Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2
Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2
Chapter 12Skin and its AppendagesSKINT e skin forms the external covering of the body. It is the largest organ constituting 15-20% of total body mass. Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2.TYPES OF SKINT ere are two types of skin.□T in or hairy skin: In this type of skin, epidermis is very thin. It contains hair and is found in all others parts of body except palms and soles (Plate 12.1).□T ick or glabrous skin: In this type of skin, epidermis is very thick with a thick layer of stra Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2tum corneum. It is found in palms of hands and soles of feel and has no hair (Plate 12.2).STRUCTURE OF SKINT e skin consists of two layers□A superfciaEbook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2
l layer the epidermis, made up ofstratifed squamous epithelium□A deeper layer, the dermis, made up of connective tissue (Fig. 12.1).T e dermis rests oChapter 12Skin and its AppendagesSKINT e skin forms the external covering of the body. It is the largest organ constituting 15-20% of total body mass. Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2yers is not straight, but is markedly wavy because of the presence of numerous fnger-like projections of dermis upwards into the epidermis. T ese projections are called dermal papillae. T e downward projections of the epidermis (in the intervals between the dermal papillae) are sometimes called epid Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2ermal papillae (Fig. 12.2).Fig. 12.1: Thin skin (Schematic representation) 1—epidermis. 2—dermis. 3—hair follicle. 4—hair, 5—sebaceous gland, 6—arrectEbook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2
or pili muscle. 7—sweat glandsTextbook of Human HistologyFig. 12.2: Dermal and epidermal papillae (Schematic representation)Fig. 12.3: Epidermal ridgeChapter 12Skin and its AppendagesSKINT e skin forms the external covering of the body. It is the largest organ constituting 15-20% of total body mass. Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2ms and ventral surfaces of the fngers. and on the corresponding surfaces of the feet. Here the elevations form characteristic epidermal ridges or rete ridges (Fig. 12.3) that are responsible for the highly speci fc f ngerprints of each individual.The EpidermisT e epidermis consists of strati fed squ Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2amous keratinised epithelium (Fig. 12.4).Stratum corneumStratum lucidumStratum granutosumStratum spinosumStratum basaleDermisArterioleFig. 12.4: SectiEbook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2
on through showing the layers of epidermis (Schematic representation)192Chapter 12 Skin and its AppendagesLayers of Epidermis (Fig. 12.4)□Stratum basaChapter 12Skin and its AppendagesSKINT e skin forms the external covering of the body. It is the largest organ constituting 15-20% of total body mass. Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2ains stem cells that undergo mitosis to give off cells called keratinocytes. Keratinocytes form the more superfcial layers of the epidermis. T e basal layer is. therefore, also called the germinal layer (stratum germinativum).□Stratum spinosum: Above the basal layer there Fig. 12.5: Cells of the str Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2atum spinosum showing are several layers of polygonal keratinocytes typical spines (Schematic representation) that constitute the stratum spinosum (orEbook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2
Malpighian layer). T e cells of this layer are attached to one another by numerous desmosomes. During routine preparation of tissue for sectioning thChapter 12Skin and its AppendagesSKINT e skin forms the external covering of the body. It is the largest organ constituting 15-20% of total body mass. Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2ng this layer the stratum spinosum (Fig. 12.5). For the same reason the keratinocytes of this layer are also called prickle cells.T e cytoplasm of cells in the stratum spinosum is permeated with fbrils (made up of bundles of keratin flaments). T e fbrils are attached to the cell wall at desmosomes. Ebook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2Some mitoses may be seen in the deeper cells of the stratum spinosum. Because of this fact the stratum spinosum is included, along with the basal cellEbook Textbook of human histology (with colour atlas and practical guide - 7th edition): Part 2
layer, in the germinative zone of the epidermis.Chapter 12Skin and its AppendagesSKINT e skin forms the external covering of the body. It is the largest organ constituting 15-20% of total body mass.Chapter 12Skin and its AppendagesSKINT e skin forms the external covering of the body. It is the largest organ constituting 15-20% of total body mass.Gọi ngay
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