BONES O sseous tissue Skeletal System
<ul><li>The  study of bones is called osteology </li></ul><ul><li>Rigid form of connective tissue forming the skeleton. </...
How many bones? <ul><li>A newborn baby has approximately  300  bones  </li></ul><ul><li>An average an adult human has  206...
<ul><li>Bones are living structures having a blood and nerve supply </li></ul><ul><ul><li>Periosteum (outer lining) </li><...
<ul><ul><li>Function s  of the bones </li></ul></ul><ul><ul><li>Protection for vital structures </li></ul></ul><ul><ul><li...
<ul><ul><li>Types of Bones </li></ul></ul><ul><ul><li>T here are t wo main types </li></ul></ul><ul><ul><ul><li>spongy  (c...
 
<ul><ul><li>Bones forming the skeleton is classified as: </li></ul></ul><ul><ul><li>Axial skeleton </li></ul></ul><ul><ul>...
<ul><ul><li>Bones are also classified according to their shape </li></ul></ul><ul><ul><li>Long bones  (humerus, bones of t...
<ul><ul><li>BONE MARKINGS </li></ul></ul><ul><ul><li>Surfaces of the bones are not smooth. </li></ul></ul><ul><ul><li>Bone...
<ul><ul><li>Linear elevation </li></ul></ul><ul><ul><ul><li>superior nuchal line, iliac crest </li></ul></ul></ul><ul><ul>...
 
 
 
<ul><ul><li>Depressions </li></ul></ul><ul><ul><ul><li>fossae (small depression), groove (sulcus, long narrow depressions)...
 
 
Anatomy of a Long Bone <ul><li>Diaphysis </li></ul><ul><ul><li>Shaft </li></ul></ul><ul><ul><li>Composed of compact bone <...
Gross Anatomy of a Long Bone <ul><li>Epiphyseal line </li></ul><ul><li>Thin line of bony tissue spanning the epiphysis tha...
Bone Growth <ul><li>Epiphyseal plates allow for growth of long bone during childhood </li></ul><ul><ul><li>New cartilage i...
Clinical Note <ul><li>Avascular necrosis </li></ul><ul><ul><li>Bones are supplied by 1-3 nutrient arteries, if these ruptu...
JOINTS
<ul><li>Arthrology is the study of joints . </li></ul><ul><li>Joints are formed by the articulation between the articular ...
 
<ul><li>Classification of joints </li></ul><ul><li>Structural classification </li></ul><ul><ul><li>Fibrous joints:  Joined...
<ul><li>Classification of joints </li></ul><ul><li>Functional classification </li></ul><ul><li>Synarthrosis  - permits lit...
<ul><li>Fibrous joints </li></ul><ul><li>There is a fibrous connective tissue b et w een  the articular surfaces. </li></u...
 
 
 
<ul><li>Cartilaginous joints </li></ul><ul><li>Cartilaginous hyaline tissue lies between the articular surfaces. </li></ul...
 
 
 
 
<ul><li>Synovial joints </li></ul><ul><li>This type of joints have three common features: </li></ul><ul><ul><li>Joint cavi...
 
 
<ul><li>Synovial joints  (continued) </li></ul><ul><li>Articular capsules  are usually strengthened by  articular ligament...
<ul><li>Synovial joints  (continued) </li></ul><ul><li>In addition to the main features of the synovial joints there are s...
 
Synovial joints  (continued) <ul><li>Classification of the synovial joints </li></ul><ul><li>Synovial joints are classifie...
<ul><li>Synovial joints </li></ul><ul><li>1- Ball and socket joint </li></ul><ul><li>2- Condyloid joint  </li></ul><ul><li...
Synovial joints  (continued) <ul><li>Plane joints </li></ul><ul><ul><li>They permit gliding or sliding movements. </li></u...
 
Synovial joints  (continued) <ul><li>Hinge joints (ginglymus, trochlear) </li></ul><ul><ul><li>This type of joints are als...
 
Synovial joints  (continued) <ul><li>Condyloid joints </li></ul><ul><ul><li>These are  biaxial joints  that permit movemen...
 
Synovial joints  (continued) <ul><li>Saddle joints </li></ul><ul><ul><li>T he articular surfaces   resembl e  a saddle sha...
 
Synovial joints  (continued) <ul><li>Ball and socket joints </li></ul><ul><ul><li>Multiaxial  (movable around all three ax...
 
