The lateral rectus muscle is one of the 6 extra-ocular muscles that control eye movements. It is responsible for abduction and is the only muscle that is innervated by the abducens nerve (CN VI).

Factor VIII is an important part of the coagulation cascade. Deficiency causes haemophilia A. It is synthesised predominantly by the vascular endothelium and is not affected by liver disease. In the circulation it is bound to von Willebrand factor and it forms a stable complex with it. It is activated by thrombin or factor Xa and acts as a co factor to factor IXa to activate factor X which is a co factor to factor Va. Thrombin cleaves fibrinogen in fibrin and forms a meshwork to trap RBC and platelets to form a clot.

Paget’s disease of the breast or nipple resembles eczema in appearance with an underlying carcinoma typically. The disease is usually unilateral and presents with inflammation, oozing and crusting along with a non-healing ulcer. Treatment is often delayed due to the innocuous appearance but can be fatal. It results due to spread of neoplastic cells from the ducts of the mammary gland to the epithelium.

Percutaneous coronary intervention (PCI), also known as coronary angioplasty, is a nonsurgical technique for treating obstructive coronary artery disease, including unstable angina, acute myocardial infarction (MI), and multivessel coronary artery disease (CAD).

Inferior STEMI is usually caused by occlusion of the right coronary artery, or less commonly the left circumflex artery, causing infarction of the inferior wall of the heart.

The ECG findings of an acute inferior myocardial infarction include the following:
ST segment elevation in the inferior leads (II, III and aVF)
Reciprocal ST segment depression in the lateral and/or high lateral leads (I, aVL, V5 and V6)

The superficial inguinal lymph nodes form a chain immediately below the inguinal ligament. They receive lymphatic supply from the skin of the penis, scrotum, perineum, buttock and abdominal wall below the level of the umbilicus.

C. botulinum is a Gram-positive, rod-shaped, spore-forming bacterium. It is an obligate anaerobe, meaning that oxygen is poisonous to the cells. Only botulinum toxin types A, B, E, and F cause disease in humans. Types A, B, and E are associated with foodborne illness. Botulism poisoning can occur due to preserved or home-canned, low-acid food that was not processed using correct preservation times and/or pressure. Signs and symptoms of foodborne botulism typically begin between 18 and 36 hours after the toxin gets into the body, but can range from a few hours to several days, depending on the amount of toxin ingested. Botulinum that is produced by Clostridium botulinum can cause respiratory and muscular paralysis.

The correct order of structures is the tendon of tibialis posterior, tendon of flexor digitorum longus, posterior tibial artery (and vein), tibial nerve and tendon of flexor hallucis longus.

The rectus sheath is a tendinous sheath that encloses the rectus abdominis muscle. It covers the entire anterior surface however on the posterior surface of the muscle the sheath is incomplete ending inferiorly at the arcuate line. Below the arcuate line, the rectus abdominis is covered by the transversalis fascia. The linea alba is a band of aponeurosis on the midline of the anterior abdominal wall, which extends from the xiphoid process to the pubic symphysis. It is formed by the combined abdominal muscle aponeuroses. This is a useful site for midline incision during abdominal surgery because it does not carry many blood vessels. All of the other answer choices are related to the inguinal canal.
The falx inguinalis (sometimes called the inguinal falx or conjoint tendon), is the inferomedial attachment of the transversus abdominis with some fibres of the internal abdominal oblique – it contributes to the posterior wall of the inguinal canal.
The inguinal ligament is the ligament that connects the anterior superior iliac spine with the pubic tubercle – it makes the floor of the inguinal canal.
The internal (deep) inguinal ring is the entrance to the inguinal canal, where the transversalis fascia pouches out and creates an opening through which structures can leave the abdominal cavity.

Proctectomy with end stoma is the best operative strategy in severe perianal and/or rectal Crohn’s disease.

Surgical resection of Crohn’s disease does not provide a complete cure but it may produce substantial symptomatic improvement. Indications for surgery include complications such as fistulae, abscess formation, and strictures.

Colonoscopy and a small bowel study (e.g. MR enteroclysis imaging) are used to stage Crohn’s disease to facilitate decision-making regarding surgery.
Complex perianal fistulae are best managed with long-term draining seton sutures. Severe perianal and/or rectal Crohn’s disease usually require proctectomy with formation of end stoma. Ileoanal pouch reconstruction carries a high risk of fistula formation and pouch failure and is, therefore, not recommended. Terminal ileal Crohn’s remains one of the most common form of the disease, and it may be treated with limited ileocaecal resections.

