The inner layer of the skin, called the dermis, contains sweat glands, blood vessels, nerve endings, and the bases of hair and nails. The outer layer, the epidermis, is only a few cells thick; it contains pigments, pores, and ducts, and its surface is made of dead cells that it sheds from the body. The sweat glands excrete waste and cool the body through evaporation of fluid droplets; the blood vessels of the dermis supplement temperature regulation by contracting to preserve body heat and expanding to dissipate it. Separate kinds of receptors convey pressure, temperature, and pain. Fat cells in the dermis insulate the body, and oil glands lubricate the epidermis.
- dermis [ˈdə:mis] n.真皮
- nail [neil] n. 指甲
- epidermis [ˌepiˈdə:mis] n.表皮
- pigment [ˈpiɡmənt] n. 色素
- pore [pɔ:] n. 毛孔
- duct [dʌkt] n. 管：管状体内通道，尤指运输腺分泌物的管道
- shed [ʃed] v. 脱落，蜕(皮)，脱(毛)
- excrete [eksˈkri:t] v.分泌, 排出
- evaporation [iˌvæpəˈreiʃən] n.蒸发；蒸腾(作用)
- droplet [ˈdrɔplit] n.小滴
- supplement [ˈsʌpliment] v. 补充
- dissipate [ˈdisipeit] v. 使耗散
- receptor [riˈseptə] n.感受器
- convey [kənˈvei] v. 转达
- insulate [ˈinsjuleit] v. 隔热
- lubricate [ˈlu:brikeit] v. 使润滑
