Bio 201 Lecture 6 PDF

**Joints** ========== Joints = Articulations ====================== Articulation = a point of contact between bones, between cartilage and bone, or between teeth and bone ------------------------------------------------------------------------------------------------------ ### Arthro = joint ###...

**Joints** ========== Joints = Articulations ====================== Articulation = a point of contact between bones, between cartilage and bone, or between teeth and bone ------------------------------------------------------------------------------------------------------ ### Arthro = joint #### Arthritis - inflammation of joints #### Arthrology = study of joints Kinesiology: the study of the muscu-skeletal movement **Functional Classification of joints:** ======================================== Functional classification - how much movement is permitted ---------------------------------------------------------- 1. ### Diarthrosis - freely movable 2. ### Amphiarthosis - slightly movable 3. ### Synarthrosis -- little or no movement **Structural Classification of the joints:** ============================================ Structural Classification - based on kind of connective tissue that binds joints together and/or a space called a joint cavity ------------------------------------------------------------------------------------------------------------------------------ 1. **Bony joints (synostosis):** 2 bones once separate fused by osseous tissue - Frontal and mandibular bones in infants - Cranial sutures in elderly - Attachment of first rib and sternum with old age **Fibrous** - no joint cavity; bones held together with fibrous connective tissue --------------------------------------------------------------------------------- ### **Sutures** - held together with thin dense fibrous connective tissue #### Unites skull bones #### Synarthrotic in adults and Amphiarthrotic in children - **Serrate suture**: wavy, interlocking - **Lap (squamous) sutures**: overlapping beveled edges - **Plane (butt) sutures:** straight nonoverlapping edges ### **Syndesmosis** - more fibrous connective tissue than in a suture; fibrous connective tissue forms an interosseus membrane or ligament #### distal articulation between tibia and fibula #### interosseus membrane between radius and ulna #### interosseus membrane between tibia and fibula #### Amphiarthrotic ### **Gomphosis** - specialized syndesmosis joint in which pegs (teeth) fit into sockets (alveoli); periodontal ligament hold teeth in sockets; teeth are in the alveoli of the maxilla and mandible #### Synarthrotic #### Periodontal disease - accumulation of plaque and bacteria that destroys periodontal ligament; leading cause of tooth loss in US **Cartilaginous** **Joints** - no joint cavity; bones connected with cartilage ------------------------------------------------------------------------------ ### **Synchondrosis** - connecting cartilage is hyaline cartilage #### epiphyseal plate - connects diaphysis and epiphysis; synarthrotic #### First rib to the sternum by hyaline costal cartilage ### **Symphysis -** fibrocartilage is connecting cartilage #### pubic symphysis; amphiarthrotic #### intervertebral disc; amphiarthrotic **Synovial** - space between articulating bones; freely movable; diarthrotic ---------------------------------------------------------------------------- ### Synovial cavity space between articulating bones ### Articular Capsule - joint capsule consisting of 2 layers: #### Outer layer (Fibrous capsule) - dense irregular connective tissue that is continuous with fibrous layer of periosteum #### Inner layer (Synovial membrane) - loose connective tissue with elastic fibers that secretes synovial fluid; lines cavity except over articular cartilage, rich in albumin and hyaluronic acid. ##### Ligaments may be outside fibrous capsule (ex. collateral ligaments of knee) ##### Ligaments may be inside articular capsule but excluded from synovial cavity because ligaments are covered with synovial membrane (ex. cruciate ligaments of knee) #### **Synovial Fluid** (ova = egg) - consistency of egg white, rich in albumin and hyaluronic acid. #### lubricates joint #### nourishes articular cartilage #### contains phagocytic cells to remove debris from joint ### **Articular Cartilage** - hyaline cartilage that covers ends of bone but does not bind bone together ### **Bursa** - Sacs lined with synovial membrane that reduce friction between body parts: #### Bursas are found between skin and bone; tendons and bone; muscle and bone; ligaments and bones ### **Tendon sheaths** - synovial membrane wrapped like hot dog bun Types of Synovial Joints ======================== Planar -- intercarpal and intertarsal, sternoclavicular, acromioclavicular, sternocostal, and vertebrocostal ------------------------------------------------------------------------------------------------------------ Hinge -- knee, elbow, ankle and interphalangeal ----------------------------------------------- Pivot -- atlanto-axial, radioulnar ---------------------------------- Condyloid -- wrist and metacarpophalangeal (2-5) ------------------------------------------------ Saddle -- carpometacarpal in thumb ---------------------------------- Ball