Joints (Articulations) Lecture Notes

Comprehensive practice questions based on Chapter 8: Joints (Articulations), covering classifications, types of joints, anatomy, and movement types.

In a structural classification system, what two criteria determine joint categories?

The type of connective tissue and whether a joint cavity is present.

How are joints categorized in the functional classification system?

Based on the degree of movement of a joint.

What is a synarthrosis joint?

A joint that allows no movement.

What are three examples of synarthroses mentioned in the text?

Sutures in the skull, synchondroses in epiphyseal plates, and gomphoses in teeth.

What is an amphiarthrosis joint?

A joint that allows limited movement.

What are two specific examples of amphiarthroses?

Symphyses in pubic symphysis (also discs) and syndesmoses in distal ends of the tibia and fibula.

What is a diarthrosis joint?

A joint that is feely movable.

Which joint is an example of a planar joint?

Vertebrae.

Which joint is an example of a hinge joint?

Elbow.

Where is a pivot joint located?

In the atlas and axis.

What does 'condyloid' mean and where are these joints found?

It means knuckle; they are found in metacarpophalangeal joints of fingers.

Where is a saddle joint found?

Thumb.

Where is a ball and socket joint found?

Hip.

What five factors limit range of movement in joints?

The shape of each bone, strength and tautness of ligaments and tendons, arrangement and tension of muscles, soft tissue, and disuse.

What are the two layers of the Articular Cavity/Capsule?

An outer fibrous layer and an inner synovial membrane.

What is synovial fluid?

A viscous liquid that lubricates the joint and nourishes cartilage, containing a high concentration of hyaluronic acid.

How does smooth articular cartilage receive nutrients and how thick is it?

It gets nutrients from compression during articulation and is $2\,mm$ thick.

What is a meniscus and what is its function?

A wedge of cartilage or articular disc dividing the cavity that allows two bones of different shapes to fit tightly.

Define gliding movement.

Side-to-side and back-and-forth movement of planar joints.

What is the difference between flexion and extension?

Flexion decreases the joint angle between articulating bones, while extension increases the joint angle in an anterior-to-posterior plane.

Define hyperextension.

Body extended beyond the normal anatomical position.

Compare abduction and adduction.

Abduction is movement away from the main axis (torso) in a lateral direction, while adduction is movement toward the main axis in a medial direction.

What sequence of movements makes up circumduction?

Flexion, extension, abduction, and adduction.

What is rotation?

Movement of bone around its own axis by $180^\circ$.

What is the difference between inversion and eversion?

Inversion moves the sole of the foot inward; eversion moves the sole of the foot outward.

Define protraction and retraction of the mandible.

Protraction moves the mandible forward on a plane parallel to the ground; retraction moves it back to normal anatomical position.

Define elevation and depression of the mandible.

Elevation moves the mandible upward; depression moves the mandible downward.

Define supination and pronation.

Supination moves palms facing upward; pronation moves palms facing downward.