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The Skeletal Sytem


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A discussion about the axial skeleton

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The Skeletal Sytem

  1. 1. THE SKELETAL SYSTEM- Axial Skeleton <ul><li>By: </li></ul><ul><li>Dr. Lorena Balacanao </li></ul>
  2. 2. OSTEOLOGY The study of all bones in the body, with their associated cartilages and membranes
  4. 4. <ul><li>Support. </li></ul><ul><li>The skeleton is said to give shape and support to the body; </li></ul><ul><li>Individual bones or group of bones provide a framework for the attachment of soft tissues and organs </li></ul>
  5. 5. <ul><li>Protection. </li></ul><ul><li>Skeleton protect structures and organs against extraneous forces. </li></ul><ul><li>For example: </li></ul><ul><li>The skull acts as barrier of the brain in any external assault. </li></ul><ul><li>The ribs provide a protective covering against external impact </li></ul>
  6. 6. <ul><li>Hematopoietic function </li></ul><ul><li> The presence of red bone marrow in spongy bones is for blood cell production </li></ul>
  7. 7. <ul><li>Storage . </li></ul><ul><li>Stores fats which are present in yellow bone marrow within the medullary cavity of long bones. </li></ul>
  8. 8. <ul><li>Leverage </li></ul><ul><li>The bones of the skeleton acts as levers that can change the magnitude and direction of forces generated by skeletal muscles. </li></ul>
  9. 9. CONSTITUENTS OF BONES <ul><li>Organic Elements – 1/3 of the bone is made up of organic elements. It gives toughness and elasticity to the bones. </li></ul><ul><ul><li>Made-up of: </li></ul></ul><ul><ul><li>Carbohydrates </li></ul></ul><ul><ul><li>Fats </li></ul></ul><ul><ul><li>Proteins </li></ul></ul>
  10. 10. <ul><li>Inorganic Elements – comprises 2/3 of the bone composition. It provides hardness and brittleness </li></ul><ul><li>made-up of: </li></ul><ul><ul><li>Calcium Salts </li></ul></ul><ul><ul><li>Phosphate </li></ul></ul><ul><ul><li>Carbonate </li></ul></ul><ul><ul><li>Sodium </li></ul></ul>
  11. 11. Classification of bones according to: <ul><li>Compact or Dense bone </li></ul><ul><li>Trabecular or Spongy Bone </li></ul>1. Microscopic Appearance of Cut Surfaces
  12. 12. <ul><li>A. Compact or Dense bone </li></ul><ul><li>- In compact bone there are no spaces between osteocytes </li></ul><ul><li>The spaces are filled with hard and dense materials; which forms the layer of bone structure ( lamellae) just beneath the periosteum. </li></ul>
  13. 13. <ul><li>Trabecular or Spongy Bone </li></ul><ul><li>– the interior of mature bone ( also termed cancellous or spongy bone) the characteristic features is the presence of spaces between osteocytes; which is filled with bone marrow. </li></ul>
  14. 14. 2. Developmental Origin <ul><li>Intramembranous (Mesenchymal or Dermal bone) </li></ul><ul><li>Intracartilaginous or Substitutuion </li></ul><ul><ul><li>( Endochondral bone) </li></ul></ul>
  15. 15. <ul><li>a. Intramembranous (Mesenchymal or Dermal bone) </li></ul><ul><li> – formed by the direct formation of condensed mesenchyme. Initially, the intramembranous bone resembles spongy bone, further remodeling around the trapped vessels can produce compact bones. </li></ul><ul><li>Several flat bones of the skull , and the lower jaw , and clavicles are formed this way. So therefore they are found in flat bones and those that remain flat on maturation. </li></ul>
