Hepatitis A is the most common acute viral hepatitis, more common in children and young adults. It is caused by Hepatitis A virus, which is a single-stranded RNA picornavirus. The primary route of spread of Hepatitis A is the faecal-oral route. Consumption of contaminated raw shellfish is also a likely causative factor. The shedding of the virus in faecal matter occurs before the onset of symptoms and continues a few days after. Hepatitis A does not lead to chronic hepatitis or cirrhosis, and there is no known chronic carrier state. Hence, a biopsy performed after recovery will show normal hepatocellular architecture.

The preauricular sinus is a benign congenital malformation of the preauricular soft tissues. Mostly it is noted during routine ear, nose and throat examination, though can present as an infected and discharging sinus. Preauricular sinus is more often unilateral, only occasionally are bilateral forms inherited. The right side is more often involved and females more than males. Most sinuses are clinically silent, eventual, however not rare, appearance of symptoms is related to an infectious process. Erythema, swelling, pain and discharge are familiar signs and symptoms of infection. The most common pathogens causing infection are Staphylococcal species and, less frequently Proteus, Streptococcus and Peptococcus species.

Courses of treatment typically include the following:
– Draining the pus occasionally as it can build up a strong odour
– Antibiotics when infection occurs.
– Surgical excision is indicated with recurrent fistula infections, preferably after significant healing of the infection.
In case of a persistent infection, infection drainage is performed during the excision operation. The operation is generally performed by an appropriately trained specialist surgeon e.g. a otolaryngologist or a specialist General Surgeon.
The fistula can be excised as a cosmetic operation even though no infection appeared. The procedure is considered an elective operation in the absence of any associated complications.

Septic arthritis, also known as infectious arthritis, may represent a direct invasion of the joint space by various microorganisms, most commonly caused by bacteria.
Neisseria gonorrhoeae remains the most common pathogen (75% of cases) among younger sexually active individuals.
Staphylococcus aureus infection causes the vast majority of acute bacterial arthritis cases in adults and in children older than 2 years.

Scalp wounds often bleed and the addition of adrenaline is, therefore, desirable. Lignocaine is fast acting and the preferred agent for local anaesthesia.

Lignocaine, also called lidocaine, is a local anaesthetic and a less commonly used antiarrhythmic. Its increased doses may be used when combined with adrenaline to limit systemic absorption. Adrenaline may be added to local anaesthetic drugs. It prolongs the duration of action at the site of injection and permits usage of higher doses. It is, however, contraindicated in patients taking monoamine oxidase inhibitors or tricyclic antidepressants.

Other listed options are ruled out in this case because:
1. Bupivacaine: has a much longer duration of action than lignocaine and, thus, may be used for topical wound infiltration at the conclusion of surgical procedures.
2. Prilocaine: the agent of choice for intravenous regional anaesthesia.

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.

The Gustilo open fracture classification system is the most commonly used classification system for open fractures.
This system uses the amount of energy, the extent of soft-tissue injury and the extent of contamination for determination of fracture severity. Progression from grade 1 to 3C implies a higher degree of energy involved in the injury, higher soft tissue and bone damage and higher potential for complications.
Grade Injury
1 Low energy wound <1cm
2 Greater than 1cm wound with moderate soft tissue damage
3 High energy wound > 1cm with extensive soft tissue damage
3 A (sub group of 3) Adequate soft tissue coverage
3 B (sub group of 3) Inadequate soft tissue coverage
3 C (sub group of 3) Associated arterial injury

It is important to recognize that a Gustilo score of grade 3C implies vascular injury as well as bone and connective-tissue damage. Grade 3C is defined as an open fracture associated with an arterial injury requiring repair, irrespective of degree of soft-tissue injury. The lack of peripheral pulses indicate arterial injury.
A less morbid damage control approach (compared with ligation) for patients with extremity vascular injury is vascular shunting, a technique that has been available for over 50 years. A vascular shunt is a synthetic tube that is inserted into the vessel and secured proximally and distally. Shunts were placed in the context of damage control to allow stabilization of Gustilo 3C fractures or limb replantation. Vascular shunts are typically used for larger, more proximal arteries and veins such as the femoral and popliteal arteries. Shunts can remain in place up to six hours, but definitive vascular reconstruction should be performed as soon as the patient is sufficiently stable to undergo the procedure. Once a fracture is identified, it is reduced as much as possible and splinted. If an open fracture is suspected, the patient should be taken to the operating room to debride and stabilize the fracture (usually with external fixation) either after life-threatening injuries have been managed or concurrently while less emergency chest, abdominal, or head injuries are being addressed. Revascularization — Ischemia due to vascular injury is a major risk factor for amputation, and, ideally, the injury will be identified and treated within six hours to minimize ischemic nerve and muscle damage.

