How are joints classified? |
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The amount of movement permitted by a particular joint is the basis for the functional classification of joints. |
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A joint united by dense fibrocartilaginous tissue that usually permits a slight degree of movement is a __________________. |
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symphysis |
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A fibrous joint that is a peg-in-socket is called a _________________ joint. |
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gomphosis |
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In _________________ joints the bones are joined together by fibrous tissue and lack a joint cavity. |
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fibrous |
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___________________ occur between bones of the skull and use very short connective tissue fibers to hold the bones together |
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sutures |
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In ___________________, the bones are connected by a ligament, which is a cord or band of fibrous tissue |
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syndesmoses |
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A _______________________ is a peg-in-socket fibrous joint. |
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gomphosis |
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In _______________________ joints, bones are joined together by cartilage and they lack a joint cavity. |
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cartilaginous joints |
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_____________________ involve a bar or plate of hyaline cartilage uniting the bones, such as the ________________________ |
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synchondroses, epiphyseal plate |
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In _____________________, such as the ________________________, the articular surfaces are covered with articular cartilage that is then fused to an intervening pad or plate of fibrocartilage. |
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symphyses |
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In ____________________ joints, the articulating bones are separated by a fluid-containing joint cavity |
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synovial |
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Five features that distinguish the general structure of a synovial joint |
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1. articular cartilage coveres the end of the articulating bones2. the joint (synovial) cavity is a space that is filled with synovial fluid.3. the two-layered articular capsule encloses the joint cavity.4. synovial fluid is a viscous, slippery fluid that fills all free space within the joint cavity.5. reinforcing ligaments cross synovial joints to strengthen the joint |
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______________________ classification is based on the amount of movement allowed at the joint. |
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functional |
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__________________ are immovable joints |
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synarthroses |
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_____________________ are slightly movable joints |
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amphiarthroses |
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____________________ are freely movable joints |
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diarthroses |
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What is the major role of ligaments at synovial joints? |
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The major role of ligaments at synovial joints is to help direct movement and restrict undesirable movement |
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____________________ are cartilaginous joints. |
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synchondroses and/or symphyses |
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What factors influence the stability of synovial joints? |
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The shapes of the articular surfaces of bones found at a synovial joint determine the movements that occur at the joint, but play a minimal role in stabilizing the joint. Ligaments at a synovial joint prevent excessive or unwanted movements and help to stabilize the joint; the greater the number of ligaments at the joint, the greater the stability. Muscle tone keeps tendons crossing joints taut, which is the most important factor stabilizing joints |
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Connective tissue sacs lined with synovial membranes that act as cushions in places where friction develops are called ___________________. |
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ligaments |
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What are menisci? |
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semilunar cartilage pads |
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The hip joint is a good example of a(n) ______________ synovial joint. |
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multiaxial |
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Movement allowed in a pivot joint is known as _______________ |
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uniaxial rotation |
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What type of movement is allowed between the first two cervical vertebrae? |
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rotation |
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Describe gliding movements |
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one flat, or nearly flat, bone surface glides or slips over another |
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Describe angular movements |
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increase or decrease the angle between two bones |
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_________________ decreases the angle of the joint and brings the articulating bones closer together |
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flexion |
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_______________ increases the angle between the articulating bones |
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extension |
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_______________ decreases the angle between the top of the foot and the anterior surface of the tibia |
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dorsiflexion |
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_______________________ decreases the angle between the sole of the foot and the posterior side of the tibia |
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plantar flexion |
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_______________________ is the movement of a limb (or fingers) away from the midline body (or of the hand). |
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abduction |
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_____________________ is the movement of a limb (or fingers) toward the midline of the body (or the hand). |
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adduction |
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_____________________ is moving a limb so that it describes a cone in the are |
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circumduction |
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_____________________ is the turning of a bone along its own long axis. |
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rotation |
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____________________ is the rotating the forearm laterally so that the palm faces anteriorly or superiorly |
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supination |
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___________________ is rotating the arm medially so that the palm faces posteriorly or inferiorly |
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pronation |
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___________________ turns the sole of the foot so that it faces medially |
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inversion |
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__________________ turns the sole of the foot so that it faces laterally |
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eversion |
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___________________ moves the mandible anteriorly, juts the jaw forward |
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protraction |
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_________________ returns the mandible to its original position |
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retraction |
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__________________ means lifting a body part superiorly |
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elevation |
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__________________ means to move an elevated body inferiorly |
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depression |
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_________________ occurs when you touch your thumb to the fingers on the same hand |
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opposition |
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The terms inversion and eversion pertain only to the _____________________ |
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feet |
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The gliding motion of the wrist is accomplished because of the ______________ joint. |
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plane |
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___________________ have flat articular surfaces and allow gliding and transitional movements |
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plane joints |
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location of plane joints |
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carpometacarpal, digits 2-5, intercarpal, acromioclavicular, vertebrocostal, etc. |
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______________________ consist of a cylindrical projection that nests in a trough-shaped structure, and allow movement along a single plane |
