Digital Anatomy Companion Site

Joints

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Learning Objectives

By the end of this section, you will be able to:

  • Distinguish between the functional and structural classifications for joints
  • Describe the three functional types of joints and give an example of each
  • List the three types of diarthrodial joints

How Joints Move: Three Functional Types

Joints are grouped by how much they move:

These joints allow no movement.

  • Sutures – Found between skull bones; held together by fibrous connective tissue.
  • Synchondroses – Found between the epiphysis and diaphysis of growing long bones, and between the first rib and the manubrium of the sternum.

These joints allow limited movement, held together by cartilage or fibrous tissue.

  • Symphysis – Found between vertebrae; a pad of fibrocartilage cushions the bones.
  • Pubic symphysis – Another example of a symphysis joint.

These joints allow full movement and are common in the limbs.

💡 Tip: Think of “diarthrosis” as “dynamic”—it moves a lot!

Key features of synovial joints:

  1. Articular cartilage – Covers and protects bone ends.
  2. Synovial cavity – Space filled with lubricating synovial fluid.
  3. Synovial fluid – Reduces friction.
  4. Articular capsule – Tough outer layer + inner synovial membrane.
  5. Ligaments – Strengthen and stabilize the joint.

Examples of Diarthrotic (Synovial) Joints

TypeExamples
Hinge JointKnee, elbow, wrist, ankle
Pivot JointProximal ends of radius & ulna, atlas & axis (dens)
Ball & SocketShoulder (humerus & scapula), hip (ilium & femur)

🦵The Knee

Learning Objectives

By the end of this section, you will be able to:

  • Describe the bones that articulate together to form the knee joint
  • Discuss the movements available at each joint
  • Describe the structures that support and prevent excess movements at each joint

The knee joint is the largest and most complex joint in the body.

  1. Before jumping into the worksheet, take time to explore the knee joint through two helpful video tutorials (below).
  2. Go to the Lab 6 worksheet tab.
  3. Open Worksheet Exercises 8 & 9 on the knee joint.
  4. As you watch each video, read through the questions and formulate your answers based on what you observe.

Video 1: Medic Tutorial-The Knee (6:14 min)

Video 2: Knee Tutorial by Randale Sechrest (10:56 min)

  1. Go to the kneeMo website and read through the information on the knee joint.
  2. Then, launch the 3D model viewer of a labelled knee or directly click here! (It may take a minute to load.)
  3. Try to identify features on your own.