  16. 16. <ul><ul><li>Intracartilaginous or Substitutuion </li></ul></ul><ul><ul><li>( Endochondral bone) </li></ul></ul><ul><ul><li>- replacing a preformed cartilage model. Most human bones are preformed cartilages; in early fetal life a long bone is prefigured by a rod of hyaline cartilage replacing a similar rod of condensed mesenchyme. </li></ul></ul>
  17. 17. 3. Shapes of Bones <ul><li>1. long, </li></ul><ul><li>2. short, </li></ul><ul><li>3. flat, and </li></ul><ul><li>4. irregular bones. </li></ul>
  18. 18. a. Long bones <ul><li>are typical of limbs </li></ul><ul><li>It is composed of shaft or diaphysis and two epiphyses. Between the epiphyses and diaphysis is the epiphyseal line where the growth and lengthening of bones occur. </li></ul><ul><li>The metacarpals, metatarsals, and phalanges are smaller groups of long bones. </li></ul>
  19. 19. Clavicle is a long bone
  20. 20. b. Short bones <ul><li>are generally cuboidal in shape. </li></ul><ul><li>It occurs in carpal and tarsal bones, </li></ul><ul><li>they typically have thin cortex of compact bone, supported by an interior which is wholly trabecular. </li></ul><ul><li>Sesamoid bones are short bones embedded in a tendon. </li></ul><ul><li>Ex. Patella (knee cap) - the largest sesamoid bone </li></ul>
  21. 21. Patella
  22. 22. c. Flat bones <ul><li>- Which includes the curved bones of the cranial vault, which have trabecular bone ( diploe) , in variable thickness, enclosed between laminae ( tables) of compact bone. </li></ul>
  23. 23. Sternum
  24. 24. d. Irregular bones <ul><li>include any element not easily assigned to the foregoing groups. </li></ul>
  25. 25. vertebra
  26. 26. 4. Location of Bones <ul><li>Axial Skeleton </li></ul><ul><li>Appendicular Skeleton </li></ul>
  27. 27. Axial skeleton are bones located at the median plane of the body. While, Appendicular skeleton is located at the lateral plane of the body
  28. 28. I. Axial Skeleton - 80 bones <ul><li>a. skull - 22 </li></ul><ul><li>b. ear ossicles - 6 </li></ul><ul><li>c. hyoid bone - 1 </li></ul><ul><li>d. vertebral column- 26 </li></ul><ul><li>e. ribs - 24 </li></ul><ul><li>d. Sternum - 1 </li></ul>
  29. 29. II. Appendicular Skeleton - 126 bones <ul><li>a. Upper Extremity </li></ul><ul><li>Clavicle - 2 </li></ul><ul><li>Scapula - 2 </li></ul><ul><li>Humerus - 2 </li></ul><ul><li>Radius - 2 </li></ul><ul><li>Ulna - 2 </li></ul><ul><li>Carpals - 16 </li></ul><ul><li>Metacarpals- 10 </li></ul><ul><li>Phalanges - 28 </li></ul><ul><li>Total - 64 </li></ul><ul><li>b. Lower Extremity - </li></ul><ul><li>Pelvic - 2 </li></ul><ul><li>Femur - 2 </li></ul><ul><li>Patella - 2 </li></ul><ul><li>Tibia - 2 </li></ul><ul><li>Fibula - 2 </li></ul><ul><li>Tarsals - 14 </li></ul><ul><li>Metatarsals- 10 </li></ul><ul><li>Phalanges - 28 </li></ul><ul><li>Total - 62 </li></ul>
  30. 30. The Characteristics of bone in fresh state
  31. 31. <ul><li>Periosteum </li></ul><ul><li>Articular Cartilage </li></ul><ul><li>  </li></ul><ul><li>Endosteum </li></ul><ul><li>  </li></ul><ul><li>Bone Marrow </li></ul><ul><ul><li>  </li></ul></ul><ul><li>Nutrient blood vessels (nutrient artery) </li></ul>
  32. 32. A. Periosteum <ul><li>vascular membranes covering most of the surfaces of bones. </li></ul><ul><li>Functions of the periosteum: </li></ul><ul><ul><li>protection </li></ul></ul><ul><ul><li>nutrition </li></ul></ul><ul><ul><li>repair and regeneration </li></ul></ul>
