Chapter 9 – Joints (Saladin, Anatomy & Physiology 10e)

Fifty question-and-answer style flashcards covering key concepts, structures, movements, and clinical correlations of joints from Chapter 9 of Saladin’s Anatomy & Physiology textbook.

What is an articulation in skeletal anatomy?

Any point where two bones meet, whether or not they are movable.

What does the discipline of arthrology study?

The structure, function, and dysfunction of joints.

Which term refers to the study of musculoskeletal movement?

Kinesiology.

Name the four major structural categories of joints.

Bony, fibrous, cartilaginous, and synovial joints.

What is a bony joint (synostosis)?

An immobile joint formed when the gap between two bones ossifies, fusing them into a single bone.

Give one example of a synostosis present in adults.

Fusion of the ilium, ischium, and pubis into a single hip bone.

What is the defining feature of a fibrous joint (synarthrosis)?

Bones are bound by collagen fibers that emerge from one bone and penetrate into the other.

List the three types of fibrous joints.

Sutures, gomphoses, and syndesmoses.

Which kind of suture has interlocking wavy lines?

A serrate suture.

Which fibrous joint attaches a tooth to its socket?

Gomphosis.

What ligament holds a tooth in place within its socket?

The periodontal ligament.

Why is a syndesmosis generally more mobile than a suture?

Because it is bound by long collagen fibers that allow greater separation of the bones.

Name a very mobile syndesmosis in the body.

The interosseous membrane between the radius and ulna.

What is a cartilaginous joint (amphiarthrosis)?

A joint where two bones are linked by cartilage.

Name the two types of cartilaginous joints.

Synchondroses and symphyses.

Give an example of a synchondrosis.

The epiphyseal plate between epiphysis and diaphysis of a growing long bone.

Which cartilaginous joint unites the bodies of adjacent vertebrae?

A symphysis via an intervertebral disc.

What is the most common, freely mobile, and complex type of joint?

A synovial (diarthrotic) joint.

What covers the facing surfaces of bones in a synovial joint?

Articular (hyaline) cartilage about 2–3 mm thick.

What fills the joint cavity of a synovial joint?

Viscous synovial fluid rich in albumin and hyaluronic acid.

What encloses a synovial joint cavity and retains fluid?

The joint (articular) capsule.

What are the two layers of a joint capsule?

Outer fibrous capsule and inner synovial membrane.

What is an articular disc?

A pad of fibrocartilage that crosses the entire joint capsule, separating it into two spaces.

Where would you find a meniscus in the body?

In each knee, as a crescent-shaped fibrocartilage pad that does not cross the whole joint.

Define tendon.

A collagenous cord or band attaching muscle to bone.

Define ligament.

A collagenous band that attaches one bone to another.

What is the function of a bursa?

To cushion muscles, help tendons slide, and modify direction of tendon pull.

Explain mechanical advantage (MA) of a lever.

The ratio of output force to input force; MA = effort arm length ÷ resistance arm length.

If MA > 1.0, what does a lever produce?

Greater force but less speed and distance than the applied effort.

Which class of lever has the fulcrum between effort and resistance?

First-class lever.

During elbow flexion with the biceps brachii, what class of lever is formed?

A third-class lever (REF).

Define range of motion (ROM).

The degrees through which a joint can move.

List three factors that determine a joint’s ROM.

Structure of articular surfaces, strength/tautness of ligaments and capsule, and action of muscles/tendons.

How many degrees of freedom does a multiaxial joint have?

Three.

Name the only multiaxial synovial joints.

Ball-and-socket joints (shoulder and hip).

Which synovial joint type is biaxial and has oval, convex-to-concave surfaces?

Condylar (ellipsoid) joint.

Give an example of a saddle joint.

The trapeziometacarpal joint at the base of the thumb.

What movement decreases a joint angle?

Flexion.

What is hyperextension?

Extension of a joint beyond its zero (anatomical) position.

Define abduction.

Movement of a body part in the frontal plane away from the midline.

What forearm movement turns the palm anteriorly?

Supination.

Which movement involves turning the soles medially?

Inversion.

What ligament prevents posterior displacement of the mandible at the TMJ?

The lateral ligament.

Name the four muscles that form the shoulder’s rotator cuff.

Supraspinatus, infraspinatus, teres minor, and subscapularis.

Which elbow ligament encircles the radial head allowing pronation and supination?

The annular ligament.

Which ligament of the hip contains an artery to the head of the femur?

The round ligament (ligamentum teres).

What two intracapsular ligaments cross inside the knee?

Anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL).

Which ankle ligament complex binds the tibia and foot on the medial side?

The medial (deltoid) ligament.

What form of arthritis results from “wear-and-tear” degeneration of articular cartilage?

Osteoarthritis (OA).

Which autoimmune disorder attacks synovial membranes, leading to ankylosis?

Rheumatoid arthritis (RA).

What is arthroplasty?

Surgical replacement of a diseased joint with an artificial prosthesis.