TY - CHAP M1 - Book, Section TI - Basic Science of the Dermis A1 - Baumann, Leslie A1 - Saghari, Sogol A2 - Baumann, Leslie A2 - Saghari, Sogol A2 - Weisberg, Edmund PY - 2009 T2 - Cosmetic Dermatology: Principles and Practice, 2e AB - The dermis lies between the epidermis and the subcutaneous fat. It is responsible for the thickness of the skin, and as a result plays a key role in the cosmetic appearance of the skin. The thickness of the dermis varies over different parts of the body and the size doubles between the ages of 3 and 7 years and again at puberty. With aging, this basic layer decreases in thickness and moisture. The dermis, which is laden with nerves, blood vessels, and sweat glands, consists mostly of collagen. The uppermost portion of this layer, which lies beneath the epidermis, is known as the papillary dermis and the lower portion is known as the reticular dermis. Smaller collagen bundles, greater cellularity, and a higher density in its vascular elements characterize the papillary dermis as compared to the reticular dermis. Fibroblasts are the primary cell type in the dermis. They produce collagen, elastin, other matrix proteins, and enzymes such as collagenase and stromelysin. These structural components will be discussed individually because each exhibits significant characteristics that influence the function of the skin. Immune cells such as mast cells, polymorphonuclear leukocytes, lymphocytes, and macrophages are also present in the dermis. SN - PB - The McGraw-Hill Companies, Inc. CY - New York, NY Y2 - 2024/04/19 UR - dermatology.mhmedical.com/content.aspx?aid=1172445577 ER -