Articulation

(arthro= joint)

Functional classification

• Synarthrosis (-syn=united; together)
• Amphiarthosis (-ampi= both)
• Diathrosis (di=apart)

how much movement is permitted

• immovable joint
• slighty movable
• freely movable

Structural Classification

• Fibrous joints
• Cartilaginous joints
• Synovial joints

the presence or absence of a space between the articulating bones and the type of C.T. that binds the bones together

• bones held together by dense irregular C.T.
• bones held together by cartilage
• bones help together by ligaments

no joint cavity; bones held together with dense irregular C.T.

• Sutures
• Syndesomoses
• Interosseous membranes

held togehter with thin dense fibrous connective tissue

• unites skull bones
• synarthrotic in adults and amphiarthrotic in children

(band or ligament) fibrous joint in which there is a greater distance between the articulation surfaces, and more dense irregular connective tissue than in a suture

• ex. between the tibia and fibula at distal tibiofibular joint and gomphosis

(bolt/nail) specialized in syndesmosis joint in which pegs (teeth) fit into sockets (alveoli); peridontal ligament hold teeth in sockets; teeth are in the alveoli of the maxilla and mandible

• synarthrotic- a healthy gomphosis permits no movement

a substantial sheet of dense irregular connective tissue that binds neighboring long bones and permits slight movement

• amphiarthrosis

no joint cavity; bones conected with cartilage, allowing little or no movement

• synchondroses-connecting cartilage is hyaline cartilage (epiphyseal plate and costal cartilage)
• symphyses- fibrocartilage is connecting cartilage (symphysis pubis; amphiarthrotic, junction of the manubrium and body of the sternum, intercertebral disc; amphiarthrotic)

space between articulating bones; freely movable (diarthrotic)

• Synovial cavity- space betwen articulaiton bones
• articular capsule-surrounds synovial joint and encloses synovial cavity

composed of 2 layers: outer fibrous membrane and inner synovial membrane

• Composed of dense irregular connective tissue
• Conctinuous with/attaches to the periosteum of the articulating bones
• Flexible allowing for movement
• Tensile strength (resistance to stretch) helps prevent dislocation

loose connective tissue with elastic fibers

• secretes synovial fluid
• lines cavity except over articular cartilage
• ligaments may be outside fibrous capsule (ex. collateral ligament of knee)

Nerve & Blood Supply:

Arterial branches

Nerve & Blood Supply:

Nerve endings

• plane
• hinge
• pivot
• condyloid
• saddle
• ball-and-socket

Synovial Joint:

Plane

• articulated surfac are flat or slighty curved
• allow movement back and forth, side to side, and sometimes rotation

ex. intercarpal joints, intertarsal joints, sternocostal joints, vertebrocostal joints

Synovial Joint:

Hinge

convex surface of one bone fits into the concave surface of another

• allows flexion and extension

ex. knee, elbow, ankle, interphalangeal

Synovial Joint:

Pivot

rounded or pointed surface of one bone fits into ring formed partly by another bone and partly by a ligament

• allows rotation

ex. atlanto-axial, radioulnar

Synovial Joint:

Condyloid

oval shaped projection fits into oval shaped depression

• allows flexion, extension, abduction, adduction

ex. wrist, metacarpophalangeal (2-5)

Synovial Joint:

Saddle

articular surface of one bone is saddle shaped; articular surface of other bone "sits" in saddle

• allows flexion, extension, abduction, adduction

ex. carpmetacarpal in thumb

Synovial Joint:

Ball and Socket

Ball-like surace fits into cuplike depression

• allows flexion, extension, abduction, adduction, rotation

ex. shoulder, hip

Joint Movement:

Gliding

relaticely flat bone surfaces move back-and-forth and from side-to-side with respect to one another

• limited in range since there is no significant alteration of the agle between the bones

ex. intercarpal joints

Joint Movement:

Angular movements

increase or a decrease in the angle between articulation bones

• Flexion- decrease in angle
• Extension- increase in angle (hyperextension- continuation of extension beyond the normal extension)
• Abduction- movement away from the midline
• Adduction- movement towards the midline
• Circumduction- movement of a body part in a circle

Joint Movement:

Rotation

a bone revolves around its own longitudinal axis

• turning the head from side to side

Joint Movement:

Elevation

an upward movement of a body part

ex. closing mouth

Joint Movement:

Depression

a downward movement of a body part

ex. opening the mouth

Joint Movement:

Protraction

&

Retraction

• movement of a body part anteriorly
• movement back to normal

ex. thrusing the mandible forward

Joint Movement:

Inversion

Joint Movement:

Dorsiflexion

Joint Movement:

Plantar Flexion

Joint Movement:

Supination

Joint Movement:

Pronation

Joint Movement:

Opposition

Knee:

Patellar joint

Knee:

Oblique popliteal ligament

Knee:

Medial Collateral Ligament (MCL) 

Knee:

Lateral Collateral Ligament (LCL)

Knee:

Intra-articular Ligament

ligament within the joint help prevent displacement of artculation surfaces= cruciate ligaments

Knee:

Anterior Cruciate Ligament 

Knee:

Posterior Cruciate Ligament

1. structure or shape
2. strength and tension
3. hormones
4. disuse

Medial meniscus

&

Lateral meniscus

• C shaped, anchored to tibial collateral ligament and is less mobile
• more circular

• decrease production of synovial fluid in joints
• Articular cartilage becomes thinner
• ligaments loose flexibility

• inflammation of joints
• rheumatoid arthritis- inflammation of the synovial membrane