Articulations Lecture Practice Questions

A set of vocabulary flashcards covering joint classifications, synovial joint types, and clinical conditions related to articulations based on lecture practice questions.

Synovial joint

A structural classification of a joint that has a joint cavity filled with lubricating fluid, is freely mobile ($Diarthrosis$), and contains ligaments, nerves, and blood vessels.

Synchondrosis

A cartilaginous joint in which bones are joined by hyaline cartilage, lacks a joint cavity, and is functionally immobile ($Synarthrosis$).

Pivot joint

A uniaxial synovial joint where one bone rotates around another, or is formed by a ligament and another bone, such as the atlantoaxial joint between $C1$ and $C2$.

Sagittal synostosis

A clinical condition involving premature fusion of the sagittal suture, causing the skull to grow in an anteroposterior fashion (forwards and backwards) because it cannot expand laterally.

Symphysis

A cartilaginous joint joined by fibrocartilage that allows slight movement ($Amphiarthrosis$), with examples including the pubic symphysis and intervertebral discs.

Plane joint

The least mobile type of synovial joint, which is uniaxial and permits sliding or gliding movements; examples include intertarsal and intercarpal joints.

Hinge joint

A uniaxial synovial joint allowing movement in one plane (flexion and extension), such as the elbow, interphalangeal joints, and the ankle joint.

Bursa

A fibrous, saclike structure lined with synovial membrane that secretes synovial fluid to alleviate friction; an elongated version may wrap around a tendon.

Saddle joint

A biaxial synovial joint where both articulating surfaces are saddle-shaped, providing greater freedom of motion than a condylar joint and allowing the thumb to move toward the fingers.

Glenohumeral joint

A multiaxial ball-and-socket joint formed by the articulation of the head of the humerus and the glenoid cavity of the scapula.

Synovial fluid

A substance found within joint cavities that lubricates the joint, nourishes chondrocytes, and acts as a shock absorber.

Knee joint

The largest and most complex diarthrosis of the body, primarily identified as a hinge joint that contains menisci for stabilization and cushioning.

Achilles tendon rupture

An injury most common in adults between $30\text{--}50$ years of age, often characterized by an audible pop followed by significant pain.

Lever

An elongated, rigid object used in movement that rotates around a fixed point called the fulcrum.

Plagiocephaly

A condition resulting in an asymmetric head shape or oblique flattening of the frontal or occipital region, often due to sleeping positions or unilateral coronal/lambdoid synostosis.

Gomphosis

A fibrous joint where a tooth is anchored into its socket in the maxilla or mandible by the periodontal ligament, functionally classified as immobile.

Syndesmosis

A fibrous joint in which bones are connected by a ligament or interosseous membrane (e.g., distal tibiofibular joint), allowing slight movement.

Condylar joint

A biaxial synovial joint that allows flexion/extension and abduction/adduction, such as the radiocarpal and metacarpophalangeal joints.

Costochondritis

Inflammation and irritation of the costochondral joints, often caused by carrying heavy loads over one shoulder, resulting in localized chest pain.

Cavitation

The process where stretching a synovial joint decreases pressure, causing dissolved gases to form bubbles that eventually burst and create a popping sound.

$$20\text{--}30\text{ minutes}$$

The typical amount of time required after cracking knuckles before the same knuckles can be cracked again, allowing gases to dissolve back into the synovial fluid.

Forward and downward

The direction the humeral head moves from the glenoid cavity in approximately $95$% of shoulder dislocation cases.

Subluxation of the head of the radius

A condition also known as nursemaid's elbow, common in children aged $1\text{--}5$ years, where the radial head partially slips from under the annular ligament.