A&P exam 2 joints

What is an articulation (joint)?

Any point where two bones are joined together.

What are the two ways joints are classified?

Structural classification (based on the material binding bones and presence of a joint cavity) and functional classification (based on amount of movement allowed).

What are the three functional classifications of joints?

Synarthrotic (immovable), amphiarthrotic (slightly movable), and diarthrotic (freely movable).

What are the three structural classifications of joints?

Fibrous, cartilaginous, and synovial joints.

What holds fibrous joints together?

Dense connective tissue fibers.

What functional classification do most fibrous joints belong to?

Mostly synarthrotic, although some are amphiarthrotic.

What are the three types of fibrous joints?

Syndesmoses, sutures, and gomphoses.

What holds cartilaginous joints together?

Cartilage.

What functional classifications can cartilaginous joints be?

Synarthrotic or amphiarthrotic.

What are the two types of cartilaginous joints?

Synchondroses and symphyses.

What holds synovial joints together?

A joint capsule.

What functional classification are all synovial joints?

Diarthrotic (freely movable).

Where are most synovial joints found?

The appendages (arms and legs).

What structures characterize a synovial joint?

Joint capsule, synovial membrane, articular cartilage, and a joint cavity containing synovial fluid.

What is the synovial membrane?

A layer of areolar connective tissue with epithelial cells that secrete synovial fluid.

What is the joint cavity?

The space inside the joint capsule containing synovial fluid.

What is supination?

Rotation of the forearm so the palm faces anteriorly or upward.

What is pronation?

Rotation of the forearm so the palm faces posteriorly or downward.

What is inversion?

Movement of the foot so the sole faces medially.

What is eversion?

Movement of the foot so the sole faces laterally.

What is protraction?

Anterior movement in the horizontal plane.

What is retraction?

Posterior movement in the horizontal plane.

What is elevation?

Superior movement of a body part.

What is depression?

Inferior movement of a body part.

What bones form the glenohumeral joint?

Head of the humerus and the glenoid cavity of the scapula.

What type of joint is the glenohumeral joint?

Diarthrotic synovial ball-and-socket joint.

What structures stabilize the glenohumeral joint?

Glenoid labrum, ligaments, rotator cuff tendons (primary stabilizers), and bursae.

What bones make up the elbow joint?

Distal humerus with the proximal radius and ulna.

What articulations form the elbow joint?

Capitulum with the head of the radius and trochlea with the trochlear notch of the ulna.

What type of joint is the elbow?

A very stable diarthrotic true synovial hinge joint.

What provides stability to the elbow joint?

Bone shape, a thick capsule, and ligaments.

What is the proximal radioulnar joint?

The head of the radius articulating with the radial notch of the ulna.

What is the distal radioulnar joint?

The head of the ulna articulating with the ulnar notch of the radius.

What movement occurs at the radioulnar joints?

Pronation and supination.

What type of joint are the radioulnar joints?

Diarthrotic synovial pivot joints.

What type of joint is the radiocarpal (wrist) joint?

Diarthrotic synovial condyloid joint.

What movements occur at the radiocarpal joint?

Flexion, extension, abduction, adduction, and circumduction.

What are intercarpal joints?

Joints between rows of carpal bones.

What type of joints are intercarpal joints?

Diarthrotic synovial gliding joints.

What type of joint is the first carpometacarpal joint (thumb)?

Diarthrotic synovial saddle joint.

What movement does the first carpometacarpal joint allow?

Opposition of the thumb.

What are the other carpometacarpal joints?

Joints between metacarpals II–V and the trapezoid, capitate, and hamate; they are synovial gliding joints.

What type of joint are metacarpophalangeal (MCP) joints?

Diarthrotic synovial condyloid joints.

What movements occur at MCP joints?

Flexion, extension, abduction, adduction, and circumduction.

What type of joints are interphalangeal joints?

Diarthrotic synovial hinge joints.

What bones form the hip joint?

Head of the femur and the acetabulum of the coxal bone.

What type of joint is the hip?

Diarthrotic synovial ball-and-socket joint.

What structures stabilize the hip?

Acetabular labrum, ligaments, and the ligamentum teres.

What is the strongest ligament in the body?

The iliofemoral ligament of the hip.

What bones form the knee joint?

Femoral condyles and tibial condylar surfaces.

What type of joint is the knee?

Modified diarthrotic synovial hinge joint.

What movements occur at the knee?

Flexion, extension, and limited rotation.

What structures support the knee?

Muscles, ligaments, menisci, bursae, and the joint capsule.

What bones form the ankle joint?

Talus with the tibia and fibula.

What type of joint is the ankle?

Modified diarthrotic synovial hinge joint.

What movements occur at the ankle?

Dorsiflexion and plantar flexion.

How does the foot compare to the hand?

The foot has greater stability and less mobility; the hallux does not have a saddle joint.

What type of joint is between vertebral bodies?

Cartilaginous symphysis; functionally amphiarthrotic.

What type of joints are vertebral facet joints?

Diarthrotic synovial gliding joints.

What limits movement at the vertebral joints?

Strong ligaments, orientation of the articular facets, and spinal processes.

What type of joint is the atlanto-axial joint?

Diarthrotic synovial pivot joint.

What movement occurs at the atlanto-axial joint?

Rotation of the head (shaking “no”).

What type of joints are rib articulations?

Diarthrotic synovial gliding joints.

What happens to bones with aging?

Loss of bone mass, slower remodeling, decreased mineralization, and greater effects in women than men.

What changes occur in aging joints?

Cartilage becomes more rigid and fragile, collagen cross-linking increases, matrix water content decreases, and range of motion decreases due to changes in muscles and ligaments.