Articulations, Joint Motion, & Muscle Contraction PDF

Y1B4M1L4 MUSCULOSKELETAL/ INTEGUMENTARY SYSTEMS LECTURER MARGRET C. LICUP, MD, FPARM, MHM OCTOBER 18, 2023 | 10 00 - 12 00 ARTICULATIONS, JOINT MOTION, & MUSCLE CONTRACTION TABLE OF CONTENTS I. Articulations 2. Temporal Summation II. Classification of Joints 3. Incomplete Tetanus A. Synarthroses 4...

Y1B4M1L4 MUSCULOSKELETAL/ INTEGUMENTARY SYSTEMS LECTURER MARGRET C. LICUP, MD, FPARM, MHM OCTOBER 18, 2023 | 10 00 - 12 00 ARTICULATIONS, JOINT MOTION, & MUSCLE CONTRACTION TABLE OF CONTENTS I. Articulations 2. Temporal Summation II. Classification of Joints 3. Incomplete Tetanus A. Synarthroses 4. Fatigue 1. Fibrous joints XI. Length-Tension Relationship 2. Cartilaginous joints for a Skeletal Muscle B. Diarthroses A. Unstretched 1. Components B. Moderately Stretched 2. Synovial Joints C. Overstretched III. Joint Motion XII. Whole Muscle Contraction A. Kinematic Chain A. Isometric B. Joint Motion B. Isotonic C. Joint Motion: XIII. Muscle Remodeling Close-Packed Position and A. Hypertrophy Loose-Packed Positions B. Atrophy IV. Comparison of Skeletal, XIV. Functional Terminology of Cardiac, and Smooth Muscle Activity Muscle Cells A. Agonist V. Organizational Level of the B. Antagonist Muscle C. Synergist A. 2 types of Myofilaments XV. Muscle Classification as to VI. Activation of Skeletal Muscle Fiber Arrangement VII. Sliding Filament Theory A. Strap/Fusiform A. Myosin B. Pennate B. Actin C. Unipennate C. Tropomyosin D. Bipennate D. Troponin E. Multipennate E. Process XVI. Spurt and Shunt Muscles VIII. Muscle Fiber Types XVII. Tonic and Phasic Muscles A. Red Muscle Fiber XVIII. Muscle Architecture B. White Muscle Fiber A. Fiber Length IX. Energetics of Muscle B. Physiologic Contraction Cross-Sectional Area A. ATP XIX. Muscle Strength B. Sources of Energy A. Fiber architecture 1. Phosphocreatine B. Age and Gender 2. Muscle Glycogen C. Length-Tension 3. Oxidative Metabolism Relationship C. Phases of ATP Production D. Speed of Contraction during exercise XX. Lever Systems X. The Motor Unit A. 3 Forces of the Mechanical A. Recruitment Lever B. Muscle Tone B. In the Body C. Muscle Twitch C. Classes of Lever Systems 1. Latent Phase 1. 1st class lever 2. Contraction Phase 2. 2nd class lever 3. Relaxation Phase 3. 3rd class lever D. Force Summation 1. Treppe (“Staircase” Effect) I. ARTICULATIONS ● Articulations – also known as joints ○ Structures that connect one bone to another regardless if movement occurs between them ○ Connect different segments together and may allow movement between the two ● Joint design ○ Function ○ Components Figure 1. Similarities of function between joints and machines Additional Information: ● Design becomes more complex as functional demands increase (joints with multiple functions are more complex than single function joints) ● More than 206 bones in the human body 270 bones at birth) ● Only 206 bones are left in the adult human body ○ 80 axial bones ○ 126 appendicular bones → 64 appendicular bones – upper limbs and shoulder girdles → 62 appendicular bones – lower limbs and pelvic girdle ● Joints function for either stability or mobility, or for both II. CLASSIFICATION OF JOINTS ● Two broad categories (based on type of material and method to unite the bone components): ○ Synarthroses ○ Diarthroses ● Each category is divided into subdivisions (based on type of materials, shape and contours of articulating set and type of motion). BARBON, CALIZO, DAQUIL, DULANA, LAYGAN, RODRIGUEZ, SOMBONG, TILOS, TUMACOLE | MG 4 1 of 22 Y1B4M1L4 ARTICULATIONS, JOINT MOTION & MUSCLE CONTRACTION A. SYNARTHROSES ● aka Non-synovial joints ● Interosseous connective tissue DIRECTLY connects one bone to another. ○ Joints where the two bones are connected