Kin 290, Chapter 8, Week 8
Kin 290, Chapter 8, Week 8 Kin 290
Popular in Anatomy & Physiology
Popular in Kinesiology
This 6 page Class Notes was uploaded by Leonard Carey on Monday April 11, 2016. The Class Notes belongs to Kin 290 at 1 MDSS-SGSLM-Langley AFB Advanced Education in General Dentistry 12 Months taught by Dr. Satern in Spring 2016. Since its upload, it has received 16 views. For similar materials see Anatomy & Physiology in Kinesiology at 1 MDSS-SGSLM-Langley AFB Advanced Education in General Dentistry 12 Months.
Reviews for Kin 290, Chapter 8, Week 8
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 04/11/16
Chapter 8 Chapter 8 The Joints Why This Matters • Understanding the nature of joints will help you treat patients with injuries such as ankle sprains 8.1 Classification of Joints • Joints, also called articulations: sites where two or more bones meet • Functions of joints: give skeleton mobility and hold skeleton together • Two classifications: 1. Structural: three types based on what material binds the joints and whether a cavity is present • Fibrous • Cartilaginous • Synovial Classification of Joints (cont.) 2. Functional classifications: three types based on movement joint allows • Synarthroses: immovable joints • Amphiarthroses: slightly movable joints • Diarthroses: freely movable joints • Structural classifications are more clear cut, so these will be used here 8.2 Fibrous Joints Bones joined by dense fibrous connective tissue No joint cavity Most are immovable • Depends on length of connective tissue fibers Three types of fibrous joints • Sutures • Syndesmoses • Gomphoses Sutures (Figure 8.1a – p. 252) Rigid, interlocking joints of skull Allow for growth during youth • Contain short connective tissue fibers that allow for expansion In middle age, sutures ossify and fuse • Immovable joints join skull into one unit that protects brain • Closed, immovable sutures referred to as synostoses © 2016 Pearson Education, Inc. 1 Chapter 8 Syndesmoses (Figure 8.1b – p. 252) Bones connected by ligaments, bands of fibrous tissue Fiber length varies, so movement varies • Short fibers offer little to no movement • Example: inferior tibiofibular joint • Longer fibers offer a larger amount of movement • Example: interosseous membrane connecting radius and ulna Gomphoses (Figure 8.1c – p. 252) Peginsocket joints Only examples are the teeth in alveolar sockets Fibrous connection is the periodontal ligament • Holds tooth in socket 8.3 Cartilaginous Joints Bones united by cartilage Like fibrous joints, have no joint cavity Not highly movable Two types • Synchondroses • Symphyses Synchondroses (Figure 8.2a – p. 253) Bar or plate of hyaline cartilage unites bones Almost all are synarthrotic (immovable) Examples • Temporary epiphyseal plate joints • Become synostoses after plate closure • Cartilage of 1st rib with manubrium of sternum Symphyses (Figure 8.2b – p. 253) Fibrocartilage unites bone in symphysis joint • Hyaline cartilage also present as articular cartilage on bony surfaces Symphyses are strong, amphiarthrotic (slightly movable) joints Examples • Intervertebral joints • Pubic symphysis 8.4 Synovial Joints Bones separated by fluidfilled joint cavity All are diarthrotic (freely movable) © 2016 Pearson Education, Inc. 2 Chapter 8 Include almost all limb joints Characteristics of synovial joints • Have six general features • Have bursae and tendon sheaths associated with them • Stability is influenced by three factors • Allow several types of movements • Classified into six different types General Structure (Figure 8.3 – p. 254) Synovial joints have six general features: 1. Articular cartilage: consists of hyaline cartilage covering ends of bones • Prevents crushing of bone ends 2. Joint (synovial) cavity: small, fluidfilled potential space that is unique to synovial joints 3. Articular (joint) capsule: two layers thick • External fibrous layer: dense irregular connective tissue • Inner synovial membrane: loose connective tissue that makes synovial fluid General Structure (cont.) 4. Synovial fluid: viscous, slippery filtrate of plasma and hyaluronic acid • Lubricates and nourishes articular cartilage • Contains phagocytic cells to remove microbes and debris 5. Different types of reinforcing ligaments • Capsular: thickened part of fibrous layer • Extracapsular: outside the capsule • Intracapsular: deep to capsule; covered by synovial membrane General Structure (cont.) 6. Nerves and blood vessels • Nerves detect pain; monitor joint position and stretch • Capillary beds supply filtrate for synovial fluid General