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hinge joints |
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location of hinge joints |
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elbow, fingers, toes, knee |
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_____________________ consist of a rounded structure that protrudes into a sleeve or ring, and allow uniaxial rotation of a bone around the long axis |
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pivot joints |
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location of pivot joints |
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provimal and distal radioulnar also atlanoaxial |
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_________________, or ______________ joints consist of an oval articular surface that nests in a complementary depression, and permit all angular movements |
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condyloid, or ellipsoid |
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location of condyloid joints |
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metatarsophalangeal, metacarpophalangeal |
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_____________________ consist of each articular surface bearing complementary concave and convex areas, and allow more freedom of movement than condyloid joints. |
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saddle joints |
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location of saddle joints |
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thumb |
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_______________________________ consist of a spherical or hemispherical structure that articulates with a cuplike structure. They are the most freely moving joints and allow multiaxial movements. |
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ball-and-socket joints |
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location of ball-and-socket joints |
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shoulder and hip |
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____________________ muscle is associated with the bony skeleton, and consists or large cells that bear striations and are controlled voluntarily. |
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skeletal muscle |
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___________________ muscle occurs only in the heart, and consists of small cells that are striated and under involuntary control |
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cardiac muscle |
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___________________ muscle is found in the walls of hollow organs, and consists of small elongated cells that are not striated and are under involuntary control |
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smooth muscle |
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________________________ is controlled by multiple motor unit summation or recruitment |
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the force of muscle contraction |
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peristalsis is characteristic of _________________ muscle. |
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smooth |
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____________________ smooth muscle is found in the intestines. |
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single-unit |
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A contraction in which the muscle does not shorten but its tension increases is called ____________________. |
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isometric |
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isometric contraction: |
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no shortening; muscle tension increases but does not exceed loadThe load is greater than the tension the muscle is able to developTension increases to the muscle's capacity, but the muscle neither shortens nor lengthens |
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Isotonic contraction: |
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muscle shortens because muscle tension exceeds the loadMuscle changes in length and moves the loadIsotonic contractions are either concentric or eccentri |
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Concentric contractions |
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the muscle shortens and doesn't work |
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Eccentric contractions |
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the muscle contracts as it lengthens |
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Functions of the muscular system |
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1) movement of bones or fluids (e.g., blood)2) maintaining posture and body position3) stabilizing joints4) heat generation (especially skeletal muscle) |
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What is the role of tropomyosin in skeletal muscles |
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tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules |
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What controls the force of muscle contraction? |
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multimotor unit |
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What structure in skeletal muscle cells functions in calcium storage? |
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sarcoplasmic reticulum |
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What causes a resting potential? |
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A difference in the concentration of certain ions inside and outside the cell. |
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During muscle contraction, myosin cross bridges attach to which active sites? |
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actin filaments |
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Describe three ways in which ATP is generated during muscle contraction. |
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Direct phosphorylation of ADP by creatine phosphate (CP)Anaerobic pathway (glycolysis)At 70% of maximum contractile activity:-Bulging muscles compress blood vessels-Oxygen delivery is impaired- pyruvic acid is converted into lactic acidLactic acid:-diffuses into the bloodstream-used as fuel by liver, kidneys, and heart-converted back into pyruvic acid by the liver-aerobic respirationProduces 95% of ATP during rest and light to moderate exerciseFuels: stored glycogen, then bloodborne glucose, pyruvic acid from glycolysis, and free fatty acids |
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Why does rigor mortis occur? |
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rigor mortis occurs because no ATP is available to release attached actin and myosin molecules |
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What is the broadest muscle of the back? |
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lattissimus dorsi |
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The ___________________ is the main chewing muscle |
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masseter |
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First class lever system |
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fulcrum between load and effort |
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Second class lever system |
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load between fulcrum and effort |
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Third class lever system |
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effort applied between fulcrum and load |
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What is the major factor controlling how levers work? |
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the difference in the positioning of the effort, load, and fulcrum |
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What muscle is responsible for keeping your toes from dragging when walking? |
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fibularis tertius |
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A muscle group that works with and assists the action of a prime mover is a |
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synergist |
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What is the main factor that determines the power of a muscle? |
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the total number of muscle cells available for contraction |
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What is a muscle that provides the major force for producing a specific movement called? |
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an agonist |
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When the terms levator, biceps, triceps, or quadriceps form part of a muscle's name, what does it tell you about the muscle? |
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The muscle elevates and/or adducts a region. The muscle has two, three, or four origins, respectively |
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What are the muscles that are found at the openings of the body collectively called |
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circular muscles |
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What do the geniohyoid, hyoglossus, and stylohyoid muscles have in common? |
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they all act on the tongue |
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____________________ is a powerful forearm extensor |
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triceps brachii |
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The ______________ is known as the boxer muscle |
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serratus anterior |
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The ________________ runs deep to the external oblique |
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internal oblique |
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The ___________________ helps keep food between the grinding surfaces of the teeth during chewing |
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buccinators |
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The ___________________ draws the corners of the mouth downward as in expressing horror |
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platysma |
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