There are two ejaculatory ducts, one on either side of the midline. Each ejaculatory duct is formed by the union of the duct from the seminal vesicles with the ductus deferens. They start at the base of the prostate and run forward and downward between the middle and lateral lobes and along the side of the prostatic utricle to end in the prostatic urethra.

Normally, the transfer of oxygen from air spaces to blood takes place across the alveolar-capillary membrane by simple diffusion and depends entirely on the amount of blood flow (perfusion-limited process). Diseases that affect this diffusion will transform the normal process to a diffusion limited process. Thus, the diseases which cause a thickened barrier (such as pulmonary oedema due to increased extravascular lung water or asbestosis) will limit the diffusion of oxygen. Chronic obstructive lung diseases will have little effect on diffusion. Inhaling hyperbaric gas mixtures might overcome the diffusion limitation in patients with mild asbestosis or interstitial oedema, by increasing the driving force. Strenuous (not mild) exercise might also favour diffusion limitation and decrease passage time. Increasing the rate of ventilation will not have this affect but will only maintain a high oxygen gradient from air to blood.

The most appropriate management option to consider, after GTN or other topical nitrates have failed, is botulinum toxin injection. In males, a lateral internal sphincterotomy would be an acceptable alternative. In a female who has yet to conceive, this may predispose to an increased risk of sphincter dysfunction. Moreover, division of the external sphincter would result in faecal incontinence and is not a justified treatment for anal fissure.

Anal fissures are a common cause of painful, bright red rectal bleeding. Most fissures are idiopathic and present as a painful mucocutaneous defect in the posterior midline (90% cases). Fissures are more likely to be anteriorly located in females, particularly if they are multiparous. Diseases associated with fissure-in-ano include:
1. Crohn’s disease
2. Tuberculosis
3. Internal rectal prolapse

Diagnostic options are as follows:
In most cases, the defect can be visualised as a posterior midline epithelial defect. Where symptoms are highly suggestive of the condition and examination findings are unclear, an examination under anaesthesia may be helpful. Atypical disease presentation should be investigated by colonoscopy and EUA, with biopsies of the area.

For management of anal fissure:
1. Stool softeners are important as hard stools may tear the epithelium and result in recurrent symptoms. The most effective first-line agents are topically applied GTN (0.2%) or Diltiazem (2%) paste.
2. Resistant cases may benefit from injection of botulinum toxin or lateral internal sphincterotomy. Advancement flaps may be used to treat resistant cases.

The rectum is part of the gastrointestinal tract that is continuous above with the sigmoid colon and below with the anal canal. It contains both longitudinal and circular smooth muscles. These are supplied by the enteric nervous system. It is about 12 cm long. It has no sacculations comparable with those of the colon. It has three permanent transverse folds called the valves of Houston. The peritoneum is related to the upper two thirds of the rectum only whereas the lower part is not covered by peritoneum. It is supplied by the superior rectal (hemorrhoidal) branch of the inferior mesenteric artery and the median sacral artery that is a direct branch from the abdominal aorta. It is drained by veins that begin as a plexus that surround the anus. These veins form anastomoses with the portal system (portocaval anastomoses).

Effective management of intracranial hypertension involves meticulous avoidance of factors that precipitate or aggravate increased intracranial pressure. When intracranial pressure becomes elevated, it is important to rule out new mass lesions that should be surgically evacuated. Medical management of increased intracranial pressure should include sedation, drainage of cerebrospinal fluid, and osmotherapy with either mannitol or hypertonic saline. For intracranial hypertension refractory to initial medical management, barbiturate coma, hypothermia, or decompressive craniectomy should be considered. Steroids are not indicated and may be harmful in the treatment of intracranial hypertension resulting from traumatic brain injury.
Mannitol is the most commonly used hyperosmolar agent for the treatment of intracranial hypertension.
Intravenous bolus administration of mannitol lowers the ICP in 1 to 5 minutes with a peak effect at 20 to 60 minutes. The effect of mannitol on ICP lasts 1.5 to 6 hours, depending on the clinical condition. Mannitol usually is given as a bolus of 0.25 g/kg to 1 g/kg body weight; when an urgent reduction of ICP is needed, an initial dose of 1 g/kg body weight should be given. Arterial hypotension (systolic blood pressure < 90 mm Hg ) should be avoided.

