Block 15 Flashcards
Stage 1 Pressure sore
Non-blanching erythema or redness of the skin in the absence of any breach in the continuity of the overlying skin
Stage 2 Pressure sore
Partial thickness loss of skin involving the epidermis and dermis
Stage 3 Pressure sore
Full thickness skin loss with exposed subcutaneous tissue but intact fascia
Stage 4 Pressure sore
Extending into deeper tissues like muscle, tendon, bones or joints
Pathological process underyling development of bladder divertuclae
Hypertrophy of the urinary bladder to counteract bladder outflow obstruction.
With continued obstruction, the intravesical pressure increases causes trabeculation.
When the obstruction is not relieved, the bladder pressure increaes causing herniation of the bladder mucosa through the trabeculation-> sacculation.
Ultimately sacculation leads to the formation of diverticulae
Underlying pathology in fibrocystic breast disease?
Hyperplasia of the breast epithelium with an exagerrated physiological response-> cystic
Associations with Wilm’s tumour
Absence of the iris
Hemi-hypertrophy of the body
Three variants of Type 4 hypersensitivity?
Contact
Tuberculin
Granulomatous
All mediated by T cells
What is the mechanism of immune priviliege of the eye?
Beneficial immune response are promoted whilst damaging ones suppressed, rather than reduced immune responses
Composition of pigment gallstones?
Calcium bilirubinate
Most appropriate IV nutrition regime for someone suitable for PN?
20% dextrose and 10% lipid
In order of frequency, which tumours are most likely to metastasise to the brain?
Lung
Breast
Melanoma
Kidney
Colon
What kcal is provided by 5% dextrose?
200kcal
Lymphatic spread of pancreatic cancer?
To 5 groups of lymph nodes:
Coeliac
Paraduodenal
Lesser curvature
Greater curvature
Hilum of the spleen
What is the most common site of nodal metastases in cervical cancer?
Obturator nodes
What are the three lymphatic trunks facilitating drainage of the cervix?
Lateral trunk-> obturator, external iliac and common iliac nodes (largest trunk)
Anterior trunk-> EIA
Posterior trunk (in uterosacral ligament)-> common iliac and para-aortic lymph nodes
What structures form the front of the perineum?
Pubic arch and arcuate ligament of the pubis
What muscles are found in the superficial perineal pouch?
Transverse perineal muscle
Bulbospongiosus
Ischiocavernosus
Names of the cuneiforms?
Medial, intermediate and lateral
Waldeyer’s ring?
Formed by the arrangement of MALT in the nasopharynx and oropharynx to create a lymphoid ring
Duane’s Syndrome
Congenital condition associated with strabismus
From which structure does the ductus arteriosus develop?
6th aortic arch
Pathophysiology of bicornate uterus?
Forms from failure of fusion of the paired mullerian ducts
Development of the external genitalia in the male fetus is dependent on which hormone?
DHT
How do motor neurones leave the spinal cord?
Via the ventral root (anterior)
Main blood supply of the spinal cord?
Derives from paired posterior spinal arteries and single anterior spinal artery and supplemented by radicular arteries
Which of the following is apparent by the fourth week of embryonal development?
Segmental differentiation of the limbs?
Cerebral hemispheres appear as hollow buds
Cloacal tubercle is evident
Embryo is less curved and the head is relatively large
Nose forms a short flattened projection
Cerebral hemisphers appear as hollow buds.
Differentitation of the limbs occurs in 6th week
Cloacal tubercle is evident in the fifth week
Narrowest part of the male urethra?
At the external urethral orifice
Membranous urethra is second narrowest part
Which of the following is true regarding lung cancer and its staging?
T1 is a tumour no greater than 1cm
Tumour invading visceral but not parietal pleura is T3
A 3cm node has a 60-70% chance of showing malignant infiltration
Majority of lung lesions are primary lung cancers
Small cell tumours are dervied from bonchopulmonary tissues and include adenocarcinoma
A 3cm node has a 60-70% chance of showing malignant infiltration
T1 >2cm
T3 tumours invade parietal pleura
Treatment of Kaposi’s sarcoma
Radiotherapy
Surgical excision is of little benefit as the tumour is often multicentric in origin and recurs rapidly
What can be used to stage thymomas?
Masaoka system
Which antibitoics are associated with achilles tendon rupture?
Quinolones
Coarse linear branching calcification
What type of DCIS?
Comedo type
Treatment of MRSA colonisation with mupirocin
Cochrane systematic review concluded that there is insufficient evidence to support the widespread use of topical or systemic antimicrobial therapy to eradicate nasal or extranasal MRSA
What type of joint is the manubriosternal joint?
Secondary cartilaginous joint
Condylar joint=
Allow movement in two planes
e.g. MCP
Development of the male urethra?
Posterior segment forms from the urogenital sinus
Spongy urethra forms under the influence of DHT causing tubularisation of the urethral fold
The most distal part of the urethra is thought to be derived from the genital tubercle
What is the most effective method for localising parathyroid adenomas?
