These are being increasingly diagnosed with more widespread use of CT and ultrasound scanning.
Accessory lobes. The livers of the pig, dog and camel are divided into distinct and separate lobes by strands of connective tissue. Occasionally, the human liver may show this reversion and up to 16 lobes have been reported. This abnormality is rare and without clinical significance. The lobes are small and usually on the undersurface of the liver so that they are not detected clinically but are noted incidentally at scanning, operation or necropsy. Rarely they are intrathoracic. An accessory lobe may have its own mesentery containing hepatic artery, portal vein, bile duct and hepatic vein.
This may twist and demand surgical intervention. Ectopic liver. Small nodules of normal liver derived from the embryologic hepatic bud may be found in less than 1% of laparoscopies and autopsies near the gallbladder, hepatic ligaments, gastrorenal ligament, omentum, retroperitorneum
and thorax. These may give rise to hepatocellular carcinoma.
Riedel’s lobe. This is fairly common and is a downward tongue - like projection of the right lobe of the liver.
ANATOMY OF THE LIVER
• The liver is derived from a foregut endodermal bud which develops in the third week of gestation and divides into two parts: hepatic and biliary.
• The Couinaud classifi cation subdivides the liver into eight segments (segments I – IV in the left lobe, segments V – VIII in the right lobe) based on vascular and biliary anatomical landmarks.
• The lobule described by Kiernan is the most widely used unit of liver microanatomy, consisting of a hexagon - like region of liver parenchyma with a central vein as its hub and portal tracts located in the periphery of the hexagon.
• Hepatocytes are functionally heterogeneous within the lobular parenchyma, whereby centrilobular cells subserve different functions (e.g. drug metabolism) from periportal cells (e.g. bile salt - dependent bile formation).
• Uncomplicated regeneration of hepatocytes and/or bile duct epithelium usually occurs by cell division of the indigenous cells; however, when normal regenerative capacity is overwhelmed there may be activation of progenitors cells located in the region of the canals of Hering.
The liver, the largest organ in the body, weighs 1200 – 1500 g and comprises one - fi ftieth of the total adult body weight. It is relatively larger in infancy, comprising one - eighteenth of the birth weight. This is mainly due to a large left lobe.
• The Couinaud classifi cation subdivides the liver into eight segments (segments I – IV in the left lobe, segments V – VIII in the right lobe) based on vascular and biliary anatomical landmarks.
• The lobule described by Kiernan is the most widely used unit of liver microanatomy, consisting of a hexagon - like region of liver parenchyma with a central vein as its hub and portal tracts located in the periphery of the hexagon.
• Hepatocytes are functionally heterogeneous within the lobular parenchyma, whereby centrilobular cells subserve different functions (e.g. drug metabolism) from periportal cells (e.g. bile salt - dependent bile formation).
• Uncomplicated regeneration of hepatocytes and/or bile duct epithelium usually occurs by cell division of the indigenous cells; however, when normal regenerative capacity is overwhelmed there may be activation of progenitors cells located in the region of the canals of Hering.
The liver, the largest organ in the body, weighs 1200 – 1500 g and comprises one - fi ftieth of the total adult body weight. It is relatively larger in infancy, comprising one - eighteenth of the birth weight. This is mainly due to a large left lobe.
SCOLIOSIS AND TREATMENT
What Is Scoliosis?
Scoliosis is a lateral (toward the side) curvature in the normally straight vertical line of the spine. When viewed from the side, the spine should show a mild roundness in the upper back and shows a degree of swayback (inward curvature) in the lower back. When a person with a normal spine is viewed from the front or back, the spine appears to be straight. When a person with scoliosis is viewed from the front or back, the spine appears to be curved.
What Causes Scoliosis?
There are many types and causes of scoliosis, including:
Congenital scoliosis. Caused by a bone abnormality present at birth.
Neuromuscular scoliosis. A result of abnormal muscles or nerves. Frequently seen in people with spina bifida or cerebral palsy or in those with various conditions that are accompanied by, or result in, paralysis.
