October 23 2014 JOINTS Joints Joints occur where

October 23, 2014 JOINTS

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 The fibers of syndesmoses are longer than the fibers of sutures – allowing syndesmoses to have slight movement Syndesmoses at distal tibiofibular joint

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

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 2 -3 7 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