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Biol 2401 Chapter 9: Articulations Dr BIOL 2401 CHAPTER 9: ARTICULATIONS DR. WELCH I. Joint aka articulation or arthrosis. Define arthrology; kinesiology. II. Joint Classifications A. Functional – based on degree of movement permitted 1. Synarthrosis (syn = together) – immovable 2. Amphiarthrosis (amphi = on both sides) – slightly movable 3. Diarthrosis – freely movable; all are synovial joints; variety of movements due to different shapes. B. Structural – based on anatomical characteristics; determined by presence or lack of synovial space and type of CT. 1. Fibrous – No synovial space; DICT (collagen); little or no movement; 3 types. a. Sutures – only between skull bones; synarthrosis (adult) & amphiarthrosis (children) i. Synostosis – suture fused & ossify (bony joint); synarthrosis ii. Define metropic suture. b. Syndesmoses (syndesmo = band or ligament) i. Anterior Tibiofibular joint – distal; amphiarthrosis ii. Gomphosis (gompho = bolt or nail) – aka. dentoalveolar joint; synarthrosis c. Interosseous Membrane – along radius & ulna, tibia & fibula; amphiarthrosis 2. Cartilaginous – No synovial space; cartilage a. Synchondroses – hyaline cartilage (review Chapter 4) i. Epiphyseal Plate (review Chapter 6) synarthrosis becomes synostosis when growth ceases. ii. What results with disruption of the joint as a child vs. adult? b. Symphyses – fibrocartilage; amphiarthrosis i. All are along the midline of the body – pubic symphysis, sternal angle, IVD ii. Limited repair/ regeneration – why? 3. Synovial – Synovial space present; DICT capsule with accessory ligaments; Diarthrosis. SYNOVIAL JOINTS III. Components of Synovial Joints A. Articular Cartilage – smooth, slippery hyaline cartilage; reduces friction & absorbs shock B. Articular Capsule – encloses synovial cavity and united articulating bones. 2 membranes: 1. Fibrous Membrane – outer layer a. DICT attached to periosteum; permits movement due to its flexibility with great tensile strength. Prevents ____________________. b. Some ligamentous formation (DRCT) – approximates bones close; resists _________________. 2. Synovial Membrane – inner layer; areolar CT with elastic fibers; articular fat pads. What is double jointed and what id the predisposition for this condition? C. Synovial Fluid – viscous material. What is the benefit of warming up prior to exercise? 1. Hyaluronic acid. What are the purposes of hyaluronic acid? 2. Phagocytic cells – engulf wear & tear debris D. Accessories 1. Ligaments (extracapsular & intracapsular) List examples for both types. 2. Articuar Discs or Menisci – fibrocartilage. List locations & functions. 3. Labra – ball & socket; Fibrocartilaginous; deepens socket to increase contact. Look up labrum tears. E. VAN – many nerve endings detects pain, stretch & proprioception. What do chondrocytes within synovial joints rely on for blood supply? Describe sprain vs. strain. F. Bursae & Tendon Sheaths 1. Bursae – saclike; located between skin and bones, tendons and bones, muscles and bones, or ligaments and bones. a. How are bursae similar to synovial cavities? 1 b. What is "bursitis"? 2. Tendon (Synovial) Sheath – tubelike bursae wrapped around tendons forming a tunnel. List locations. IV. Types of Synovial Movements – refer to p. 301 Table 9.1. Describe each movement and give examples of each. V. Types of Synovial Joints – refer to bottom section of p. 304 Table 9.2 Describe each type and give examples of each. VI. Factors Affecting Synovial Joints – Define active vs. passive ROM. Discuss the following. A. Structure & Shape of bones B. Strength & tension of ligaments C. Arrangement & tension of surrounding musculature D. Contact of soft tissue E. Hormones F. Disuse VII. Specific Synovial Joints (Although each joint includes more structure, concentrate on the following for the exam.) A. Temporomandibular Joint (TMJ) – only Diarthrosis joint in skull except ______________. List movements. 1. Articular disc – fibrocartilage; separates cavity 2. Lateral ligament – covered by __________ gland; prevents ________________. 3. Stylomandibular Ligament – separates parotid and limits movement. 4. Injuries: Define the difference between types of dislocations. B. Shoulder (humeroscapular or glenohumeral) joint – Ball & socket. List movements. 1. Articular capsule – Which is the weakest area? 2. Transverse humeral ligament – “retinaculum” holding the _____________________________. 3. Glenoid labrum – ID tissue and function. What are the causes of a glenoid labrum tear? 4. Rotator cuff muscles – ID rotator cuff muscles and their purpose. 5. Injuries: ID most common rotator cuff injured & why. Describe the difference between dislocation & separation. List three reasons (based on anatomical structure) why the shoulder joint so easily dislocated (luxated)? C. Elbow Joint – hinge; list movements. 1. Annular ligament of the radius – holds radial head in place. 2. Injuries: Describe Tennis Elbow, Little-League Elbow, and radial head dislocation. D. Hip Joint – ball & socket; List movements & structure that limit them. 1. Articular capsule – assisted by 3 ligaments a. Iliofemoral ligament – body’s strongest ligament; prevents ______________________. b. Pubofemoral ligmnet – prevents _______________. c. Ischiofemoral ligament – slackens with adduction & tenses during abduction. 2. Femoral head ligament – usually with small artery to head of femur. 3. Acetabula labrum – tissue & function? E. Knee Joint – largest and most complex joint; modified hinge joint with 3 joints within a single cavity: medial & lateral tibiofemoral, and patellofemoral joints. 1. Patellar ligament – strengthen anterior aspect; infrapatellar fat pad. 2. Collateral ligaments a. Tibial (medial) – Strengthens medial aspect; crossed by sartorius, gracilis & semitendinosus muscles. Attached to medial meniscus. b. Fibular (lateral) – Strengthens lateral aspect; biceps femoris muscle. 3. Intracapsular ligaments – 2 cruciate ligaments; crisscross a. ACL – limits _____________ of knee; involved in 70% of all knee injuries. Why are injuries more common in women than men? b. PCL – Prevents ___________ sliding of the tibia and anterior sliding of the femur; important when walking __________________________________. 4. Articular discs (menisci) – fibrocartilage a. Medial meniscus – C-shaped b. Lateral meniscus – O-shaped 5. Injuries: Discuss immediate vs. delayed swelling, unhappy “terrible” triad, & dislocation. List aging affect on joints. Review all Clinical Connections, Disorders: Homeostatic Imbalances, & Medical Terminology (back of chapter). 2 This is only a general outline. There may be material that has been discussed in lecture that is not included in this outline and there may be material on this outline that has not been discussed in lecture. Any material discussed in lecture or listed in this outline is "fair game" for the test. 3 .
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