Degenerative scoliosis. This may result from traumatic (from an injury or illness) bone collapse, previous major back surgery, or osteoporosis (thinning of the bones).
Idiopathic scoliosis. The most common type of scoliosis, idiopathic scoliosis, has no specific identifiable cause. There are many theories, but none have been found to be conclusive. There is, however, strong evidence that idiopathic scoliosis is inherited.
Scoliosis is a lateral (toward the side) curvature in the normally straight vertical line of the spine. When viewed from the side, the spine should show a mild roundness in the upper back and shows a degree of swayback (inward curvature) in the lower back. When a person with a normal spine is viewed from the front or back, the spine appears to be straight. When a person with scoliosis is viewed from the front or back, the spine appears to be curved.
What Causes Scoliosis?
There are many types and causes of scoliosis, including:
Congenital scoliosis. Caused by a bone abnormality present at birth.
Neuromuscular scoliosis. A result of abnormal muscles or nerves. Frequently seen in people with spina bifida or cerebral palsy or in those with various conditions that are accompanied by, or result in, paralysis.
Degenerative scoliosis. This may result from traumatic (from an injury or illness) bone collapse, previous major back surgery, or osteoporosis (thinning of the bones).
Idiopathic scoliosis. The most common type of scoliosis, idiopathic scoliosis, has no specific identifiable cause. There are many theories, but none have been found to be conclusive. There is, however, strong evidence that idiopathic scoliosis is inherited.
WHAT IS THE HISTORY OF DIABETES
Diseases with the clinical features of diabetes have been recognised since antiquity. The Ebers papyrus, dating from 1550 BC, describes a polyuric state that resembles diabetes.
The word ‘ diabetes ’ was fi rst used by Aretaeus of Cappadocia in the second century AD. Aretaeus gave a clinical description of the disease, noting the increased urine flow, thirst and weight loss, features that are instantly recognizable today.
The sweet, honey - like taste of urine in polyuric states, which attracted ants and other insects, was reported by Hindu physicians such as Sushrut (Susruta) during the fifth and sixth centuries AD. These descriptions even mention two forms of diabetes, the more common occurring in older, overweight and indolent people, and the other in lean people who did not survive for long. This empirical subdivision predicted the modern classification into type 1 and type 2 diabetes.
Diabetes was largely neglected in Europe until a 17th - century English physician, Thomas Willis (1621 – 75), rediscovered the sweetness of diabetic urine. Willis, who was physician to King Charles II, thought that the disease had been rare in ancient times, but that its frequency was increasing in his age ‘ given to good fellowship ’. Nearly a century later, the Liverpool physician Matthew Dobson
(1735 – 84) showed that the sweetness of urine and serum was caused by sugar. John Rollo (d. 1809) was the first to apply the adjective ‘ mellitus ’ to the disease.
The word ‘ diabetes ’ was fi rst used by Aretaeus of Cappadocia in the second century AD. Aretaeus gave a clinical description of the disease, noting the increased urine flow, thirst and weight loss, features that are instantly recognizable today.
The sweet, honey - like taste of urine in polyuric states, which attracted ants and other insects, was reported by Hindu physicians such as Sushrut (Susruta) during the fifth and sixth centuries AD. These descriptions even mention two forms of diabetes, the more common occurring in older, overweight and indolent people, and the other in lean people who did not survive for long. This empirical subdivision predicted the modern classification into type 1 and type 2 diabetes.
Diabetes was largely neglected in Europe until a 17th - century English physician, Thomas Willis (1621 – 75), rediscovered the sweetness of diabetic urine. Willis, who was physician to King Charles II, thought that the disease had been rare in ancient times, but that its frequency was increasing in his age ‘ given to good fellowship ’. Nearly a century later, the Liverpool physician Matthew Dobson
(1735 – 84) showed that the sweetness of urine and serum was caused by sugar. John Rollo (d. 1809) was the first to apply the adjective ‘ mellitus ’ to the disease.
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