Looking Inside Your Body
Just What is Inside You?
Homeostasis and Cells
Tissues, Organs, and Organ Systems
Feedback Regulation and Positive and Negative Feedback Loops
stops water from getting into the body. Your skin controls body temperature, it does this by making sweat, a watery substance that cools the body when it evaporates. Your skin gathers information about your environment. Special nerve endings in your skin sense heat, pressure, cold and pain. It helps the body get rid of some types of waste, which are removed in sweat. It acts as a sun block. A chemical called melanin is made by certain skin cells when they are exposed to sunlight. Melanin blocks sun light from getting to deeper layers of skin cells, which are easily damaged by sunlight. Your skin has two main types of skin on it, Thin and hairy, which is the most common type on the body, and thick and hairless, which is found on parts of the body that experience a lot of contact with the environment, such as the palms of the hands or the soles of the feet. Your skin is precious because it protects us in so many ways, but it too can be easily harmed. Sunlight is good for your skin, but if exposed the sun for too long without sunblock, it can become burned. If children and teenagers get too much exposure to the sun, it can lead to skin cancer, later on in adulthood. Too much exposure to the sun is the leading cause of skin cancer.
Injuries and Hygiene
on the skin surface. If not washed away, the mix of sweat, oil, dirt, and dead skin cells can encourage the excess growth of bacteria. These bacteria feed on these substances and cause a smell that is commonly known as body odor. Dirty skin is also more prone to infection. Bathing every day helps to remove dirt, sweat and extra skin cells, and helps to keep your skin clean and healthy.
You've probably noticed that your skin is easily able to heal itself. Even large cuts are able to be healed, because your skin puts new scales up in the place of the cut away or damaged cells, that were hurt. But if a cut becomes too large, the cells are unable to reproduce themselves. Stitching the edges of the injured skin together can help the skin to repair itself. When the damaged cells and tissues have been replaced, the stitches can be removed.
The Bones in Your Body
marrow. Red marrow makes red blood cells, platelets, and most of the white blood cells for the body. Yellow marrow makes white blood cells. Bones come in four main shapes. They can be long, short, flat, or irregular. Bones are identified by their shape - never their size.