Gap junctions are attachments between cells that permit intercellular communication e.g. they permit current flow and electrical coupling between myocardial cells. They allow direct electrical transmission among cells and also permit certain substance to pass through as well. They are either homotypic, formed by two identical hemichannels or heterotypic, formed by different hemichannels.

The omental foramen is the pathway that connects the greater peritoneal sac and the lesser peritoneal sac. The omental foramen is bordered posteriorly by the inferior vena cava. This is the blood vessel that would most likely be punctured. The aorta and its branch, the renal artery, lie postero-lateral to the omental foramen and are deeper than the inferior vena cava hence making them less likely to be injured. The hepatic portal vein, the hepatic artery and the superior mesenteric vein borders the omental foramen anteriorly and would not be injured by a jab on the posterior border of the omental foramen. Finally, the splenic artery is found in the splenorenal ligament that borders the omental foramen laterally to the left.

As most of the coagulation factors are synthesized in the liver, liver diseases like hepatitis or cirrhosis will depress the coagulation system. Vitamin K deficiency can also decrease the production of vitamin K dependent coagulation factors VII, XI, X and prothrombin.

A small number of foreign body aspirations are incidentally found after chest radiography or bronchoscopic inspection. Patients may be asymptomatic or may be undergoing testing for other diagnoses. If present, physical findings may include stridor, fixed wheeze, localized wheeze, or diminished breath sounds. If obstruction is severe, cyanosis may occur. Signs of consolidation can accompany post obstructive pneumonia.

Bronchoscopy can be used diagnostically and therapeutically. Most aspirated foreign bodies are radiolucent. Radiologic procedures do not have extreme diagnostic accuracy, and aspiration events are not always detected. Rigid bronchoscopy usually requires heavy intravenous sedation or general anaesthesia. The rigid bronchoscope has important advantages over the flexible bronchoscope. The larger diameter of the rigid bronchoscope facilitates the passage of various grasping devices, including a flexible bronchoscope. A better chance of quick, successful extraction and better capabilities of suctioning clotted blood and thick secretions are offered by the rigid bronchoscope. The paediatric flexible bronchoscope lacks a hollow working channel through which instruments may be inserted or blood and secretions may be aspirated.
Unlike the flexible bronchoscope, the patient can be ventilated through the rigid scope; therefore, ventilation of the patient can be maintained. Rigid bronchoscopy is the procedure of choice for removing foreign bodies in children and in most adults. Success rates for extracting foreign bodies are reportedly more than 98%. Large solid and semisolid objects are best managed emergently in the operating room with a rigid bronchoscope and appropriate grasping instruments.

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.

Myopia or near-sightedness is a disease due to elongated eyeballs or too strong a lens. For far accommodation (focus of a distant object onto the retina), the lens needs to decrease its refractive power, or in other words, increase its focal length. This is done by relaxation of ciliary muscles which tightens the zonular fibres and flattening of the lens. Relaxation of the zonular fibres, rounding of the lens, shortening of the focal length and constriction of the pupil occurs during near accommodation.

This patient is a case of fistula-in-ano.

A fistula-in-ano is an abnormal hollow tract or cavity that is lined with granulation tissue and that connects a primary opening inside the anal canal to a secondary opening in the perianal skin; secondary tracts may be multiple and can extend from the same primary opening. Fistulae usually occur following previous ano-rectal sepsis. The discharge may be foul smelling and troublesome.

