Joint | Definition, Anatomy, Movement, & Types | Britannica
Joint, in humans and other animals, structure connecting two or more adjacent parts of the skeleton. Not all joints move, but, among those that do, motions include spinning, swinging, gliding, rolling, and approximation. Learn about the different types of …
Plane joint | Description & Examples | Britannica
Plane joint, structure formed between two bones that is characterized by flat or nearly flat articular surfaces, enabling the free surfaces of the bones to slide over each other. The plane joint is a type of synovial joint.
Pivot joint | Definition, Examples, Function, & Facts | Britannica
pivot joint, in vertebrate anatomy, a freely moveable joint (diarthrosis) that allows only rotary movement around a single axis. The moving bone rotates within a ring that is formed from a second bone and adjoining ligament. The pivot joint is exemplified by the joint between the atlas and the axis (first and second cervical vertebrae ...
Human muscle system - Shoulder Muscles, Joints, Movements
2024年9月9日 · Human muscle system - Shoulder Muscles, Joints, Movements: The shoulder is a complex ball-and-socket joint comprising the head of the humerus, the clavicle (collarbone), and the scapula. The shoulder’s main motions are flexion, extension, abduction, adduction, internal rotation, and external rotation. Shoulder flexion is movement of the ...
Elbow | Joints, Muscles, Movements | Britannica
elbow, in human anatomy, hinge joint formed by the meeting of the humerus (bone of the upper arm) and the radius and ulna (bones of the forearm). The elbow allows the bending and extension of the forearm, and it also allows the rotational movements of the radius and ulna that enable the palm of the hand to be turned upward or downward.
Joint - Symphyses, Cartilage, Ligaments | Britannica
Joint - Symphyses, Cartilage, Ligaments: A symphysis (fibrocartilaginous joint) is a joint in which the body (physis) of one bone meets the body of another. All but two of the symphyses lie in the vertebral (spinal) column, and all but one contain fibrocartilage as a constituent tissue.
Thumb | Muscles, Movement, Joints | Britannica
thumb, short, thick first digit of the human hand and of the lower-primate hand and foot. It differs from other digits in having only two phalanges (tubular bones of the fingers and toes). The thumb also differs in having much freedom of movement and being opposable to tips of other digits.
Skeleton - Joints, Muscles, Movement | Britannica
2024年10月2日 · The freely moving joints permit a twisting movement, with extra support being gained by two sets of sliding facets between each pair of consecutive vertebrae. Ball-and-socket joints, common in vertebrates, are easily contrived in animals with an endoskeleton.
Joint - Ligaments, Cartilage, Fibrous | Britannica
Joint - Ligaments, Cartilage, Fibrous: In fibrous joints the articulating parts are separated by white connective tissue (collagen) fibres, which pass from one part to the other. There are two types of fibrous joints: suture and gomphosis.
Rotation | movement of joints | Britannica
In order to describe the main types of joint structures, it is helpful first to summarize the motions made possible by joints. These motions include spinning, swinging, gliding, rolling, and approximation. Spin is a movement of a bone around its own long axis; it is denoted by the anatomical term rotation.