Norepinephrine is synthesized from dopamine by dopamine β-hydroxylase.[7] It is released from the adrenal medulla into the blood as a hormone, and is also a neurotransmitter in the central nervous system and sympathetic nervous system where it is released from noradrenergic neurons.

Understand the adrenal gland with a focus on the adrenal cortex with this clear explanation .

Hepatitis and chronic alcohol abuse are frequent causes. Liver damage caused by cirrhosis can't be undone, but further damage can be limited. Initially patients may experience fatigue, weakness, and weight loss. During later stages, patients may develop jaundice (yellowing of the skin), gastrointestinal bleeding, abdominal swelling, and confusion. Treatments focus on the underlying cause. In advanced cases, a liver transplant may be needed.

Some of these advancements include the use of robots to perform the surgery and the use of computer mapping scanners and software and even 3D printers to make the artificial knee implant. We are also seeing a lot of different advances being made by the medical device manufacturers.Some of these changes are designed to make the devices more durable than the 10 to 20 years they are currently rated to last. This is important when younger patients who are years away from being considered elderly have a total knee replacement, they will typically need another artificial knee implanted at a later date since they are likely to outlive the implant, which doesn’t always happen with elderly patients.

The epididymis is a long coiled tube that lies above and behind each testicle. The epididymis collects and transports sperm from the testis to the vas deferens (tubes that transport sperm to the urethra). An epididymal cyst is a cyst-like mass in the epididymis that contains clear fluid. Typically, epididymal cysts and spermatoceles do not cause symptoms. When discovered, the epididymal cyst is usually about the size of a pea and feels separate from the top of the testis. Spermatoceles typically arise from the head of the epididymis, and are felt on the top portion of the testicle. Epididymal cysts and spermatoceles are often incidental findings on testicular self-examination or routine physical examination. It is important that any mass noted in the scrotum be examined by a urologist in order to obtain an accurate diagnosis, especially a mass on the testicle itself. Our team in the Division of Urology will typically be able to confirm the diagnosis on physical exam. However, a scrotal ultrasound may also be used in order to rule out other conditions.

Both lower extremities must be evaluated to determine the presence or extent of any disease and to ascertain the pulse status of the patient. The feet are examined for signs of peripheral vascular disease and the anterior and posterior tibial pulses are palpated. Because an intact arch can supply retrograde flow to the major vessels of the foot, it can be helpful to put pressure on the anterior tibial artery when detecting the presence of a posterior tibial pulse and visa-versa. This "modified Allen's test" may detect proximal vessel obstruction masked by an intact foot arch. The need for preoperative angiography in young, healthy patients with a normal physical examination has been hotly debated. Our tendency has been to obtain preoperative angiograms as a guide. Although rare, we have seen lower extremities with a dominant peroneal artery nourishing the foot and distal anterior and posterior vessels, contraindicating sacrifice of the peroneal artery. MRI or CT angiography can also be used in many circumstances.

Ascites, the collection of fluid within the peritoneal space is caused due to a variety of causes including cirrhosis, cardiac causes, sinusoidal obstruction syndrome, tubercular peritonitis and pancreatitis, amongst others. Most commonly, the cause of ascots may be cirrhosis , which in turn, is most frequently causes by alcohol use, hepatitis C and non-alcoholic steatohepatitis. At the heart of the ascitic fluid analysis is the serum albumin ascitic gradient, the differential diagnosis of which has been discussed in detail in this presentation. Both low SAAG and high SAAG ascites have been dealt with in some depth, with a brief overview of the management of these conditions

Acute respiratory distress syndrome is characterised by rapid onset dyspnea, bilateral infiltrates on chest x-ray and respiratory failure. This may be due to conditions which directly affect the lung such as pneumonia, aspiration and near drowning. It may also be due to indirect lung injury, as in conditions like sepsis, pancreatitis, trauma and poisoning. The diagnostic criteria of ARDS, often described as the Berlin criteria is discussed in this presentation along with various management aspects of ARDS including ventilation strategies and use of antibiotics and diuretics. Finally prognostic features and alternative strategies are also discussed.

Acute mesenteric ischemia (AMI) is a syndrome caused by inadequate blood flow through the mesenteric vessels, resulting in ischemia and eventual gangrene of the bowel wall. Although relatively rare, it is a potentially life-threatening condition. Broadly, AMI may be classified as either arterial or venous. AMI as arterial disease may be subdivided into nonocclusive mesenteric ischemia (NOMI) and occlusive mesenteric arterial ischemia (OMAI); OMAI may be further subdivided into acute mesenteric arterial embolism (AMAE) and acute mesenteric arterial thrombosis (AMAT). AMI as venous disease takes the form of mesenteric venous thrombosis (MVT).

Buerger's disease (thromboangiitis obliterans) is a rare disease of the arteries and veins in the arms and legs. In Buerger's disease, your blood vessels become inflamed, swell and can become blocked with blood clots (thrombi). This eventually damages or destroys skin tissues and may lead to infection and gangrene. Buerger's disease usually first shows in your hands and feet and may eventually affect larger areas of your arms and legs. Virtually everyone diagnosed with Buerger's disease smokes cigarettes or uses other forms of tobacco, such as chewing tobacco. Quitting all forms of tobacco is the only way to stop Buerger's disease. For those who don't quit, amputation of all or part of a limb is sometimes necessary.

Diabetic ketoacidosis is an acute complication of uncontrolled hyperglycaemia characterised by high anion gap metabolic acidosis, dehydration and other metabolic abnormalities. Upto half of patients with Type 1 diabetes mellitus may have DKA. The incidence in T2DM is also rising. Precipitants include acute illness such as myocardial infarction, trauma and infection. Paitents of diabetic ketoacidosis may present with vomiting, pain abdomen and lethargy. Mental obtundation may also be present. Management of diabetic ketoacidosis revolves around administration of IV normal saline, insulin, replacement of potassium with frequent monitoring of sugars and electrolytes.

This procedure, and other types of soft palate surgery, targets the back of the roof of your mouth. It involves removing and repositioning excess tissue in the throat to make the airway wider. The surgeon can trim down your soft palate and uvula, remove your tonsils, and reposition some of the muscles of the soft palate. UPPP and other soft palate procedures are the most common type of surgery for sleep apnea. But UPPP alone is unlikely to cure moderate to severe sleep apnea. It may be combined with surgeries that target other sites in the upper airway.

A cervical herniated disc may be treated by removing part of the disc through a small incision (microdiscectomy). If this is done from the back (posteriorly) rather than from the front of the neck, a spinal fusion is not necessary. The alternative is an anterior cervical discectomy and fusion procedure.

Compartment syndrome can develop in the foot following crush injury or closed fracture. Following some critical threshold of bleeding and/or swelling into the fixed space compartments, arterial pulse pressure is insufficient to overcome the osmotic tissue pressure gradient, leading to cell death. The complicating factor is related to the magnitude of the force of the crush injury. The amount of swelling or bleeding has to be sufficient to impair arterial inflow, while not being of sufficient magnitude to produce an open injury, which decompresses the pressure within the affected compartments. When the injury is open, we then attribute the late disability primarily to the crushing injury to the involved muscles.

Educational video describing injection techniques for painful conditions of the foot and ankle.

Biceps tenodesis is a common procedure performed for tendinopathy of the long head of the biceps brachii (LHB). Indications include partial-thickness LHB tear, tendon subluxation with or without subscapularis tear, and failed conservative management of bicipital tenosynovitis. Biceps tenodesis may also be performed for superior labrum anterior to posterior tears.

A walk through of an interactive about male to female sex reassignment surgery.