Mean corpuscular haemoglobin concentration (MCHC) is calculated simply by dividing the haemoglobin concentration (8 g/dl) by the haematocrit (0.3). The normal range is 31–36 g/dl. This patient has a hypochromic anaemia (MCHC = 8/0.3 = 26.7 g/dl). Dividing the haemoglobin concentration × 10 by erythrocyte number yields mean corpuscular haemoglobin (MCH). Normal range is 25.4–34.6 pg/cell and this patient has a significantly reduced cellular haemoglobin content (MCH = 8 × 10/4 = 20 pg/cell). Mean corpuscular volume (MCV) is calculated by dividing haematocrit × 1000 by erythrocyte number (4 × 106/μl). Normal range is 80–100 fl and this patient has a microcytic anaemia (MCV = 0.3 × 1000/4 = 75 fl). Microcytic, hypochromic anaemia is characteristic for iron-deficiency.

Transverse sinus: part of pericardial cavity that is behind the aorta and pulmonary trunk and in front of the superior vena cava separating the outflow vessels from the inflow vessels.
Oblique pericardial sinus: is behind the left atrium where the visceral pericardium reflects onto the pulmonary veins and the inferior vena cava. Sliding a finger under the heart will take you to this space.
Cardiac notch: indentation of the ‘of the heart’ on the superior lobe of the left lung.
Hilar reflection: the reflection of the pleura onto the root of the lung to continue as mediastinal pleura.
Costomediastinal recess: part of the pleural sac where the costal pleura transitions to become the mediastinal pleura.
Sulcus terminalis: a groove between the right atrium and the vena cava

Three main types of variations in the relations of the occipital artery and the hypoglossal nerve are found according to the level at which the nerve crosses the external carotid artery and the point of origin of the occipital artery. In Type I, the hypoglossal nerve crosses the external carotid artery inferior to the origin of the occipital artery; in Type II, the nerve crosses the external carotid artery at the level of origin of the occipital artery; and in Type III, it crosses superior to that level. In Type III the occipital artery makes a loop around the hypoglossal nerve and is in a position to pull and exert pressure on the nerve. This possibility should be taken into consideration in the diagnosis of peripheral paresis or paralysis of the tongue and during surgery in this area.

Carpal tunnel syndrome tends to occur in women between the ages of 30-50. There are many risk factors, including diabetes, hypothyroidism, obesity, pregnancy, and repetitive wrist work. Symptoms include pain in the hand and wrist, tingling, and numbness distributed along the median nerve (the palmar side of the thumb, the index and middle fingers, and the radial half of the ring finger), which worsens at night.

The inferior sagittal sinus is also known as the inferior longitudinal sinus. It courses along the inferior border of the falx cerebri, superior to the corpus callosum. It is cylindrical in shape and increases in size as it passes backward ending in the straight sinus. It receives blood from the deep and medial aspects of the cerebral hemispheres and drains into the straight sinus.

The pterion is the area where four bones, the parietal, frontal, greater wing of sphenoid and the squamous part of the temporal bone meet. It overlies the anterior branch of the middle meningeal artery on the internal aspect of the skull. The pterion is the weakest part of the skull. Slight trauma to this region can cause extradural hematoma.

A congenital heart disease, ASD or atrial septal defect leads to a communication between the right and left atria due to a defect in the interatrial septum. This leads to mixing of arterial and venous blood from the right and left side of the heart. The hemodynamic significance of this defect depends on the presence of shunting of blood. Normally, the left side of the heart has higher pressure than the right as the left side has to pump blood throughout the body. A large ASD (> 9 mm) will result in a clinically significant left-to-right shunt, causing volume overload of the right atrium and ventricle, eventually leading to heart failure. Cardiac catheterization would reveal very high oxygen saturation in the right atrium, right ventricle and pulmonary artery. Eventually, the left-to-right shunt will lead to pulmonary hypertension and increased afterload in the right ventricle, along with the increased preload due to the shunted blood. This will either cause right ventricular failure, or raise the pressure in the right side of the heart to equal or more than that in the left. Elevation of right atrial pressure to that of left atrial pressure would thus lead to diminishing or complete cessation of the shunt. If left uncorrected, there will be reversal of the shunt, known as Eisenmenger syndrome, resulting in clinical signs of cyanosis as the oxygen-poor blood form right side of the heart will mix with the blood in left side and reach the peripheral vascular system.

