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The sole is the bottom of the foot. In humans the sole of the foot is anatomically referred to as the plantar aspect. The equivalent surface in ungulates is the hoof. ==Structure== The skin on the sole of the foot lacks the vellus hair and pigmentation found on the rest of the body, and has a high concentration of sweat pores. The soles are crossed by a set of creases that form during embryogenesis and contain the thickest layers of skin on the human body due to the weight that is continually placed on them. Like the palm, the sweat pores of the sole lack sebaceous glands. The sole is a sensory organ through which we can perceive the ground while standing and walking. The subcutaneous tissue in the sole has adapted to deal with the high local compressive forces on the heel and the balls (distal end of metatarsals) of the big and little toes by developing a system of pressure chambers. Each chamber is composed of internal fibrofatty tissue covered by external collagen connective tissue. The septa (internal walls) in these chambers are permeated by numerous blood vessels, making the sole one of the most vascularized regions in the human body. The sole and the longitudinal arch of the foot are supported by a thick connective tissue, the plantar aponeurosis, the thin borders of which blend with the dorsal fascia of the foot. The central portion of the aponeurosis extends down to the underlying bones as two septa, the medial and lateral plantar septa so that they define the boundaries of the three plantar muscle compartments (see below). The bones underlying sole form the arches of the foot. Arches may fail to develop during childhood or may flatten during pregnancy and old age resulting in flat feet. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Sole (foot)」の詳細全文を読む スポンサード リンク
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