First half of Chapter 9 Flashcards
Defining joints
Joints link the bones of the skeletal system, permit effective movement, and protect the softer organs.Joint anatomy and movements will provide a foundation for the study of muscle actions
Joints and Their Classification
Joint (articulation)
Joint (articulation)—any point where two bones meet, whether or not the bones are movable at that interface.
Joints and Their Classification
Arthrology
Arthrology—science of joint structure, function, and dysfunction.
Joints and Their Classification
Kinesiology
Kinesiology—the study of musculoskeletal movement
A branch of biomechanics, which deals with a broad variety of movements and mechanical processes.
There are many different types of joints; we will discuss only some of them
There are many different types of joints; we will discuss only some of them
Fibrous joints
Cartilaginous joints
Synovial joints
Fibrous joint (= synarthrosis, or synarthrodial joint)—
Fibrous joint (= synarthrosis, or synarthrodial joint)—adjacent bones are bound by collagen fibers that emerge from one bone and penetrate into the other
Three kinds of fibrous joints
Sutures (eg., in skull).Gomphoses (i.e., tooth socket).Syndesmosis (i.e., radio-ulnar, tibio-fubular)
Fibrous Joints: Sutures
Sutures—immobile or slightly mobile fibrous joints in which short collagen fibers bind the bones of the skull to each other
Fibrous Joints: Gomphoses
Gomphosis—attachment of a tooth to its socket
Fibrous Joints: Syndesmoses
Syndesmosis—a fibrous joint at which two bones are bound by long collagen fibers
Cartilaginous Joints
Cartilaginous joint (= amphiarthrosis, or amphiarthrodial joint)—two bones are linked by cartilage Examples include pubic symphysis and intervertebral discs
Cartilaginous Joints: Symphyses
Pubic symphysis joins right and left pubic bones with interpubic disc
Bodies of vertebrae joined by intervertebral discs
Only slight movements between adjacent vertebrae
Collective effect of all 23 discs gives spine considerable flexibility
Synovial Joints
Synovial joint (= diarthrosis, or diarthrodial joint)—joint in which two bones are separated by a joint cavity Most familiar type of joint Most are freely mobile Most structurally complex type of joint
Synovial Joints, continued
Most likely to develop painful dysfunction
Most important joints for physical and occupational therapists, athletic coaches, nurses, and fitness trainers
Their mobility makes them important to quality of life.
General Anatomy of Synovial Joints
Articular cartilage
Articular cartilage—layer of hyaline cartilage that covers the facing surfaces of two bones.Usually 2 or 3 mm thick
General Anatomy of Synovial Joints
Joint (articular) cavity
Joint (articular) cavity—separates articular surfaces
Outer fibrous capsule: continuous with periosteum of adjoining bones. Inner, cellular, synovial membrane: composed mainly of fibroblast-like cells that secrete synovial fluid and macrophages that remove debris from the joint cavity.
General Anatomy of Synovial Joints, continued
Synovial fluid—slippery lubricant in joint cavity
Rich in albumin and hyaluronic acid.Gives it a viscous, slippery texture like raw egg whites.Nourishes articular cartilage and removes waste.Makes movement of synovial joints almost friction free
General Anatomy of Synovial Joints, continued
Joint (articular) capsule
Joint (articular) capsule—connective tissue that encloses the cavity and retains the fluid.
General Anatomy of Synovial Joints, continued
Specialized synovial joints:
Specialized synovial joints:
In a few synovial joints, fibrocartilage grows inward from the joint capsule, forming a meniscus
Meniscus: moon-shaped cartilage in knee
These cartilages absorb shock and pressure
Guide bones across each other and improve their fit together .Stabilize the joints, reducing the chance of dislocation
General Anatomy of Synovial Joints, continued
Acessory structure, Ligament
Ligament: strip of collagenous tissue attaching one bone to another
General Anatomy of Synovial Joints, continued
Accessory structures- tendon
Tendon: strip of collagenous tissue attaching muscle to bone
General Anatomy of Synovial Joints, continued
Acessory structure:Bursa
Bursa: fibrous sac filled with synovial fluid, located between muscles, where tendons pass over bone, or between bone and skin.Cushions muscles, helps tendons slide more easily over joints, modifies direction of tendon pull
