Learning Objectives By the end of this section, you will be able to: Drawer speed: Fibroblasts produces collagen. The stratum corneum is the most superficial layer of the epidermis and is the layer exposed to the outside environment see Figure 5. The epidermis is epithelium composed of multiple layers of cells. The keratinocytes that compose the stratum lucidum are dead and flattened see Figure 4.
Fluid, Electrolyte, and Acid-Base Balance 26. Men tend to accumulate fat in different areas neck, arms, lower back, and abdomen than do women breasts, hips, thighs, and buttocks. Most skin disorders are relatively benign, but a few, including melanomas, can be fatal if untreated. In addition, collagen binds water to keep the skin hydrated. Although neither is fatal, it would be hard to claim that they are benign, at least to the individuals so afflicted.
Skip to content Increase Font Size. It is made of four or five layers of epithelial cells, depending on its location in the body.
Regulation of Fluid Volume and Composition 25. All of the keratinocytes are produced from this single layer of cells, which are constantly going through mitosis to produce new cells.
The Central Nervous System 14. Cholinergic; sympathetic c.
Site Preferences Log out Send mail as: Interspersed among the keratinocytes of this layer is a type of dendritic cell called the Langerhans cell , which functions as a macrophage by engulfing bacteria, foreign particles, and damaged cells that occur in this layer. Not only is this a problem for the individuals affected, but it also has a severe impact on our healthcare system. Too much sun exposure can eventually lead to wrinkling due to the destruction of the cellular structure of the skin, and in severe cases, can cause sufficient DNA damage to result in skin cancer.
The cells in the stratum basale bond to the dermis via intertwining collagen fibers, referred to as the basement membrane.
Tumors of the pituitary gland can result in the secretion of large amounts of melanocyte-stimulating hormone MSH , which results in a darkening of the skin. In addition, collagen binds water to keep the skin hydrated. Search for: In much of the developed world, insufficient exercise coupled with the ready availability and consumption of high-calorie foods have resulted in unwanted accumulations of adipose tissue in many people.
What is the hypodermis?