Synovial joints  (continued) <ul><li>Pivot joints </li></ul><ul><ul><li>Uniaxial joints that allow rotation. </li></ul></u...
 
<ul><li>Nerve supply  of the joints </li></ul><ul><li>According to the Hilton’s law the nerves innervating a joint are the...
<ul><li>Vessel  supply  of the joints </li></ul><ul><li>There are a number of vessels that supply the blood circulation in...
<ul><li>Features supplying the joint stability </li></ul><ul><li>These features prevent the dislocation of the joint. </li...
Clinical Note <ul><li>Degenerative Joint disease/ Osteoarthitis </li></ul><ul><li>Over use of a joint wears the cartilage ...
<ul><li>MUSCLES </li></ul>
<ul><li>Myology, musculus (mus-mouse) </li></ul><ul><li>Muscles move the skeleton, face and organs. </li></ul>
<ul><li>There are three types of muscles </li></ul><ul><li>Striated muscle (skeletal muscles)- voluntarily controlled, tho...
<ul><li>Striated muscle s are innervated by the  somatic nervous system </li></ul><ul><li>Non-striated  and c ardiac muscl...
 
 
 
<ul><li>Muscles are formed of fusiform type cells. </li></ul><ul><li>Muscle cells are also referred as  muscle fibers . </...
<ul><li>Superficial fascia   and   deep fascia </li></ul>
 
 
 
<ul><li>Parts of a muscle </li></ul><ul><li>Belly  (fleshy part) </li></ul><ul><li>T endon   (in certain muscles termed as...
<ul><li>Tendons attach to the bones and cartilage, skin or to the superficial fascia. </li></ul><ul><li>Origin  and  inser...
<ul><li>Bursae </li></ul><ul><li>Tendinous sheats </li></ul><ul><ul><li>Both are  soft tissue pads containing synovial flu...
 
 
<ul><li>Muscle terminology </li></ul><ul><li>Muscles are generally given names according to their shapes, location, number...
<ul><li>Contraction </li></ul><ul><li>When a muscle contracts its length decreases by 1/3 or ½ </li></ul><ul><li>Isotonic ...
<ul><li>Motor unit </li></ul><ul><li>A motor neuron and  all  the muscle cells (fibers) inervated by this neuron </li></ul>
 
<ul><ul><li>A single motor neuron may innervate thousands of muscle fibers but in certain muscles a motor neuron may inner...
<ul><li>During a single joint movement a number of muscles contract. </li></ul><ul><ul><li>Prime mover </li></ul></ul><ul>...
<ul><li>Innervation of the muscles </li></ul><ul><ul><li>Motor nerves  (somatic or autonomic) </li></ul></ul><ul><ul><li>S...
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02 Bones, Joints, Muscles General Considerations

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02 Bones, Joints, Muscles General Considerations

