New words
epidermis – эпидермис dermis – дерма weight – вес to protect – защищать injury – рана
cytoplasmic – цитоплазматический
level – уровень
flat – плоский
palm – ладонь
thick – толстый
pigment – пигмент
melanin – меланин
nerve – нерв
Dermis is a connective tissue layer of mesodermal origin subjacent the epidermis and its basement membrane. The dermis—epidermal junction, especially in thick skin, is characterized by numerous papillary interdigitations of the dermal connective tissue and epidermal epithelium. This increases the surface area of attachment and brings blood vessels in closer proximity to the epidermal cells. The epidemis, like epithelia in general, is devoid of blood vessel. Histologically, dermis consists of two identifiable regions.
Papillary layer, associated principally with the dermal papillae, is the most superficial layer. It consists of a loosely packed, irregular meshwork of collagen fibrils that contain fine blood vessels and nerve endings.
Reticular layer is the deeper dermal layer and consists of coarse collagen bundles intertwined with elastic fibers in a gel matrix. This layer is a typical dense irregular connective tissue.
HYPODERMIS: this layer of loose vascular connective tissue is infiltrated with adipocytes and corresponds to the superficial fascia of gross anatomy. However, since it contains the deepest portions of the cutaneous glands and hairs, it is also an important part of the skin. The hypoder—mis fastens the skin to underlying muscles and other structures.
New words
dermis – дерма connective – соединительный membrane – мембрана junction – соединение
to be characterized by – характеризоваться чем—то numerous – значительный
to increase – увеличивать
surface – поверхность area – площадь epidermal – эпидермальный thick – толстый skin – кожа
papillary – папиллярный devoid – происходить meshwork – ячеистая сеть coarse – грубый bundle – связка interwine – сплетаться bring – приносить to consists of – состоять из to contain – содержать collagen – коллагеновый adipocyte – жировая клетка
Cutaneous appendages are all derivatives of the epidermis.
Eccrine (merocrine) sweat glands are simple, coiled, tubular glands that are widely distributed over the body. Secretory portions are tightly coiled and consist of a single layer of columnar—like pyramidal cells.
Duct portions, composed of two cuboidal cell layers, are corkscrew—shaped and open onto the epidermal surface. These glands are important in thermal regulation.
Control of the eccrine glands is mainly by the innerva—tion of cholinergic fibers.