from the endoderm of the urogenital sinus
whereas the epithelium of the ureters and renal pelvis are derived from mesoderm.
Factors controlling ADH release
1) Hypothalamic osmoreceptors that secrete ADH in response to raised plasma osmolarity.
(2) Stretch receptors (baroreceptors) that are situated in the atria of the heart- resulting in inhibition of ADH secretion when streched
(3) Stretch receptors that are situated in the aorta and carotid arteries are stimulated when the circulating volume decreases and the blood pressure falls, thereby stimulating ADH secretion.
(4) Trauma, such
as head injury or burns, or any cause of prolonged hypoxia can also stimulate ADH secretion.
Areas affected ini prostate in BPH and cacner
Transitional- BPH
Posterior- cancer
Effects of NO
Vasodilation and muscle relaxation
Prevents platelet aggregation and adhesion as part of the negative feedback mechanism which ensures clot formation at the site of injury
Sites of narrowing of ureters
Pelviureteric junction
The point at which the iliac vessels cross the ureter
the vesicoureteric junction.
Major bleed with warfarin
withhold warfarin and administer IV vitamin K, together with either fresh frozen plasma (FFP) or prothrombin complex concentrate (PCC
Le Fort classification
- Le Fort I: transverse maxillary fracture with two segments; the floating palate contains the alveolus, palate, and pterygoid bones.
- Le Fort II: pyramidal fracture across nasal bones, the medial orbital wall, and down into the maxilla.
- Le Fort III: craniofacial dysfunction with detachment of the midfacial skeleton from the skull base.
Areas ini brain stimulating vomiting reflex
Chemoreceptor trigger zone senses potentially toxic substances in blood and initiates emesis.
Nausea due to motion sickness, inner ear disease, and disequilibrium produced by alcohol excess is sensed through the vestibular apparatus and mediated largely by acetylcholine and histamine receptors.
The central cortex and the limbic systems modulate complex experiences such as taste, smell, memory, and emotion
MOA of atropine
Anti muscarinic
Borders of omental foremen
z Anterior: the free border of the lesser omentum (i.e. the hepatoduodenal ligament). This has two layers and within these layers are the common bile duct, hepatic artery and hepatic portal vein.
z Posterior: the peritoneum covering the inferior vena cava.
z Superior: the peritoneum covering the caudate lobe of the liver.
z Inferior: the peritoneum covering the first part of the duodenum and the hepatic artery, the
latter passing forward below the foramen before ascending between the two layers of the
lesser omentum.
z Left lateral: gastrosplenic ligament and splenorenal ligament.
PBC findings
AMA
portal inflammatory infiltrate composed of lymphocytes, histiocytes, and macrophages surrounding the bile ducts causing peri-portal fibrosis and moderate biliary stasis.
Treatment of radiation prostatitis
sucralfate, metronidazole, prednisolone enemas or mesalazine enemas.
Absorption occurring in duodenum, jejenum and ileum
The duodenum is responsible mainly for the absorption of carbohydrates, protein, minerals
(e.g. calcium, magnesium, iron, chloride, sodium and zinc)
jejunum, responsible for the absorption of glucose, protein, folic acid, and vitamins C, B1 (thiamine), B2, and B6.
The terminal ileum, however, is the main site of absorption of amino acids, lipids, cholesterol, and the fat-soluble vitamins (e.g. A, D, E and K).
intrinsic factor-dependent receptors- can lead to B12 deficiency
Mx of meconium ileus - uncomplicated
Gastrografin enemas after adequate intravenous fluid administration. If this fails, laparotomy is indicated to evacuate the obstructing meconiu
Tx of Conns
Spiro
Surgery
Steps of angiogenesis
(1) proteolytic degradation of the parent vessel basement membrane, allowing formation of a capil- lary sprout;
(2) migration of endothelial cells towards the angiogenic stimulus;
(3) proliferation
of endothelial cells behind the leading front of migrating cells; and
(4) maturation of endothelial cells with organization into capillary tubes.
Artery most commonly affected by mesenteric ischaemia
Middle colic
Metabolic complications of TPN
z Hypo/hyperglycaemia
z Deranged LFTs
z Hyperchloraemic acidosis
z Hypophosphataemia
z Hypercalcaemia
z Hypo/hyperkalaemia
z Hypo/hypernatraemia
z Deficiency of trace elements such as vitamins, essential fatty acids, folate, zinc, and
magnesium.
Management of achalasia
Balloon dilation
Hellers cardiomyotomy
Which nerves are at risk from different approach to hip surgery
Anterior- lateral femoral cutaneous
Posterior- sciatic
Lateral- superior gluteal
Most common oesophageal fistula
Distal
Presentation of oesophageal fistula and mx
Antenatal with polyhydramnios, or postnatal with frothy oral secretions and feeding difficulty. Pneumonitis and sepsis can occur due to aspiration. Early definitive surgical cor- rection is very successful with survival approaching 100%.
Thrombin time vs bleeding time
Thrombin- common pathway
Bleeding- platelet function