The rectus abdominis muscle is supplied by the superior epigastric artery which is a branch of the internal thoracic artery. If the internal thoracic artery is thus ligated, blood would no longer flow to it. However, the superior epigastric artery communicates with the inferior epigastric artery (a branch of the external iliac artery). This means that blood could flow from the external iliac, to the inferior epigastric, to the superior epigastric to the rectus abdominis.
The superficial circumflex iliac artery and the superficial epigastric are two superficial branches of the femoral artery and do not supply the deep branches of the abdomen.
The deep circumflex iliac artery travels along the iliac crest on the inner surface of the abdominal wall; being too lateral it doesn’t supply blood to the rectus abdominis.
The distal portions of the umbilical arteries are obliterated in adults to form the medial umbilical folds.

The loop of Henlé leads from the proximal convoluted tubule to the distal convoluted tubule. Its primary function uses a counter current multiplier mechanism in the medulla to reabsorb water and ions from the urine. It can be divided into four parts:
1. Descending limb of loop of Henlé – low permeability to ions and urea, while being highly permeable to water 2. Thin ascending limb of loop of Henlé – not permeable to water, but it is permeable to ions
3. Medullary thick ascending limb of loop of Henlé – sodium (Na+), potassium (K+) and chloride (Cl–) ions are reabsorbed by active transport. K+ is passively transported along its concentration gradient through a K+ channel in the basolateral aspect of the cells, back into the lumen of the ascending limb.
4. The cortical thick ascending limb – the site of action where loop diuretics such as furosemide block the K+/Na+/2Cl− co-transporters = reduced active transport.

The basal metabolic rate (BMR) is defined as the rate of calorie consumption after an overnight fast, in the absence of any muscular activity, with the patient in a restful state. Various factors affect the BMR including weight, body surface area and age. The BMR is 30 kcal/m2 per hour at birth; at age 2, the rate is 57 kcal/m2 per hour; and at age 20, 41 kcal/m2 per hour. After this, the BMR decreases by 10% between 20-60 years of age. Women are known to have a 10% lower BMR than men (due to higher fat content). A one-degree change in body temperature leads to a 10% change in BMR in the same direction. However, shivering and increasing ambient temperature brings about a rise in BMR, and so does stress, physical activity, caffeine, theophylline and hyperthyroidism. Also, thermogenesis induced by diet results in increased metabolic rate and hence, BMR should be ideally measured after overnight fasting.

Patients with paralysis of the right pterygoid muscle are unable to move their mandible laterally to the left.

Compound Sodium Lactate (Hartmann’s) is used:
• for intravenous fluid and electrolyte replacement
• as a source of bicarbonate in the treatment of mild to moderate metabolic acidosis associated with dehydration or associated with potassium deficiency
• as a vehicle for intravenous drug delivery, if the drugs are compatible with the solutions

The total amount of electrolytes per litre are: sodium 131 mmol, potassium 5mmol, chloride 112 mmol, calcium 2mmol, bicarbonate (as lactate) 28 mmol.
The osmolality is approximately 255 mOsm/kg water. The solutions are isotonic, sterile, non-pyrogenic and do not contain antimicrobial agent or added buffers. The pH range is 5.0 to 7.0. Compound Sodium Lactate

Ringer’s lactate solution (RL), also known as sodium lactate solution and Hartmann’s solution, is a mixture of sodium chloride, sodium lactate, potassium chloride, and calcium chloride in water. It is used for replacing fluids and electrolytes in those who have low blood volume or low blood pressure.

Hartmann’s solution is often preferred over normal saline as it contains both fluids and electrolytes. The solution is also associated with fewer adverse effects and it can be administered to both adults and children.

Heparin is a natural highly-sulphated glycosaminoglycan that has anticoagulant functions. It is produced by the body basophils and mast cells.

A pleural effusion is defined as an abnormal collection of fluid in the pleural space. Pleural effusion can result from excess fluid production or decreased absorption or both. Thoracentesis and laboratory testing help determine the origin of the accumulated fluid. Serous fluid accumulation in the pleural space indicates the presence of a hydrothorax and is most likely to develop secondary to congestive heart failure.

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

Structures that pass through the lesser sciatic foramen include:
– the pudendal nerve
– the nerve to obturator internus
– internal pudendal artery
– the tendon of obturator internus

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 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.

Embryologically the testes are retroperitoneal structures in the posterior abdominal wall, attached to the anterolateral abdominal wall by the gubernaculum. The gubernaculum ‘pulls’ the testes through the deep inguinal ring, inguinal canal and superficial inguinal ring and over the pelvic brim. The gubernaculum is preceded by the processus vaginalis that is derived from the peritoneum anterior to the testes. The processus vaginalis pushes the muscle and fascial layers. These eventually make up the canal and the spermatic cord, into the scrotum. The gubernaculum persists as the scrotal ligament while part of the processus vaginalis remains as a bursa-like sac i.e. the tunica vaginalis testes. The testes therefore could be caught in any one of these places along its path of descending. The testes are never in the perineum.

