The skeletal System: joints MSS10 Anatomy & Physiology
Overview: Defining Joints Structural and Functional Classifications The Importance of Synovial Joints Synovial Joint Structure Movement Classification
What is a Joint? Where 2 or more bones meet an articulation or joint exists. Movement doesn’t always occur at these sites however. Joints are typically classified according to the degree of movement permitted.
Structural Classification of Joints Based on 2 criteria: The presents or absence of a synovial cavity The type of connective tissue that binds the bones Structurally, joints are classified as either: Fibrous (Synarthrosis) - Immovable Cartilaginous (Amphiarthrosis) – Slightly movable Synovial (Diarthrosis) – Freely movable An example of each?
Fibrous Joints Lack a synovial cavity, bones held closely together by connective tissue There is little or no movement The most common type is suture - thin layer of dense fibrous connective tissue unites bones of the skull Another type is teeth in sockets of alveolar processes
Cartilaginous Joints Lack a synovial cavity; allows very little movement Bones tightly connected by fibrocartilage The best examples are intervertebral discs and pubic symphysis
Synovial Joints Synovial cavity separates articulating bones Bones covered by articular (hyaline) cartilage - reduce friction - works as a shock absorber Articular capsule surrounds joint - fibrous bundles (ligaments) mechanically hold bones close and provide stability Synovial membrane: inner layer of articular capsule - secretes viscous synovial fluid - brings nutrients to articular cartilage
Types of Synovial Joint HINGE PIVOT BALL AND SOCKET SADDLE CONDYLOID GLIDING These are complex joints which enable a wide range of movement-
Synovial Joint: Movement Types Specific terminology is used to designate the movement of the human body –
Quiz! What is a joint? What are the 3 types of structural classification? What do fibrous and cartilaginous joints lack? Ligaments are a component of the ______ capsule. Name the 6 types of synovial joint? In kayaking, what movement types would you see when paddling?
Further reading: Calais-Germain, B. (1993) Anatomy of Movement, Eastland Press,. ISBN 0-939616-17-3 Drake, R. Vogl, W. Mitchell, A. (2004) Gray’s Anatomy for Students, Churchill Livingstone. ISBN 0-443-06612-4 Martini, F. Timmons, M. McKinnley, M. (2000) Human Anatomy,3rd Edition, Prentice-Hall. ISBN 0-13-010011-0 Marieb, E. (2000) Essentials of Human Anatomy and Physiology, 6th Edition. Addison Wesley Longman. ISBN 0-8053-4940-5 Muscolino, E. (2005) The Muscular System Manual: The Skeletal Muscles of the Human Body, 2nd Edition, C.V. Mosby. ISBN 0-323-02523-4