10/15/2018 http://vanat.cvm.umn.edu/ http://www.cvmbs.colostate.edu/vetneuro/VCA3/vca.html Arthrology 1 10/15/2018 • Where a bone joins … Synchondrosis Range of motion (ROM) 2 basic types of joint structure classification Synarthrosis Amphiarthrosis Diarthroses (synovial) No movement (synostosis) Slightly movable Freely movable Without a cavity (2 types) With a cavity (1 type) Bones joined by solid Masses of connective Bones joined by a CT capsule tissue (CT) surrounding a synovial cavity Fibrous Synovial Cartilaginous 2 10/15/2018 Fibrous joints • Syn • Gomphosis • Suture Gomphosis Horse Radius and Ulna desmo Gomphosis Dog Tibia and fiula 3 10/15/2018 Suture Types of Sutures • According to the form of the united margins: Cartilaginous: Synchondrosis Cartilaginous joints • Synchondrosis (primary) -- hyaline cartilage union • Symphysis (secondary) ostoses 4 10/15/2018 Cartilaginous: (symphysis) Nucleus pulposus Anulus fibrosus Intervertebral Disk The ossification process • These provide for bone growth and then subside once bone has reached mature length • Make junvenile radiographic interpretation challenging • Common fracture sight in young • Must know typical closure dates for radiology 5 10/15/2018 Essential structures 1. Articular capsule: Synovial = Diarthrodial - Fibrous layer - Synovial membrane: joints 6 types Articular cartilage: Articular cartilage: 6 10/15/2018 Articular or joint Capsule Articular (Synovial) cavity and Articular Cavity Synovial Fluid 7 10/15/2018 Joint Taps - Synovial Fluid Analysis Synovial fluid Accessory structures Ligaments • Ligamensts • Extracapsular • Intracapsular • Intra-articular fibrocartilage - Capsular • Marginal cartilage (labra) • Fat pads 8 10/15/2018 Fat Pads Articular Discs • Between fibrous and synovial layers • may protrude into joint cavity (pushing the synovial membrane into folds inside the synovial cavity) • e.g., parapatellar fat pads of the stifle joint Meniscus Labrum 9 10/15/2018 Classification of synovial joints According to # of bones forming the joint • According to # of bones forming the joint • According to shape of articular surface • According to axis of movement According to shape of articular surface 1- Plane Spheroidal (ball and socket) • e.g., carpal, tarsal joints, and vertebrae (dorsal articulation) • Gliding or sliding movement Equine cervical vertebra 10 10/15/2018 Ellipsoidal Saddle Condylar Pivot 11 10/15/2018 Pivot (Trochoid) Ex. Atlantoaxial j. According to axis of movement Uniaxial Biaxial According to axis of movement Multiaxial 12 10/15/2018 Movements of synovial joint General Myology Myo + ology = The study of muscle 13 10/15/2018 Types of muscle tissue (3 types): Muscle Skeletal • Smooth Striated Smooth • Cardiac Skeletal Cardiac Skeletal muscle fibers are enveloped by connective tissue epimysium • Epimysium muscle belly perimysium endomysium • Perimysium muscle fascicles endomysium Nucleus • Endomysium muscle fibers (cells) Tendons Muscle muscle fascicle 14 10/15/2018 Types of attachments • Regions: h • Tendons may be: • Very Very short • Very broad aponeurosis • Sharpey's fibers: Sensory innervation of tendons and Panniculus reflex ligaments reflex inhibition 15 10/15/2018 Types of skeletal muscles (according to orientation of fibers in the muscle) Pennate Muscles • Parallel (Strap) ex. Sartorius M. • Fusiform Unipennate Bipennate Multipennate • Appears as a series of • Fibers attach obliquely • Fibers running obliquely along Flat bipennate muscles set side by • along one side of the both sides of a centrally located side. Circular (sphincter muscles) --- fibers arranged in concentric rings → closes the tendon tendon. • Like a number of feathers Like half a feather Like a whole feather • openings. e.g., orbicularis oris and orbicularis oculi • • placed next to one another Genioglosseus M. Common digital extensor M. Pennate fibers join the tendon obliquely → more fibers → more powerful • Abductor pollicis longus M. Gastrocnemius M. Deltoideus M. Psoas minor M. Rectus femoris M. Flat muscle Bipennate muscle Mulitpennate muscle Unipennate muscle Unipennate Bipennate 16 10/15/2018 Types of skeletal muscles (according to number of joints it crosses) Grouping According to action: • Uniarticular • Biarticular • Polyarticular Muscle Nomenclature According to Flexion shape Extension Size Relative position/direction Pronation Abduction Supination Origin and insertion Adduction Function Structure Depression Combination Elevation 17 10/15/2018 Muscle Nomenclature Accessory structures associated Muscle injuries with skeletal muscles • Superficial fascia • Deep fascia endomyseal sheathing and sarcolemma intact regenerates CT (scarring). 18 10/15/2018 Modification Fascia of the deep fascia: clinical importance Carpal flexor approach retinaculum Digital annular ligaments • Compartmental syndrome Synovial Bursa Navicular bursa • A sac-like structure between 2 different tissues to reduce friction. • Structure ----- as the j. capsule, i.e. its wall consists of a fibrous layer lined by a synovial membrane. • E.g., Bicipital bursa • Navicular bursa 19 10/15/2018 Synovial sheath Mesotendon Vascularization of skeletal Muscles Innervation of skeletal Muscles • Motor nerves • Arteries • Veins • Lymphatic • Sensory nerves 20.