Articulations Flashcards
How many joints are there in the body?
230 +
What are the three different joint structures?
Fibrous Joints
Cartilaginous Joints
Synovial Joints
What are fibrous joints?
fixed/ immoveable joints
connected by dense connective tissues consisting mainly of collagen and do not have a joint cavity
What is a common example of a fibrous joint?
A common example of a fibrous joint are sutures.
➢ Sutures join adjacent bones of the cranium together.
Another example of a fibrous joint are gomphosis.
➢ Gomphosis bind the teeth to the socket of the maxilla mandible.
➢ This is the only joint type that does not join bone to another
bone.
What are cartilaginous joints?
Cartilaginous joints are connected entirely by cartilage (fibrocartilidge or
hyaline cartilage).
Cartilaginous joints allow more movement between bones than fibrous joints,
but less than synovial joints.
There are two types of cartilaginous joints:
➢ Synchondrosis
➢ Symphysis
A synchondrosis is a cartilaginous joint where bones are joined by hyaline
cartilage.
A synchondrosis can be temporary or permanent.
What are examples of cartilaginous joints (Synchondrosis)?
An example of a temporary synchondrosis includes
the epiphyseal plate of a long bone (i.e. the femur)
The first sternocostal joint is an example of a permanent
synchondrosis.
What are examples of cartilaginous joints (Symphysis)?
A symphysis is a cartilaginous joint where bones are joined by fibrocartilage.
➢ Fibrocartilidge is extremely strong (multiple bundles of thick collagen
fibres) and allows limited movement to occur.
An example of this joint type includes the pubic symphysis.
➢ This joins the left and right pubic bone (narrow gap).
The intervertebral symphysis is a wide gap symphysis located between
vertebrae. A thick pad of fibrocartilage forms the intervertebral discs.
➢ The width allows for small movements and cushioning between vertebrae.
What are synovial joints?
Synovial joints are the most common and most mobile joint in the human body.
A synovial joint contains:
➢ A synovial cavity filled with synovial fluid
➢ A joint capsule uniting the articulating bones.
The outer fibrous membrane may contain ligaments.
The inner synovial membrane secretes lubricating,
shock absorbing, and joint-nourishing synovial fluid.
➢ Articular (hyaline) cartilage lines the epiphyses (end of a
long bone) to absorb shock and reduce friction between
bones.
What are examples of synovial joints?
Examples of synovial joints include:
➢ Ball and Socket Joints
➢ Hinge Joints
➢ Condyloid Joints
➢ Gliding (or Plane) Joints
➢ Pivot Joints
➢ Saddle Joints
What is a ball and socket joint?
A ball and socket joint is a joint in which the
rounded surface of a bone (the ball) rotates with a
depression of another bone (the socket).
This joint type allows for the greatest freedom of
movement than any other type of joint
(triaxial/multiaxial).
Examples include the acetabulofemoral (hip) and
glenohumeral (shoulder) joint.
What is a hinge joint?
A hinge joint is where two or more bones meet and move along an axis to bend.
This joint allows movement in one direction (uniaxial)
Hinge joints are assisted by cartilage, ligaments and
muscles to bend.
Examples include the ankle, knee and elbow joint.
What is a condyloid joint?
A condyloid joint consists of an oval-shaped end of one bone rotating within an
oval-shaped depression in another bone.
Condyloid joints allow movement with two degrees of freedom (biaxial)
Unlike ball and socket joints, a condyloid joint does
not allow axial rotation.
Examples include the radiocarpal joint,
metacarpophalangeal joint and metatarsophalangeal joint
What is a gliding or plane joint?
A gliding joint (also called a plane joint) is formed between two bones that meet at
flat (or nearly flat) articular surface.
Gliding joints allow bones to “glide” or “slide” past one another.
Unlike other joints, the angle between the two bones forming the
joint rarely changes, only their position relative to one another
(non-axial).
Synovial fluid lubricates the joint, reducing friction when the bones pass each other.
An example of a gliding joint is the zygapophyseal joint (facet joints).
What is a pivot joint?
A pivot joint (also referred to as a rotary or trochoid joint) is a freely moveable
joint that allows only rotary movement around a single axis (uniaxial).
Pivot joints are formed by one bone rotating within
a ring of a concave surface of another bone.
The best example is that of the atlanto-axial joint which
allows for the horizontal rotation of the head (try it!).
Another example is the radio-ulnar joint which allows
the palm of the hand to face upwards or downwards (try it!).
What is a saddle joint?
A saddle joint is where one bone forms a support for the other bone to rest on.
(Like a horse rider sitting on a saddle)
A saddle joint is a biaxial joint which allows double motion
(biaxial) due to one bone forming a concave shape and the other a
convex shape.
Examples includes the carpometacarpal joint at the base
of the thumb or the sternoclavicular joint.