directly to each other. ● Function: stability ● Two types of synarthroses: ○ Fibrous joints ○ Cartilaginous joints → E.g. temporoparietal suture (suture between temporal and parietal bones) ○ Plane suture (aka butt suture) → Where two bones have straight, non-overlapping edges. ■ The two bones merely border on each other. → Between the palatine processes of the maxillae Table 1. Summary of Synarthroses FIBROUS JOINT CARTILAGINOUS JOINT Suture Symphysis Gomphosis Synchondrosis Syndesmosis FIBROUS JOINT ● Fibrous tissue unites one bone to another bone ● Articulating surfaces of the bones that are joined by fibrous tissue, thus very little movement is possible. ● Types: ○ Suture joint ○ Gomphosis joint ○ Syndesmosis joint Figure 3. Sutures of the Skull SUTURE JOINT ● A thin layer of DENSE connective tissue unites the bones. ● Found only in the skull. ● There are three types: ○ Serrate suture → Appear as wavy lines along which the adjoining bones firmly interlock with each other by their serrated margins → E.g. coronal, sagittal, lambdoid sutures Figure 4. Suture Joints A - Serrate, B - Lap, C - Plane) GOMPHOSIS JOINT ● Like a peg in a hole ● E.g. tooth in mandible Periodontal ligament) Figure 2. Serrated Sutures in the Skull ○ Lap suture (aka squamous sutures) → Occur where two bones have overlapping beveled edges. → Appear as a relatively smooth line on the surface. Figure 5. Gomphosis between Tooth and Mandible BARBON, CALIZO, DAQUIL, DULANA, LAYGAN, RODRIGUEZ, SOMBONG, TILOS, TUMACOLE | MG 4 2 of 22 Y1B4M1L4 ARTICULATIONS, JOINT MOTION & MUSCLE CONTRACTION SYNDESMOSIS JOINT B. DIARTHROSES ● A ligament, cord, or aponeurotic membrane joins the two bony components. ● E.g. shafts of tibia and fibula or in between the radius and the ulna. ● aka Synovial joints ● The ends of the bony components are free to move in relation to one another. ● INDIRECT connection ● Function: mobility > stability Figure 6. Syndesmosis between Tibia and Fibula Figure 8. Frontal Section: Synovial Joint COMPONENTS Figure 7. Types of Cartilaginous Joints CARTILAGINOUS JOINT ● Either fibrocartilage or hyaline growth cartilage. ● Types: ○ Symphysis joint ○ Synchondrosis joint SYMPHYSIS JOINT ● Fibrocartilage in the form of disks or plates. ● E.g. symphysis pubis, intervertebral discs ● Joint capsule ○ Encloses the joint cavity. ○ Has 2 layers: → Stratum fibrosum (outer layer) ■ Dense fibrous tissue ■ Attached to the periosteum of the bones by Sharpeyʼs fibers. ■ Poorly vascularized ■ Richly innervated with joint receptors. → Stratum synovium (inner layer) ■ Entry points for nutrients and exit points for waste materials. ■ Has synoviocytes that secrete synovial fluid. ■ Highly vascularized ■ Poorly innervated ● Joint cavity ● Synovial membrane ○ With synoviocytes that make the synovial fluid. ● Synovial fluid ○ Has the same components with that of plasma, but only with hyaluronic acid and lubricin. ● Hyaline cartilage ○ Covers the ends of the bones. ● Accessory structures ○ Fat pads ○ Tendons ○ Ligaments SYNCHONDROSIS JOINT ● Hyaline growth cartilage bonds two ossifying centers of bone. ● Permits bone growth while also providing stability and some mobility. ● 1st sternocostal joint BARBON, CALIZO, DAQUIL, DULANA, LAYGAN, RODRIGUEZ, SOMBONG, TILOS, TUMACOLE | MG 4 3 of 22 Y1B4M1L4 ARTICULATIONS, JOINT MOTION & MUSCLE CONTRACTION Tendons of Movement: ● Flexion - bending or decreasing the angle between the bones or parts in the body ○ For most joints (e.g. elbow), involves movement in an anterior direction ● Extension – straightening or increasing the angle between the bones or parts of the body ○ Occurs in a posterior direction ● Dorsiflexion – flexion at the ankle joint, as occurs when walking uphill or lifting the front of the foot and toes