Definition: Defining the Meaning of Bones & Joints
Bursa - A small fluid-filled sac made of white fibrous tissue and lined with synovial membrane. It provides a cushion between bones and tendons and/or muscles around a joint
Ligament - A small band of dense, white, fibrous elastic tissue. Ligaments connect the ends of bones together in order to form a joint.
Tendon - A tough, flexible band of fibrous connective tissue that connects muscles to bones.
Joints - Structures that connect individual bones and may allow bones to move against each other to cause movement. There are two divisions of joints, diarthroses which allow extensive mobility between two or more articular heads, and false joints or synarthroses, joints that are immovable, that allow little or no movement and are predominantly fibrous.
Orthopedics is the study of the musculoskeletal system. Orthopedic doctors specialize in diagnosis and treatment of problems of the musculoskeletal system. Over the years, the field has expanded to encompass many sub-specialties and the treatment of a wide variety of musculoskeletal disorders in patients of all ages.
Orthopedic surgeons use both surgical and non-surgical means to treat musculoskeletal trauma, sports injuries, degenerative diseases, infections, tumors, and congenital conditions. The musculoskeletal system provides form, stability, and movement to the human body. It is made up of the body's bones (the skeleton), muscles, cartilage, tendons, ligaments, joints, and other connective tissue.
There are two main parts to your skeleton:
- the bones of your head and torso
- the bones in the arms and legs
Bones are made up of two types of bone:
- Compact bone is the solid, hard, outside part of the bone,
- Cancellous bone, which looks like a sponge, is inside the compact bone.
There are five general classifications of bones:
- Long bones
- Short bones
- Flat bones
- Irregular bones
- Sesamoid bones
The human skeleton is composed of both fused and individual bones supported by ligaments, tendons, muscles and cartilage.
Bones can move because of the way they are joined together. The place where two or more bones come together is called a joint. The bones at a joint are held together by strong bands of tissue called ligaments which allow the bones to move.
Bones are made up of calcium, phosphorus, sodium, and other minerals, as well as the protein collagen. Calcium is needed to make bones hard, which allows them to support body weight. The soft bone marrow inside many of the bones is where most of the blood cells are made. The bone marrow contains stem cells, which produce the body's red blood cells and platelets.
Conditions that can affect the bones, muscles, and joints include:
- Strains and sprains
- Muscular dystrophy
- Osgood-Schlatter disease (OSD)
- Repetitive stress injuries
Quick Facts: Joint Type
- A joint that permits no movement is known as a synarthrosis. The sutures of the skull and the gomphoses that connect the teeth to the skull are examples of synarthroses.
- An amphiarthrosis allows a slight amount of movement at the joint. Examples of amphiarthroses include the intervertebral disks of the spine and the pubic symphysis of the hips.
- The third functional class of joints is the freely movable diarthrosis joints. Diarthroses have the highest range of motion of any joint and include the elbow, knee, shoulder, and wrist.