  33. 33. B. Articular Cartilage <ul><li>- plate of cartilage which covers the articulating surface of bones. </li></ul>
  34. 34. C. Endosteum <ul><li>- a membrane that lines the medullary cavity of long bones. </li></ul>
  35. 35. D. Bone Marrow <ul><li>- connective tissue found within bones. </li></ul><ul><li>Types of Bone Marrow: </li></ul><ul><ul><li>Red bone marrow - concerned with production of RBC </li></ul></ul><ul><ul><li>Yellow bone marrow – for the storage of fat. It is found within the medullary cavities of long bones </li></ul></ul>
  36. 36. E. Nutrient blood vessels (nutrient artery) <ul><li>- enters thru the nutrient foramen to give nutrition to bones. </li></ul>
  37. 37. The Axial Skeleton <ul><li>The Skull </li></ul><ul><ul><li>Has a total of 22 bones </li></ul></ul><ul><ul><li>Cranial bones 8 </li></ul></ul><ul><ul><li>Facial bones 14 </li></ul></ul>
  38. 38. The cranial vault <ul><li>Bones of the cranium </li></ul><ul><li>Frontal 1 </li></ul><ul><li>Parietal 2 </li></ul><ul><li>Temporal 2 </li></ul><ul><li>Occipital 1 </li></ul>
  39. 39. <ul><li>Bones of the cranium (Base) </li></ul><ul><li>Sphenoid bone 1 </li></ul><ul><li>Ethmoid Bone 1 </li></ul>
  40. 40. Bones of the face <ul><li>Facial bones </li></ul><ul><li>Nasal bone- 2 </li></ul><ul><li>Maxillary bone 2 </li></ul><ul><li>Zygomatic bone 2 </li></ul><ul><li>Lacrimal bone 2 </li></ul><ul><li>Inferior nasal bone 2 </li></ul>
  41. 41. The facial bones <ul><li>Palatine bone 2 </li></ul><ul><li>Vomer 1 </li></ul>
  42. 42. The facial bones <ul><li>Mandible 1 </li></ul>
  43. 43. The Axial Skeleton Definition of each bone
  44. 44. Bones of the Cranium <ul><li>The Frontal Bone </li></ul><ul><li>The frontal bone of the cranium forms the forehead and superior surface of each eye socket or orbit. </li></ul><ul><li>  </li></ul>Green - frontal bone
  45. 45. <ul><li>The Parietal Bones </li></ul><ul><li>2 in number </li></ul><ul><li>It forms the roof/ superior wall of the skull. </li></ul><ul><li>The bone is posterior to the frontal bone and anterior to occipital bone. </li></ul><ul><li>The 2 bones articulates to form the sagittal suture. </li></ul><ul><li>  </li></ul>Green - parietal bone
  46. 46. <ul><li>The Occipital Bone </li></ul><ul><li>The occipital bone forms the posterior and inferior portions of the cranium. </li></ul><ul><li>Along its superior margins, the occipital bone articulates with parietal bones forming the lambdoidal suture. </li></ul><ul><li>  </li></ul>Yellow - parietal bone Red - lambdoidal suture Green - Occipiltal bone
  47. 47. <ul><li>The Temporal Bones </li></ul><ul><li>Lying below the parietal bones and contributing to the sides and base of the cranium. </li></ul><ul><li>It comes it contact with the parietal bone it forms the squamosal suture. </li></ul><ul><li>  </li></ul>Green - frontal bone Yellow- parietal bone Light green- occipital Blue- temporal bone
  48. 48. <ul><li>The Sphenoid Bone </li></ul><ul><li>The sphenoid bone forms the floor of the cranium. It also acts as a bridge uniting the cranial and facial bones, and it braces the sides of the skull. </li></ul><ul><li>  </li></ul>
  49. 49. <ul><li>The Ethmoid Bone </li></ul><ul><li>The Ethmoid bone consists of two honeycombed masses of bone. </li></ul><ul><li>It forms part of the cranial floor, contributes to the medial surface of the orbit of each eye, and forms the roof and the sides of the nasal cavity. </li></ul>