off the ground. ● Plantar flexion – bends the foot and toes toward the ground, as when standing on your toes ● Abduction – moving away from the median plane ● Adduction – movement toward the median plane ● Circumduction – circular movement that involves sequential flexion, abduction, extension, and adduction ● Rotation – turning or revolving a part of the body around its longitudinal axis such as turning oneʼs head sideways ○ Medial rotation brings the anterior surface of a limb closer to the median plane ○ Lateral rotation takes the anterior surface away from the median plane ● Pronation – rotates the radius medially so that the palm of the hand faces posteriorly and its dorsum face anteriorly. ● Supination – rotating the radius laterally and uncrossing it from the ulna, returning the pronated forearm to the anatomical position ● Eversion – moving the sole of the foot away from the median plane, turning the sole laterally ● Inversion – moving the sole of the foot toward the median plane ● Elevation – raising or moving a part superiorly, as in elevating the shoulders when shrugging ● Depression – lowers or moves a part inferiorly Figure 9. Hinge Joint Elbow Joint) ○ Pivot joint (aka trochoid joint) → One component is shaped like a ring and the other is shaped so that it can rotate within the ring. → E.g. atlantoaxial joint, radioulnar joint ■ Atlantoaxial joint - found at the first 2 cervical vertebrae; used when head is shaken to say “no.” ■ Superior radioulnar joint (at elbow area) SYNOVIAL JOINTS ● Classification ○ According to the number of axes about which motion occurs. ○ All of these types and all six subtypes are found in the upper extremity: → Uniaxial joints → Biaxial joints → Triaxial/multiaxial joint ● Subdivision ○ Based on shape and configuration of the ends of the bony components. SYNOVIAL JOINTS ACCORDING TO CLASSIFICATION UNIAXIAL JOINTS ● Motion that is in one plane around one axis ● 1° of freedom ● 2 types ○ Hinge joint → E.g. Humeroulnar joint, knee, sternoclavicular joint, acromioclavicular joint → Flexion/extension → Most common type Figure 10. Pivot Joint Atlantoaxial Joint) BIAXIAL JOINTS ● Motion is in two planes around two axes. ● 2° of freedom ● 2 types ○ Condyloid joints → Two distinct concave surface that articulate (slides over) with two convex surfaces in two directions. → E.g. Metacarpophalangeal MCP joint ■ Flexion/extension (sagittal plane) ■ Abduction/adduction (frontal plane) BARBON, CALIZO, DAQUIL, DULANA, LAYGAN, RODRIGUEZ, SOMBONG, TILOS, TUMACOLE | MG 4 4 of 22 Y1B4M1L4 ARTICULATIONS, JOINT MOTION & MUSCLE CONTRACTION TRIAXIAL JOINTS ● Motion is in three planes in three axes ○ Including: sagittal plane, coronal plane, transverse plane ● 3° of freedom ● 2 types ○ Ball-and-socket joint → A ball-like convex surface fits into a concave socket. → E.g. hip joint (between the femoral head and acetabulum of the pelvis); humerus, humeral head, and glenoid fossa of the shoulder. ■ flexion/extension ■ abduction/adduction ■ internal/external rotation Figure 11. Condyloid Joint MCP Joint) Figure 14. Ball-and-socket Joint Hip Joint) ○ Plane joint → Found between the two rows of carpal bones of the wrist. → Permits gliding between two or more bones. → E.g. carpal bones Figure 12. Condyloid Joint Sternoclavicular & Acromioclavicular Joints) ○ Saddle joints → joints in which the articular surfaces are reciprocally concave or convex and resemble a saddle on a horseʼs back. → E.g. Carpometacarpal CMC joint of the thumb ■ flexion/extension (coronal plane) ■ abduction/adduction (sagittal plane) Figure 15. Plane Joint Figure 13. Saddle Joint CMC Joint of Thumb) Figure 16. Types of Synovial Joints BARBON, CALIZO, DAQUIL, DULANA, LAYGAN, RODRIGUEZ, SOMBONG, TILOS, TUMACOLE | MG 4 5 of 22