Phimosis is the inability to fully retract the foreskin of the penis in an uncircumcised male. It can be physiological in infancy, in which it could be referred to as ‘developmental non-retractility of the foreskin. However, it is almost always pathological in older children and men. Causes include chronic inflammation (e.g. balanoposthitis), multiple catheterisations, or forceful foreskin retraction. One of the causes is chronic balanitis xerotica obliterans. It leads to development of a ring of indurated tissue near the tip of the prepuce, which prevents retraction. Contributory factors include infections, hormonal and inflammatory factors. The recommended treatment includes circumcision.

The rhomboid major arises from the second, third, fourth and fifth thoracic vertebrae. It is inserted into a narrow tendinous arch attached to the root of the spine of the scapula and the inferior angle. By its insertion in the inferior angle of the scapula, it acts on this angle and produces a slight rotation of the scapula on the side of the chest. It also retracts the scapula by working with the trapezius muscle.

The parotid duct or Stensen duct is a duct and the route that saliva takes from the major salivary gland, the parotid gland into the mouth. The parotid duct is formed when several interlobular ducts—the largest ducts inside the parotid gland join. It emerges from the gland and runs forward along the lateral side of the masseter muscle. In this course, the duct is surrounded by the buccal fat pad. It takes a steep turn at the border of the masseter and passes through the buccinator muscle, opening into the vestibule of the mouth, between the cheek and the gums, at the parotid papilla, which lies across the second superior molar tooth.

Rejection is related primarily to activation of T cells, which, in turn, stimulate specific antibodies against the graft. Various clinical syndromes of rejection can be correlated with the length of time after transplantation.

Hyperacute rejection
Hyperacute rejection of the renal allograft happens in the operating room within hours of the transplant, when the graft becomes mottled and cyanotic. This type of rejection is due to unrecognized compatibility of blood groups A, AB, B, and O (ABO) or to a positive T-cell crossmatch (class I human leukocyte antigen [HLA] incompatibility).
It is thought that IgG antibodies from the host bind to HLA-1 antigen of the donated organ.
No treatment exists, and nephrectomy is indicated.

Acute rejection
Acute rejection appears within the first 6 months after transplantation and affects approximately 15% of transplanted kidneys. Rejection is secondary to prior sensitization to donor alloantigens (occult T-cell crossmatch) or a positive B-cell crossmatch.
Acute tubular interstitial cellular rejection is the most common type of rejection reaction, with an incidence of approximately 20-25%. Typically, it occurs between 1 and 3 months after transplantation. It is T-cell mediated, and injury is directed to the renal tubules. The standard for diagnosis is renal allograft biopsy. Mild rejections may be successfully reversed with corticosteroids alone, whereas moderate or severe rejections may require the use of anti–T-cell antibodies, either polyclonal or monoclonal.
Late acute rejection is strongly correlated with the scheduled withdrawal of immunosuppressive therapy 6 months after transplantation.

Chronic rejection
Chronic rejection occurs more than 1 year after transplantation and is a major cause of allograft loss. It is a slow and progressive deterioration in renal function characterized by histologic changes involving the renal tubules, capillaries, and interstitium. Its precise mechanism is poorly defined and is an area of intense study. Diagnosis is by renal biopsy, and treatment depends on the identified cause if any. Application of conventional antirejection agents (e.g., corticosteroids or anti–T-cell antibodies) does not appear to alter the progressive course.

The deep plantar artery is a branch of the dorsalis pedis artery.

Mesenteric venous thrombosis (MVT) is a blood clot in one or more of the major veins that drain blood from the intestine. The superior mesenteric vein is most commonly involved. The exact cause of MVT is unknown. However, there are many diseases that can lead to MVT. Many of the diseases cause swelling (inflammation) of the tissues surrounding the veins, and include:
Appendicitis
Cancer of the abdomen
Diverticulitis
Liver disease with cirrhosis
High blood pressure in the blood vessels of the liver
Abdominal surgery or trauma
Pancreatitis
Inflammatory bowel disorders
Heart failure
Protein C or S deficiencies
Polycythaemia vera
Essential thrombocythemia
People who have disorders that make the blood more likely to stick together (clot) have a higher risk for MVT. Birth control pills and oestrogen medicines also increase risk.