  50. 50. <ul><li>The Maxillary Bones </li></ul><ul><li>The maxillary bones or Maxillae, articulate with all other facial bones except the mandible. </li></ul><ul><li>It forms the mid-face; houses the maxillary sinus and the upper teeth </li></ul>Yellow -maxilla
  51. 51. <ul><li>The Palatine Bones </li></ul><ul><li>The paired palatine bones form the posterior surface of the bony hard palate, or the roof of the mouth. </li></ul><ul><li>Superiorly it communicates the orbit, forming its floor. </li></ul>
  52. 52. <ul><li>The Zygomatic Bones </li></ul><ul><li>On each side of the skull (facial). </li></ul><ul><li>It is also known as the cheek or malar bone </li></ul><ul><li>Zygomatic bone articulates with the frontal bone and the maxilla to complete the lateral wall of the orbit.   </li></ul>Black- Zygomatic bone
  53. 53. <ul><li>The Nasal Bones </li></ul><ul><li>Forming the bridge of the nose. </li></ul><ul><li>It is located midway between the orbits, the nasal bones and it articulate with the frontal bone and the maxillary bones. </li></ul><ul><li>  </li></ul>Red - Nasal bone
  54. 54. <ul><li>The Lachrymal Bones </li></ul><ul><li>The lachrymal bones are found within the medial wall of the orbit. </li></ul><ul><li>They articulate with the frontal, Ethmoid and maxillary bones. </li></ul><ul><li>  </li></ul>Aqua blue- Lachrymal bone
  55. 55. <ul><li>The Inferior Nasal Conchae </li></ul><ul><li>The paired inferior nasal conchae project from the lateral wall of the nasal cavity.   </li></ul>Green - Inferior nasal concha
  56. 56. <ul><li>The Mandible </li></ul><ul><li>It is the bone of the lower jaw. </li></ul><ul><li>It has a body and two upward processes called ramus </li></ul><ul><li>The superior part of the ramus has a condlye and a coronoid process, the first forms part the TMJ and the latter form part of the attachment of the muscles of mastication. </li></ul>
  57. 57. The Ossicles
  58. 58. The Ossicles <ul><li>A chain of three mobile ossicles, that transfers sound waves across the tympanic cavity from its membrane to the inner ear. </li></ul><ul><li>The malleus, </li></ul><ul><li>incus and </li></ul><ul><li>stapes </li></ul>
  59. 60. The Hyoid Bone
  60. 61. The Hyoid Bone <ul><li>A small u-shaped bone that hangs at the mid part of the neck, it is suspended by ligaments from the styloid processes of the temporal bones. </li></ul><ul><ul><li>serves a base for muscles associated with the tongue and larynx, </li></ul></ul><ul><ul><li>supports and stabilizes the position of the larynx. </li></ul></ul>
  61. 63. The Vertebral Column
  62. 64. The Vertebral Column <ul><li>- 33 in number (adult) </li></ul><ul><li>- Each is separated by fibro-cartilaginous discs. </li></ul><ul><li>Its function is to support the trunk and to protect the spinal cord. </li></ul><ul><li>Its total length in males is about 70cm and in females about 60cm. </li></ul>
  63. 65. Classification of Vertebra a. According to the region which they occupy <ul><li>Individual regions of the column account for approximately: </li></ul><ul><li>8% of the whole body length for the cervical, </li></ul><ul><li>20% for the thoracic, </li></ul><ul><li>12% for the lumbar, and </li></ul><ul><li>8% for the sacrococcygeal. </li></ul>
