韧带、肌腱和关节

so ligaments and tendons are types of extra strong and dense connective tissues ligaments connect bones to other bones and tendons connect muscle to bone and the point where one bone articulates or meets up with another is called a joint now there are different types of joints found throughout the body and the first type is called synarthrosis which are in movable joints where two bones are fused together for example you'll find these types of joints in the skull when you're a baby your skull was made up of a bunch of different pieces that grew as your brain grew and then as an adult the joints between these bones then fused and became synarthrosis the next type of joint is called an ant feet are throws ease and fee meaning it's both stiff but also slightly movable and an example of an fie are throw seeds would be your vertebral joints and then finally we have what are synovial joints which are also known as diarthrosis of which there are a couple different types one type for example is the ball-and-socket synovial joint and you'll find examples of bone socket joints in your shoulders or in your hips these are joints that have many degrees of motion and then another type of synovial joint is the hinge joint an example of a hinge joint would be say your elbow or your knee where that joint pretty much moves in just one plane like the hinge of a door now synovial joints are named so because they are lubricated by a fluid called synovial fluid which is contained within the synovial capsule that surrounds the whole joint now the services of bones that meet up in a joint are lined by a special kind of smooth cartilage called articular cartilage which is composed of specifically hyaline cartilage and articular cartilage like all cartilage is a vascular meaning it any sort of vasculature of blood vessels and so it has a hard time getting the nutrients it needs to heal and recover if it were to become damaged by overuse or infection and as you might be somewhat familiar with the overuse of joints over time can lead to inflammation which is called arthritis from arth meaning joint and itis meaning inflammation and this can lead to permanent destruction of articular cartilage which causes the pain and stiffness of arthritis