In children, more common causes of Urinary tract obstruction include the following:
UPJ or UVJ obstruction
Ectopic ureter
Ureterocoele
Megaureter
Posterior urethral valves

Posterior urethral valves:

During the early stages of embryogenesis, the most caudal end of the wolffian duct is absorbed into the primitive cloaca at the site of the future verumontanum in the posterior urethra. In healthy males, the remnants of this process are the posterior urethral folds, called plicae colliculi. Histologic studies suggest that PUVs are formed at approximately 4 weeks’ gestation, as the wolffian duct fuses with the developing cloaca.
Congenital obstructing posterior urethral membrane (COPUM) was first proposed by Dewan and Goh and was later supported by histologic studies by Baskin. This concept proposes that instead of a true valve, a persistent oblique membrane is ruptured by initial catheter placement and, secondary to rupture, forms a valve like configuration.
Indicators of possible PUVs later in childhood include the following:
Urinary tract infection (UTI)
Diurnal enuresis in boys older than 5 years
Secondary diurnal enuresis
Voiding pain or dysfunction
Abnormal urinary stream

Prolactinoma is the mot common pituitary adenoma; leading to hyperprolactinaemia. By virtue of their size, macroprolactinomas press on the adjacent structures leading to headaches and loss of vision due to the pressure effect on optic chiasm. Women notice a change in their menstrual cycle due to raised prolactin levels. In comparison, the problem goes unnoticed in men in the initial stages. Craniopharyngioma is a less common space-occupying lesions affecting children and young adults.

In a developing foetus, the stomach has two mesogastria from which most of the abdominal ligaments develop. These two mesogastria are the; ventral mesogastrium and the dorsal mesogastrium. During the embryological development of the gut, different organs develop in each mesogastrium; the spleen and pancreas in the dorsal mesogastrium while the liver in the ventral mesogastrium (with their associated ligaments). In the dorsal mesogastrium the following structures develop; the greater omentum (containing the gastrophrenic ligament and the gastrocolic ligament), gastrosplenic ligament, mesentery, splenorenal ligament and phrenicocolic ligament. The structures that develop from the ventral mesogastrium include the; lesser omentum (containing the hepatoduodenal ligament and the hepatogastric ligament) in association with the liver; the coronary ligament (left triangular ligament, right triangular ligament and hepatorenal ligament) and the falciform ligament (round ligament of liver and ligamentum venosum within).
There are also folds that develop from the dorsal mesogastrium which include; umbilical folds, supravesical fossa, medial inguinal fossa, lateral umbilical fold, lateral inguinal fossa and Ileocecal fold.

Atrophy is the decrease in the size of cells, tissues, or organs. There are several causes including inadequate nutrition, poor circulation, loss of hormonal support or nerve supply, disuse, lack of exercise, or disease. An increase in cell size is termed hypertrophy which is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number.

Formation of granulation tissue at the periphery of the hematoma is a normal process leading to resolution. This granulation tissue is composed of new capillaries, fibroblasts and collagen. Lysis of a blood clot can occur, but the actual process of this response is known as organization, wherein the scar tissue will become part of the vessels. This is followed by recanalization and embolization which can lead to eventual complications. Proliferation of a clot will occur due to an imbalance in the clotting and lysing systems. Thrombosis has nothing to do with the process described above.

The musculoskeletal nerve supplies the muscles of the anterior compartment of the arm including the coracobrachialis, biceps brachii and the greater part of the brachialis. This nerve derives its fibres from the fifth, sixth and seventh cervical nerves and arises from the lateral cord of the brachial plexus. It also provides a branch to the elbow joint.

Bladder pressures below 5mm Hg are expected in healthy patients. Pressures between 10 to 15 mmHg can be expected following abdominal surgery and in obese patients. Bladder pressures over 25 mmHg are highly suspicious of abdominal compartment syndrome and should be correlated clinically. It is recommended that pressure measurements be trended to show and recognize the worsening of intra-abdominal hypertension. Recommended management at this stage includes fluid resuscitation and if the pressure rises beyond the critical threshold of 25 mmHg, abdominal decompression is required.