  64. 66. Classification of Vertebra b. According to mobility <ul><ul><li>True or movable vertebra - these are bones comprising the cervical, thoracic, and lumbar regions which maintain separate throughout life. </li></ul></ul><ul><ul><li>False or fixed vertebrae - bones comprising the sacral and coccygeal regions which in adult fuse into the sacrum and coccyx respectively. </li></ul></ul>
  65. 67. VERTEBRA YOUNG ADULT Cervical 7 7 Thoracic 12 12 Lumbar 5 5 Sacral 5 1 Coccygeal 4 1
  66. 68. General Vertebral Features: <ul><li>Body </li></ul><ul><li>Vertebral arch </li></ul><ul><li>Vertebral foramen </li></ul><ul><li>Paired superior and inferior articular processes </li></ul><ul><li>Pedicles </li></ul><ul><li>Transverse processes </li></ul><ul><li>Spine </li></ul><ul><li>Laminae </li></ul>
  67. 69. 1. Body <ul><li>varies in size, shape and proportion in different regions </li></ul><ul><li>It forms the central axis of the body supporting the full weight of the head and the trunk. </li></ul><ul><li>It also transmits even greater forces due to muscles attached to it directly or indirectly. </li></ul>
  68. 70. The Body
  69. 71. 2. Vertebral Arch <ul><li>extends by a lever-like processes which has on each side </li></ul><ul><li>It forms the posterior wall of the neural canal </li></ul>
  70. 72. 3. Vertebral Foramen <ul><li>which is formed by a series of vertebrae enclosing the spinal cord. </li></ul>
  71. 73. 4. Paired superior and inferior articular processes <ul><li>It arises from the vertebral arch at the pedicolaminar junctions. </li></ul><ul><li>The superior articular processes projects cranially while the inferior articular processes bulge caudally. </li></ul>
  72. 74. 5. Pedicles <ul><li>Is the lateral wall of the vertebral canal </li></ul>
  73. 75. 6. Transverse Processes <ul><li>2 processes that project laterally from the pedicolaminar junctions </li></ul>
  74. 76. 7. Lamina <ul><li>directly continuous with pedicles, it is vertically flattened and curve dorsomedially to complete spinous process of the vertebra </li></ul>
  75. 77. 8. Spine <ul><li>projects dorsally and often caudally from the junction of the laminae. </li></ul><ul><li>They act as levers for muscles which control posture and active movements (flexion/extension, lateral flexion and rotation) of the vertebral column. </li></ul>
  76. 78. <ul><li>Let us Identify </li></ul>
  77. 79. The Cervical Vertebrae <ul><li>7 in number </li></ul><ul><li>It is the smallest of the movable vertebrae </li></ul><ul><li>It has a transverse foramina, a unique feature of the cervical vertebra </li></ul><ul><li>The first, second, and seventh cervical vertebrae have special features and collectively known as atypical cervical vertebra </li></ul><ul><li>The third, fourth, and fifth are almost identical; while the sixth , while typical in its general features, has minor differences which usually enable its distinction from others also known as typical cervical vertebra </li></ul>
  78. 81. Typical Cervical Vertebra <ul><li>small, relatively broad ventral body, </li></ul><ul><li>pedicles projects posterolaterally, </li></ul><ul><li>longer and broader laminae, </li></ul><ul><li>triangular vertebral foramen which accommodates the enlargement of the spinal cord, </li></ul><ul><li>the spinous processes are short and bifid </li></ul><ul><li>transverse foramen on each transverse processes. </li></ul>
  79. 82. Atlas or First Cervical Vertebra <ul><li>The atlas, the first cervical vertebra, supports the head </li></ul><ul><li>It articulates with the occipital bone via occipital condyle of the skull </li></ul>
