Although gastric emptying is under both neural and hormonal control, it does not require brainstem co-ordination. Increased motility of the orad stomach (decreased distensibility) or of the distal stomach (increased peristalsis), decreased pyloric tone, decreased duodenal motility or a combination of these, all increase the rate of gastric emptying. The major control mechanism for gastric emptying is through duodenal gastric feedback. The duodenum has receptors for the presence of acid, carbohydrate, fat and protein digestion products, osmolarity different from that of plasma, and distension. Activating these receptors decreases the rate of gastric emptying. Neural mechanisms involve both enteric and vagal pathways and a vagotomy impairs the gastric emptying regulation. CCK (cholecystokinin) slows gastric emptying at physiological levels of the hormone. Gastrin, secretin and glucose-1-phosphate also slow gastric emptying, but require higher doses.

Acute renal artery thrombosis is a devastating complication of renal transplantation that can result in graft loss if not detected early. Surgical and technical errors are the major cause of renal artery thrombosis. Renal artery thrombosis usually presents with sudden onset oliguria or anuria accompanied by pain and tenderness over the graft site. Patients may develop thrombocytopenia due to platelet aggregation at the thrombosis site. The imaging modality of choice for diagnosis of renal artery thrombosis is colour Doppler sonography. Conventional, computed tomography (CT) and magnetic resonance (MR) angiography may also be used to confirm the presence of renal artery thrombosis. Although there are reports of successful resolution of post-transplant acute renal artery thrombosis with endovascular and surgical modalities such as percutaneous thrombus aspiration, intra-arterial injection of fibrinolytic agents and surgical thrombectomy, renal artery thrombosis usually results in ischemic necrosis and graft loss.

The cricothyroid muscle is the only tensor muscle of the larynx aiding with phonation. It attaches to the anterolateral aspect of the cricoid and the inferior cornu and lower lamina of the thyroid cartilage. Its action tilts the thyroid forward to help tense the vocal cords.

A Spigelian hernia (or lateral ventral hernia) is a hernia through the Spigelian fascia, which is the aponeurotic layer between the rectus abdominis muscle medially, and the semilunar line laterally. These are generally interparietal hernias, meaning that they do not lie below the subcutaneous fat but penetrate between the muscles of the abdominal wall; therefore, there is often no notable swelling.

Spigelian hernias are usually small and therefore risk of strangulation is high. Most occur on the right side. (4th–7th decade of life.) Compared to other types of hernias they are rare.

The most likely vascular structure is the inferior vena cava. The inferior vena cava is formed by the joining of the two common iliac arteries, the right and the left iliac artery, at the level of the fifth lumbar vertebra( L5). The inferior vena cava passes along the right side of the vertebral column. It enters the thoracic cavity into the underside of the heart through the caval opening of the diaphragm at the level of the eight thoracic vertebra (T8).

Legg-Calvé-Perthes (LCP) disease is a common cause of hip pain and limp in preadolescent children. Early in its course, this condition, a form of idiopathic osteonecrosis (or osteochondrosis), may be difficult to diagnose both clinically and radiographically. MRI is a useful tool for the evaluation of LCP disease that may assist with prompt diagnosis, staging, and evaluation of associated complications. In addition, a variety of MRI findings may provide valuable prognostic information. The MRI findings of LCP disease are quite variable depending on the different stages of the disease (avascular, revascularization, and healing phases).

THE correct answer is A. The posterior cord derives its fibres from the spinal nerves C5,C6,C7,C8,T1. This cord is formed from the fusion of the posterior divisions of the upper, lower, and middle trunks.

A thyroglossal duct cyst (TGDC) is the most common mass found in the midline of the neck. The mass is usually located at or below the level of the hyoid bone, although a TGDC can be located anywhere from the foramen cecum to the level of the thyroid gland.
Most patients with a TGDC present with asymptomatic masses in the midline of the neck.
Recurrent inflammation associated with infection of a TGDC is not uncommon. When an infection is present, the cyst often enlarges and an abscess may form. Spontaneous rupture with secondary sinus tract formation can also occur.

