Chapter 8: Classification of Joints

Comprehensive vocabulary flashcards covering the structural and functional classification of joints, synovial joint anatomy, joint movements, selected synovial joints, and common joint disorders based on Chapter 8 lecture notes.

Joint (Articulation)

A site where two or more bones meet, determining how bones move relative to each other.

Synarthrosis

A functional joint classification referring to an immovable joint.

Amphiarthrosis

A functional joint classification referring to a slightly movable joint.

Diarthrosis

A functional joint classification referring to a freely movable joint.

Fibrous Joints

Joints where bones are joined by dense fibrous connective tissue with no joint cavity present; most are immovable.

Suture

A fibrous joint held together with very short, interconnecting fibers and interlocking bone edges; found only in the skull.

Synostoses

Closed, completely ossified, and immovable sutures.

Syndesmosis

A fibrous joint held together by a ligament, in which the fibrous connective tissue fibers vary in length but are longer than in sutures.

Gomphosis

A "peg-in-socket" fibrous joint in which the periodontal ligament anchors a tooth into the socket of the alveolar process.

Periodontal Ligament

The specialized fibrous connective tissue that secures and holds a tooth firmly within its bony alveolar socket.

Cartilaginous Joints

Joints in which the articulating bones are united by cartilage and lack a joint cavity.

Synchondrosis

A cartilaginous joint united by a bar or plate of hyaline cartilage, virtually all of which are synarthrotic.

Symphysis

A cartilaginous joint united by fibrocartilage that forms strong, amphiarthrotic (slightly movable) joints.

Synovial Joints

Joints in which the articulating bones are separated by a fluid-filled joint cavity; all are diarthroses.

Articular Cartilage

Glassy-smooth hyaline cartilage covering the opposing ends of bones in synovial joints to cushion and absorb compression.

Joint (Synovial) Cavity

A unique, fluid-filled potential space enclosed by the articular capsule in synovial joints.

Articular (Joint) Capsule

A two-layered sleeve enclosing the joint cavity, composed of an external tough fibrous layer and an inner synovial membrane.

Synovial Fluid

A viscous, slippery filtrate of blood plasma combined with hyaluronic acid that lubricates joint surfaces and nourishes cartilage.

Bursa

A flattened fibrous sac filled with synovial fluid that decreases friction where ligaments, muscles, skin, tendons, or bones rub together.

Tendon Sheath

An elongated, fluid-filled bursa that wraps completely around a tendon subjected to friction.

Muscle Tone

The low level of contractile force in resting muscles that keeps tendons taut; the single most important factor stabilizing synovial joints.

Origin

The site of muscle attachment to an immovable or less movable bone.

Insertion

The site of muscle attachment to a movable bone.

Uniaxial Movement

Movement permitted in only one plane or around one single axis.

Biaxial Movement

Movement permitted in two planes or around two axes.

Multiaxial Movement

Movement permitted in or around all three planes of space.

Gliding Movement

A simple joint motion that occurs when flat or nearly flat bone surfaces slide or slip across one another.

Flexion

An angular movement in the sagittal plane that decreases the angle between two articulating bones.

Extension

An angular movement in the sagittal plane that increases the angle between two articulating bones.

Hyperextension

An extension movement of a joint past the normal anatomical position.

Abduction

Movement of a limb away from the median (midsagittal) plane in the frontal (coronal) plane.

Adduction

Movement of a limb toward the median (midsagittal) plane in the frontal (coronal) plane.

Circumduction

Movement of a limb in a cone-like shape where the distal end moves in a circle while the proximal end stays relatively stationary.

Rotation

The turning or spinning of a bone around its own long axis.

Pronation

Forearm movement that rotates the radius over the ulna, positioning the palm facing posteriorly or downward.

Supination

Forearm movement that rotates the radius and ulna parallel to each other, positioning the palm facing anteriorly or upward.

Opposition

A saddle joint movement that brings the tip of the thumb into direct contact with any fingertip on the same hand.

Dorsiflexion

Movement of the ankle that raises the superior surface of the foot toward the shin.

Plantar Flexion

Movement of the ankle that depresses the superior surface of the foot farther away from the shin (pointing toes).

Inversion

Special movement of the foot that turns the sole medially toward the midline.

Eversion

Special movement of the foot that turns the sole laterally away from the midline.

Elevation

Lifting a body part superiorly, such as moving the mandible up to close the mouth.

Depression

Moving an elevated body part inferiorly, such as moving the mandible down to open the mouth.

Protraction

A nonangular anterior movement in the transverse plane, such as moving the mandible forward.

Retraction

A nonangular posterior movement in the transverse plane, such as moving the mandible back.

Plane Joint

A synovial joint with flat articular surfaces allowing nonaxial gliding movements.

Hinge Joint

A synovial joint where a cylinder-shaped bone fits into a trough-shaped surface, permitting uniaxial flexion and extension.

Pivot Joint

A synovial joint where a rounded bone fits inside a sleeve of bone and ligament, allowing uniaxial rotation.

Condylar Joint

A synovial joint featuring oval articular surfaces that allow biaxial flexion, extension, abduction, and adduction.

Saddle Joint

A synovial joint where both articulating surfaces have complementary concave and convex areas, allowing biaxial motion.

Ball-and-Socket Joint

A multiaxial synovial joint where a spherical head fits into a cuplike socket, permitting full three-dimensional movement.

Temporomandibular Joint (TMJ)

A modified hinge synovial joint where the mandibular condyle articulates with the mandibular fossa and articular tubercle of the temporal bone.

Lateral Excursion

Side-to-side grinding movement of the mandible at the temporomandibular joint.

Glenoid Labrum

A fibrocartilaginous rim that lines and deepens the shallow glenoid cavity of the scapula.

Rotator Cuff

A stabilizing group of four muscle tendons crossing the shoulder joint: subscapularis, supraspinatus, infraspinatus, and teres minor.

Anular Ligament

A collar-like ligament encircling the head of the radius that secures it within the radial notch of the ulna.

Acetabular Labrum

A fibrocartilage rim encircling the acetabulum that enhances the depth of the hip joint socket.

Ligamentum Teres (Ligament of the Head of the Femur)

An intracapsular flat band extending from the fovea capitis on the femoral head to the inferior lip of the acetabulum.

Tibiofemoral Joint

The bicondylar modified hinge joint of the knee between the femoral condyles and the menisci of the tibia.

Femoropatellar Joint

The plane synovial joint of the knee between the patella and lower femur that permits gliding during flexion.

Menisci (Lateral and Medial)

C-shaped fibrocartilaginous pads on the tibial condyles that absorb shock and deepen the shallow articular surfaces of the knee.

Patellar Ligament

A distal continuation of the quadriceps tendon connecting the patella to the tibia, tapped clinically to test the knee-jerk reflex.

Anterior Cruciate Ligament (ACL)

An intracapsular knee ligament that attaches to the anterior tibia, preventing forward sliding of the tibia and stopping hyperextension.

Posterior Cruciate Ligament (PCL)

An intracapsular knee ligament that attaches to the posterior tibia, preventing backward sliding of the tibia and forward sliding of the femur.

Sprain

A joint injury in which reinforcing ligaments are stretched or torn; partial tears heal slowly due to poor vascularization.

Luxation

A dislocation injury in which articulating bones are forced out of their normal anatomical alignment.

Subluxation

A partial dislocation of a joint.

Arthritis

A group of inflammatory or degenerative diseases affecting joints, characterized by pain, stiffness, and joint swelling.