Chapter 9, Lesson 2: Synovial Joints (to slide 44)

Flashcards from Chapter 9, Lesson 2 of McGraw Hill Anatomy and Physiology, Ninth Edition, by Kenneth S. Saladin.

Synovial joints (diarthroses)

Joints in which two bones are separated by a joint cavity; they are the most familiar and mobile type of joint important for quality of life

Articular cartilage

Layer of hyaline cartilage covering the facing surfaces of two bones in a synovial joint

Joint cavity (articular cavity)

Separates the articular surfaces in the synovial joint

Synovial fluid

Slippery lubricant in the joint cavity; it is rich in albumin making it slippery like egg whites while removing waste and reducing friction

Joint capsule (articular capsule)

The connective tissue enclosing the synovial cavity and retaining the fluid; made of an outer layer of the periosteum of the bones and inner layer of fibroblasts and macrophages to remove debris

Articular disc

A growth of fibrocartilage inward from the joint capsule between the articulating bones to form a pad

Meniscus

The moon-shaped cartilage in the knee, extending inward from the left and right to absorb shock and pressure while stabilizing joints

Tendon

The strip of collagenous tissue tying the muscle to bone

Ligament

The strip of collagenous tissue linking one bone to another

Bursa

A fiborus sack filled with synovial fluid between muscle, bone-tendon passes, or bone-skin passes as a cushion or lubricant

Tendon sheath

An elongated cylindrical bursa wrapped around a tendon

Exercise

Warms the synovial fluid and helps cartilage swell to provide a more effective cushion; compression can squeeze metabolic waste out and take in more oxygen and nutrients

Range of motion (ROM)

The degrees through which a joint can move; assesses joint flexibility and performance and is determined by structure, strength of ligaments and joint capsules, and the action of muscles and tendons

Multiaxial joint

Having three degrees of freedom like in the shoulder (abduction, flexion, and internal rotation); others have monoaxial or biaxial movement

Classes of synovial joints

Six classes: ball-and-socket, condylar, saddle, plane, hinge, and pivot

Ball-and-socket joints

Joint where a smooth, hemispherial head fits within a cup-like socket for multiaxial movement, includes the shoulder and hip

Condylar joints (ellipsoid joints)

Joing where an oval convex surface fits into a complementary-shaped depression on the other; are biaxial for two planes and includes the radiocarpal (radius and wrist) joint and metacarpophalangeal (palm-finger) joints

Saddle joints

Joint where bones have a concave and convex surface; are biaxial and are located in the thumb

Plane joints (gliding joints)

Joints with flat articular surfaces with sliding bones; usually biaxial and are in the vertebral discs and between carpal bones