  80. 83. <ul><li>No body </li></ul><ul><li>Anterior arch is slightly convex anteriorly and carries a roughened anterior tubercle to which is attached the anterior longitudinal ligament. It presents a facet for the dens of the axis which forms a pivot around which the head rotates. </li></ul><ul><li>Posterior arch forms three-fifths of the circumference of the atlantal ring. It bears a small bony projection called the posterior tubercle. </li></ul><ul><li>Transverse processes are longer than those of all the cervical vertebrae except the seventh cervical. </li></ul><ul><li>Superior articular facet is larger, oval and concave for articulation with the occipital condyles </li></ul>
  81. 84. Atlas or Cervical # 1 or C1 <ul><li>Superior View </li></ul><ul><ul><li>Anterior tubercle </li></ul></ul><ul><ul><li>Facet for the articulation of dens </li></ul></ul><ul><ul><li>Superior articular facet </li></ul></ul><ul><ul><li>Anterior Arch </li></ul></ul><ul><ul><li>Posterior Arch </li></ul></ul><ul><ul><li>Transverse process </li></ul></ul><ul><ul><li>Transverse formina </li></ul></ul>
  82. 85. Atlas <ul><li>Inferior view </li></ul><ul><ul><li>Anterior tubercle </li></ul></ul><ul><ul><li>Facet for the articulation of dens </li></ul></ul><ul><ul><li>Inferior articular facet </li></ul></ul><ul><ul><li>Anterior Arch </li></ul></ul><ul><ul><li>Posterior Arch </li></ul></ul><ul><ul><li>Transverse process </li></ul></ul><ul><ul><li>Transverse formina </li></ul></ul>
  83. 87. Axis or Epistropheus <ul><li>The axis, the second cervical vertebra </li></ul><ul><li>Presence of DENS or odontoid, that articulates with the inferior articular facet of Atlas </li></ul><ul><li>Atlantoaxis joint – provide simple movement of the head like nodding/ saying yes </li></ul>
  84. 88. <ul><li>Presence of dens which projects upward from the body into the anterior section of the vertebral foramen of the atlas. </li></ul><ul><li>The body consists of less compact bone than the dens. </li></ul><ul><li>The pedicles are stout, with superior surface carrying part of the superior articular facet, which also projects laterally and downwards on to the transverse process. </li></ul><ul><li>The transverse processes are pointed and project inferiorly and laterally, arising from the peducololaminar junction and the lateral aspect of the interarticular area of the pedicle. </li></ul><ul><li>The laminae are thick. </li></ul><ul><li>The spinous process is large, with a bifid tip and a broad base, concave inferiorly. </li></ul>
  85. 89. C2 <ul><li>Superior View </li></ul><ul><ul><li>Dens </li></ul></ul><ul><ul><li>Superior articular facet </li></ul></ul><ul><ul><li>Vertebral canal </li></ul></ul><ul><ul><li>Spine </li></ul></ul><ul><ul><li>Lamina </li></ul></ul><ul><ul><li>Body </li></ul></ul><ul><ul><li>Transverse process </li></ul></ul><ul><ul><li>Transverse foramina </li></ul></ul>
  86. 90. C2 <ul><li>Inferior View </li></ul><ul><ul><li>Dens </li></ul></ul><ul><ul><li>Inferior articular facet </li></ul></ul><ul><ul><li>Vertebral canal </li></ul></ul><ul><ul><li>Spine </li></ul></ul><ul><ul><li>Lamina </li></ul></ul><ul><ul><li>Body </li></ul></ul><ul><ul><li>Transverse process </li></ul></ul><ul><ul><li>Transverse foramina </li></ul></ul>
  87. 91. <ul><li>Let us identify </li></ul>