MVT is more common in men than women. It mainly affects middle aged or older adults. Symptoms may include any of the following:
Abdominal pain, which may get worse after eating and over time; Bloating; Constipation; Bloody diarrhoea; Fever; Septic shock; Lower gastrointestinal bleeding; Vomiting and nausea.
Blood thinners (most commonly heparin or related medicines) are used to treat MVT when there is no associated bleeding. In some cases, medicine can be delivered directly into the clot to dissolve it. This procedure is called thrombolysis. Less often, the clot is removed by thrombectomy.

The combination of a crush injury, limb swelling, and inability to move digits raises suspicion of compartment syndrome that would require a fasciotomy.

Compartment syndrome is a particular complication that may occur following fractures, especially supracondylar fractures and tibial shaft injuries. It is characterised by raised pressure within a closed anatomical space which may, eventually, compromise tissue perfusion, resulting in necrosis.

The clinical features of compartment syndrome include:
1. Pain, especially on movement
2. Paraesthesia
3. Pallor
4. Paralysis of the muscle group may also occur

Diagnosis is made by measurement of intracompartmental pressure. Pressures >20mmHg are abnormal and >40mmHg are diagnostic.

Compartment syndrome requires prompt and extensive fasciotomy. Myoglobinuria may occur following fasciotomy, resulting in renal failure. Therefore, aggressive IV fluids are required. If muscle groups are frankly necrotic at fasciotomy, they should be debrided, and amputation may have to be considered.

A ventricular septal defect (VSD) is a common form of congenital heart defects and is characterised by the presence of a hole in the wall that separates the right from the left ventricle. Medium or large defects can cause many complications. One of these complication is Eisenmenger syndrome, characterised by reversal of the shunt (from left-to-right shunt into a right-to-left) ,cyanosis and pulmonary hypertension.

The cholera toxin (CTX or CT) is an oligomeric complex made up of six protein subunits: a single copy of the A subunit (part A), and five copies of the B subunit (part B), connected by a disulphide bond. The five B subunits form a five-membered ring that binds to GM1 gangliosides on the surface of the intestinal epithelium cells. The A1 portion of the A subunit is an enzyme that ADP-ribosylates G proteins, while the A2 chain fits into the central pore of the B subunit ring. Upon binding, the complex is taken into the cell via receptor-mediated endocytosis. Once inside the cell, the disulphide bond is reduced, and the A1 subunit is freed to bind with a human partner protein called ADP-ribosylation factor 6 (Arf6). Binding exposes its active site, allowing it to permanently ribosylate the Gs alpha subunit of the heterotrimeric G protein. This results in constitutive cAMP production, which in turn leads to secretion of H2O, Na+, K+, Cl−, and HCO3− into the lumen of the small intestine and rapid dehydration. The gene encoding the cholera toxin was introduced into V. cholerae by horizontal gene transfer.

The sartorius muscle arises from tendinous fibres from the superior iliac spine. It passes obliquely across the thigh from lateral to medial and is inserted into the upper part of the medial side of the tibia. When the sartorius muscle contracts it will flex the leg at the knee joint.

Cerebellar disease leads to intention tremors, which is absent at rest and appears at the onset of voluntary movements. In comparison, Parkinson’s tremor is present at rest. Frequency of tremor is a less reliable means to differentiate between the two as the oscillation amplitude of the tremor is not constant throughout a voluntary action.

Trophoblast is the layer of cells surrounding the blastocyst and that later develops into the chorion and amnion. Gestational trophoblastic disease is a tumour arising from this trophoblast. It can occur during or after either an intrauterine or ectopic pregnancy. If it occurs in a pregnant woman, it usually leads to spontaneous abortion, eclampsia or fetal death. It can be either malignant or benign.
In suspected cases, investigations include measurement of serum beta subunit of human chorionic gonadotrophin (β-hCG) and pelvic ultrasound. Confirmatory test is a biopsy. Post-removal, the disease is classified clinically to assess further treatment. To assess the presence of metastases, further work-up includes computed tomography of the brain, chest, abdomen and pelvis. Chemotherapy is usually needed for persistent disease. If at least three consecutive, weekly serum β-hCG measurements are normal, treatment is considered successful. Follow-up is also done by measuring β-hCG.

