Classifications
What is the definition of a joint (articulation)?
A place where two or more bones come together.
What is the primary function of synovial fluid?
To act as a viscous lubricating film to decrease friction.
Which joint allows for "no" movement of the head?
Atlantoaxial (Pivot) joint.
What is the difference between flexion and extension?
Flexion moves a joint into a more acute angle; extension moves it into a more obtuse angle.
What is a dislocation (luxation)?
When articulating surfaces of bones are moved out of proper alignment.
What are the three functional classifications of joints based on motion?
Synarthrosis (non-movable), Amphiarthrosis (slightly movable), Diarthrosis (freely movable).
What is the difference between a tendon and a ligament?
A tendon attaches muscle to bone; a ligament attaches bone to bone.
What type of joint is the shoulder (glenohumeral)?
Synovial ball-and-socket.
How do abduction and adduction differ?
Abduction is movement away from the median plane; adduction is movement toward it.
What is a sprain?
Damage to ligaments, often resulting in inflammation, swelling, and pain.
What is a synostosis?
Two bones grown together across a joint to form a single bone.
What is the difference between an articular disc and a meniscus?
An articular disc spans the entire synovial cavity; a meniscus only partially spans it.
Which joint is a combination of plane and ellipsoid, and allows for excursion?
Temporomandibular joint (TMJ).
Define supination and pronation.
Supination: palm faces up ("soup bowl"); Pronation: palm faces down.
What is the difference between Osteoarthritis and Rheumatoid arthritis?
Osteoarthritis is degenerative/wear-and-tear; Rheumatoid is an autoimmune disease.
What are the three types of fibrous joints?
Sutures, syndesmoses, and gomphoses.
Why is movement essential for the nourishment of articular cartilage?
Cartilage is avascular/aneural; compression during movement is required for nutrient diffusion.
Which three structures are commonly injured in the "Unhappy Triad" of the knee?
Medial collateral ligament (MCL), Anterior cruciate ligament (ACL), and Medial meniscus.
What are the two special movements of the foot involving the plantar surface?
Inversion (faces medially) and Eversion (faces laterally).
What is the relationship between joint mobility and stability?
There is an inverse relationship: as mobility increases, stability decreases.
What is the specific structural difference between a suture and a syndesmosis?
Syndesmoses have longer fibers (ligaments) than the dense connective tissue found in sutures.
What is the function of a bursa?
An extended pocket of synovial membrane filled with fluid that cushions structures that would rub against each other.
Which specific ligament in the hip joint carries a small nutrient artery to the head of the femur?
The round ligament.
Describe the movement of circumduction.
A combination of flexion, extension, abduction, and adduction; common in ball-and-socket joints.
Why does the production rate of synovial fluid decline with age, and what is the consequence?
It declines as part of the aging process, leading to decreased joint flexibility and strength.