  88. 92. C7 or Seventh Cervical Vertebra <ul><li>The spine is not bifid </li></ul><ul><li>It resembles the 1 st thoracic vertebra </li></ul>
  89. 93. Seventh Cervical Vertebra <ul><li>Superior View </li></ul><ul><ul><li>Spine </li></ul></ul><ul><ul><li>Lamina </li></ul></ul><ul><ul><li>Transverse process </li></ul></ul><ul><ul><li>Superior articular facet </li></ul></ul><ul><ul><li>Transverse foramina </li></ul></ul><ul><ul><li>Body </li></ul></ul><ul><ul><li>Pedicle </li></ul></ul><ul><ul><li>Vertebral arch </li></ul></ul><ul><ul><li>Neural canal </li></ul></ul>
  90. 94. <ul><li>inferior View </li></ul><ul><ul><li>Spine </li></ul></ul><ul><ul><li>Lamina </li></ul></ul><ul><ul><li>Transverse process </li></ul></ul><ul><ul><li>Inferior articular facet </li></ul></ul><ul><ul><li>Transverse foramina </li></ul></ul><ul><ul><li>Body </li></ul></ul><ul><ul><li>Pedicle </li></ul></ul><ul><ul><li>Vertebral arch </li></ul></ul><ul><ul><li>Neural canal </li></ul></ul>
  91. 95. Typical cervical vertebra/ C5 <ul><li>Identify the parts </li></ul><ul><li>What view is this </li></ul><ul><li>What is the Characteristic feature of this vertebra </li></ul>
  92. 96. Typical cervical/ C5 <ul><li>Identify the parts </li></ul><ul><li>What view is this? </li></ul>
  93. 97. The Thoracic vertebra <ul><li>- There are 12 thoracic vertebrae </li></ul><ul><li>- Each thoracic vertebra increases in size caudally like other vertebrae this is due to increased loading from above. </li></ul>
  94. 98. Characteristic Features: <ul><li>All their bodies present lateral costal facets for the head of the rib, </li></ul><ul><li>Bodies are larger than the cervical vertebrae, </li></ul><ul><li>All but the lowest two or three transverse processes also have facets for the tubercle of the rib, </li></ul><ul><li>The vertebral foramen is small and circular, </li></ul><ul><li>Pedicles do not diverge, </li></ul><ul><li>Laminae are short, thick, and broad overlapping from above, downwards </li></ul><ul><li>The spinous process slants downwards. </li></ul>
  95. 100. <ul><li>Superior View </li></ul><ul><ul><li>Spine </li></ul></ul><ul><ul><li>Transverse process </li></ul></ul><ul><ul><li>Costal pit </li></ul></ul><ul><ul><li>Superior articular process </li></ul></ul><ul><ul><li>Pedicle </li></ul></ul><ul><ul><li>Vertebral canal and arch </li></ul></ul><ul><ul><li>Body </li></ul></ul><ul><ul><li>Facet for the articulation of the head of the rib </li></ul></ul>
  96. 101. <ul><li>Inferior view </li></ul><ul><ul><li>All are present, except the superior articular process, here is the inferior articular process </li></ul></ul>
  97. 102. <ul><li>Let us identify the parts </li></ul><ul><ul><li>Light blue </li></ul></ul><ul><ul><li>Red </li></ul></ul><ul><ul><li>Green </li></ul></ul><ul><ul><li>Maroon </li></ul></ul><ul><ul><li>Pink </li></ul></ul><ul><ul><li>orange </li></ul></ul>
  98. 103. <ul><li>Let us identify the parts </li></ul><ul><ul><li>Red </li></ul></ul><ul><ul><li>Pink </li></ul></ul><ul><ul><li>Orange </li></ul></ul><ul><ul><li>Light blue </li></ul></ul><ul><ul><li>Yellow </li></ul></ul><ul><ul><li>Dark green </li></ul></ul>
  99. 104. The Lumbar Vertebra
  100. 105. <ul><li>There are 5 lumbar vertebra </li></ul><ul><li>They are distinguished by their large size </li></ul><ul><li>and absence of costal facets and transverse foramina. </li></ul><ul><li>They are located in the posterior abdominal wall. </li></ul>The Lumbar Vertebra