Bilateral neck exploration
The inferior saggital sinus:
Drains directly into the confluence of sinuses
Is found in the falx cerebelli
Is formed within the free, inferior border of the falx cerebri
Drains into the superior petrosal sinus
Contains valves unlike the other venous dural sinuses
It is formed in the free margin of the falx cerebri, not cerebelli
It drains directly into the straight sinus
It has no valves.
The inferior hypogastric plexus
Bilateral structure located on either lateral pelvic wall
Which of the following is true regarding the phrenic nerve?
Arises from ventral rami of C2-4
Lies in contact with the pericardium of the right atrium
Lies superficial to the pre-vertebral fascia
Passes medially across the border of stylopharyngeus
Pierces the diaphragm at the level of T12
Lies in contact with the pericardium of the right atrium.
It lies deep to the pre-vertebral fascia.
Antianginal mechanism of nitrates mediated predominantly by?
Vasodilatation of the venous system, leading to a fall in left ventricular preload
Which of the following is true regarding SGLT receptors?
There are three primary membrane transporters responsible for glucose reabsorption in the kidney
SLGT1 is the main primary transporter responsible for glucose reabsorption in the kidney
90% of glucose reabsorption occurs in the S1 and S2 segments of the PCT
SGLT1 is a low affinity, high capacity transporter requiring one glucose and 2 Na molecules
SGLT is the primary glucose transporter in the GIT
90% of glucose reabsorption occurs in the S1 and S2 segments of the PCT, this is due to the action of SGLT2
SGLT is the main transporter in the GIT
There are only 2 renal glucose transporters
SGLT1 is a high affinitiy, low capacity transporter requiring one glucose and two Na.
SGLT2 is a low affinity, high capacity transporter requiring one glucose and one Na molecule
The partial pressure of which gas has the greatest impact on the autoregulation of CBF?
PaO2
What is the most common benign tumour of the ovaries in premenopausal women?
Dermoid cyst aka benign cystic teratoma
What is the most effective modality at detecting early soft tissue changes in RA?
US
What is the main site of gastric acid production?
Body of the stomach
What part of the vertebra is responsible for causing spondylosis?
Pars interarticularis
The straight sinus is formed by the union of
The inferior saggital sinus and great cerebral vein
What is the paralytic position in RLN palsy?
Slightly abducted from the midline
Where does the MMA originate?
Branches off the maxillary artery in the infratemporal fossa
Peri-operative beta blockade and moratlity after major non-cardiac surgery in patients with pre-exisiting cardiac disease?
Does not improve mortality
Where is Na reabsorbed in the loop of Henle?
Thick ascending loop
What proportion of sodium reabsorption occurs in the DCT?
10%, against electrochemical gradient
Where does most of the sodium reabsorption occur?
PCT (65%)
In a patient developing septic CSVT, the primary site of infection is most likely to be?
Chin
Occipital region
Skin over parotid gland
Pinna of the ear
Upper lip
Upper lip, anterior fascia drain drains the upper lip and communicates with the ophthalmic veins in the cavernous sinus.
Where does the ICA begin?
C4
Having first degree relative with testicular teratoma increases risk by?
4 times for a father
9 times for a brother
Oblique fissure of the lung corresponds to?
Medial border of the scapula when the arm is fully abducted
Surface markings of the lungs?
6th, 8th, 10th ribs
Surface markings of the pleura?
8th, 10th, 12th
Transpyloric plane passes through which border of L1?
The inferior border and through the neck of the pancreas
Which of the following nerves is embedded in the carotid sheath and thus vulnerable to injury during carotid endarterectomy?
Spinal accessory nerve
Ansa cervicalis
Cervical sympathetic chain
Phrenic nerve
Suprascapular nerve
Ansa cervicalis
Where is naturally occuring heparin found?
Mast cells
Changes to blood pressure during exercise?
Increase in systolic and reduciton in diastolic
What is the value of the normal negative intrathoracic pressure produced during normal breathing?
1-3mmHg
Which of the following organisms is the most likely cause of a cavitating pnuemonia affecting the right middle lobe in a patient with previous cardiac transplant?
Candida
CMV
Nocardia asteroides
PCP
Strep pneumonia
N. asteroides
Infection tends to be subacute in nature and progressive with radiographs showing lobar or multilobar consolidation
What is the best modality used to image chemodectoma pre-operatively to plan for surgical excision?
IV digital subtraction angiography
Traction on which structure during extended right hemicolectomy can damage the spleen?
Splenorenal and splenocolic ligaments
Which of the following is true regarding the clinical physiology of the ear?
High frequency waves are detected in the scala tympani
Low frequency waves are detected at the apex of the organ of Corti
The scala media is filled with perilymph
Scala media contains the organ of Corti
Normal hearing frequency ranges from 20-2000Hz
Scala media contains the organ of corti.
High frequency waves are detected at the base of the organ of corti
Low frequency waves are detected in the scala tmypani
Scala media is filled with K rich endolymp
Normal hearing frequency ranges from 20-20000 Hz
Causes of balanitis
Strep infection is the most common cause, though staph can do also
Candida albicans can cause balanitis.
Allergy to patent V blue dye used in SLN mapping occurs in what proportion of cases?
