The drainage of cerebral spinal fluid from the third ventricle to the fourth ventricle is carried out by the cerebral aqueduct. The cerebral aqueduct is the narrowest passageway in the entire ventricular system and thus forms the most common site of blockage of flow of cerebrospinal fluid. The interventricular foramen allows passage of CSF to the third ventricle. The foramen of Luschka and Magendie are located on the fourth ventricle and allow passage of CSF to the subarachnoid space from the ventricular system. The pontine cistern is a space located on the ventral aspect of the pons. The cisterna magna is an opening on the subarachnoid space between the pia matter and the arachnoid.

Duct ectasia is the cause of nipple discharge, with different percentages recorded in different articles (>10%, >30% and >50%). Duct ectasia differs from cystic disease since it is an inflammatory process, usually affecting the ducts below the nipple. It develops gradually, either through the ductal system or the breast lobes. The acute inflammation may be caused by epithelial rupture and diffusion of the contents into the fibrous duct-wall and the underlying structures. These contents consist of neutral fat and lipid crystals that are typical of duct ectasia. The chronic granulation-type reaction may develop foreign body-like giant cells and a multiform inflammatory cell population. Since the whole process in duct ectasia is long in duration, plasma cells are sometimes dominant in the inflammatory infiltrations. Other findings in duct ectasia include the following:
-Serous or green-white nipple discharge in 20% of cases;
-Nipple inversion that leads to fibrosis and development of ring or tubular calcification (this finding is typical in the mammogram and especially when the disease is in its advanced stages);
-Apocrine metaplasia with or without epithelial hyperplasia. The epithelial layer consists of widened atrophic cells.
The condition may be managed symptomatically and/or with antibiotics, but in persistent or recurrent cases it is managed with surgical excision of the ducts below the nipple. A focused excision is preferred to a complete subareolar excision since the later technique is associated with higher rates of seroma formation, nipple numbness and nipple inversion. The Hadfield’s procedure (major duct excision) is an option.

A week following a MI attack, a little collagen starts to form and deposit. By the end of the 2nd week, neovascularisation of the scar occurs, with some collagen being laid down in a haphazard fashion. By this time the scar attains some strength. During the next 6 months, collagen is constantly being laid down and is rearranged in order to shrink the scar. Most of the blood vessels by this time have regenerated, decreasing vascularity of the scar reaching full maturity.

Aortic injuries not resulting in immediate death may be due to a contained haematoma. Clinical signs are subtle, and diagnosis may not be apparent on clinical examination. Without prompt treatment, the haematoma usually bursts and the patient dies.

Traumatic aortic disruption, or aortic transection, is typically the result of a blunt aortic injury in the context of rapid deceleration. This condition is commonly fatal as blood in the aorta is under great pressure and can quickly escape the vessel through a tear, resulting in rapid haemorrhagic shock and death. A temporary haematoma may prevent the immediate death. Injury to the aorta during a sudden deceleration commonly originates near the terminal section of the aortic arch, also known as the isthmus. This portion lies just distal to the take-off of the left subclavian artery at the intersection of the mobile and fixed portions of the aorta. As many as 80% of the patients with aortic transection die at the scene before reaching a trauma centre for treatment.

A widened mediastinum may be seen on the X-ray of a person with aortic rupture. Other findings on CXR may include:
1. Deviation of trachea/oesophagus to the right
2. Depression of left main stem bronchus
3. Widened paratracheal stripe/paraspinal interfaces
4. Obliteration of space between aorta and pulmonary artery
5. Rib fracture/left haemothorax

Diagnosis can be made by angiography, usually CT aortogram.

Treatment options include repair or replacement. The patient should, ideally, undergo endovascular repair.

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.