  1. 1. BONES O sseous tissue Skeletal System
  2. 2. <ul><li>The study of bones is called osteology </li></ul><ul><li>Rigid form of connective tissue forming the skeleton. </li></ul><ul><li>Supporting framework of the body consists of over 200 bones. </li></ul><ul><li>In average adult human skeleton has around 206 bones </li></ul><ul><li>It comprises around 14% of the total body weight </li></ul>
  3. 3. How many bones? <ul><li>A newborn baby has approximately 300 bones </li></ul><ul><li>An average an adult human has 206 bones (these numbers can vary slightly). </li></ul>
  4. 4. <ul><li>Bones are living structures having a blood and nerve supply </li></ul><ul><ul><li>Periosteum (outer lining) </li></ul></ul><ul><li>Living bones have some elasticity (results from the organic matter) and great rigidity (results from microscopic tubes of inorganic calcium phosphate) </li></ul>
  5. 5. <ul><ul><li>Function s of the bones </li></ul></ul><ul><ul><li>Protection for vital structures </li></ul></ul><ul><ul><li>Support ; forms a rigid framework for the body </li></ul></ul><ul><ul><li>Forms the mechanical basis for movement </li></ul></ul><ul><ul><li>Formation of blood cells (bone marrow) </li></ul></ul><ul><ul><li>Storage of salts ; calcium, phosphorus, iron, magnesium-thus provide a mineral reservoir </li></ul></ul><ul><ul><ul><li>Bones are not entirely made of calcium, but a mixture of chondroitin sulfate and hydroxyapatite (70% of a bone) </li></ul></ul></ul><ul><li>NEW: Endocrine regulation by hormone Osteocalcin , (regulation of blood sugar and fat deposition) </li></ul>
  6. 6. <ul><ul><li>Types of Bones </li></ul></ul><ul><ul><li>T here are t wo main types </li></ul></ul><ul><ul><ul><li>spongy (cancellous) and compact bone </li></ul></ul></ul>
  7. 8. <ul><ul><li>Bones forming the skeleton is classified as: </li></ul></ul><ul><ul><li>Axial skeleton </li></ul></ul><ul><ul><ul><li>skull, vertebrae, ribs, and sternum </li></ul></ul></ul><ul><ul><li>Appendicular skeleton </li></ul></ul><ul><ul><ul><li>bones of the upper and lower limbs and the associated bones </li></ul></ul></ul>
  8. 9. <ul><ul><li>Bones are also classified according to their shape </li></ul></ul><ul><ul><li>Long bones (humerus, bones of the fingers) </li></ul></ul><ul><ul><ul><ul><li>have a shaft and two extremities </li></ul></ul></ul></ul><ul><ul><li>Short bones (foot and wrist bones) </li></ul></ul><ul><ul><ul><ul><li>more or less cuboidal in shape </li></ul></ul></ul></ul><ul><ul><li>Flat bones (bones forming the calvaria, sternum, scapula) </li></ul></ul><ul><ul><li>Irregular bones (facial bones and the vertebrae) </li></ul></ul><ul><ul><li>Pneumatic bones (maxilla, frontal bone) </li></ul></ul><ul><ul><ul><ul><li>contains air cells or sinuses </li></ul></ul></ul></ul><ul><ul><li>Sesamoid bones </li></ul></ul><ul><ul><ul><ul><li>round or oval nodules of bones that develop in certain tendons </li></ul></ul></ul></ul><ul><ul><li>Accessory bones </li></ul></ul><ul><ul><ul><li>develops as a result of additional ossification center or lack of fusion (mainly in foot) </li></ul></ul></ul><ul><ul><li>Heterotopic bones </li></ul></ul><ul><ul><ul><li>develops as a result of trauma or constant strain (thigh muscles of horseback rider) </li></ul></ul></ul>
  9. 10. <ul><ul><li>BONE MARKINGS </li></ul></ul><ul><ul><li>Surfaces of the bones are not smooth. </li></ul></ul><ul><ul><li>Bones display elevations, depressions and holes. </li></ul></ul><ul><ul><li>The surface features on the bones are given names to distinguish and define them. </li></ul></ul>
  10. 11. <ul><ul><li>Linear elevation </li></ul></ul><ul><ul><ul><li>superior nuchal line, iliac crest </li></ul></ul></ul><ul><ul><li>Round elevation </li></ul></ul><ul><ul><ul><li>tubercule (small eminence), protuberance (swelling) </li></ul></ul></ul><ul><ul><li>Sharp elevation </li></ul></ul><ul><ul><ul><li>spine, process </li></ul></ul></ul><ul><ul><li>Facets </li></ul></ul><ul><ul><ul><li>area with a smooth surface where a bone articulates with another bone </li></ul></ul></ul><ul><ul><li>Rounded articular area </li></ul></ul><ul><ul><ul><li>head, condyle </li></ul></ul></ul>