Congenital neck masses are developmental anomalies typically seen in infants or children. Common conditions include thyroglossal duct cysts, branchial cleft cysts, and cystic hygromas. These malformations present as painless neck masses, which can cause dysphagia, respiratory distress, and neck pain due to compression of surrounding structures. The location of the mass depends on the embryological structure the cysts arise from. Diagnosis is made based on clinical findings and imaging results (ultrasound, CT, MRI), which also help in surgical planning. Treatment consists of complete surgical resection to prevent recurrence and complications such as infection or abscess formation.
The thyroglossal cyst is present from birth and usually detected during early childhood. It presents as a painless, firm midline neck mass, usually near the hyoid bone, which elevates with swallowing and tongue protrusion. May cause dysphagia or neck/throat pain if the cyst enlarges.

Answer: The burn area is extremely painful until skin grafted

Third-degree burns destroy the epidermis and dermis. Third-degree burns may also damage the underlying bones, muscles, and tendons. The burn site appears white or charred. There is no sensation in the area since the nerve endings are destroyed. These are not normally painful until after skin grafting is done since the nerve endings have been destroyed.

Alveolar ventilation = respiratory rate × (tidal volume − anatomical dead space volume). Increase in respiratory rate simply causes movement of air in the anatomical dead space, with no contribution to the alveolar ventilation. By use of a shorter snorkel, the effective anatomical dead space will decrease and will cause a maximum rise in alveolar ventilation along with doubling of tidal volume.

Intercostal nerves are the ventral primary rami of spinal nerves T1–T11. They give branches which supply the thoracic wall.

During the generation of an action potential, the membrane gets depolarized which cause the voltage gated sodium channels to open and sodium diffuses inside the neuron, resulting in the membrane potential moving towards a positive value. This positive potential will then open the voltage gated potassium channels and cause more K+ to move out decreasing the membrane potential and restoring the membrane potential to its resting value.

The obturator nerve is formed from the ventral divisions of the 2nd, 3rd and 4th lumbar nerves. It courses through the fibres of the psoas major and emerges from the medial border near the pelvic brim.
The iliohypogastric nerve comes from the first lumbar nerve and emerges from the upper part of the lateral border of psoas major.
The ilioinguinal nerve arises with the iliohypogastric nerve from the first lumbar nerve and also emerges from the lateral border of the psoas major muscle.
The lateral femoral cutaneous nerve comes from the posterior division of the 2nd and 3rd lumbar nerves to emerge from the lateral border of the psoas major muscle near its middle.
The femoral nerve also arises from the dorsal divisions, but of the 2nd, 3rd and 4th lumbar nerves and courses through the muscle fibres to emerge at the lower part of the lateral border.
The coccygeal nerve doesn’t arise from the lumbar plexus but from the sacral plexus.

Fat is mainly transported in the body as free fatty acids. Once out of the adipose cell, the free fatty acids get ionized and combine with albumin.

ECG characteristics of hyperkalaemia may show the following changes: P-waves are widened and of low amplitude due to slowing of conduction, widened QRS complex, QRS-T fusion, loss of ST segment and tall tented T waves.

Viral infections will cause necrosis of the hepatocytes with characteristic changes of karyorrhexis and cell fragmentation.
Brown atrophy of the heart is due to accumulation of lipofuscin in the myocardium.
Tissue destruction associated with transplant rejection leads to widespread loss of structural integrity.
Single cell necrosis is not characteristically seen in chronic alcoholic liver.
Barbiturate overdose will result in hypertrophy of the smooth endoplasmic reticulum.
Carcinoma insitu will cause dysplastic cells without the overall structural integrity being disrupted.
Atrophy is due to apoptosis with ordered cellular fragmentation and phagocytosis and will not induce an inflammatory process unlike necrosis.

An anal fistula is an abnormal tract between the anal canal and the skin around the anus.
Anal fistulas can be classified according to their relationship with the external sphincter. A fistula may be complex, with several openings onto the perianal skin. Intersphincteric fistulas are the most common type and cross only the internal anal sphincter. Trans-sphincteric fistulas pass through both the internal and external sphincters.

The aim is to drain the infected material and encourage healing.
For simple intersphincteric and low trans-sphincteric anal fistulas, the most common treatment is a fistulotomy or laying open of the fistula tract.
For high and complex (deeper) fistulas that involve more muscle, with a high risk of faecal incontinence or recurrence, surgery aims to treat the fistula and preserve sphincter-muscle function. Techniques include a 1‑stage or 2‑stage seton (suture material or rubber sling) either alone or in combination with fistulotomy, ligation of an intersphincteric fistula tract, creating a mucosal advancement flap, injecting glue or paste, or inserting a fistula plug .