Answer: Myoglobin

When muscle is damaged, a protein called myoglobin is released into the bloodstream. It is then filtered out of the body by the kidneys. Myoglobin breaks down into substances that can damage kidney cells.
Compartment syndrome is a painful condition that occurs when pressure within the muscles builds to dangerous levels. This pressure can decrease blood flow, which prevents nourishment and oxygen from reaching nerve and muscle cells.

Compartment syndrome can be either acute or chronic.

Acute compartment syndrome is a medical emergency. It is usually caused by a severe injury. Without treatment, it can lead to permanent muscle damage.

Chronic compartment syndrome, also known as exertional compartment syndrome, is usually not a medical emergency. It is most often caused by athletic exertion. Compartments are groupings of muscles, nerves, and blood vessels in your arms and legs. Covering these tissues is a tough membrane called a fascia. The role of the fascia is to keep the tissues in place, and, therefore, the fascia does not stretch or expand easily.
Compartment syndrome develops when swelling or bleeding occurs within a compartment. Because the fascia does not stretch, this can cause increased pressure on the capillaries, nerves, and muscles in the compartment. Blood flow to muscle and nerve cells is disrupted. Without a steady supply of oxygen and nutrients, nerve and muscle cells can be damaged.

In acute compartment syndrome, unless the pressure is relieved quickly, permanent disability and tissue death may result. This does not usually happen in chronic (exertional) compartment syndrome.

Compartment syndrome most often occurs in the anterior (front) compartment of the lower leg (calf). It can also occur in other compartments in the leg, as well as in the arms, hands, feet, and buttocks.

Acute compartment syndrome usually develops after a severe injury, such as a car accident or a broken bone. Rarely, it develops after a relatively minor injury.

Conditions that may bring on acute compartment syndrome include:

A fracture.
A badly bruised muscle. This type of injury can occur when a motorcycle falls on the leg of the rider, or a football player is hit in the leg with another player’s helmet.
Re-established blood flow after blocked circulation. This may occur after a surgeon repairs a damaged blood vessel that has been blocked for several hours. A blood vessel can also be blocked during sleep. Lying for too long in a position that blocks a blood vessel, then moving or waking up can cause this condition. Most healthy people will naturally move when blood flow to a limb is blocked during sleep. The development of compartment syndrome in this manner usually occurs in people who are neurologically compromised. This can happen after severe intoxication with alcohol or other drugs.
Crush injuries.
Anabolic steroid use. Taking steroids is a possible factor in compartment syndrome.
Constricting bandages. Casts and tight bandages may lead to compartment syndrome. If symptoms of compartment syndrome develop, remove or loosen any constricting bandages.

In an emergency, where consent cannot be obtained, doctors should provide medical treatment that is in the patient’s best interests and is immediately necessary to save a life or avoid significant deterioration in the patient’s health. There is clearly insufficient time here to apply to a court. The GMC and common law advises that emergency life saving treatment can be given to a child irrespective of the parents views.

The patient has Pulmonary embolism (PE).
PE is when a thrombus becomes lodged in an artery in the lung and blocks blood flow to the lung. Pulmonary embolism usually arises from a thrombus that originates in the deep venous system of the lower extremities; however, it rarely also originates in the pelvis, renal, upper extremity veins, or the right heart chambers. After travelling to the lung, large thrombi can lodge at the bifurcation of the main pulmonary artery or the lobar branches and cause hemodynamic compromise.
The classic presentation of PE is the abrupt onset of pleuritic chest pain, shortness of breath, and hypoxia. However, most patients with pulmonary embolism have no obvious symptoms at presentation. Rather, symptoms may vary from sudden catastrophic hemodynamic collapse to gradually progressive dyspnoea.
Physical signs of pulmonary embolism include the following:
Tachypnoea (respiratory rate >16/min): 96%
Rales: 58%
Accentuated second heart sound: 53%
Tachycardia (heart rate >100/min): 44%
Fever (temperature >37.8°C [100.04°F]): 43%
Diaphoresis: 36%
S3 or S4 gallop: 34%
Clinical signs and symptoms suggesting thrombophlebitis: 32%
Lower extremity oedema: 24%
Cardiac murmur: 23%
Cyanosis: 19%
Management
Anticoagulation and thrombolysis
Immediate full anticoagulation is mandatory for all patients suspected of having DVT or PE. Diagnostic investigations should not delay empirical anticoagulant therapy.
Thrombolytic therapy should be used in patients with acute pulmonary embolism who have hypotension (systolic blood pressure< 90 mm Hg) who do not have a high bleeding risk and in selected patients with acute pulmonary embolism not associated with hypotension who have a low bleeding risk and whose initial clinical presentation or clinical course suggests a high risk of developing hypotension.
Long-term anticoagulation is critical to the prevention of recurrence of DVT or pulmonary embolism because even in patients who are fully anticoagulated, DVT and pulmonary embolism can and often do recur.
Thrombolytic agents used in managing pulmonary embolism include the following:
– Alteplase
– Reteplase

