October 23, 2014

Joints  Joints occur where two or more bones join together, or articulate  Functions: Hold bones together Allow motion  The structure of the joint determines the type and range of motion allowed

Types of Joints  Fibrous Joints Bones joined by fibrous tissue Essentially immovable Examples: sutures, syndesmoses Syndesmoses at distal tibiofibular joint The fibers of syndesmoses are longer than the fibers of sutures – allowing syndesmoses to have slight movement

Types of Joints  Cartilaginous Joints Bones are connected by cartilage Immovable or slightly moveable Examples: immoveable Slightly moveable

Types of Joints  Synovial Joints Bones are connected by a joint cavity containing synovial fluid ‘freely’ moveable

Synovial Joint Structure  Structures which facilitate movement Articular cartilage lines the ends of the bones, reducing friction Synovial membrane lines the inside of the joint capsule, reducing friction Synovial fluid fills the joint cavity, reducing friction and acting as a shock absorber

Synovial Joint Structure  Structures which hold the bones together Joint capsule made of fibrous connective tissue surrounds ends of bones Ligaments made of dense connective tissue connect the two bones are reinforce the joint capsule

Think, Pair, Share Older scholar …  What are the two functions of joints?  What would happen if the synovial membrane became inflamed? Younger scholar …  What special features give synovial joints the greatest freedom of movement?  What would happen if articular cartilage wore away?

Types of Synovial Joints The shape of synovial joints determines the allowable movements. Plane joints  Sliding movement  Can move short distances only  Ex: the vertebral arches

Types of Synovial Joints The shape of synovial joints determines the allowable movements. Pivot joints  rotational movement  Ex: the radioulnar joint

Types of Synovial Joints The shape of synovial joints determines the allowable movements. Hinge Joints  allow flexion / extension  Ex: humeroulnar joint

Types of Synovial Joints The shape of synovial joints determines the allowable movements. Saddle Joints  allow side-to-side AND back-and-forth motion  Both bones have concave and convex areas  Ex: carpometacarpal joint of thumb

Types of Synovial Joints The shape of synovial joints determines the allowable movements. Condyloid Joints (aka Ellipsoid)  allow side-to-side AND back-and-forth motion  One bone is convex and fits inside the other, concave bone  Ex: atlanto-occipital joint

Types of Synovial Joints The shape of synovial joints determines the allowable movements. Ball-and-socket joints  allow side-to-side AND back-and-forth motion AND rotation  Ex: shoulder (humerus – scapula)

Use the movement to guess the joint type!  Atlanto-axial joint (first two cervical vertibrae) Intercarpal joints  Interphalangeal joints  Tibia-talar joint  Acetobular-femoral joint  Metacarpalphalangeal joint Work in groups of minutes

Use the movement to guess the joint type!  Atlanto-axial joint (first two cervical vertibrae) – pivot joint  Intercarpal joints – (wrist) plane joints  Interphalangeal joints – (finger) hinge joints  Tibia-talar joint – (ankle) hinge joints  Acetobular-femoral joint – (hip) ball and socket joint  Metacarpalphalangeal joint – (knuckles) condyloid joint

Closure  What were our objectives and how did we accomplish them?  How does it relate to our overall unit question?  What was our learner profile trait and how did we use it?

Exit Ticket  Rank the following joints in order from most mobile to least Ball and socket, sutures, plane, saddle, pivot, cartilaginous