Joints and Motion

Comprehensive vocabulary flashcards covering joint classifications, anatomy, and specific body joints from Lecture Exam 3 study material.

Arthrology

The study of joints.

Fibrous Joint

A joint where bones are held together by dense connective tissue and lacks a joint cavity, such as sutures or gomphosis.

Cartilaginous Joint

A joint where bones are joined by hyaline or fibrocartilage and lacks a joint cavity.

Synovial Joint

A joint where bones are joined by ligaments with a fluid-filled joint cavity separating the bone surfaces; classified as diarthroses.

Synarthroses

Immobile joints, such as fibrous or cartilaginous joints like skull sutures.

Amphiarthroses

Slightly mobile joints, such as intervertebral joints.

Diarthroses

Freely mobile joints; this category includes all synovial joints.

Mobility and Stability Relationship

An inverse relationship where more stable joints (like skull sutures) are less mobile, and more mobile joints (like the shoulder) are more unstable.

Articular Capsule

A double-layered capsule in synovial joints consisting of an outer fibrous layer for strength and an inner synovial membrane.

Synovial Membrane

The inner layer of the articular capsule composed primarily of areolar connective tissue that produces synovial fluid.

Joint Cavity

The space between bones in a synovial joint containing synovial fluid.

Synovial Fluid

A viscous, oily substance that lubricates articular cartilage, nourishes chondrocytes, removes waste, and acts as a shock absorber.

Articular Cartilage

Hyaline cartilage on bone surfaces that reduces friction and absorbs compression; it is avascular and lacks a perichondrium.

Perichondrium

A sheath of dense irregular connective tissue that surrounds most cartilage, helping maintain its shape.

Extrinsic Ligaments

Ligaments that are separate from the articular capsule.

Intrinsic Ligaments

Thickenings of the articular capsule itself.

Bursae

Fibrous, saclike structures containing synovial fluid that alleviate friction between bones, ligaments, or tendons.

Tendon Sheaths

Elongated bursae that wrap around tendons where friction is excessive, commonly found in the wrist and ankle.

Subluxation

A partial or incomplete dislocation where the bone is not completely displaced.

Shoulder Joint

A ball-and-socket joint formed by the head of the humerus and the glenoid cavity of the scapula; it has the greatest range of motion but is the most unstable.

Elbow Joint

A hinge joint where the trochlear notch of the ulna articulates with the trochlea of the humerus.

Hip Joint

A freely movable ball-and-socket joint formed by the head of the femur and the acetabulum of the pelvic girdle.

Sternoclavicular Joint

A saddle joint formed by the manubrium of the sternum and the sternal end of the clavicle.

Plane Joint

A uniaxial joint with flat articulating surfaces that allow bones to slide past one another, such as intercarpal joints.

Hinge Joint

A uniaxial joint where a convex surface fits into a concave depression, moving like a door hinge; examples include the elbow and knee.

Pivot Joint

A uniaxial joint where a rounded bone surface fits into a ring formed by a ligament and another bone, allowing rotation on an axis; example is the neck joint.

Condylar (Ellipsoid) Joint

A biaxial joint characterized as a 'stick in a hole,' such as the metacarpophalangeal (MP) joints.

Saddle Joint

A biaxial joint where articular surfaces resemble a person sitting on a horse, such as the sternoclavicular joint

Ball-and-Socket Joint

A multiaxial joint in which a ball rests within the cup of a second bone; examples include the shoulder and hip joints.