Chapter 09 Lecture Outline See separate PowerPoint slides for all figures and tables pre- inserted into PowerPoint without notes. Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1 9.1 Classification of Joints • Joints (articulations) – Places of contact between bones, bones and cartilage, or bones and teeth – Arthrology—study of joints 2 9.1 Classification of Joints • Range of motion at joints – Motion ranges from no movement to extensive movement – Structure of each joint determines its mobility and stability – Inverse relationship (tradeoff) between mobility and stability o For example, skull sutures are immobile but very stable 3 9.1 Classification of Joints • What are the functional classes of joints? – Synarthroses o Immobile joints o Can be fibrous or cartilaginous joints – Amphiarthroses o Slightly mobile joints o Can be fibrous or cartilaginous joints – Diarthroses o Freely mobile joints o All synovial joints 4 9.1 Classification of Joints • What are the structural classes of joints? – Fibrous joint o Bones held together by dense connective tissue – Cartilaginous joint o Bones joined by cartilage – Synovial joint o Bones joined by ligaments with fluid-filled joint cavity separating bone surfaces 5 Figure 9.1 6 9.2 Fibrous Joints • Characteristics of fibrous joints – Connected by dense regular connective tissue – Have no joint cavity – Immobile or only slightly mobile – Three most common types o Gomphoses o Sutures o Syndesmoses 7 9.2a Gomphoses • Gomphoses (peg in a socket) – Articulations of teeth with sockets of mandible and maxillae – Tooth held in place by fibrous periodontal membranes – Function as synarthroses Figure 9.2a 8 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 9.2b Sutures • Sutures (seams) – Found between some skull bones o Very short fibers – Interlocking, irregular edges o Increase strength and decrease risk of fracture – Function as synarthroses – Allow growth in childhood – Become ossified synostoses in older adults Figure 9.2b Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 9 9.2c Syndesmoses • Syndesmoses – Bound by interosseous membrane, broad ligamentous sheet – Found between radius and ulna and between tibia and fibula – Function as amphiarthroses o Provide pivot for two long bones Figure 9.2c Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 10 What did you • Where are gomphoses located? learn? • Where can I find syndesmoses joints? • Functionally, how are syndesmoses classified? (In other words, how much movement do they allow?) Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 11 9.3 Cartilaginous Joints • Properties of cartilaginous joints – Either hyaline cartilage or fibrocartilage between bones – Lack a joint cavity – Immobile or slightly mobile – Synchondroses or symphyses 12 9.3a Synchondroses • Synchondroses – Bones joined by hyaline cartilage – Immobile (synarthroses) Figure 9.3a 13 9.3b Symphyses • Symphyses – Pads of fibrocartilage between articulating bones o Resist compression and act as shock absorbers – Allow slight mobility (amphiarthroses) Figure 9.3b 14 What did you learn? • What type of cartilage is found in a synchondrosis? • What type of cartilage is found in a symphyses? Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 15 9.4a Distinguishing Features and Anatomy of Synovial Joints • Synovial joints – Bones separated by a joint cavity – Include most joints in the body – Diarthroses (freely mobile) 16 Figure 9.4 17 9.4a Distinguishing Features and Anatomy of Synovial Joints All with the basic features o Articular capsule and joint cavity o Outer fibrous layer and Inner synovial membrane o Joint cavity o synovial fluid lubricates articular cartilage o Articular cartilage o Hyaline cartilage (avascular) o Reduces friction during movement o Ligaments, nerves, and blood vessels o Stabilize, strengthen, and reinforce synovial joints o Numerous nerves detect painful stimuli 18 9.4a Distinguishing Features and Anatomy of Synovial Joints • Bursae – Fibrous, saclike structures containing synovial fluid – Lined internally by synovial membrane – Found in synovial joints where bones, ligaments, muscles, skin, or tendons rub together – Connected to or separate from joint cavity – Alleviate friction 19 9.4a Distinguishing Features and Anatomy of Synovial Joints • Other accessory structures – Tendon sheaths, elongated bursae o Wrap around tendons where friction is excessive o Common in wrist and ankle – Fat pads o Act as protective packing material in joint periphery o Can fill spaces when joint shape changes 20 Figure 9.5a 21 Figure 9.5b 22 9.4b Classification of Synovial