The surgical treatment of choice for thyroglossal cysts is the Sistrunk operation, in which an en block resection of the sinus tract and above (including the midportion of the hyoid bone) is performed. Recurrence is approximately 3-5% and is increased by incomplete excision and a history of recurrent infections.

An increase in the frequency of sound waves results in a change in the position of maximal displacement of the basilar membrane in the cochlea. Low pitch sound produces maximal displacement towards the cochlear apex and greatest activation of hair cells there. With an increasing pitch, the site of greatest displacement moves towards the cochlear base. However, increased amplitude of displacement, increase in the number of activated hair cells, increased frequency of discharge of units in the auditory nerve and increase in the range of frequencies to which such units respond, are all seen in increases in the intensity or a sound stimulus.

The fundus of the bladder is related anatomically to the anterior surface of the vagina and the urethra as well. If there was a malignant growth in the anterior surface of the vagina, then most likely the fundus of the bladder would be involved as well aspotentially the urethra.

A cerebral abscess can result from direct extension of cranial infections, penetrating head trauma, haematogenous spread, or for unknown causes. An abscess forms when an area of cerebral inflammation becomes necrotic and encapsulated by glial cells and fibroblasts. Oedema around the abscess can increase the intracranial pressure. Symptoms result from increased intracranial pressure and mass effects. In a CT scan, an abscess appears as an oedematous mass with ring enhancement.

High-voltage electrical burns are associated with rhabdomyolysis. Acute tubular necrosis may also occur.

Electrical burns occur following exposure to electrical current. Full-thickness burns are third-degree burns. With these types of burns, the epidermal and dermal layers of skin are destroyed, and the damage may even penetrate the layer of fat beneath the skin.

Following the burn, there is a local response with progressive tissue loss and release of inflammatory cytokines. Systemically, there are cardiovascular effects resulting from fluid loss and sequestration of fluid into the third space. There is a marked catabolic response as well. Immunosuppression is common with large burns, and bacterial translocation from the gut lumen is a recognised event. Sepsis is a common cause of death following major burns.

After the initial management and depth assessment of the burn, the patient is transferred to burn centre if:
1. Needs burn shock resuscitation
2. Face/hands/genitals affected
3. Deep partial-thickness or full-thickness burns
4. Significant electrical/chemical burns

Management options include:
1. The initial aim is to stop the burning process and resuscitate the patient. Adults with burns greater than 15% of total body surface area require burn fluid resuscitation. Fluids administration is calculated using the Parkland formula. Half of the fluid is administered in the first eight hours. A urinary catheter should be inserted and analgesics should be started.

2. Conservative management is appropriate for superficial burns and mixed superficial burns that will heal in two weeks. More complex burns may require excision and skin grafting. Excision and primary closure is not generally practised as there is a high risk of infection.

3. Circumferential full-thickness burns affecting a limb or severe torso burns impeding respiration may require escharotomy to divide the burnt tissue.

4. There is no evidence to support the use of antimicrobial prophylaxis or topical antibiotics in burn patients.

Hypomagnesaemia is a condition characterised by a low level of magnesium in the blood. The normal range for serum magnesium level is 0.75-1.05 mmol/l. In hypomagnesaemia serum levels of magnesium are less than 0.75 mmol/l. The cardiovascular and nervous systems are the most commonly affected. Neuromuscular manifestations include symptoms like tremor, tetany, weakness, apathy, delirium, a positive Chvostek and Trousseau sign, nystagmus and seizures. Cardiovascular manifestations include electrocardiographic abnormalities and arrhythmias e.g. ventricular fibrillation.

Purkinje fibres control the heart rate along with the sinoatrial node (SA node) and the atrioventricular node (AV node). The QRS complex is associated with the impulse passing through the Purkinje fibres. These fibres conduct action potential about six times faster than the velocity in normal cardiac muscle.

The optic foramen is the opening to the optic canal. The canal is located in the sphenoid bone; it is bounded medially by the body of the sphenoid and laterally by the lesser wing of the sphenoid. The superior surface of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove). The groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery into the orbital cavity. Compared to the optic nerve, the ophthalmic artery is located inferolaterally within the canal.