Urinary incontinence is the involuntary excretion of urine from one’s body. It is often temporary and it almost always results from an underlying medical condition. Several types include:
– Stress incontinence is the voiding of urine following increased abdominal pressure e.g. laughing, coughing, pregnancy etc. It is the most common form of incontinence in women, most commonly due to pelvic floor muscle weakness, physical changes from pregnancy, childbirth and menopause. In men it is a common problem following a prostatectomy. Most lab results such as urine analysis, cystometry and postvoid residual volume are normal.
– Urge incontinence is involuntary loss of urine occurring for no apparent reason while suddenly feeling the need or urge to urinate. The most common cause of urge incontinence are involuntary and inappropriate detrusor muscle contractions.
– Functional incontinence – occurs when a person does not recognise the need to go to the toilet, recognise where the toilet is or get to the toilet in time. The urine loss may be large. Causes of functional incontinence include confusion, dementia, poor eyesight, poor mobility, poor dexterity or unwillingness. t
– Overflow incontinence – sometimes people find that they cannot stop their bladders from constantly dribbling or continuing to dribble for some time after they have passed urine.

Answer: Mittelschmerz

Mittelschmerz is midcycle abdominal pain due to leakage of prostaglandin-containing follicular fluid at the time of ovulation. It is self-limited, and a theoretical concern is treatment of pain with prostaglandin synthetase inhibitors, which could prevent ovulation. The pain of mittelschmerz usually occurs in the lower abdomen and pelvis, either in the middle or to one side. The pain can range from a mild twinge to severe discomfort and usually lasts from minutes to hours. In some cases, a small amount of vaginal bleeding or discharge might occur. Some women have nausea, especially if the pain is very strong.
Diagnosis of pelvic pain in women can be challenging because many symptoms and signs are insensitive and nonspecific. As the first priority, urgent life-threatening conditions (e.g., ectopic pregnancy, appendicitis, ruptured ovarian cyst) and fertility-threatening conditions (e.g., pelvic inflammatory disease, ovarian torsion) must be considered.
Many women never have pain at ovulation. Some women, however, have mid-cycle pain every month, and can tell by the pain that they are ovulating.
As an egg develops in the ovary, it is surrounded by follicular fluid. During ovulation, the egg and the fluid, as well as some blood, are released from the ovary. While the exact cause of mittelschmerz is not known, it is believed to be caused by the normal enlargement of the egg in the ovary just before ovulation. Also, the pain could be caused by the normal bleeding that comes with ovulation.
Pelvic inflammatory disease can be ruled out if the patient is not sexually active.

Carcinoembryonic antigen (CEA) is used as a tumour marker. CEA test measures the amount of this protein that may appear in the blood of some people who have certain types of cancers especially cancer of the colon and rectal cancer. It may also be present in the pancreas, breast, ovary or lung.

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.

Residual volume is the air left in the lungs after maximal expiration is done. Thus, this is not a part of vital capacity and cannot be measured with a spirometer directly. It can be measured by the methods such as body plethysmography or inert gas dilution. Expiratory reserve volume is vital capacity minus inspiratory capacity. Resting volume of lungs is he sum of residual volume and expiratory reserve volume. Lungs recoil inward until the recoil pressure becomes zero, which corresponds to a volume significantly lower than residual volume.

Early antibiotic treatment of anthrax is essential. A delay may significantly lessen the chances for survival of the patient. Treatment for anthrax infection include large doses of intravenous and oral antibiotics, such as fluoroquinolones (ciprofloxacin), doxycycline, erythromycin, vancomycin, or penicillin.

The child has VACTERL
Over 50% of infants with oesophageal atresia have one or more additional anomalies.
The VATER association consists of a combination of anomalies including vertebral, anorectal, tracheooesophageal and renal or radial abnormalities. This association was later expanded as the VACTERL association to include cardiac and limb defects.
Other associations which may include oesophageal atresia are the CHARGE association (coloboma, heart defects, atresia choanal, retarded growth and development, genital hypoplasia and ear deformities), POTTER’S syndrome (renal agenesis, pulmonary hypoplasia, typical dysmorphic facies) and SCHISIS association (omphalocele, cleft lip and/or palate, genital hypoplasia). Genetic defects associated with oesophageal atresia include Trisomy 21 and 18, and 13q deletion. Of the cardiac anomalies, the most common are ventricular septal defect and tetralogy of Fallot. Major cardiac malformations are one of the main causes of mortality in infants with oesophageal atresia.

