First half of Chapter 9

Question 1

Defining joints

Answer 1

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

Question 2

Joints and Their Classification

Joint (articulation)

Answer 2

Joint (articulation)—any point where two bones meet, whether or not the bones are movable at that interface.

Question 3

Joints and Their Classification

Arthrology

Answer 3

Arthrology—science of joint structure, function, and dysfunction.

Question 4

Joints and Their Classification

Kinesiology

Answer 4

Kinesiology—the study of musculoskeletal movement

A branch of biomechanics, which deals with a broad variety of movements and mechanical processes.

Question 5

There are many different types of joints; we will discuss only some of them

Answer 5

There are many different types of joints; we will discuss only some of them
Fibrous joints
Cartilaginous joints
Synovial joints

Question 6

Fibrous joint (= synarthrosis, or synarthrodial joint)—

Answer 6

Fibrous joint (= synarthrosis, or synarthrodial joint)—adjacent bones are bound by collagen fibers that emerge from one bone and penetrate into the other

Question 7

Three kinds of fibrous joints

Answer 7

Sutures (eg., in skull).Gomphoses (i.e., tooth socket).Syndesmosis (i.e., radio-ulnar, tibio-fubular)

Question 8

Fibrous Joints: Sutures

Answer 8

Sutures—immobile or slightly mobile fibrous joints in which short collagen fibers bind the bones of the skull to each other

Question 9

Fibrous Joints: Gomphoses

Answer 9

Gomphosis—attachment of a tooth to its socket

Question 10

Fibrous Joints: Syndesmoses

Answer 10

Syndesmosis—a fibrous joint at which two bones are bound by long collagen fibers

Question 11

Cartilaginous Joints

Answer 11

Cartilaginous joint (= amphiarthrosis, or  amphiarthrodial joint)—two bones are linked by cartilage
Examples include pubic symphysis and intervertebral discs

Question 12

Cartilaginous Joints: Symphyses

Answer 12

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

Question 13

Synovial Joints

Answer 13

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

Question 14

Synovial Joints, continued

Answer 14

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.

Question 15

General Anatomy of Synovial Joints

Articular cartilage

Answer 15

Articular cartilage—layer of hyaline cartilage that covers the facing surfaces of two bones.Usually 2 or 3 mm thick

Question 16

General Anatomy of Synovial Joints

Joint (articular) cavity

Answer 16

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.

Question 17

General Anatomy of Synovial Joints, continued

Answer 17

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

Question 18

General Anatomy of Synovial Joints, continued

Joint (articular) capsule

Answer 18

Joint (articular) capsule—connective tissue that encloses the cavity and retains the fluid.

Question 19

General Anatomy of Synovial Joints, continued

Specialized synovial joints:

Answer 19

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

Question 20

General Anatomy of Synovial Joints, continued

Acessory structure, Ligament

Answer 20

Ligament: strip of collagenous tissue attaching one bone to another

Question 21

General Anatomy of Synovial Joints, continued

Accessory structures- tendon

Answer 21

Tendon: strip of collagenous tissue attaching muscle to bone

Question 22

General Anatomy of Synovial Joints, continued

Acessory structure:Bursa

Answer 22

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