1%
Most common cause of primary hyperaldosternoism?
Con’s syndrome
?Nerve injury in epidural insertion
What action is most appropriate?
MRI spine to show any gross neural damage
Epidural catheter should not be removed until this is done
What artery supplies the posterior scalp?
Occipital artery
What can be used to relocate a posterior hip dislocation?
Allis technique
Patient supine and given sedation/general anaesthetic
Flex the hip and knee to 90 degrees and apply longitudinal traction in the line of the femur while an assistant provides counter traction by applying pressure to ASIS
The surgeon than adducts and internally rotates the hip, before extending the hip whilst externally rotating the leg
Position of a posteriorly dislocated hip
Shortened, flexed, adducted and internally rotated
Decorticate posutring
Flexion, scores 3
Decerebrate posturing
Extensions, scores 2
Neonates following bowel surgery
Often unable to tolerate oral feeds and may thus require parenteral nutrition
Rate of feeding in neonates
150ml/kg/day
Definite indications for splenectomy
Primary benign or malignant splenic neoplasm
Splenic abscess
Splenic echinococci cyst
Splenic venous thrombosis with left sided portal HTN and gastric varices
Splenic artery aneurysm
Radical operation for malignant lesion of stomach, tail of pancreas or hepatic flexure
Staging of Hodgkins
Splenic injury not amenable to salvage
Why is an impalpable dorsalis pedis pulse not necessarily an indicator of PAD?
The artery is absent in 3-10% of population
What is an effective way to confrim ?compartment syndrome when there is diagnostic uncertainty?
Measure the pressure in each leg and compare values
What is the risk associated with human albumin solution?
Anaphylaxis
What is the mortality associated with an open pelvic fracture?
50%
Patient presents with penile fracture
If Buck’s fascia remains intact, where will the haematoma be visible?
Penile shaft only
Meconium should be passed by what point?
24h
How is oesohpageal cancer staged?
EUS and PET scan
Staging laparoscopy is not indicated if the tumour does not involve the GOJ
What is seen in an avulsion fracture of the tibial spine
Impaired resistance in the anterior translation of the tibia on the femur. i.e. Anterior draw on Lachman’s
The tibial spine is the site of insertion for the ACL
Therefore in the context of a tibial spine fracture, the ACL is likely avulsed
Incidentaloma of the adrenal usually represents what?
Non functioning adrenal adneoma
What is the maximum amount of blood that can be collected for autologous transfusion of pre-collected blood?
4-5 units
EDH caused by damage to which branch of MMA?
Anterior branch
In a seriously injured child what is the bolus used?
20ml/kg of Ringer’s lactate
Pathophysiology of trench foot
Disease of the sympathetic nerves and blood vessels in the feet observed when the feet have been wet for a prolonged period of time.
Skin is initially red and progressively becomes pale, mottled and grey or cyanotic.
How are bladder lacerations repaired?
In layers with absorbable sutures
Thompson technique in lymphoedema
Excision of subcutaneous tissue and tunnelling of a dermal flap through the fascia into a muscular compartment of the leg
Which of the following is a sign of isolated cervical spine injury?
Inability to shrug shoulders
HTN with bradycardia
Grimacing to pain below the clavicle
Diaphragmatic breathing
Unilateral pupillary dilatation
Cord injury above T1 will remove intercostal muscle function, as such the sole muscle involved in ventilation is the diaphragm, leading to diaphragmatic breathing.
An injury of the cord above C3 will lead to total diaphragmatic paralysis if the injury is bilateral.
What is the necessary size of the patient electrode in monopolar diathermy?
70cm^2
Use of monopolar diathermy in pacemaker
Should be used for <2 seconds and away from site of pacemaker
Acid base disturbance in cardiopulmonary arrest
Mixed metabolic and respiratory acidosis
Comminuted intra-articular fracture to the base of the first metacarpal
Rolando’s fracture (Bennett’s is not comminuted)
A complete fracture through the femoral neck with rotation of the femoral head within the acetabulum, demonstrating minimal displacement
Garden III fracture
Brainstem rule of 4s
4 rules
4 structures in the midline beginning with M
4 sturcutres to the side beginning with S
4 cranial nerves in the medulla, 4 in the pons and 4 above the pons
The 4 motor nuclei in the midline are those that divide equally in the 12 (except for 1 and 2) i.e. 3, 4, 6, 12
What are the 4 medial structures?
Motor pathway- corticospinal tract
Medial lemniscus- contralateral dorsal sensation
MLF- ipsilateral INO
Motor nucleus and nerve (3, 4, 6, 12)
What are the 4 lateral structures?
Spinocerebellar pathway
Spinothalamic pathway
Sensory nucelus of the 5th cranial nerve
Sympathetic pathway
4 cranial nerves in the medulla
9-12
4 cranial nerves in the pons
5-8
4 cranial nerves above the pons?
1-4
Medial brainstem syndrome will thus comprise of?
4Ms and relevant motor cranial nerves
Lateral brainstem syndrome will thus comprise of the
4Ss and the relevant cranial nerves
If there are signs of both medial and lateral brainstem syndromes, what should be considered?
Basilar artery problem
