Articulations Claudia Stanescu, Ph.D. Office Hours in Gittings 108 Tue 10-11am and Thurs 1-2pm or by appointmentObjectives: 1. List the 3 structural classifications of articulations. 2. List and describe the 3 functional classifications of articulations. 3. Define the subtypes of the three functional classifications of articulations discussed in lecture and give examples of each. 4. Describe the basic components of a synovial joint.Objectives: 5. List the functions of synovial fluid. 6. Describe the shoulder joint and the knee joint including the ligaments and tendons that stabilize each joint. 7. Describe the two types of arthritis and list the major risk factors for osteoarthritis.Articulation Definition: a point of contact between 1) Bones (elbow) 2) Bones and cartilage (epiphyseal plates) 3) Bones and teeth (teeth articulate with alveoli)Structural classification of joints Based on anatomical structure • Fibrous • Cartilaginous • Synovial (fibrous CT)(cartilage)(most common)Functional classification of joints Based on amount of movement at a joint • Immovable  synarthrosis • Slightly movable  amphiarthrosis • Freely movable  diarthrosis (most joints in skull) -arthrosis refers to join-syn is together-amphi is 2 different things(knee hip fingers)(ie sutures, tooth(gomphosis), synchondrosis(epiphyseal) (ie syndesmoses (band of tissue) between tibia + fibulapelvic symphysis) (ie elbow (mono-axial), ulna + radius joint, ball and socket joint(head of femur and hip)Types of synarthroses (immovable joints) Cartilaginous joint Fibrous jointsTypes of amphiarthroses (slightly movable joints) Fibrous joint Cartilaginous jointTypes of diarthroses (freely movable joints) All diarthroses are synovial joints Mono-axial joint: elbow (hinge joint)(pivot joint)Types of diarthroses (freely movable joints) Tri-axial joints: hip and shoulder (ball and socket)Types of diarthroses (freely movable joints) (planar)Structure of diarthroses (synovial joints)Functions of synovial fluid: 1) Lubricates joint 2) Provides nutrients to articular cartilage (avascular) 3) Shock absorption Accessory structures of synovial joints: • Ligaments: intracapsular and extracapsular • Tendons • Bursae • MenisciShoulder joint • Diarthrosis – freely movable • Tri-axial joint – more prone to injury • Stabilized by 5 ligaments and the tendons of 5 musclesShoulder Joint - Ligaments 3Shoulder joint - Tendons Rotator Cuff Muscles: 1. Supraspinatus 2. Infraspinatus 3. Subscapularis 4. Teres minorKnee joint • Diarthrosis • Mono-axial joint • Medial and lateral menisci cushion the joint • 7 ligaments stabilize the joint – 2 intracapsular ligaments – 5 extracapsular ligamentsKnee joint – extracapsular ligamentsKnee Joint – intracapsular ligamentsArthritis 2 Common Types: 1) Osteoarthritis (OA) – degenerative 2) Rheumatoid arthritis (RA) - inflammatory http://www.medicinenet.com/rheumatoid_arthritis_pictures_slideshow/article.htmOsteoarthritis Risk Factors • Heredity • Overweight • Joint injury • Repeated overuse • Aging • Lack of physical activity • Nerve