Kulit adalah meliputi dari luar jaringan hidup dari binatang (atau tanaman). Ini merupakan organ dari yg menutupi sistem yang terdiri dari beberapa lapisan epithelial tisu, dan menjaga yang melandasi otot, tulang, ligaments, organ internal. [1] kata sifat yg berhubung dgn kulit yang harfiah berarti "dari kulit" (dari Latin cutis, kulit ).
karena antarmuka dengan lingkungan, kulit memainkan peran yang sangat penting dalam melindungi (tubuh) terhadap patogen. Fungsi yang lain adalah isolasi, suhu peraturan, sensasi, sintesis vitamin D, dan perlindungan vitamin B folates. Rusak kulit akan mencoba untuk menyembuhkan dengan membentuk jaringan parut.Hal ini sering dihitamkan dan depigmented.
Pada manusia, kulit pigmentasi (lihat: warna kulit manusia atau pewarnaan) bervariasi antara penduduk, dan jenis kulit dapat beragam, mulai dari kulit kering untuk kulit berminyak.
Kulit memiliki pigmentasi, atau melanin, yang disediakan oleh melanocytes, yang menyerap beberapa yang berpotensi berbahaya radiasi ultraungu (UV) di sinar matahari. Ia juga berisi DNA-perbaikan enzim yang membantu membalikkan UV kerusakan, dan orang-orang yang tidak memiliki gen untuk enzim tersebut tingkat tinggi menderita kanker kulit. Salah satu bentuk dominan dihasilkan oleh lampu UV, ganas melanoma, terutama adalah penyerbuan, menyebabkan ke menyebar dengan cepat, dan sering bisa mematikan. Pigmentasi kulit manusia bervariasi antara masyarakat di sebuah cara mogok. Hal ini untuk klasifikasi orang (s) berdasarkan warna kulit.
Binatang menyusui kulit sering berisi rambut, yang memadai di kepadatan disebut bulu. Rambut terutama berfungsi untuk menambah yang menyediakan isolasi kulit, tetapi juga dapat digunakan sebagai karakteristik seksual sekunder atau sebagai kamuflase.Pada beberapa hewan, kulit sangat keras dan tebal, dan dapat diproses untuk membuat kulit. Reptil dan ikan memiliki skala keras perlindungan pada kulit mereka untuk perlindungan, dan burung memiliki bulu keras, semua dilakukan dengan ketatnya β-keratins. Amfibi kulit bukan penghalang kuat untuk selat bahan kimia dan sering terganggu pelajaran secara berangsur-angsur.Sebuah katak duduk di sebuah yg menyebabkan kehilangan kesadaran solusi dapat dengan cepat pergi tidur.
Kulit sering dikenal sebagai terbesar organ tubuh manusia. Hal ini berlaku untuk permukaan luar, karena meliputi tubuh, yang telah muncul ke permukaan wilayah terbesar dari semua organ. Untuk rata-rata manusia dewasa, yang memiliki permukaan kulit kawasan antara 1,5-2,0 meter persegi (16.1-21.5 sq ft.), sebagian besar adalah antara 2-3 mm (0,10 inci) tebal. Rata-rata persegi inci (6,5 cm ²) dari kulit memegang 650 kelenjar keringat, 20 pembuluh darah, 60000 melanocytes, dan lebih dari seribu saraf akhir.
Jumat, 10 Oktober 2008
report text "skin"
The skin is the outer covering of living tissue of an animal (or plant). It is the largest organ of the integumentary system made up of multiple layers of epithelial tissues, and guards the underlying muscles, bones, ligaments, internal organs.[1] The adjective cutaneous literally means "of the skin" (from Latin cutis, skin).
Because it interfaces with the environment, skin plays a very important role in protecting (the body) against pathogens. Its other functions are insulation, temperature regulation, sensation, synthesis of vitamin D, and the protection of vitamin B folates. Severely damaged skin will try to heal by forming scar tissue. This is often discolored and depigmented.
In humans, skin pigmentation (see: human skin color or coloring) varies among populations, and skin type can range from dry skin to oily skin.
Skin has pigmentation, or 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, and people who lack the genes for these enzymes suffer 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 color.[2]
Mammalian skin often contains hairs, which in sufficient density is called fur. The hair mainly serves to augment the insulation the skin provides, but can also serve as a secondary sexual characteristic or as camouflage. On some animals, the skin is very hard and thick, and can be processed to create leather. Reptiles and fish have hard protective scales on their skin for protection, and birds have hard feathers, all made of tough β-keratins. Amphibian skin is not a strong barrier to passage of chemicals and is often subject to osmosis. A frog sitting in an anesthetic solution could quickly go to sleep.
The skin is often known as the largest organ of the human body. This applies to exterior surface, as it covers the body, appearing to have the largest surface area of all the organs. For the average adult human, the skin has a surface area of between 1.5-2.0 square meters (16.1-21.5 sq ft.), most of it is between 2-3 mm (0.10 inch) thick. The average square inch (6.5 cm²) of skin holds 650 sweat glands, 20 blood vessels, 60,000 melanocytes, and more than a thousand nerve endings.
Because it interfaces with the environment, skin plays a very important role in protecting (the body) against pathogens. Its other functions are insulation, temperature regulation, sensation, synthesis of vitamin D, and the protection of vitamin B folates. Severely damaged skin will try to heal by forming scar tissue. This is often discolored and depigmented.
In humans, skin pigmentation (see: human skin color or coloring) varies among populations, and skin type can range from dry skin to oily skin.
Skin has pigmentation, or 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, and people who lack the genes for these enzymes suffer 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 color.[2]
Mammalian skin often contains hairs, which in sufficient density is called fur. The hair mainly serves to augment the insulation the skin provides, but can also serve as a secondary sexual characteristic or as camouflage. On some animals, the skin is very hard and thick, and can be processed to create leather. Reptiles and fish have hard protective scales on their skin for protection, and birds have hard feathers, all made of tough β-keratins. Amphibian skin is not a strong barrier to passage of chemicals and is often subject to osmosis. A frog sitting in an anesthetic solution could quickly go to sleep.
The skin is often known as the largest organ of the human body. This applies to exterior surface, as it covers the body, appearing to have the largest surface area of all the organs. For the average adult human, the skin has a surface area of between 1.5-2.0 square meters (16.1-21.5 sq ft.), most of it is between 2-3 mm (0.10 inch) thick. The average square inch (6.5 cm²) of skin holds 650 sweat glands, 20 blood vessels, 60,000 melanocytes, and more than a thousand nerve endings.
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