  11. 15. <ul><ul><li>Depressions </li></ul></ul><ul><ul><ul><li>fossae (small depression), groove (sulcus, long narrow depressions) </li></ul></ul></ul><ul><ul><li>Foramen </li></ul></ul><ul><ul><ul><li>hole </li></ul></ul></ul><ul><ul><li>Canal </li></ul></ul><ul><ul><ul><li>a foramen having length </li></ul></ul></ul><ul><ul><li>Orifice </li></ul></ul><ul><ul><ul><li>opening </li></ul></ul></ul><ul><ul><li>Meatus </li></ul></ul><ul><ul><ul><li>a canal entering a structure </li></ul></ul></ul>
  12. 18. Anatomy of a Long Bone <ul><li>Diaphysis </li></ul><ul><ul><li>Shaft </li></ul></ul><ul><ul><li>Composed of compact bone </li></ul></ul><ul><li>Epiphysis </li></ul><ul><ul><li>Ends of the bone </li></ul></ul><ul><ul><li>Composed mostly of spongy bone </li></ul></ul>Figure 5.2a
  13. 19. Gross Anatomy of a Long Bone <ul><li>Epiphyseal line </li></ul><ul><li>Thin line of bony tissue spanning the epiphysis that looks different from the rest. </li></ul><ul><li>Is the remnant of the epiphyseal plate. (growth) </li></ul><ul><li>The epiphyseal plate (hyaline cartilage) is seen in young, growing bone. </li></ul>Figure 5.2a
  14. 20. Bone Growth <ul><li>Epiphyseal plates allow for growth of long bone during childhood </li></ul><ul><ul><li>New cartilage is continuously formed </li></ul></ul><ul><ul><li>Older cartilage becomes ossified </li></ul></ul><ul><ul><ul><li>Cartilage is broken down </li></ul></ul></ul><ul><ul><ul><li>Bone replaces cartilage </li></ul></ul></ul>
  15. 21. Clinical Note <ul><li>Avascular necrosis </li></ul><ul><ul><li>Bones are supplied by 1-3 nutrient arteries, if these rupture, or in some types of fracture there may be necrosis (death) of bone. </li></ul></ul>
  16. 22. JOINTS
  17. 23. <ul><li>Arthrology is the study of joints . </li></ul><ul><li>Joints are formed by the articulation between the articular surfaces of two or more bones. </li></ul><ul><li>Articular system consists of joints and their associated bones and ligaments. </li></ul>
  18. 25. <ul><li>Classification of joints </li></ul><ul><li>Structural classification </li></ul><ul><ul><li>Fibrous joints: Joined by fibrous connective tissue </li></ul></ul><ul><ul><li>Cartilaginous joints: Joined by cartilage </li></ul></ul><ul><ul><li>Synovial joints: Joined by a capsule </li></ul></ul>
  19. 26. <ul><li>Classification of joints </li></ul><ul><li>Functional classification </li></ul><ul><li>Synarthrosis - permits little or no mobility. Most synarthrosis joints are fibrous joints (e.g. The Skull). </li></ul><ul><li>Amphiarthrosis - permits slight mobility. Most amphiarthrosis joints are cartilaginous joints (e.g. Vertebrae). </li></ul><ul><li>Diarthrosis - permits a variety of movements. All diarthrosis joints are synovial joints (e.g. Shoulder, Hip, Elbow, Knee etc) </li></ul>
  20. 27. <ul><li>Fibrous joints </li></ul><ul><li>There is a fibrous connective tissue b et w een the articular surfaces. </li></ul><ul><ul><li>Syndesmosis: Articulating surfaces are connected firmly by a connective tissue e.g. distal tibio-fibular joint </li></ul></ul><ul><ul><li>Suture: Found between the skull bones </li></ul></ul><ul><ul><li>Gomphosis: Found between the dentures and the alveoles of the upper and lower jaw </li></ul></ul>
  21. 31. <ul><li>Cartilaginous joints </li></ul><ul><li>Cartilaginous hyaline tissue lies between the articular surfaces. </li></ul><ul><li>These joints can make very limited amount of movement. </li></ul><ul><ul><li>Synchodros i s: The cartilaginous tissue between the articular surfaces are lost within time and the joint loose the ability of movement e.g. sphenoid-occipital </li></ul></ul><ul><ul><li>Symphys is : There is a di s c made of fibrocartilaginous tissue between the articular surfaces. e.g. joints between the vertebrae (vertebral discs), symphysis of the pubis (pelvis). All symphysis are found in the midline. </li></ul></ul>
  22. 36. <ul><li>Synovial joints </li></ul><ul><li>This type of joints have three common features: </li></ul><ul><ul><li>Joint cavity </li></ul></ul><ul><ul><li>Articular cartilage: The articular surfaces are covered by hyaline cartilage </li></ul></ul><ul><ul><li>Articular capsule: This structure surrounds the joint and formed of two layers. </li></ul></ul><ul><ul><ul><ul><li>Fibrous membrane: Protects and gives firmness to the joint stability, continues with the periosteum </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Synovial membrane: Lines the inner surface of the fibrous membrane but does not cover the articular cartilage. Secretes a fluid known as synovial fluid . This fluid helps to minimize the friction between articular sufaces. </li></ul></ul></ul></ul>