The second pharyngeal arch or hyoid arch, is the second of six pharyngeal arches that develops in fetal life during the fourth week of development and assists in forming the side and front of the neck. Derivatives:
Skeletal – From the cartilage of the second arch arises:
Stapes,
Temporal styloid process,
Stylohyoid ligament, and
Lesser cornu of the hyoid bone.
Muscles:
Muscles of face
Occipitofrontalis muscle
Platysma
Stylohyoid muscle
Posterior belly of Digastric
Stapedius muscle
Auricular muscles
Nerve supply: Facial nerve

The spinothalamic tract is a sensory pathway originating in the spinal cord that transmits information to the thalamus. There are two main parts of the spinothalamic tract: the lateral spinothalamic tract transmits pain and temperature and the anterior spinothalamic tract transmits touch (crude touch). The decussation of this pathway occurs at the level of the spinal cord. Hence, a unilateral lesion of the lateral spinothalamic tract causes contralateral loss of pain and temperature.

On transmission of a loud sound into the central nervous system, an attenuation reflex occurs after a latent period of 40-80 ms. This reflex contracts the two muscles that pull malleus and stapes closer, developing a high degree of rigidity in the entire ossicular chain. This reduces the ossicular conduction of low frequency sounds to the cochlea by 30-40 decibels. In this way, the cochlea is protected from damage due to loud sounds (these are low frequency sounds) when they develop slowly.

Answer: Staphylococcus aureus

Mastitis is defined as inflammation of the breast. Although it can occur spontaneously or during lactation, this discussion is limited to mastitis in breastfeeding women, with mastitis defined clinically as localized, painful inflammation of the breast occurring in conjunction with flu-like symptoms (e.g., fever, malaise). Mastitis is especially problematic because it may lead to the discontinuation of breast-feeding, which provides optimal infant nutrition. Mastitis occurs in approximately 10 percent of U.S. mothers who are breastfeeding, and it can lead to the cessation of breastfeeding. The risk of mastitis can be reduced by frequent, complete emptying of the breast and by optimizing breastfeeding technique. Sore nipples can precipitate mastitis. The differential diagnosis of sore nipples includes mechanical irritation from a poor latch or infant mouth anomalies, such as cleft palate or bacterial or yeast infection. The diagnosis of mastitis is usually clinical, with patients presenting with focal tenderness in one breast accompanied by fever and malaise. Treatment includes changing breastfeeding technique, often with the assistance of a lactation consultant. When antibiotics are needed, those effective against Staphylococcus aureus (e.g., dicloxacillin, cephalexin) are preferred. As methicillin-resistant S. aureus becomes more common, it is likely to be a more common cause of mastitis, and antibiotics that are effective against this organism may become preferred. Continued breastfeeding should be encouraged in the presence of mastitis and generally does not pose a risk to the infant. Breast abscess is the most common complication of mastitis. It can be prevented by early treatment of mastitis and continued breastfeeding. Once an abscess occurs, surgical drainage or needle aspiration is needed. Breastfeeding can usually continue in the presence of a treated abscess.

Hageman factor/factor XII in the intrinsic pathway activates prekallikrein and factor XI. Deficiency will not cause excessive bleeding as other coagulation factors will be utilized but the PTT will be greater than 200 seconds.
Thromboxane promotes platelet aggregation and causes vasoconstriction.
Plasmin, which is cleaved from plasminogen acts as an anticoagulant which breaks down thrombi.
Platelet activating factor promotes platelet aggregation and is also chemotactic to neutrophils.
Histamine acts as a vasodilator.
Platelet inhibiting factor acts an anticoagulant.
Renin is a hormone released from the kidney that causes vasoconstriction and water retention.

The hoarseness of voice implies vocal cord paralysis denoting the spread of malignancy which is a contraindication to surgery.