The adrenal glands or the suprarenal glands are small glands that are found on top of each of the kidneys. They are retroperitoneal glands. The right adrenal gland is found on top of the right kidney and is closely associated with the inferior vena cava as it directly drains into this large vein. In the case where the right adrenal gland is to be surgically removed, the inferior vena cava might prove a problem to manoeuvre as it overlies the right suprarenal gland. The other blood vessels such as the aorta, right renal, superior mesenteric, splenic artery and the hepatic vein as well as the right crus are not closely associated with either of the suprarenal glands.

Answer: Excision biopsy of a lymph node

Hodgkin lymphoma is an uncommon cancer that develops in the lymphatic system, which is a network of vessels and glands spread throughout your body. In Hodgkin lymphoma, B-lymphocytes (a particular type of lymphocyte) start to multiply in an abnormal way and begin to collect in certain parts of the lymphatic system, such as the lymph nodes (glands). The affected lymphocytes lose their infection-fighting properties, making you more vulnerable to infection. The most common symptom of Hodgkin lymphoma is a painless swelling in a lymph node, usually in the neck, armpit or groin.
A histologic diagnosis of Hodgkin lymphoma is always required. An excisional lymph node biopsy is recommended because the lymph node architecture is important for histologic classification.

Features of Hodgkin lymphoma include the following:

Asymptomatic lymphadenopathy may be present (above the diaphragm in 80% of patients)

Constitutional symptoms (unexplained weight loss [>10% of total body weight] within the past 6 months, unexplained fever >38º C, or drenching night sweats) are present in 40% of patients; collectively, these are known as B symptoms

Intermittent fever is observed in approximately 35% of cases; infrequently, the classic Pel-Ebstein fever is observed (high fever for 1-2 week, followed by an afebrile period of 1-2 week)

Chest pain, cough, shortness of breath, or a combination of those may be present due to a large mediastinal mass or lung involvement; rarely, haemoptysis occurs

Pruritus may be present

Pain at sites of nodal disease, precipitated by drinking alcohol, occurs in fewer than 10% of patients but is specific for Hodgkin lymphoma

Back or bone pain may rarely occur

A family history is also helpful; in particular, nodular sclerosis Hodgkin lymphoma (NSHL) has a strong genetic component and has often previously been diagnosed in the family.

The dural venous sinuses lies between the periosteal and meningeal layer of the dura mater. Dural venous sinuses is unique because it does not run parallel with arteries and allows bidirectional flow of blood intracranially as it is valve-less.

Burn depth is classified as first, second, third, or fourth degree, as follows:
First-degree burns are usually red, dry, and painful. Burns initially termed first-degree are often actually superficial second-degree burns, with sloughing occurring the next day.
Second-degree burns are often red, wet, and very painful. Their depth, ability to heal, and propensity to form hypertrophic scars vary enormously.
Third-degree burns are generally leathery in consistency, dry, insensate, and waxy. These wounds will not heal, except by contraction and limited epithelial migration, with resulting hypertrophic and unstable cover. Burn blisters can overlie both second- and third-degree burns. The management of burn blisters remains controversial, yet intact blisters help greatly with pain control. Debride blisters if infection occurs.
Fourth-degree burns involve underlying subcutaneous tissue, tendon, or bone. Usually, even an experienced examiner has difficulty accurately determining burn depth during an early examination. As a general rule, burn depth is underestimated upon initial examination.

The management plan for patients with large burns that require inpatient care is usually determined by the physiology of the burn injury.
Hospitalization is divided into 4 general phases, including (1) initial evaluation and resuscitation, (2) initial wound excision and biologic closure, (3) definitive wound closure, and (4) rehabilitation and reconstruction.