A scaphoid fracture is a break of the scaphoid bone in the wrist. Symptoms generally include pain at the base of the thumb which is worse with use of the hand. The anatomic snuffbox is generally tender and swelling may occur. Complications may include non-union of the fracture, avascular necrosis, and arthritis.

Scaphoid fractures are most commonly caused by a fall on an outstretched hand. Diagnosis is generally based on examination and medical imaging. Some fractures may not be visible on plain X-rays. In such cases a person may be casted with repeat X-rays in two weeks or an MRI or bone scan may be done.
Scaphoid fractures are often diagnosed by PA and lateral X-rays. However, not all fractures are apparent initially. Therefore, people with tenderness over the scaphoid (those who exhibit pain to pressure in the anatomic snuff box) are often splinted in a thumb spica for 7–10 days at which point a second set of X-rays is taken. If there was a hairline fracture, healing may now be apparent. Even then a fracture may not be apparent. A CT Scan can then be used to evaluate the scaphoid with greater resolution. The use of MRI, if available, is preferred over CT and can give one an immediate diagnosis. Bone scintigraphy is also an effective method for diagnosing a fracture which does not appear on x-ray.

Nocardia is a Gram-positive aerobic actinomycete. Several species have been identified but the most common human pathogen is Nocardia asteroides. The predominant clinical finding in the majority of patients affected by nocardiosis is pulmonary disease. Predisposing factors for pulmonary nocardiosis include leukaemia, human immunodeficiency virus (HIV) infection, organ transplantation, diabetes and receiving prolonged corticosteroids.

Absence of comorbidities and a small procedure with no likelihood of systemic compromise will equate to an ASA score of 1.

The ASA physical status classification system is a system for assessing the fitness of patients before surgery. It has six grades, as described below:

ASA 1: No physiological, biochemical, or psychiatric disturbance. The surgical pathology is localised and has not invoked systemic disturbance.

ASA 2: Mild or moderate systemic disruption caused either by the surgical disease process or through an underlying pre-existing disease.

ASA 3: Severe systemic disruption, not life-threatening, caused either by the surgical pathology or a pre-existing disease.

ASA 4: Patient has severe systemic disease that is a constant threat to life.

ASA 5: Patient is moribund and will not survive without surgery.

ASA 6: A brain-dead patient whose organs are being removed with the intention of transplanting them into another patient.

Medulloblastoma is the most common malignant brain tumour in children, accounting for 10-20% of primary CNS neoplasms. Most of the tumours originate in the cerebellar vermis.

The right bronchus is supplied by one right bronchial artery that may branch from one of the left bronchial arteries or from the right 3rd posterior intercostal artery (this is the first intercostal artery that arises from the aorta). Damage to this artery might stop blood supply to the main bronchus. Intercostal arteries that go to the first and the second interspaces originate from the highest intercostal artery such that blood supply to either of these spaces would not be interfered with.
The left bronchus receives blood from 2 left bronchial arteries which are direct branches from the descending aorta.
Fibrous pericardium is the sac that contains the heart. Its blood supply is not a major concern.
Visceral pericardium receives its blood supply from the coronary vessels.

Non-neoplastic proliferation of leucocytes causes an increase in leukocyte alkaline phosphatase (LAP). This is referred to as ‘leukemoid reaction’ because of the similarity to leukaemia with an increased white cell count (>50 × 109/l) with immature forms. Causes of leukemoid reaction includes haemorrhage, drugs (glucocorticoids, all-trans retinoic acid etc), infections such as tuberculosis and pertussis, and as a paraneoplastic phenomenon. Leukemoid reaction can also be seen in infancy as a feature of trisomy 21. This is usually a benign condition, but can be a response to a disease state. Differential diagnosis include chronic myelogenous leukaemia (CML).

Renal vein thrombosis (RVT) is the formation of a clot in the vein that drains blood from the kidneys, ultimately leading to a reduction in the drainage of one or both kidneys and the possible migration of the clot to other parts of the body.

Venous thrombosis is a rare occurrence, occurring in 0.5% of kidney transplants. With aggressive treatment,
i.e. thrombectomy, the chances of success are very poor, but treatment is successful in rare cases. More often, patients are treated with transplantectomy.

The left side is preferred for live donor transplants due to longer renal vein while right side has been associated with renal vein thrombosis and shorter vessels.

