Joints of the Human Body

These flashcards cover the key concepts related to the joints of the human body from Chapter 8 of A&P I, focusing on classifications, structures, and movements associated with joints.

What is a joint?

A joint (also known as an articulation) is where two or more bones meet.

Mobility and Stability

There is an inverse relationship between mobility and stability in joints; as mobility increases, stability decreases.

Functional classifications of joints

Joints can be classified functionally into three types: Synarthroses (no movement), Amphiarthroses (slightly moveable), and Diarthroses (freely moveable).

Structural classifications of joints

Joints can be classified structurally into three types: Fibrous, Cartilaginous, and Synovial.

Fibrous joints

Joints where bones are joined by collagen fibers of dense connective tissue, with no joint cavity.

Cartilaginous joints

Joints where bones are joined by cartilage, also without a joint cavity.

Synovial joints

Joints that have a joint cavity filled with synovial fluid and are characterized by features like articular cartilage and a joint capsule.

Types of synovial joints

There are six types of synovial joints: Plane joints, Hinge joints, Pivot joints, Condylar joints, Saddle joints, and Ball-and-socket joints.

Bursae

Bursae are flattened fibrous sacs filled with synovial fluid that help reduce friction in joints.

Tendon sheaths

Tendon sheaths are elongated bursae that wrap around tendons to reduce friction and protect them from rubbing against other structures.

Definition of gliding movement

Gliding involves sliding the flat surfaces of two bones across each other.

What is the primary function of Synovial joints?

Synovial joints are the weakest part of the skeleton, designed for a high range of mobility.

What happens during flexion?

Flexion decreases the angle between two bones, usually in the sagittal plane.

What happens during extension?

Extension increases the angle between two bones, usually in the sagittal plane.

Hip Flexion

Hip flexion closes the joint at the front, reducing the angle.

Knee Extension

Knee extension opens the joint, increasing the joint angle.