Early excision and closure of full-thickness wounds change the natural history of burn injury, avoiding the otherwise common occurrence of wound sepsis. Wound size is the most important factor in determining the need for early operation

Medications
See the list below:
– Silver sulfadiazine – Broad antibacterial spectrum; painless application
– Aqueous 0.5% silver nitrate – Broad-spectrum coverage, including fungi; leeches electrolytes
– Mafenide acetate – Broad antibacterial spectrum; penetrates eschar best
– Petrolatum – Bland and nontoxic
– Various debriding enzymes – Useful in selected partial-thickness wounds
– Various antibiotic ointments – Useful in many superficial partial-thickness wounds
Membranes
See the list below:
– Porcine xenograft – Adheres to wound coagulum and provides excellent pain control
– Split-thickness allograft – Vascularizes and provides durable temporary closure of wounds
– Various hydrocolloid dressings – Provide vapour and bacteria barrier while absorbing wound exudate
– Various impregnated gauzes – Provide vapour and bacteria barrier while allowing drainage
– Various semipermeable membranes – Provide vapour and bacteria barrier
– Acticoat (Westhaim Biomedical, Saskatchewan, Canada) – Nonadherent wound dressing that delivers a low concentration of silver for antisepsis
– Biobrane (Dow-Hickman, Sugarland, Tex) – Synthetic bilaminate that facilitates fibrovascular tissue growth into the inner layer and provides temporary vapour and bacteria barrier
– Transcyte (Smith and Nephew, Largo, Fla) – Synthetic bilaminate that facilitates fibrovascular tissue growth into the inner layer populated with allogenic fibroblasts and overlying layer that provides temporary vapour and bacteria barrier
– AlloDerm R – Consists of cell-free allogenic human dermis; requires an immediate thin overlying autograft
– Integra R – Provides scaffold for neodermis; requires delayed thin autograft

Hashimoto thyroiditis is part of the spectrum of autoimmune thyroid diseases (AITDs) and is characterized by the destruction of thyroid cells by various cell- and antibody-mediated immune processes.
The thyroid gland may become firm, large, and lobulated in Hashimoto’s thyroiditis, but changes in the thyroid can also be nonpalpable. Enlargement of the thyroid is due to lymphocytic infiltration and fibrosis, rather than tissue hypertrophy.

Laboratory studies and potential results for patients with suspected Hashimoto thyroiditis include the following:
– Serum thyroid-stimulating hormone (TSH) levels: Sensitive test of thyroid function; levels are invariably raised in hypothyroidism due to Hashimoto thyroiditis and in primary hypothyroidism from any cause
– Free T4 levels: Needed to correctly interpret the TSH in some clinical settings; low total T4 or free T4 level in the presence of an elevated TSH level further confirms diagnosis of primary hypothyroidism
– T3 levels: Low T3 level and high reverse T3 level may aid in the diagnosis of nonthyroidal illness

Thyroid autoantibodies: Presence of typically anti-TPO (anti-thyroid peroxidase) and anti-Tg (anti-thyroglobulin) antibodies delineates the cause of hypothyroidism as Hashimoto thyroiditis or its variant; however, 10-15% of patients with Hashimoto thyroiditis may be antibody negative.
While their role in the initial destruction of the follicles is unclear, antibodies against thyroid peroxidase (TPO) (also called TPOAb) or thyroglobulin are relevant, as they serve as markers for detecting the disease and its severity. They are hypothesized to be the secondary products of the T cell mediated destruction of the gland.

Mirizzi’s syndrome is a rare complication in which a gallstone becomes impacted in the cystic duct or neck of the gallbladder causing compression of the common hepatic duct, resulting in obstruction and jaundice. The obstructive jaundice can be caused by direct extrinsic compression by the stone or from fibrosis caused by chronic cholecystitis (inflammation).

Type I – No fistula present

Type IA – Presence of the cystic duct
Type IB – Obliteration of the cystic duct

Types II–IV – Fistula present

Type II – Defect smaller than 33% of the CHD diameter
Type III – Defect 33–66% of the CHD diameter
Type IV – Defect larger than 66% of the CHD diameter

Simple cholecystectomy is suitable for type I patients. This patient has type I because no fistula is present.