and Socket -- shoulder and hip ----------------------------------- Types of Movements at Synovial Joints ===================================== Gliding -- planar ----------------- Flexion and Extension --------------------- Lateral flexion -- intervertebral joints ---------------------------------------- Hyperextension -------------- Abduction and Adduction ----------------------- Circumduction ------------- Rotation -- lateral and medial ------------------------------ Elevation and Depression ------------------------ Protraction and Retraction -------------------------- Inversion and Eversion ---------------------- Dorsiflexion and Plantar Flexion -------------------------------- Supination and Pronation ------------------------ Opposition ---------- Knee ==== Largest and most complex of synovial joints; ligaments strengthen joint ----------------------------------------------------------------------- Patellar ligament - continuation of Quadriceps femoris tendon and inserts into tibial tuberosity ------------------------------------------------------------------------------------------------ Oblique popliteal ligament - connects lateral condyle of femur to the medial margin of the head of tibia -------------------------------------------------------------------------------------------------------- Tibial Collateral (medial collateral) ligament - broad flat ligament that connects medial condyle of femur to medial condyle of tibia ------------------------------------------------------------------------------------------------------------------------------------- Fibular Collateral (lateral collateral) ligament - rounded ligament on the lateral surface of joint that extends from lateral condyle of the femur to the lateral side of the fibula ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Intra-articular ligaments - Ligaments within the joint help prevent displacement of articulating surfaces = cruciate ligaments ------------------------------------------------------------------------------------------------------------------------------ ### Cruciates named according to tibial attachment site ### **Anterior cruciate ligament** - originates anterior to intercondylar eminence of tibia and extends posterior and laterally to medial side of lateral condyle of femur, ACL prevents hyperextension of the knee. #### ACL is stretched or torn in about 70% of all serious knee injuries ### Posterior cruciate ligament - originates on the posterior intercondylar area of the tibia and extends anteriorly and medially to the medial surface of the medial condyle of the femur Medial and lateral menisci (fibrocartilage) - semilunar cartilage - wedge shaped fibrocartilage that attaches to condyles of tibia and serves to deepen condyles of tibia for articulation with condyles of femur ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ### Medial meniscus - C shaped - medial meniscus is anchored to tibial collateral ligament and is less mobile and more frequently ruptured during injuries from twisting of flexed knee ### Lateral meniscus - more circular Most sports injuries involve lateral blow to knee so anterior cruciate, tibial collateral and medial meniscus are injured ------------------------------------------------------------------------------------------------------------------------- Arthritis ========= Inflammation of joints ---------------------- Rheumatoid arthritis - inflammation of the synovial membrane and can progress to fusion at joint - autoimmune disease - strikes small joints and is likely to be bilaterally symmetrical ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Osteoarthritis - more common than rheumatoid arthritis and less damaging; usually affects only articular cartilage and not membrane as in rheumatoid arthritis; strikes big joints like knee and hips; \"wear and tear\" arthritis ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Gouty arthritis - Uric acid is a product of purine metabolism of DNA and RNA and is usually excreted in urine; person has accumulation of sodium urate in cartilage at joints ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Answer the following questions: 1. Joint b/w the first costal cartilage and sternum is\_\_\_\_\_\_\_\_\_\_ and rest of the rest of the costal cartilages and sternum connection is \_\_\_\_\_\_\_\_\_\_\_\_. 2. Joint found only in skull is called\_\_\_\_\_\_\_\_\_\_\_ 3. Tooth in socket\_\_\_\_\_\_\_\_\_\_\_\_ 4. Bones united by fibrocartilage\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 5. Synovial fluid rich in\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 6. Epiphysis and diaphysis connected by (in children) \_\_\_\_\_\_\_\_\_\_\_\_\_\_ 7. Which joint has wide range of motion hip or shoulder? 8. Anterior cruciate ligament (ACL) of the knee prevents \_\_\_\_\_\_\_\_\_\_\_of the knee 9. Bending your head back until it hurts is an example of \_\_\_\_\_\_\_\_. 10. Holding your arm up is \_\_\_\_\_\_\_\_\_\_\_\_ of your arm, know adduction, abduction, circumduction, heyperextension, supination and pronation. 11. What are menisci (articular discs)? 12. What is moving a limb away from the midline of the body along the frontal plane called? 13. Explain briefly what is rheumatoid arthritis