With the iliac artery anatomically located lateral to iliac vein, one would need a longer vein in the graft to enable the graft placement in the iliac fossa, its final location. Most renal transplant surgeons would intuitively prefer to implant a graft harvested from the left side. The right kidney has a simpler anatomy for retrieval, with no adrenal or lumbar veins to tackle. However, a long artery and short vein make this kidney’s anatomy skewed for grafting. Studies on cadavers have shown significantly shorter right renal vein length (average 13.7%) on the right side. With its weak posterior wall, there is an added risk of tear of the right renal vein if there is tension during anastomosis. Overzealous manoeuvres and stretching of a short vein during retrieval, or handling during allografting may also risk intimal damage, a possible aetiology for some early reports of right grafts lost to renal vein thrombosis following laparoscopic harvest.

Recommendations:
• On the right, lengthen the renal vein with the infra renal vena cava in order to avoid an anastomosis
under tension.
• Carry out a large venous anastomosis; at declamping, if the renal vein is tight, re-do the venous anastomosis.

Pyloric stenosis is a narrowing of the opening from the stomach to the first part of the small intestine (the pylorus). Symptoms include projectile vomiting without the presence of bile. This most often occurs after the baby is fed. The typical age that symptoms become obvious is two to twelve weeks old.

The cause of pyloric stenosis is unclear. Risk factors in babies include birth by caesarean section, preterm birth, bottle feeding, and being first born. The diagnosis may be made by feeling an olive-shaped mass in the baby’s abdomen. This is often confirmed with ultrasound. It is four times more likely to occur in males, and is also more common in the first born. Rarely, infantile pyloric stenosis can occur as an autosomal dominant condition.

It is uncertain whether it is a congenital anatomic narrowing or a functional hypertrophy of the pyloric sphincter muscle.
Babies with this condition usually present any time in the first weeks to months of life with progressively worsening vomiting. The vomiting is often described as non-bile stained (non bilious) and projectile vomiting, because it is more forceful than the usual spitting up (gastroesophageal reflux) seen at this age. Some infants present with poor feeding and weight loss but others demonstrate normal weight gain. Dehydration may occur which causes a baby to cry without having tears and to produce less wet or dirty diapers due to not urinating for hours or for a few days. Symptoms usually begin between 3 to 12 weeks of age. Findings include epigastric fullness with visible peristalsis in the upper abdomen from the person’s left to right. Constant hunger, belching, and colic are other possible signs that the baby is unable to eat properly.

Head and neck cancer is a group of cancers that starts within the mouth, nose, throat, larynx, sinuses, or salivary glands. The TNM staging system used for head and neck cancers is a clinical staging system that allows physicians to compare results across patients, assess prognosis, and design appropriate treatment regimens. The staging is as follows; Primary tumour (T): Tis: pre-invasive cancer (carcinoma in situ), T0: no evidence of primary tumour, T1: tumour 2 cm or less in its greatest dimension, T2: tumour more than 2 cm but not more than 4 cm, T3: tumour larger than 4 cm, T4: tumour with extension to bone, muscle, skin, antrum, neck, etc and TX: minimum requirements to assess primary tumour cannot be met. Regional lymph node involvement (N): N0: no evidence of regional lymph node involvement, N1: evidence of involvement of movable homolateral regional lymph nodes, N2: evidence of involvement of movable contralateral or bilateral regional lymph nodes, N3: evidence of involvement of fixed regional lymph nodes and NX: Minimum requirements to assess the regional nodes cannot be met. Distant metastases (M): M0: no evidence of distant metastases, M1: evidence of distant metastases and MX: minimum requirements to assess the presence of distant metastases cannot be met. Staging: Stage I: T1 N0 M0, Stage II: T2 N0 M0, Stage III: T2NOMO and T3N1MO, Stage IV: T4N1M0, any TN2M0, any TN3M0, any T and any NM1. The depth of infiltration is predictive of the prognosis. With increasing depth of invasion of the primary tumour, the risk of nodal metastasis increases and survival decreases. The patient in this scenario therefore has a T2 tumour.