  101. 106. <ul><li>The vertebral foramen is triangular, larger than thoracic but smaller than cervical. </li></ul><ul><li>The body is wider transversely and deeper in front. </li></ul><ul><li>The pedicles are short. </li></ul><ul><li>The spinous process is almost horizontal, quadrangular, and thickened along its posterior and inferior borders. </li></ul><ul><li>The superior articular processes bear a vertical concave articular facets facing posteromedially, with rough mamillary process on their posterior borders. </li></ul><ul><li>The inferior articular processes are thin and long, except the more substantial fifth. </li></ul><ul><li>A small accessory process marks the posteroinferior aspect of the root of each transverse process. </li></ul>
  102. 107. <ul><li>Superior view </li></ul><ul><ul><li>Spine </li></ul></ul><ul><ul><li>Lamina </li></ul></ul><ul><ul><li>Superior articular process </li></ul></ul><ul><ul><li>Transverse Process </li></ul></ul><ul><ul><li>Mamiliary process </li></ul></ul><ul><ul><li>Accessory process </li></ul></ul><ul><ul><li>Body </li></ul></ul><ul><ul><li>pedicle </li></ul></ul>
  103. 108. <ul><li>Inferior view </li></ul><ul><ul><li>All are present except for the superior articular process, instead it is the inferior articular process </li></ul></ul>
  104. 109. <ul><li>Let us label the parts </li></ul><ul><ul><li>Blue </li></ul></ul><ul><ul><li>Yellow </li></ul></ul><ul><ul><li>Pink </li></ul></ul><ul><ul><li>Orange </li></ul></ul><ul><ul><li>Light blue </li></ul></ul><ul><ul><li>gray </li></ul></ul>
  105. 110. <ul><li>Identify the parts </li></ul><ul><ul><li>Green </li></ul></ul><ul><ul><li>Red </li></ul></ul>
  106. 111. <ul><li>The sacrum is a large, wedged triangular shaped bone that forms the postero-superior wall of the pelvic cavity. The caudal apex articulates with the coccyx and its superior, articulates with the fifth lumbar vertebra at the lumbosacral angle. </li></ul><ul><li>The dorsal surface is convex, the pelvic or the anterior surface is concave. </li></ul>The Sacrum
  107. 112. The Base This is the upper surface of the first sacral vertebra <ul><li>The body </li></ul><ul><li>sacral promontory. </li></ul><ul><li>vertebral foramen </li></ul><ul><li>pedicles . </li></ul><ul><li>laminae </li></ul><ul><li>superior articular process </li></ul><ul><li>transverse process </li></ul>
  108. 113. Pelvic Surface <ul><li>sacral foramina </li></ul><ul><li>transverse ridges . </li></ul>
  109. 114. Dorsal Surface <ul><li>median sacral crest </li></ul><ul><li>sacral hiatus </li></ul><ul><li>dorsal sacral foramina </li></ul><ul><li>Intermediate sacral crests </li></ul><ul><li>lateral sacral crest </li></ul><ul><li>sacral cornua </li></ul>
  110. 115. The Lateral Surface <ul><li>Articular surface </li></ul>
  111. 116. <ul><li>Label the parts </li></ul>
  112. 117. <ul><li>Label the parts </li></ul>
  113. 118. <ul><li>The coccyx, a small triangular bone, is usually composed of four fused rudimentary vertebrae but the number varies from five to three, the first being separate. </li></ul><ul><li>It descends ventrally from the sacral apex, its pelvic surface being tilted upwards and forwards, its dorsum downwards and backwards. Orientation varies with its mobility. </li></ul>The Coccyx
  114. 119. The Coccyx <ul><li>base , </li></ul><ul><li>Transverse process </li></ul><ul><li>rudimentary vertebral bodies. </li></ul>
  115. 120. To be continue