Joints • Classified by movements allowed and shapes of joint surfaces • Classes by movement – Uniaxial joint o Bone moves in just one plane or axis – Biaxial joint o Bone moves in two planes or axes – Multiaxial joint o Bone moves in multiple planes or axes 23 9.4b Classification of Synovial Joints • Classes by shape of joint surfaces (from least to most mobile) – Plane joints – Hinge joints – Pivot joints – Condylar joints – Saddle joints – Ball-and-socket joints 24 Figure 9.6 25 9.4b Classification of Synovial Joints • Plane joint – Articular surfaces flat – Simplest, least mobile synovial articulation – Uniaxial: limited side-to-side gliding movement in a single plane • Hinge joint – Convex surface within concave depression – Uniaxial: like the hinge of a door • Pivot joint – Bone with rounded surface fits into ligament ring – Uniaxial joint: rotation on longitudinal axis 26 9.4b Classification of Synovial Joints • Condylar joint – Oval, convex surface articulating with concave surface – Biaxial • Saddle joint – Convex and concave surfaces resembling saddle shape – Biaxial • Ball-and-socket joint – Spherical head of one bone fitting into cuplike socket – Multiaxial, permitting movement in three planes – The most freely mobile type of joint 27 9.6b Angular Motion • Angular motion – Increases or decreases angle between two bones – Includes specific types o Flexion and extension o Hyperextension o Lateral flexion o Abduction and adduction o Circumduction 28 9.6b Angular Motion • Flexion – Movement in an anterior-posterior plane – Decreases the angle between bones: brings bones closer together – E.g., bending finger • Extension – Also in anterior-posterior plane, but opposite of flexion – Increases angle between articulating bones – E.g., straightening your fingers after making a fist 29 9.6b Angular Motion • Hyperextension – Joint extended more than 180 degrees – E.g., glancing up at the ceiling while standing • Lateral flexion – Trunk of body moving in coronal plane laterally – Occurs between vertebrae in the cervical and lumbar region 30 Flexion, Extension, Hyperextension, and Lateral Flexion Figure 9.8 31 9.6b Angular Motion • Abduction – Lateral movement of body part away from midline – E.g., arm or thigh moved laterally from body midline • Adduction – Medial movement of body part toward midline – E.g., thigh brought back to midline 32 Abduction and Adduction Figure 9.9 33 9.6b Angular Motion • Circumduction – Proximal end of appendage relatively stationary – Distal end makes a circular motion – Movement makes an imaginary cone shape – E.g., drawing a circle on the blackboard (both) © The McGraw-Hill Companies, Inc./JW Ramsey, photographer Figure 9.10 34 9.6c Rotational Motion • Rotation – Bone pivots on its own longitudinal axis – Lateral rotation o Turns anterior surface of bone laterally – Medial rotation o Turns anterior surface of bone medially – Pronation o Medial rotation of forearm so palm of hand posterior – Supination o Lateral rotation of forearm so palm of hand anterior 35 Rotational Movements Figure 9.11 36 9.6d Special Movements • Depression – Inferior movement of a body part – E.g., movement of mandible while opening mouth • Elevation – Superior movement of a body part – E.g., movement of mandible when closing mouth 37 Special Movements Allowed at Synovial Joints Figure 9.12a 38 9.6d Special Movements • Dorsiflexion – Limited to ankle joint – Talocrural (ankle) joint bent so the dorsum (superior surface) of foot moves toward the leg – E.g., when digging in your heels • Plantar flexion – Talocrural joint bent so dorsum pointed inferiorly – E.g., ballerina on tiptoes in full plantar flexion Figure 9.12b 39 9.6d Special Movements • Inversion – Occurs only at intertarsal joints of the foot – Sole turns medially • Eversion – Occurs only at intertarsal joints of foot – Sole turns laterally Figure 9.12c 9.6d Special Movements • Protraction – Anterior movement from anatomic position – E.g., jutting jaw anteriorly at temporomandibular joint • Retraction – Posterior movement from anatomic position – E.g., pulling in jaw posteriorly at temporomandibular joint Figure 9.12d 9.6d Special Movements • Opposition – Movement of thumb toward tips of fingers at carpometacarpal joint – Enables the thumb to grasp objects • Reposition – Opposite movement Figure 9.12e 9.7a Temporomandibular Joint • Features of the temporomandibular joint (TMJ) – Head of mandible articulates with temporal bone – Only mobile joint between bones in the skull – Has loose articular capsule • Surrounds joint • Promotes extensive range of motion – Hinge, gliding, and some