  23. 39. <ul><li>Synovial joints (continued) </li></ul><ul><li>Articular capsules are usually strengthened by articular ligaments </li></ul><ul><ul><li>These are from dense connective tissue and they connect the articulating bones to each other. </li></ul></ul><ul><ul><li>Articular ligaments limit the undesired and/or excessive movements of the joints. </li></ul></ul><ul><ul><li>Articular ligaments are classified as intrinsic and extrinsic ligaments. </li></ul></ul><ul><ul><ul><li>Intrinsic ligaments are the thickening of a portion of the articular capsule. </li></ul></ul></ul>
  24. 40. <ul><li>Synovial joints (continued) </li></ul><ul><li>In addition to the main features of the synovial joints there are some additional features that are common ly seen : </li></ul><ul><ul><li>Articular disc: Help to hold the bones together. In some joints it is attached to only one of the bones. </li></ul></ul><ul><ul><li>Labrum: Some synovial joints have a fibrocartilaginous ring called labrum which deepens the articular surface for one of the bones. e.g. glenoid labrum </li></ul></ul>
  25. 42. Synovial joints (continued) <ul><li>Classification of the synovial joints </li></ul><ul><li>Synovial joints are classified according to the shape of articulating surfaces and/or the type of movement they can make. </li></ul>
  26. 43. <ul><li>Synovial joints </li></ul><ul><li>1- Ball and socket joint </li></ul><ul><li>2- Condyloid joint </li></ul><ul><li>3- Saddle joint </li></ul><ul><li>4- Hinge joint </li></ul><ul><li>5- Pivot joint </li></ul><ul><li>6- Plane </li></ul>
  27. 44. Synovial joints (continued) <ul><li>Plane joints </li></ul><ul><ul><li>They permit gliding or sliding movements. </li></ul></ul><ul><ul><li>Articular surfaces are almost flat. </li></ul></ul><ul><ul><li>e.g. acromioclavicular joint, carpometacarpal joint </li></ul></ul>
  28. 46. Synovial joints (continued) <ul><li>Hinge joints (ginglymus, trochlear) </li></ul><ul><ul><li>This type of joints are also uniaxial and permits flex. and ext. around the transverse axis. </li></ul></ul><ul><ul><li>Bones are joined with strong collateral ligaments. e.g. elbow and knee joints </li></ul></ul>
  29. 48. Synovial joints (continued) <ul><li>Condyloid joints </li></ul><ul><ul><li>These are biaxial joints that permit movement in in two axes (trans.-sagit.) </li></ul></ul><ul><ul><li>e.g. radiocarpal joint, metacrpophalyngeal joints </li></ul></ul>
  30. 50. Synovial joints (continued) <ul><li>Saddle joints </li></ul><ul><ul><li>T he articular surfaces resembl e a saddle shape and are concave and convex respectively . </li></ul></ul><ul><ul><li>e.g. carpometacarpal joint of the thumb </li></ul></ul>
  31. 52. Synovial joints (continued) <ul><li>Ball and socket joints </li></ul><ul><ul><li>Multiaxial (movable around all three axes) </li></ul></ul><ul><ul><li>The spheroidal surface of a bone articulates with the socket shaped articular surface of another bone. </li></ul></ul><ul><ul><li>e.g. shoulder joint </li></ul></ul>
  32. 54. Synovial joints (continued) <ul><li>Pivot joints </li></ul><ul><ul><li>Uniaxial joints that allow rotation. </li></ul></ul><ul><ul><li>Rounded part of a bone rotates in a sleeve or ring like osteofibrous structure </li></ul></ul><ul><ul><li>e.g. prox-dist radioulnar joints </li></ul></ul>
  33. 56. <ul><li>Nerve supply of the joints </li></ul><ul><li>According to the Hilton’s law the nerves innervating a joint are the branches of the nerves that innervate the muscles acting on that joint and the nerves innervating the sensory areas around that region. </li></ul><ul><li>The nerves convey impulses regarding conscious proprioception (from the joint capsule) and pain (from the fibrous membrane). </li></ul>
