Explain how bone tissue changes throughout life

From about age 30, the density of bones begins to diminish in men and women. This loss of bone density accelerates in women after menopause. As a result, bones become more fragile and are more likely to break especially in old age.
As people age, their joints are affected by changes in cartilage and in connective tissue. The cartilage inside a joint becomes thinner, and components of the cartilage (the proteoglycans—substances that help provide the cartilage's resilience) become altered, which may make the joint less resilient and more susceptible to damage. Thus, in some people, the surfaces of the joint do not slide as well over each other as they used to. This process may lead to osteoarthritis. Additionally, joints become stiffer because the connective tissue within ligaments and tendons becomes more rigid and brittle. This change also limits the range of motion of joints.

Muscles in the body us with a lot of things for example, if i wanted to lift a heavy box and had no muscle i would just collapse where i was because of the fact muscles hold us together. overall they are 650 muscle in the human body, all of them have different purposes and ways to keep us together. there are three types of muscle in the body skeletal, smooth, and cardiac muscle. skeletal muscle are attached to the bone and with movement. smooth muscle, this is found in the wall of our organs, such as our stomach, this muscle with movement   as well, without this muscle, we would only be allowed to eat small amounts. the cardiac muscle is the heart muscle and probably the most important one. these are only found in the walls of the heart and the heart pump blood to the other parts of your body. we have two different types of muscle fibers, slow twitch and fast twitch. slow twitch muscles enable long-endurance feats such as distance running. fast twitch fatigue faster but are used in powerful bursts of movements like sprinting. there are three different types of muscle contractions concentric, eccentric, isometric. concentric contraction causes muscles to shorten, thereby generating force.   eccentric contractions cause muscles to elongate in response to a greater opposing force. isometric contractions generate force without changing the length of the muscle.: //athleticquickness.com/muscle-contraction-types-part-1/