Structure (cont.) Other features of some synovial joints: • Fatty pads • For cushioning between fibrous layer of capsule and synovial membrane or bone • Articular discs (menisci) • Fibrocartilage separates articular surfaces to improve “fit” of bone ends, stabilize joint, and reduce wear and tear Bursae and Tendon Sheaths (Figure 8.4 – p. 255) Bags of synovial fluid that act as lubricating “ball bearing” © 2016 Pearson Education, Inc. 3 Chapter 8 • Not strictly part of synovial joints, but closely associated Bursae: reduce friction where ligaments, muscles, skin, tendons, or bones rub together Tendon sheaths: elongated bursae wrapped completely around tendons subjected to friction Factors Influencing Stability of Synovial Joints (Table 8.2 – pp. 256257) Three factors determine stability of joints to prevent dislocations: 1. Shape of articular surface (minor role) • Shallow surfaces less stable than ballandsocket 2. Ligament number and location (limited role) • The more ligaments, the stronger the joint 3. Muscle tone keeps tendons taut as they cross joints (most important) • Extremely important in reinforcing shoulder and knee joints and arches of the foot Movements Allowed by Synovial Joints All muscles attach to bone or connective tissue at no fewer than two points • Origin: attachment to immovable bone • Insertion: attachment to movable bone Muscle contraction causes insertion to move toward origin Movements occur along transverse, frontal, or sagittal planes Movements Allowed by Synovial Joints (cont.) Range of motion allowed by synovial joints • Nonaxial: slipping movements only • Uniaxial: movement in one plane • Biaxial: movement in two planes • Multiaxial: movement in or around all three planes Three general types of movements • Gliding • Angular movements • Rotation Movements Allowed by Synovial Joints (cont.) (Figure 8.5a – p. 258) Gliding movements • One flat bone surface glides or slips over another similar surface • Examples • Intercarpal joints • Intertarsal joints • Between articular processes of vertebrae © 2016 Pearson Education, Inc. 4 Chapter 8 Movements Allowed by Synovial Joints (cont.) (Figure 8.5b, c, & d – pp. 258259) Angular movements • Increase or decrease angle between two bones • Movement along sagittal plane • Angular movements include: • Flexion: decreases the angle of the joint • Extension: increases the angle of the joint • Hyperextension: movement beyond the anatomical position Movements Allowed by Synovial Joints (cont.) (Figure 8.5e – p. 259) Angular movements (cont.) • Abduction: movement along frontal plane, away from the midline • Adduction: movement along frontal plane, toward the midline • Circumduction • Involves flexion, abduction, extension, and adduction of limb • Limb describes cone in space Movements Allowed by Synovial Joints (cont.) (Figure 8.5f – p. 260) Rotation: turning of bone around its own long axis, toward midline or away from it • Medial: rotation toward midline • Lateral: rotation away from midline • Examples • Rotation between C an1 C ver2ebrae • Rotation of humerus and femur Movements Allowed by Synovial Joints (cont.) (Figure 8.6a & b – p. 261) Special movements • Supination and pronation: rotation of radius and ulna • Supination: palms face anteriorly • Radius and ulna are parallel • Pronation: palms face posteriorly • Radius rotates over ulna • Dorsiflexion and plantar flexion of foot • Dorsiflexion: bending foot toward shin • Plantar flexion: pointing toes Movements Allowed by Synovial Joints (cont.) (Figure 8.6c & d – p. 261) Special movements (cont.) • Inversion and eversion of foot • Inversion: sole of foot faces medially • Eversion: sole of foot faces laterally • Protraction and retraction: movement in lateral plane © 2016 Pearson Education, Inc. 5 Chapter 8 • Protraction: scapulae move away from the spine • Retraction: scapulae move toward the spine Movements Allowed by Synovial Joints (cont.) (Figure 8.6e & f – p. 261) Special movements (cont.) • Elevation and depression of mandible • Elevation: lifting body part superiorly • Example: shrugging shoulders • Depression: lowering body part • Example: opening jaw • Opposition: movement of thumb • Example: touching thumb to tips of other fingers on same hand or any grasping movement Types of Synovial Joints (Focus Figure 8.1 – pp. 262263) There are six different types of synovial joints • Categories are based on shape of articular surface, as well as movement joint is capable of • Plane • Hinge • Pivot • Condylar • Saddle © 2016 Pearson Education, Inc. 6
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'