Summary of Guidelines on the selection of patients with lung cancer for surgery (Related to this case)

PART I: FITNESS FOR SURGERY
Age:
1. Perioperative morbidity increases with advancing age. Elderly patients undergoing lung resection are more likely to require intensive perioperative support. Preoperatively, a careful assessment of co-morbidity needs to be made.
2. Surgery for clinically stage I and II disease can be as effective in patients over 70 years as in younger patients. Such patients should be considered for surgical treatment regardless of age.
3. Age over 80 alone is not a contraindication to lobectomy or wedge resection for clinical stage I disease.
4. Pneumonectomy is associated with higher mortality risk in the elderly. Age should be a factor in deciding suitability for pneumonectomy.

Pulmonary function:
There should be a formal liaison in borderline cases between the referring chest physician and the thoracic surgical team.
2.No further respiratory function tests are required for a lobectomy if the post-bronchodilator FEV1 is >1.5 litres and for a pneumonectomy, if the post-bronchodilator FEV1 is >2.0 litres, provided that there is no evidence of interstitial lung disease or unexpected disability due to shortness of breath.
STEP 1
3.All patients not clearly operable on the basis of spirometry should have: (a) full pulmonary function tests including estimation of transfer factor (TLCO); (b) measurement of oxygen saturation on air at rest; and (c) a quantitative isotope perfusion scan if a pneumonectomy is being considered.
4.These data should be used to calculate estimated postoperative FEV1 expressed as % predicted and the estimated postoperative TLCO expressed as % predicted, using either the lung scan for pneumonectomy or an anatomical equation for lobectomy, taking account of whether the segments to be removed are ventilated or obstructed.
STEP 2
5.(a) Estimated postoperative FEV1 >40% predicted and estimated postoperative TLCO >40% predicted and oxygen saturation (SaO 2) >90% on air: average risk.
(b)Estimated postoperative FEV1 <40% predicted and estimated postoperative TLCO <40% predicted: high risk.
(c)All other combinations: consider exercise testing.
6.Patients for whom the risk of resection is still unclear after step 2 tests should be referred for exercise testing.
STEP 3
7.(a) The best distance on two shuttle walk tests of <25 shuttles (250 m) or desaturation during the test of more than 4% SaO 2 indicates a patient is a high risk for surgery.
(b)Other patients should be referred for a formal cardiopulmonary exercise test. For cardiopulmonary exercise testing peak oxygen consumption (V˙O 2peak) of more than 15 ml/kg/min indicates that a patient is an average risk for surgery.
(c)A V˙O 2peak of <15 ml/kg/min indicates that a patient is a high risk for surgery. PART II: OPERABILITY
Diagnosis and staging
1.All patients being considered for surgery should have a plain chest radiograph and a computed tomographic (CT) scan of the thorax including the liver and adrenal glands.
2.Confirmatory diagnostic percutaneous needle biopsy in patients presenting with peripheral lesions is not mandatory in patients who are otherwise fit, particularly if there are previous chest radiographs showing no evidence of a lesion.
3.Patients with mediastinal nodes greater than 1 cm in short-axis diameter on the CT scan should undergo biopsy by staging mediastinoscopy, anterior mediastinotomy, or needle biopsy as appropriate.
Operability and adjuvant therapy
1.The proportion of patients found to be inoperable at operation should be 5–10%.
2.Patients with stage I (cT1N0 and cT2N0) and stage II (cT1N1, cT2N1 and cT3N0) tumours should be considered operable.
3.Patients with stage I tumours have a high chance and those with stage II tumours a reasonable chance of being cured by surgery alone.
4.Patients who are known preoperatively to have stage IIIA (cT3N1 and cT1–3N2) tumours have a low chance of being cured by surgery alone but might be considered operable in the context of a trial of surgery and adjuvant chemotherapy.
5.Participation in prospective trials of multimodality treatment for locally advanced disease is strongly recommended.
6.Some small individual studies indicate a place for surgery in T4N0 and T4N1 tumours within stage IIIB, few long term data are available. Generally, stage IIIB tumours with node involvement and stage IV tumours should be considered inoperable.
7.There is no place for postoperative radiotherapy following complete primary tumour resection.

Lymphadenopathy is common in children and is usually reactive in nature. The description fits that of a benign, reactive lymph node.

PR interval extends from the beginning of the P-wave until the beginning of the QRS complex. The normal duration of the PR interval is 0.12-0.20 s. It can be prolonged in first degree heart block, and reduced in Wolff-Parkinson-White syndrome.