At the level mentioned in the question, the lateral portion of dorsal columns comprises of the fasciculus cuneatus. Axons carrying the sensations of touch, vibration and proprioception from the ipsilateral arm enter the spinal cord and ascend in the fasciculus cuneatus, synapsing in the nucleus cuneatus of the caudal medulla. Secondary neurons from this nucleus give rise to internal arcuate fibres, which decussate and ascend to the thalamus as the medial lemniscus. Tertiary neurons from there project to the ipsilateral somatosensory cortex. Thus, any damage to the fasciculus cuneatus will result in a deficit in tactile, proprioceptive and vibratory sensations in the ipsilateral arm, and not the contralateral arm.
Fine motor control of the fingers is mainly carried by the ipsilateral lateral corticospinal tract in the lateral funiculus of the cord. Motor control of the contralateral foot is carried by the ipsilateral corticospinal tract in the lateral funiculus of the cord. Lack of sweating of the face could be produced by interruption of sympathetic innervation. Proprioception from the ipsilateral leg is carried by the fasciculus gracilis in the medial part of the dorsal columns.

The patient is in hypovolemic shock, he is transfused with blood, this fluid resuscitation will result in a decreased sympathetic discharge and adequate ventricular filling which will result in the decreases TPR with an increased CO and cardiac filling pressures

Answer: Acute subdural haematoma

An acute subdural haematoma (SDH) is a clot of blood that develops between the surface of the brain and the dura mater, the brain’s tough outer covering, usually due to stretching and tearing of veins on the brain’s surface. These veins rupture when a head injury suddenly jolts or shakes the brain.
Traumatic acute SDHs are among the most lethal of all head injuries. Associated with more severe generalized brain injury, they often occur with cerebral contusions.
SDHs are seen in 10 percent to 20 percent of all traumatic brain injury cases and occur in up to 30 percent of fatal injuries.
Diagnosis:

SDHs are best diagnosed by computed tomography (CT) scan. They appear as a dense, crescent-shaped mass over a portion of the brain’s surface.
Most patients with acute SDHs have low Glasgow Coma Scale (GCS) scores on admission to the hospital.

Acute traumatic subdural haematoma often results from falls, violence, or motor vehicle accidents. Suspect acute subdural haematoma whenever the patient has experienced moderately severe to severe blunt head trauma. The clinical presentation depends on the location of the lesion and the rate at which it develops. Often, patients are rendered comatose at the time of the injury. A subset of patients remain conscious; others deteriorate in a delayed fashion as the haematoma expands.
A GCS score less than 15 after blunt head trauma in a patient with no intoxicating substance use (or impaired mental status baseline) warrants consideration of an urgent CT scan. Search for any focal neurologic deficits or signs of increased ICP. Any abnormality of mental status that cannot be explained completely by alcohol intoxication or the presence of another mind-altering substance should increase suspicion of subdural hematoma in the patient with blunt head trauma.

The clinical presentation of a patient with an acute subdural haematoma depends on the size of the hematoma and the degree of any associated parenchymal brain injury. Symptoms associated with acute subdural haematoma include the following:

Headache

Nausea

Confusion

Personality change

Decreased level of consciousness

Speech difficulties

Other change in mental status

Impaired vision or double vision

Weakness

On noncontrast CT scan, an acute subdural haematoma appears as a hyperdense (white), crescent-shaped mass between the inner table of the skull and the surface of the cerebral hemisphere.

Short gastric arteries arise from the splenic artery at the end or from its terminal divisions. They are about 5 or 7 in number, passing from the left to the right in between the layers of the gastrosplenic ligament to be distributed along the greater curvature of the stomach.

The costomediastinal recess is the point where the costal pleura becomes the mediastinal pleura, located right next to the cardiac notch.
The cupola: part of the parietal pleura that extends above the first rib to the root of the lung.
Hilum: located on the medial surface of the lung where neurovascular structures enter and leave the lung.
Pulmonary ligament: pleural fold found below the root of the lung, is a point of continuity between the visceral and mediastinal pleura.
Costodiaphragmatic recess: the lowest extent of the pleural cavity.
Superior mediastinum: part of the mediastinum that contains the great vessels leaving and entering the heart.
The cardiac notch is in the inferior mediastinum.

The posterior humeral circumflex artery arises from the axillary artery and runs with the axillary nerve through the quadrangular space which is bounded laterally by the surgical neck of the humerus. After winding around the surgical neck of the humerus, it is distributed to the deltoid muscle and the shoulder joint. Thus fractures in the surgical neck of the humerus could result in an injury to this artery.