Extradural haematoma (EDH) is defined as an acute bleed between the dura mater and the inner surface of the skull. This then causes increased intracranial pressure, which puts vital brain structures at risk. The question asks for the least likely cause, and extradural hematoma would be acute in onset.

A renogram, which may also be known as a MAG3 scan, allows a nuclear medicine physician or a radiologist to visualize the kidneys and learn more about how they are functioning.
After injection into the venous system, the compound is excreted by the kidneys and its progress through the renal system can be tracked with a gamma camera. A series of images are taken at regular intervals.

If the kidney is not getting blood for example, it will not be viewed at all, even if it looks structurally normal in medical ultrasonography or magnetic resonance imaging. If the kidney is getting blood, but there is an obstruction inferior to the kidney in the bladder or ureters, the radioisotope will not pass beyond the level of the obstruction, whereas if there is a partial obstruction then there is a delayed transit time for the MAG3 to pass. More information can be gathered by calculating time activity curves; with normal kidney perfusion, peak activity should be observed after 3–5 minutes. The relative quantitative information gives the differential function between each kidney’s filtration activity.

QT interval extends from beginning of the QRS complex till the end of he T-wave and normally lasts for 0.40 s. It is important in the diagnosis of long-QT and short-QT syndrome. The QT interval varies on the basis of heart rate and may need to be corrected.

von Hippel-Lindau (VHL) disease, or von Hippel-Lindau syndrome, is a rare genetic disorder characterized by visceral cysts and benign tumours in multiple organ systems that have a subsequent potential for malignant change.
Clinical hallmarks of VHL disease include the development of retinal and central nervous system (CNS) hemangioblastomas (blood vessel tumours), pheochromocytomas, multiple cysts in the pancreas and kidneys, and an increased risk for malignant transformation of renal cysts into renal cell carcinoma. The wide age range and the pleiotropic manner in which VHL disease presents complicates diagnosis and treatment in affected individuals, as well as their at-risk relatives.

Because VHL disease is a multiple-organ disease that widely varies in clinical presentation, various manifestations may lead to the diagnosis. Criteria are the following:
More than one hemangioblastoma in the CNS (brain, spinal cord) or eye
A single hemangioblastoma in the CNS or retina, plus a visceral manifestation (multiple renal, pancreatic, or hepatic cysts; pheochromocytoma; renal cancer)
Positive family history plus any one of the above clinical manifestations
Elucidation of a deleterious mutation in the VHL gene

Acetylcholine is released from the presynaptic membrane into the cleft where it binds to the ion gated channels on the post synaptic membrane, causing them to open. This results in sodium entering into the fibre and further depolarizing it, creating an action potential.

Answer: Curling’s ulcers

Curling’s ulcer is an acute gastric erosion resulting as a complication from severe burns when reduced plasma volume leads to ischemia and cell necrosis (sloughing) of the gastric mucosa. The most common mode of presentation of stress ulcer is the onset of acute upper GI bleed like hematemesis or melena in a patient with the acute critical illness.

A similar condition involving elevated intracranial pressure is known as Cushing’s ulcer. Cushing’s ulcer is a gastro-duodenal ulcer produced by elevated intracranial pressure caused by an intracranial tumour, head injury or other space-occupying lesions. The ulcer, usually single and deep, may involve the oesophagus, stomach, and duodenum. Increased intracranial pressure may affect different areas of the hypothalamic nuclei or brainstem leading to overstimulation of the vagus nerve or paralysis of the sympathetic system. Both of these circumstances increase secretion of gastric acid and the likelihood of ulceration of gastro-duodenal mucosa.

Mallory-Weiss syndrome is characterized by upper gastrointestinal bleeding secondary to longitudinal mucosal lacerations (known as Mallory-Weiss tears) at the gastroesophageal junction or gastric cardia. However, Mallory-Weiss syndrome may occur after any event that provokes a sudden rise in the intragastric pressure or gastric prolapse into the oesophagus, including antecedent transoesophageal echocardiography. Precipitating factors include retching, vomiting, straining, hiccupping, coughing, primal scream therapy, blunt abdominal trauma, and cardiopulmonary resuscitation. In a few cases, no apparent precipitating factor can be identified. One study reported that 25% of patients had no identifiable risk factors.