Joints in the Human Body [Applied Science 25%] Flashcards
What is a joint?
A crucial component of human movement. The articulation point between two bones.
How are joints calssified?
Joints are classified by the type of tissue they contain: fibrous, cartilaginous, or synovial.
What are fibrous joints?
Joints with fibrous connective tissue joining two bones that allow for very little movement.
What are the 3 types of fibrous joints?
- Sutures or synarthrodial joints
- Syndesmoses joints
3.Gomphosis joints
What is a synarthrodial joint?
Also known as sutures. This fibrous joint is found in the skull. During birth, sutures are flexible to allow the baby to pass through the birth canal, and they become more rigid with age.
What is the syndesmosis joint?
Fibrous joint found between long bones, like the tibia and fibula.
What are Gomphosis joints?
Fibrous joints that attach teeth to the sockets of the maxilla and mandible.
What are cartilaginous joints?
Joints that are joined by either fibrocartilage, the most rigid and strong cartilage, or hyaline cartilage, which is softer and more widespread.
Cartilaginous joints are slightly movable and are further divided into primary and secondary joints.
Describe the cartilaginous joint categories.
- Primary: epiphyseal (growth) plates.
- Secondary: intervertebral discs (layers of cartilage between vertebrae).
What are synovial joints (aka, diarthrodial joints)?
The most common and most movable joints in the body. They are fluid-filled joints found between bones that move against one another.
What are non-synovial joints (aka, synarthroses)?
Fibrous and cartilaginous joints that lack a fluid junction, and do not allow for much movement.
How do synovial joints work?
In synovial joints, bones are separated by a synovial joint cavity made of dense, irregular connective tissue.
The outside of the cavity, known as the articular capsule, is part of the periosteum.
The cavities are filled with synovial fluid to reduce friction and form a film over joint surfaces, and they are lined by a synovial membrane.
What are the 6 classifications of synovial joints?
- Ball-and-socket joint
- Saddle joint
- Hinge joint
- Gliding joint
- Pivot joint
- Condyloid joint
Ball & Socket Joint
Also known as an enarthrodial joint, this joint allows a wide range of movement in many directions. Examples are the shoulder and hip joints.
Saddle Joint
Similar to ball-and-socket joints but cannot rotate. Examples include the trapezium and the first metacarpal joint (joint between the thumb and wrist).
Hinge Joint
Joints that include the elbows, ankles, and knee joints. They allow a wide range of movement in one plane (direction).
Gliding Joint
The arthrodial joints of the body include the tarsals and metatarsal of the foot. In these joints, two flat bones press up against each other.
Pivot Joint
Trochoidal joints rotate around a long axis (line that runs parallel to the joint). The radioulnar joint of the forearm is a pivot joint.
Condyloid Joint
Also known as an ellipsoid joint, these joints move in two directions—one direction primarily with a small range in another direction. Rotation is not allowed in these joints. The radiocarpal joint at the wrist is a prime example.
Proximal Joint Category
Joints closest to the midline of the body, which are the foundation for the legs and arms.
Middle Joint Category
These are generally hinge joints with a motion primarily moving forward and backward like the knee.
Distal Joint Category
Joints that are farther from the midline of the body. They create a variety of intricate movements. The wrist is an example.
Close-packed Joint Position
The most stable joint position, when the connective tissue is taut and neighboring bones have the most contact.
