There are four types of tissues in the body: connective, epithelial, muscular, and neural. Today, we will be learning about connective tissue. Connective tissue supports body structures through a matrix. Think of the matrix like a net that holds living cells and a non-living substance, called ground substance. This matrix is made by cells called fibroblasts. There are also fibers in the matrix. There are collagen fibers that give the tissue strength and elastin fibers that allow for flexibility. The ratio of collagen to elastin varies by organ. For example, your skin has more collagen since it needs to be a strong barrier for your body.

Cartilage and bones are special types of connective tissue. Cartilage is in your joints to provide strength and flexibility for range of motion. You should take very good care of your joints, because cartilage is hard to regenerate once it’s damaged. Bone is formed from cartilage, and this process is called endochondral ossification. The bone in your body is always being remade, and the cell turnover is achieved by osteoblasts and osteoclasts. Osteoclasts destroy the bone, while osteoblasts build the bone. The bone is also important for storage of calcium and vitamins. The outside of the bone is “compact” because it’s made of many layers of strong collagen. The inside is “spongy” and light in weight to decrease the stress on the body.

It becomes a problem when bones lose their mass, though. This disease is called osteoporosis, which is common in older women with low estrogen levels. The bones become brittle, and falling or even sneezing can cause the weak bones to break. It’s important to have a diet rich in calcium, vitamin D, and other nutrients to keep your bones healthy.