Articulations – Joint Anatomy and Function Flash Cards

The Shoulder Joint The shoulder joint (glenohumeral joint) permits the greatest range of motion of any joint, but is also the least stable It is a freely movable (diarthrosis), ball-and-socket joint, placed between the head of the humerus and the glenoid cavity of the scapula The glenoid labrum is the fibro-cartilage lining that extends past the bone and deepens the socket, which is enclosed by the articular capsule The acromion (clavicle) and coracoid process (scapula) project laterally and superior to the humerus, stabilizing the joint It is supported by numerous skeletal muscles, tendons, ligaments and bursae

Acromioclavicular ligament Coracoclavicular ligaments Tendon of supraspinatus muscle Clavicle Acromion Articular capsule Coraco-acromial ligament Subdeltoid bursa Coracoid process Scapula Synovial membrane Articular cartilages Glenoid (joint) cavity Glenoid labrum Humerus Head of humerus Articular capsule Anterior view, frontal section 3

Shoulder Ligaments Shoulder Muscles Shoulder Bursae Glenohumeral Coracohumeral Coracoacromial Coracoclavicular Acromioclavicular* Shoulder separation Shoulder Muscles (Rotator Cuff) Supraspinatus Infraspinatus Subscapularis Teres minor Shoulder Dislocation Shoulder Bursae Subacromial Subcoracoid Subdeltoid Subscapular

The Elbow Joint The elbow joint is a stable hinge joint with articulations involving the humerus, radius, and the ulna; it has limited movement The humeroulnar joint is the largest articulation of the elbow, involving the trochlea of the humerus and the trochlear notch of the ulna; it is stabilized by the ulnar collateral ligament

The humeroradial joint is the smaller articulation of the elbow, involving the capitulum of the humerus and the head of the radius; it is stabilized by the radial collateral ligament

The Hip Joint The hip joint is also called the coxal joint; it is a strong ball-and-socket (diarthrosis) with a wide range of motion The head of the femur fits into the acetabulum of the hip, which is extended by the acetabular labrum

The hip joint is also stabilized by the iliofemoral, pubofemoral, ischiofemoral, transverse acetabular, and femoral head ligaments (ligamentum teres)

The Knee Joint The knee joint is a complicated hinge joint that transfers weight from the femur to the tibia There are two femur to tibia articulations at the medial and lateral condyles, and one articulation between the patella and the patellar surface of femur The articular capsule envelopes the joint; menisci cushion and stabilize the joint

Accessory Structures: Cartilages, Fat pads, Ligaments, Tendons, Bursae Landmarks Include Articular cartilage pads articulating surfaces, preventing bones from touching. They are hyaline-based (porous) and filled with water Synovial fluid contains slippery proteoglycans that are secreted by fibroblasts. The fluid lubricates, distributes nutrients and helps to absorb shock Accessory Structures: Cartilages, Fat pads, Ligaments, Tendons, Bursae Meniscal cartilage cushions the joint; it contains a fibrocartilage rich pad called a meniscus (or articular disc) Fat Pads are superficial to the joint capsule; they protect articular cartilages Ligaments support and strengthen joints. A sprain is caused by ligaments with torn collagen fibers Tendons attach to muscles around the joint (support like a “wrapper”) Bursa is a pouch of synovial fluid; it cushions areas where tendons or ligaments rub. Excessive use (pressure) can cause painful inflammation, resulting in bursitis and the formation of a bunion All of these structures, as well as other bones and muscles, stabilize the joint!

The Structure of a Synovial Joint Quadriceps tendon Bursa Joint capsule Femur Patella Synovial membrane Articular cartilage Meniscus Fat pad Patellar ligament Intracapsular ligament Joint cavity Tibia Meniscus Knee joint, sagittal section 11

The knee has seven supporting ligaments (anterior) patellar ligament (posterior) 2 popliteal ligaments (medial) tibial collateral ligament (lateral) fibular collateral ligament (anterior) cruciate ligament* (posterior) cruciate ligament* *(located inside joint capsule)