Joints Flashcards
What are Joints?
The Joint is the site at which any two or more bones meet.
Joints are the body’s hinges.
The three types of joints
- Fibrous or fixed joints (Immovable)
- Cartilaginous or Slightly moveable joints
- Synovial or Freely moveable joints
SLIGHTLY MOVEABLE, OR CARTILAGINOUS JOINTS.
Slightly moveable,
Moves by compression of the cartilage
pad of white fibrocartilage between the bones,
e.g. spine.
FIXED, OR FIBROUS JOINTS
No movement
Fibrous tissue between the ends of the bones
E.g. sutures in the skull, innominate (pelvic girdle) bones.
FREELY MOVEABLE, OR SYNOVIAL JOINTS
Varied degrees of movement depending on sub-type
Six Types of freely moveable or synovial joints
Ball and socket
Hinge
Gliding
Pivot
Saddle
Ball and socket
Most moveable of all joints.
Allow flexion, extension, adduction, abduction, rotation and circumduction
E.g. shoulder and hip joints.
Gliding
The bones glide over each other.
The least moveable of synovial joints .
e.g. between tarsals and carpals.
Hinge
Movement in one direction (plane) only.
Movements are flexion and extension
e.g. elbow, knee, ankle, joints between phalanges of fingers and toes.
Saddle
Movement around two axes allows flexion, extension, adduction, abduction, circumduction.
Found between trapezium of the carpus (wrist) and metacarpal of thumb.
Pivot
Movement around one axis only and a rotary movement
e.g. first two cervical vertebrae (atlas and axis) which allow the head to rotate and proximal ends of radius and ulna.
Synovial fluid
Synovial fluid, also called synovia, is a viscous fluid found in the cavities of synovial joints.
Egg white–like consistency
Function of synovial fluid
The principal role of synovial fluid is to reduce friction between the articular cartilage of synovial joints during movement.
Synovial membrane
A layer of connective tissue that lines the cavities of joints
Cartilage
A flexible connective tissue is found in various forms in the larynx and respiratory tract, the external ear and the articulating surfaces of joints.