Heparin should be given to patients with intermediate or high clinical probability before imaging.
Unfractionated heparin (UFH) should be considered (a) as a first dose bolus, (b) in massive PE, or (c) where rapid reversal of effect may be needed.
Otherwise, low molecular weight heparin (LMWH) should be considered as preferable to UFH, having equal efficacy and safety and being easier to use.
Oral anticoagulation should only be commenced once venous thromboembolism (VTE) has been reliably confirmed.
The target INR should be 2.0–3.0; when this is achieved, heparin can be discontinued.
The standard duration of oral anticoagulation is: 4–6 weeks for temporary risk factors, 3 months for first idiopathic, and at least 6 months for other; the risk of bleeding should be balanced with that of further VTE.

An acute dystonic reaction is characterized by involuntary contractions of muscles of the extremities, face, neck, abdomen, pelvis, or larynx in either sustained or intermittent patterns that lead to abnormal movements or postures. The symptoms may be reversible or irreversible and can occur after taking any dopamine receptor-blocking agents.
The aetiology of acute dystonic reaction is thought to be due to a dopaminergic-cholinergic imbalance in the basal ganglia. Reactions usually occur shortly after initiation of an offending agent or an increased dose of a possible offending agent.
Anticholinergic agents and benzodiazepines, procyclidine are the most commonly used agents to reverse or reduce symptoms in acute dystonic reaction. Acute dystonic reactions are often transient but can cause significant distress to the patient. Although rare, laryngeal dystonia can cause life-threatening airway obstruction.

The cranial nerves emerge directly from the brain and the brain stem. They provide sensory, motor or both motor and sensory innervation. Here is a summary of the cranial nerves and their function:
Olfactory – Purely sensory
Optic – Sensory
Oculomotor – Mainly motor
Trochlear – Motor
Trigeminal – Both sensory and motor
Abducens – Mainly motor
Facial – Both sensory and motor
vestibulocochlear – Mostly sensory
Glossopharyngeal – Both sensory and motor
Vagus – Both sensory and motor
Accessory – Mainly motor
Hypoglossal – Mainly motor

The bronchial circulation is part of the systemic circulation and receives about 2% of the cardiac output from the left heart. Bronchial arteries arise from branches of the aorta, intercostal, subclavian or internal mammary arteries. The bronchial arteries supply the tracheobronchial tree with both nutrients and O2. It is complementary to the pulmonary circulation that brings deoxygenated blood to the lungs and carries oxygenated blood away from them in order to oxygenate the rest of the body.

Thoracentesis is performed in the costodiaphragmatic recess. The needle needs to be inserted below the level of the lungs to avoid injury to the lungs. At the paravertebral line, is between ribs 10 and 12, at the midaxillary line between ribs 8 and 10 and at the midclavicular line between interspaces 6 and 8. The needle should be inserted at the top of the rib (or the bottom of the interspace) to avoid damage to the neurovascular structures found below the rib running in the costal groove.

Medial extension of an appendicectomy incision carries a risk of injury to the inferior epigastric artery which can bleed briskly. It is best managed by ligation.

Bleeding is a complication encountered in all branches of surgery. The decision as to how best to manage the bleed, depends upon its site, vessel, and circumstances.

1. Superficial dermal bleeding:
This will usually cease spontaneously. If not, then direct use of a monopolar or a bipolar cautery device will usually control the situation. Scalp wounds are a notable exception and bleeding from them may be brisk. In this situation, use of a mattress suture as a wound closure method will usually address the problem.

2. Superficial arterial bleeding:
If the vessel can be safely identified in superficial arterial bleeding, then the easiest method is to apply a haemostatic clip and ligate the vessel.

3. Major arterial bleeding:
If the vessel can be clearly identified and is accessible, then it may be possible to apply a clip and ligate the vessel. If the vessel is located in a pool of blood, then blind application of haemostatic clips is highly dangerous and may result in collateral injury. In this situation, evacuating the clot and packing the area is often safer. The pack can then be carefully removed when the required instruments are available. Some vessels may retract and bleeding may then be controlled by dissection of surrounding structures or underrunning the bleeding point.

