Our bodies are covered with skin and hair that help guard us internally from hazardous elements entering externally. The system of skin and hair is known as the integumentary system. The skin is made up of multiple layers of tissue and cells, connective tissue, and sensory and nerve fibers. The layers of the skin are the dermis, epidermis and hypodermis. The layers all serve various purposes in providing our bodies with protection as well as water loss. Skin also contains pigmentation that helps prevent with UV ray damage to our skin. Hair is a keratinous that grows out of the epidermis and is called a hair follicle. Hair on our bodies is located in those areas for a reason. Hair on our head protects it from the sun, the hair in our nose, ears and eyes protect them from dust and other particles. Hair also serves as a sensory function in detecting something on the surface of the skin.
The skeletal system is made up of bone and osseous tissue which is the support structure of the body. Where the bone can bend and are flexible there is cartilage. The skeletal system provides support, enables movement, protects internal organs, and produces blood cells, and stores and releases minerals and fat. Bones have four cell groups, osteoblasts, osteocytes, osteogenic cells, and osteoclasts. Osteoblasts are responsible for creating new bone. Osteogenic cells develop into osteoblasts. Osteocytes maintain mineral concentration of matrix. Osteoclasts is responsible for bone resorption and breakdown. There are various types of bones in the skeletal system, the long bone, short bone, flat bone, irregular, and sesamoid. Certain vitamins and minerals are important for healthy bones. Calcium is critical to keep our bones healthy. In order for our intestines to process calcium our bodies need vitamin D. We can get these nutrients from most foods vitamin D can be absorbed through the skin from the sun, it is then synthesized to help assist with the absorption of calcium in the intestines.
The endocrine system creates hormones that are involved in bone growth, and sustaining bone once it is made. The pituitary gland secretes growth hormone that encourages growth, it also increases calcium preservation and encourages osteoblastic activity and improves bone density. There are other hormones estrogen in girls and testosterone in boys that play a role in healthy bones and bone growth. As we age bone mass decreases this happens when bone resorption exceeds bone production. In women when they go through menopause their ovaries stop producing estrogen which is needed for healthy bones. Because of this a disease called osteoporosis is more common in woman as they age, however men can get it too it isn’t as common. If you are diagnosed with osteoporosis your bones become weak and you are at higher risk of broken bones. If you eat properly and make sure your body is getting proper exercise and the right amount of nutrients from a young age you can increase bone strength which can reduce the risk of osteoporosis when you get older. Women do have the option of using hormone replacement therapy to replace the estrogen needed to keep healthy bones. Hormone replacement isn’t for everyone and has been associated with some forms of cancer.
Calcium homeostasis is important to maintaining healthy bones. The normal calcium blood level is 10mg/dl if your body cannot maintain that level you can develop hypocalcemia. This is a condition that develops with low calcium levels and can have a negative effect on other systems in the body. The opposite when you have too much calcium present is called hypercalcemia which can cause side effects such as lethargy, sluggish reflexes, loss of appetite, and possibly coma in severe cases. Calcium is not produced by our body it has to be ingested through our diet. For overall bone health it is important to keep your calcium in check by eating a diet that includes foods that contain calcium.