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Skin Follicles
The hair follicle is an Organ (anatomy), organ found in mammalian skin. It resides in the Dermis, dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between hormones, neuropeptides, and immune cells. This complex interaction induces the hair follicle to produce different types of hair as seen on different parts of the body. For example, terminal hairs grow on the scalp and lanugo hairs are seen covering the bodies of fetuses in the uterus and in some Infant, newborn babies. The process of Human hair growth, hair growth occurs in distinct sequential stages. The first stage is called ''anagen'' and is the active growth phase, ''telogen'' is the resting stage, ''catagen'' is the regression of the hair follicle phase, ''exogen'' is the active shedding of hair phase and lastly ''kenogen'' is the phase between the empty hair follicle and the growth of new hair. The function of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integumentary System
The integumentary system is the set of organs forming the outermost layer of an animal's body. It comprises the skin and its appendages, which act as a physical barrier between the external environment and the internal environment that it serves to protect and maintain the body of the animal. Mainly it is the body's outer skin. The integumentary system includes hair, Scale (zoology), scales, feathers, Hoof, hooves, and Nail (anatomy), nails. It has a variety of additional functions: it may serve to maintain water balance, protect the deeper tissues, excrete wastes, and regulate Core temperature, body temperature, and is the attachment site for sensory receptors which detect pain, sensation, pressure, and temperature. Structure Skin The skin is one of the largest organs of the body. In humans, it accounts for about 12 to 15 percent of total body weight and covers 1.5 to 2 m2 of surface area. The skin (integument) is a composite organ, made up of at least two major layers of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