Birds, with their broad geographic ranges and close association with humans, have historically played an important role as carriers of human disease and as reservoirs for drug-resistant bacteria.
The highest diversity of bacteria were found on birds in natural habitats. The most frequently reported bacteria were Escherichia coli, Salmonella enterica, and Campylobacter jejuni. Of the bacteria species reported, 54% have shown pathogenicity toward humans. Percentage-wise, more pathogens were found in tropical (vs. temperate) habitats and natural (vs. suburban, urban, or agricultural) habitats.

Campylobacter jejuni is usually the most common cause of community-acquired inflammatory enteritis.

The symptoms and severity of the gastroenteritis produced can vary.
Patients may have a history of ingestion of inadequately cooked poultry, unpasteurized milk, or untreated water. The incubation period is 1-7 days and is probably related to the dose of organisms ingested.
A brief prodrome of fever, headache, and myalgias lasting up to 24 hours is followed by crampy abdominal pain, fever as high as 40°C, and as many as 10 watery, frequently bloody, bowel movements per day. Fever, which develops in more than 90% of patients, maybe low or high grade and can persist for a week.
Patients with C jejuni infection who report vomiting, bloody diarrhoea, or both tend to have a long illness and require hospital admission.
Abdominal pain and tenderness may be localized. Pain in the right lower quadrant may mimic acute appendicitis (pseudo appendicitis).
Tenesmus occurs in approximately 25% of patients.

Answer: Waterhouse- Friderichsen syndrome

Waterhouse-Friderichsen syndrome is a condition characterized by the abrupt onset of fever, petechiae, arthralgia, weakness, and myalgias, followed by acute haemorrhagic necrosis of the adrenal glands and severe cardiovascular dysfunction. The syndrome is most often associated with meningococcal septicaemia but may occur as a complication of sepsis caused by other organisms, including certain streptococcal species. This disorder may be associated with a history of splenectomy.

Fulminant infection from meningococcal bacteria in the bloodstream is a medical emergency and requires emergent treatment with vasopressors, fluid resuscitation, and appropriate antibiotics. Benzylpenicillin was once the drug of choice with chloramphenicol as a good alternative in allergic patients. Ceftriaxone is an antibiotic commonly employed today. Hydrocortisone can sometimes reverse the adrenal insufficiency. Amputations, reconstructive surgery, and tissue grafting are sometimes needed as a result of tissue necrosis (typically of the extremities) caused by the infection.

One of the characteristic features of the pacemaker cell is the generation of a gradual diastolic depolarization also called the pacemaker potential. In phase 0, the upstroke of the action potential caused by an increase in the Ca2+ conductance, an influx of calcium occurs and a positive membrane potential is generated. The next is phase 3 which is repolarization caused by increased K+ conductance as a result of outwards K+ current. Phase 4 is a slow depolarization which accounts for the pacemaker activity, caused by increased conductance of Na+, inwards Na+ current called IF. it is turned on by repolarization.

Pancreatitis is inflammation of the pancreas with variable involvement of regional tissues or remote organ systems. Acute pancreatitis (AP) is characterized by severe pain in the upper abdomen and elevation of pancreatic enzymes in the blood. In the majority of patients,
Biliary pancreatitis should always be treated eventually with a cholecystectomy after the process has subsided.
Feeding should be introduced enterally as the patient’s anorexia and pain resolves.
The use of nasogastric aspiration offers no clear advantage in patients with mild AP, but is beneficial in patients with profound pain, severe disease, paralytic ileus, and intractable vomiting.
AP is a mild, self-limiting disease that resolves spontaneously without complications. Patients can be initiated on a low-fat diet initially and need not invariably start their dietary advancement using a clear liquid diet. Systematic reviews and meta-analyses have shown that administration of enteral nutrition may reduce mortality and infectious complications compared with parenteral nutrition. Although the ideal timing to initiate enteral feeding remains undetermined, administration within 48 hours appears to be safe and tolerated.

Making up 4-5% of total body weight, the skin receives approximately 2% of cardiac output.