Fistula-in-ano is classified into two groups based on its anatomical location.
1. Low fistula: relatively close to the skin and passes through a few or no sphincter muscle fibres, crosses <30% external sphincter
2. High fistula: passes through a large amount of muscle

Assessment of fistula-in-ano includes:
1. Examination of the perineum
2. Digital rectal examination (DRE)
Low, uncomplicated fistulas may not require any further assessment. Other groups will usually require more detailed investigation.
3. Endo-anal USS
4. Ano-rectal MRI scan

Treatment options include:
1. Seton suture
2. Fistulotomy: Low fistulas that are simple should be treated by fistulotomy once the acute sepsis has been controlled. Fistulotomy (where safe) provides the highest healing rates.
3. Anal fistula plugs and fibrin glue
4. Ano-rectal advancement flaps: primarily for high fistulae

Answer: Ganglion

A ganglion cyst is a fluid-filled swelling that usually develops near a joint or tendon. The cyst can range from the size of a pea to the size of a golf ball. Ganglion cysts look and feel like a smooth lump under the skin.

They’re made up of a thick, jelly-like fluid called synovial fluid, which surrounds joints and tendons to lubricate and cushion them during movement.

Ganglions can occur alongside any joint in the body, but are most common on the wrists (particularly the back of the wrist), hands and fingers.

Ganglions are harmless, but can sometimes be painful. If they do not cause any pain or discomfort, they can be left alone and may disappear without treatment, although this can take a number of years.

It’s not clear why ganglions form. They seem to happen when the synovial fluid that surrounds a joint or tendon leaks out and collects in a sac.
They are most common in younger people between the ages of 15 and 40 years, and women are more likely to be affected than men. These cysts are also common among gymnasts, who repeatedly apply stress to the wrist.

Patient-controlled analgesia (PCA) is a delivery system with which patients self-administer predetermined doses of analgesic medication to relieve their pain. The use of PCA in hospitals has been increasing because of its proven advantages over conventional intramuscular injections. These include improved pain relief, greater patient satisfaction, less sedation and fewer postoperative complications.

The pathogenicity of an organism or its ability to cause disease is determined by its virulence factors. Many bacteria produce virulence factors that inhibit the host’s immune system. The virulence factors of bacteria are typically proteins or other molecules that are synthesized by enzymes. These proteins are coded for by genes in chromosomal DNA, bacteriophage DNA or plasmids. The proteins made by the bacteria can poison the host cells and cause tissue damage.

Metoclopramide is a potent dopamine-receptor antagonist with anti-emetic and prokinetic properties. It is therefore commonly used to treat nausea and vomiting, and to facilitate gastric emptying in patients with gastric stasis. The anti-emetic action of metoclopramide is due to its antagonist activity at D2 receptors in the chemoreceptor trigger zone (CTZ) in the central nervous system. Common adverse drug reactions associated with metoclopramide include restlessness (akathisia), and focal dystonia.

Unlike other cancers for which a biopsy is performed, when testicular cancer is suspected the entire testicle is removed in a procedure called an orchiectomy through an incision in the groin and pulling the testicle up from the scrotum. A biopsy through the scrotum for testicular cancer runs the risk of spreading the cancer, and can complicate future treatment options. Removing the entire testicle out of the scrotum is the only safe way to diagnose for testicular cancer. Only the cancer-containing testicle is removed, and it is important to do so promptly.
If there is any uncertainty, the urologists can examine the testicle by pulling the testicle out of the scrotum; if a condition other than testis cancer is found, the testicle is placed back into the scrotum.

Testicular cancer is the most common malignancy in men aged 20-30 years. Around 95% of cases of testicular cancer are germ-cell tumours.

Tracheostomy is an operative procedure that creates a surgical airway in the cervical trachea. It is most often performed in patients who have had difficulty weaning off a ventilator, followed by those who have suffered trauma or a catastrophic neurologic insult. High-flow oxygen via tracheostomy may reduce the inspiratory effort and enhance tidal volume by delivering high-flow oxygen and facilitate weaning from prolonged mechanical ventilation in patients with restrictive pulmonary dysfunction.

Worldwide, approximately 500,000 new cases of cervical cancer and 274,000 deaths are attributable to cervical cancer yearly. This makes cervical cancer the second most common cause of death from cancer in women. The mainstay of cervical cancer screening has been the Papanicolaou test (Pap smear).