4. Major venous bleeding:
The safest initial course of action is to apply digital pressure to the bleeding point. To control the bleeding, thereafter, the surgeon will need a working suction device. Divided veins may require ligation.

5. Bleeding from raw surfaces:
This may be mixed bleeding and can be troublesome. Spray diathermy and argon plasma coagulation are both useful agents. Certain topical haemostatic agents, such as surgicel, are useful in encouraging clot formation and may be used in conjunction with, or instead of, the above agents.

The loss of ability to initiate abduction means paralysis of the supraspinatus muscle. This muscle is supplied by the supraclavicular nerve.

Adrenal adenomas are common, benign lesions which are asymptomatic and seen in 10% of population. Usually detected incidentally on Computed tomography (‘incidentaloma’), only around 1 in 10,000 are malignant (adenocarcinoma). Adrenal adenomas rarely need to be investigated, especially if they are homogenous and less than 3 cm in diameter. Follow-up imaging can be done after an interval of 3-6 months to assess any change in size. Some adenomas can secrete cortisol (leading to Cushing syndrome), or aldosterone (leads to Conn syndrome) or androgens (leading to hyperandrogenism).
Haematomas and simple cysts are not usually seen in adrenal gland. Infection due to Histoplasma capsulatum is usually bilateral and leads to multiple granulomas. Adrenal metastasis will usually demonstrate a lung primary and the adrenal lesions will be often multiple and larger than 1 cm.

Osler nodes are small, usually raised, purplish red lesions, which are always tender, appear suddenly, and last 4 to 5 days. Painful fingers may be the earliest complaint or the chief complaint as with this patient. The nodes can appear on the dorsa of the feet and elsewhere. Osler nodes sometimes also accompany bacteraemia without endocarditis as well as septic endarteritis, typhoid fever, gonococcemia, systemic lupus erythematosus, and nonbacterial thrombotic endocarditis.

A history of weight loss and intermittent diarrhoea makes inflammatory bowel disease (IBD) the most likely diagnosis. Conditions such as appendicitis and infections have a much shorter history. Although Meckel’s diverticulum can bleed and cause inflammation, it seldom causes marked weight loss. Irritable bowel syndrome (IBS) presents with alternating episodes of constipation and diarrhoea along with abdominal pain, bloating, and gas.

Carcinoid tumours are of neuroendocrine origin and derived from primitive stem cells in the gut wall, especially the appendix.
Signs and symptoms of carcinoid tumours vary greatly. Carcinoid tumours can be non-functioning presenting as a tumour mass or functioning. The sign and symptoms of a non-functioning tumour depend on the tumour location and size as well as on the presence of metastases. Therefore, findings range from no tumour-related symptoms (most carcinoid tumours) to full symptoms of carcinoid syndrome (primarily in adults).
– Periodic abdominal pain: Most common presentation for a small intestinal carcinoid; often associated with malignant carcinoid syndrome
– Cutaneous flushing: Early and frequent (94%) symptom
– Diarrhoea and malabsorption (84%)
– Cardiac manifestations (60%): Valvular heart lesions, fibrosis of the endocardium; may lead to heart failure with tachycardia and hypertension
– Wheezing or asthma-like syndrome (25%)
– Pellagra
– Carcinoid crisis can be the most serious symptom of carcinoid tumours and can be life-threatening. It can occur suddenly, after stress, or following chemotherapy and anaesthesia.

Two surgical procedures can be applied to treat appendiceal Neuroendocrine Neoplasm (NEN): simple appendicectomy and oncological right-sided hemicolectomy.
– For T1 (ENETS) or T1a (UICC/AJCC) NEN (i.e. <1 cm), generally simple appendicectomy is curative and sufficient.
– For NEN >2 cm with a T3 stage (ENETS) or higher and T2 (UICC/AJCC) or higher respectively, a right-sided hemicolectomy is advised due to the increased risk of lymph node metastasis and long-term tumour recurrence and/or distant metastasis. The right-sided hemico- lectomy should be performed either as the initial surgical intervention should the problem be overt at that time, or during a second intervention.

The first branches off spinal nerves are called the dorsal and ventral rami. The dorsal rami mediate sensation of the skin over the back and motor supply to the true muscles of the back whilst the ventral rami gives sensation to the skin over the limbs and the skin that is over the ventral side of the trunk. It also gives motor supply to the skeletal muscles of the neck, the trunk and extremities. Hence, itchiness of the part of the skin that is over the spine of the scapula would be mediated by the primary ramus of C7. Accessory nerve doesn’t have any sensory innervation.