  34. 57. <ul><li>Vessel supply of the joints </li></ul><ul><li>There are a number of vessels that supply the blood circulation in a joint. </li></ul><ul><li>These are the branches of surrounding vessels. </li></ul>
  35. 58. <ul><li>Features supplying the joint stability </li></ul><ul><li>These features prevent the dislocation of the joint. </li></ul><ul><ul><li>The negative pressure within the joint cavity </li></ul></ul><ul><ul><li>Joint capsule and the ligaments </li></ul></ul><ul><ul><li>Muscles and their tendons around the joint </li></ul></ul><ul><ul><li>Shapes of the articular surfaces </li></ul></ul>
  36. 59. Clinical Note <ul><li>Degenerative Joint disease/ Osteoarthitis </li></ul><ul><li>Over use of a joint wears the cartilage causing degenerative changes, common in hip, knee, vertebral column & hands. </li></ul><ul><li>Increased friction causes pain. </li></ul><ul><li>May require pain management, change in lifestyle, surgery or joint replacement. </li></ul>
  37. 60. <ul><li>MUSCLES </li></ul>
  38. 61. <ul><li>Myology, musculus (mus-mouse) </li></ul><ul><li>Muscles move the skeleton, face and organs. </li></ul>
  39. 62. <ul><li>There are three types of muscles </li></ul><ul><li>Striated muscle (skeletal muscles)- voluntarily controlled, though exceptions exist </li></ul><ul><li>Non-striated muscle (smooth muscle) - involuntary </li></ul><ul><li>Cardiac muscle </li></ul>
  40. 63. <ul><li>Striated muscle s are innervated by the somatic nervous system </li></ul><ul><li>Non-striated and c ardiac muscle are innervated by the autonomic nervous system </li></ul>
  41. 67. <ul><li>Muscles are formed of fusiform type cells. </li></ul><ul><li>Muscle cells are also referred as muscle fibers . </li></ul>
  42. 68. <ul><li>Superficial fascia and deep fascia </li></ul>
  43. 72. <ul><li>Parts of a muscle </li></ul><ul><li>Belly (fleshy part) </li></ul><ul><li>T endon (in certain muscles termed as aponeurosis ) </li></ul>
  44. 73. <ul><li>Tendons attach to the bones and cartilage, skin or to the superficial fascia. </li></ul><ul><li>Origin and insertion (prox.-dist, fixed-moving) </li></ul>
  45. 74. <ul><li>Bursae </li></ul><ul><li>Tendinous sheats </li></ul><ul><ul><li>Both are soft tissue pads containing synovial fluid that prevents the friction of tendons from the surrounding tissue. </li></ul></ul>
  46. 77. <ul><li>Muscle terminology </li></ul><ul><li>Muscles are generally given names according to their shapes, location, number of their bellies, function, and size </li></ul><ul><ul><li>rhomboideus major </li></ul></ul><ul><ul><li>palmaris longus </li></ul></ul><ul><ul><li>biceps brachii </li></ul></ul><ul><ul><li>tibialis posterior </li></ul></ul><ul><ul><li>flexor carpi ulnaris </li></ul></ul><ul><ul><li>teres major-teres minor </li></ul></ul>
  47. 78. <ul><li>Contraction </li></ul><ul><li>When a muscle contracts its length decreases by 1/3 or ½ </li></ul><ul><li>Isotonic contraction - the length decreases </li></ul><ul><li>Isometric contraction - the length does not decrease </li></ul>
  48. 79. <ul><li>Motor unit </li></ul><ul><li>A motor neuron and all the muscle cells (fibers) inervated by this neuron </li></ul>
  49. 81. <ul><ul><li>A single motor neuron may innervate thousands of muscle fibers but in certain muscles a motor neuron may innervate less number of muscles (e.g. eye mm. 3-4 fibers are innervated by a motor neuron). </li></ul></ul><ul><ul><li>There are many motor units in a single muscle. </li></ul></ul><ul><ul><li>Whole of the motor units does not necessarily contract during a muscle contraction. </li></ul></ul><ul><ul><li>Number of contracting units determines the force of contraction. </li></ul></ul>
  50. 82. <ul><li>During a single joint movement a number of muscles contract. </li></ul><ul><ul><li>Prime mover </li></ul></ul><ul><ul><li>Synergist muscles (support the movement) </li></ul></ul><ul><ul><li>Antagonist muscles (oppose the movement) </li></ul></ul><ul><ul><li>Fixator muscle (the muscle that prevents the undesired movements) </li></ul></ul>
  51. 83. <ul><li>Innervation of the muscles </li></ul><ul><ul><li>Motor nerves (somatic or autonomic) </li></ul></ul><ul><ul><li>S ensory nerves ( for striated muscles; muscle spindle-golgi tendon organs) </li></ul></ul>
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