Juvenile polyps are benign hamartomas with neoplastic potential that are the most frequent gastrointestinal polyp of childhood, with the peak incidence between 3 and 5 years of age.. The presence of multiple juvenile polyps may indicate a premalignant condition commonly named juvenile polyposis coli or juvenile polyposis syndrome (JPS). In contrast, single or solitary juvenile polyps generally are considered benign sporadic lesions that confer little to no future risk of malignancy. Most frequent presentation is painless rectal bleeding. Other features include a prolapsing rectal mass and abdominal pain.

Answer: Stress fracture

A stress fracture is caused by repetitive and submaximal loading of the bone, which eventually becomes fatigued and leads to a true fracture. The typical presentation is a complaint of increasing pain in the lower extremity during exercise or activity. The patient’s history usually reveals a recent increase in either training volume or intensity. Stress fractures result from recurrent and repetitive loading of bone. The stress fracture differs from other types of fractures in that in most cases, no acute traumatic event precedes the symptoms.

Normal bone remodelling occurs secondary to increased compressive or tensile loads or increased load frequency. In the normal physiologic response, minor microdamage of the bone occurs. This is repaired through remodelling. Stress fractures develop when extensive microdamage occurs before the bone can be adequately remodelled.
Common findings on physical examination may include tenderness or pain on palpation or percussion of the bone. Erythema or oedema may be present at the site of the stress fracture. Loading or stress of the affected bone may also produce symptoms.

A stress fracture can be difficult to see on an X-ray, because the bone often appears normal in the X-ray, and the small cracks can’t be seen. X-rays may not help diagnose a stress fracture unless it has started to heal. When the bone starts to heal, it creates a callus, or lump, that can be seen on X-rays. The doctors may recommend a bone scan or magnetic resonance imaging (MRI), which is more sensitive than an X-ray and can spot stress fractures early.

Freiberg disease is a degenerative process involving the epiphyses resulting in osteonecrosis of subchondral cancellous bone. If the process is altered in such a way as to restore normal physiology, this may be followed by regeneration or recalcification. If not, the process continues to subchondral collapse and eventual fragmentation of the joint surface.
Patients who have Freiberg disease typically present with complaints of activity-related forefoot pain. Walking alone is often sufficient to cause pain. Some patients describe an extended (months to years) history of chronic forefoot pain with episodic exacerbation, whereas others present with pain of recent onset that is related to a specific injury or event. A history of trauma may not be noted. Patients may present with stiffness and a limp. The pain is often vague and poorly localized to the forefoot. Some patients describe the sensation of a small, hard object under the foot.

Physical examination typically reveals a limited range of motion (ROM), swelling, and tenderness with direct palpation of the metatarsophalangeal (MTP) joint. In early stages of the disease, MTP tenderness may be the only finding. In later stages, crepitus or deformity may be present. A skin callus may be seen on the plantar surface of the affected metatarsal head.

Radiography
Depending on the stage of the disease, radiographs may show only sclerosis and widening of the joint space (early), with complete collapse of the metatarsal head and fragmentation later. Osteochondral loose bodies may be seen late in the disease as well. Oblique views may be especially useful for achieving a full appreciation of subtle changes early in the disease. One study advocated the use of radiographs to assess musculoskeletal foot conditions in women related to poorly fitting shoes.
Occasionally, patients are completely asymptomatic, with changes noted on radiographs taken for other reasons. Whether these patients later develop symptomatic Freiberg disease is not known.

As the cochlea is embedded into bone, the vibrations from the bone are transmitted directly to the fluid in the cochlea. Hence, any damage to the ossicles or tympanic membrane will not show an abnormal result on bone conduction test.

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.

The symptoms suggest Cushing syndrome due to increased glucocorticoid levels. One cause of Cushing syndrome is ectopic production of adrenocorticotrophic hormone from oat cell carcinoma. As oat cell carcinoma is known to be highly metastatic, the tenderness in lower back could represent metastatic involvement.

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.

Transverse pericardial sinus: located behind two great vessels (aorta and pulmonary trunk) and in front of the superior vena cava and is accessed from above as in this case. The brachiocephalic trunk is located above the pericardium and the right pulmonary artery is above the pericardial reflections.