Something that very few people know the true meaning of. Even though deja vu is French for already seen, it actually is used to describe the strange feeling you get when you're in a situation, and feel like you've been in the exact same situation before, but really haven't. Most people think it means the same thing happening twice, which is wrong. Get it right people!
Muscle tissue functions mainly as a source of power and motion in the body. Muscles' main responsibility is for changing or maintaining posture, locomotion, and movement of internal organs. The human body has about 650 muscles, which make up approximately half our bodyweight. All muscles are basically made of the same material, a kind of elastic tissue; packages of stretchable fiber-like material, similar to what goes into making a rubber band. Each muscle is made of thousands, and sometimes tens of thousands of small musculus fibers. Each muscle fiber is about 40 mm in length and is made up of tiny strands of fibrils. Each muscle fiber is commanded by a nerve which makes it contract. How strong a muscle is depends mainly on how many fibers are present.
Ligaments are made of tough protein fibers and connect bones to each other. Your bones, cartilage, and ligaments make up your skeletal system. The skeletal system is made up of bones, cartilage, and ligaments. The skeletal system has many important functions in your body.