Pig skin shares similar epidermal and dermal thickness ratios to human skin; pig and human skin share similar hair follicle and blood vessel patterns; biochemically the dermal collagen and elastic content is similar in pig and human skin; and pig skin and human skin have similar physical responses to various growth factors.Skin has mesodermal cells, pigmentation, such as melanin provided by melanocytes, which absorb some of the potentially dangerous ultraviolet radiation (UV) in sunlight. It also contains DNA repair enzymes that help reverse UV damage, such that people lacking the genes for these enzymes have high rates of skin cancer. One form predominantly produced by UV light, malignant melanoma, is particularly invasive, causing it to spread quickly, and can often be deadly. Human skin pigmentation varies among populations in a striking manner. This has led to the classification of people(s) on the basis of skin colour.In terms of surface area, the skin is the second largest organ in the human body (the inside of the small intestine is 15 to 20 times larger). For the average adult human, the skin has a surface area of from 1.5–2.0 square metres (16–22 sq ft). The thickness of the skin varies considerably over all parts of the body, and between men and women and the young and the old. An example is the skin on the forearm which is on average 1.3 mm in the male and 1.26 mm in the female.
Mirizzis 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). A cholecystocholedochal fistula can occur. Presentation
Mirizzis syndrome has no consistent or unique clinical features that distinguish it from other more common forms of obstructive jaundice. Symptoms of recurrent cholangitis, jaundice, right upper quadrant pain, and elevated bilirubin and alkaline phosphatase may or may not be present. Acute presentations of the syndrome include symptoms consistent with cholecystitis. Surgery is extremely difficult as Calots triangle is often obliterated and the risks of causing injury to the CBD are high. Pathophysiology
Multiple and large gallstones can become impacted in the Hartmanns pouch of the gallbladder, leading to chronic inflammation—which leads to compression of the common bile duct (CBD), necrosis, fibrosis, and ultimately fistula formation into the adjacent common hepatic duct (CHD) or common bile duct (CBD). As a result, the CHD/CBD becomes obstructed by either scar or stone, resulting in obstructive jaundice. It can be divided into four types.