As people age, their bodies change in many ways that affect the ways their cells and organ systems function. These changes occur little by little, progress over time, and are different for every man and woman. We all lose height as we age, and by the time we reach 80 years old, our height may have decreased by two inches (five centimeters). Changes in posture, in the growth of our spine’s vertebrae, and joint changes all contribute to our loss of height. With aging, the hair follicles produce less melanin, the pigment that gives hair its color. Hair becomes lighter, gray, and eventually turns white. The nails also change with aging: they grow slower, may become dull and brittle, and may become yellowed and opaque. With aging, the outer skin layer (epidermis) thins and the number of pigment-containing cells (called melanocytes) decreases, but the remaining melanocytes increase in size. Aging skin thus appears thinner, more pale, and translucent. Changes in the connective tissue reduce the skin’s strength and elasticity, resulting in a wrinkly, leathery skin.

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• What causes goose bumps?
• Why do I have a belly button?
• Why is the skin between my toes sometimes red and itchy?
• Will a wart go away if I wrap it in duct tape?
• What is a seed drill?
• My grandmother has a lump on her chin that sprouts hair. What is this?
• Why doesn’t it hurt to cut my hair?
• Why do my fingers get all pruney in the bathtub?
• How does the body cool off?
• Why do some people have freckles?
• Why do people have different color skin?
• Which hair grows the fastest?
• How many hairs do I have on my head?
• What is pus?
• Why do scabs form?
• Who invented the earliest milking machines?
• What causes a bruise?
• Which is the body’s biggest organ?
• How much air does a person breathe in a lifetime?