Joints And I’m not talking about the illegal kind.

Joints Joints (articulations) hold bones together giving stability & mobility. Classified according to the degree of movement: Immovable – Fibrous joints Slightly movable – Cartilaginous joints Freely movable – Synovial joints

Immovable Joints Fibrous joints Bones are held together by collagenous fibers Are collagenous fibers stretchy or strong? No joint cavity Example: Skull sutures, tibiofibular joints

Slightly movable Cartilaginous joints Bones are held together by cartilage No joint cavity Example: costosternal joints, pubic symphysis, intervertebral discs

Freely movable joints Synovial Joints Most common type of joint in the body The bones that articulate are separated by a joint cavity that is filled with synovial fluid and joined together by ligaments Allows for more movement Examples: Shoulder Hip Elbow Knee Carpal Interphalangeal joints

Synovial Joints Structures in a synovial joint Articulating cartilage Joint capsule Synovial membrane Joint cavity Bursae Meniscus

Synovial joints Structure of a synovial joint Articulating Cartilage – hyaline cartilage on the ends of articulating bones Joint Capsule – layer of dense connective tissue that joins with the periosteum

Synovial joints Structure of a synovial joint Synovial Membrane – inner layer of joint capsule, secretes synovial fluid Joint Cavity – lubricates articulating surfaces within joints, has the consistency of egg whites

Synovial Joints Structure of a synovial joint Bursae – fibrous membrane bags filled with synovial fluid Often found where bones, muscles, tendons, or ligaments rub together

Synovial joints Structure of a synovial joint Meniscus – fibrous cartilage pads found between the bones that act as shock absorbers and stabilize the joint Found in the knee, jaw, sternoclavicular joints

Meniscal tear

Synovial joints Structure of a synovial joint Ligaments – made up of dense connective tissue and connect bone to bone

Types of synovial joints Ball and socket Hinge Pivot Gliding Condyloid Saddle

Types of synovial joints Ball and Socket Allows for the most movement Surface of a rounded head moves in a cup-like cavity of another bone Examples: Shoulder, Hip

Types of synovial joints Hinge Joint Movement resembles a door hinge A convex surface of one bone fits into a concave surface of another Examples: Elbow, Knee, and Interphalangeal joints

Types of synovial joints Pivot Joint Bone rotates/pivots on a ring around a central axis Examples: Radius on Ulna, Skull on Spine (atlas/axis)

Types of synovial joints Gliding Joint One bone slides from side to side over another bone Examples: Carpals and Metacarpals, Tarsals and Metatarsals

Types of synovial joints Condyloid Joint Oval surface of one bone fits into a complementary depression on another Example: Metacarpal and Proximal Phalanx

Types of synovial joints Saddle Joint Saddle-shaped articular surfaces Both bones have a concave and convex articular surface Example: Thumb metacarpal - carpal

ACL Tear