The superior vena cava that empties blood into the right atrium is formed by the right and the left brachiocephalic veins. Hence, the left brachiocephalic has to course across the mediastinum horizontally to join with its right ‘counterpart’. The left subclavian artery and vein being lateral to the mediastinum do not cross the mediastinum while the left jugular and the common carotid artery course vertically.

Seminoma is the most radiosensitive tumour and responds well to radiation therapy after unilateral orchidectomy. The ipsilateral inguinal areas are routinely not treated however, depending on the stage, the mediastinum and the left supraclavicular regions may also be irradiated.

Multiple myeloma is a plasma cell malignancy that produce excessive monoclonal immunoglobulins. The disease presents with bone pains, renal dysfunction, increased calcium, anaemia and recurrent infections. Diagnosis is by demonstrating the presence of M-protein in urine or serum, lytic bone lesions, light chain proteinuria or excessive plasma cells on marrow biopsy.

The correct answer is the teres minor muscle. These group of muscles play an important role in protecting the shoulder joint and keeping the head of the humerus in the glenoid fossa of the scapula. This fossa is somehow shallow and needs support to allow for the full mobility that the shoulder joint has.

The tensor veli palatini is innervated by the medial pterygoid nerve, a branch of mandibular nerve, the third branch of the trigeminal nerve (CN V3) – the only muscle of the palate not innervated by the pharyngeal plexus, which is formed by the vagal and glossopharyngeal nerves.

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.

By Fick’s principle, VO2 = Q × (CA (O2) − CV (O2)) where VO2 = O2 consumption, Q = cardiac output and CA(O2) and CV(O2) are arterial and mixed venous O2 content respectively. Thus, in the given problem, 300 ml O2/min = Q × (20−15) ml O2/100 ml. Thus, Q = 6000 ml blood/min. Then, we can calculate stroke volume by dividing the cardiac output with heart rate. Thus, stroke volume = 6000 ml/min divided by 60/min stroke volume = 100 ml.

Familial adenomatous polyposis (FAP) is an autosomal dominant, hereditary colon cancer syndrome that is characterized by the presence of innumerable adenomatous polyps in the colon and rectum. Gardner’s syndrome is a variant of FAP, which in addition to the colonic polyps, also presents extracolonic manifestations, including desmoid tumours, osteomas, epidermoid cysts, various soft tissue tumours, and a predisposition to the thyroid and periampullary cancers.
Of patients with FAP, 75%-80% have a family history of polyps and/or colorectal cancer at age 40 years or younger.
Mutations of the APC gene are thought to be responsible for the development of FAP, and the location of the mutation on the gene is thought to influence the nature of the extracolonic manifestations that a given patient might develop.
Though patients are often asymptomatic, bleeding, diarrhoea, abdominal pain and mucous discharge frequently occur. Diagnostic tools include genetic testing, endoscopy, and monitoring for extra-intestinal manifestations.
If left untreated, all patients with this syndrome will develop colon cancer by age 35-40 years. Besides, an increased risk exists for the development of other malignancies.
Currently, surgery is the only effective means of preventing progression to colorectal carcinoma. Restorative proctocolectomy with ileal pouch-anal anastomosis (RPC/IPAA) with mucosectomy is the preferred surgical procedure since it attempts to eliminate all colorectal mucosa without the need for an ostomy. Periampullary carcinoma and intra-abdominal desmoid tumours are a significant cause of morbidity and mortality in these patients after colectomy. Frequent endoscopy is needed to prevent the former, while there is no definitive treatment available yet for the latter.

A foreign body reaction Is characteristic of giant cells. Glass being the foreign object initiates an inflammatory response in this condition.
Mast cells are involved in allergic reactions.
Eosinophils are characteristic of a parasitic infection and allergic inflammatory process but are not due to foreign bodies.
Plasma cells are typical of chronic inflammation.
Lymphocytes are involved in viral infections.
Macrophages combine together to form giant cells.

With a constant blood flow to a given tissue bed, there will be an increase in oxygen extraction by the tissue with the following; an increase in tissue metabolism and oxygen requirements: warming (or fever), exercise, catecholamines and thyroxine. With cooling, the demand for oxygen decreases, leading to decreased oxygen extraction.