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Anatomy & Physiology: Skeletal System and Axial Skeleton

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Terms in this set (21)

  • What is an osteon?
    An osteon, or Haversian system, is the microscopic structural unit of compact bone composed of concentric rings of calcified matrix called lamellae.
  • What is the function of the central (Haversian) canal?
    The central canal contains blood vessels, nerves, and lymphatic vessels that supply nutrients and remove waste from osteocytes.
  • What are canaliculi and their role in bone?
    Canaliculi are tiny channels that connect lacunae and the central canal, allowing nutrient and waste exchange between osteocytes.
  • Differentiate between compact and spongy bone.
    Compact bone is dense and forms the outer walls of bones, while spongy bone is porous and found mainly in the epiphysis, containing red marrow.
  • What are the two main parts of a long bone?
    A long bone consists of the diaphysis (shaft) and the epiphysis (ends), with the diaphysis containing the medullary cavity filled with yellow marrow.
  • What is the chemical composition of bone?
    Bone matrix is made of organic collagen fibers for flexibility and inorganic hydroxyapatite crystals for hardness and strength.
  • How does acid affect bone composition?
    Acid dissolves the inorganic mineral salts in bone, making it flexible but weak due to loss of hardness.
  • How does heat affect bone composition?
    Heat destroys the organic collagen fibers, making bone brittle and prone to breaking.
  • What are the primary functions of the skeleton?
    The skeleton protects organs, supports body weight, and provides attachment points for muscles to enable movement.
  • What bones make up the axial skeleton?
    The axial skeleton includes the skull, vertebral column, ribs, and sternum, forming the body's central axis.
  • What are the two subdivisions of the skull?
    The skull is divided into the cranial bones (protect the brain) and the facial bones (form the face).
  • Name three important markings on the temporal bone.
    The temporal bone has the external auditory meatus, zygomatic process, and mastoid process.
  • What is the foramen magnum?
    The foramen magnum is the large opening at the base of the skull allowing the spinal cord to connect with the brain.
  • What are the four major sutures of the skull?
    The major sutures are the coronal, sagittal, squamous, and lambdoid sutures.
  • How many vertebrae are in the cervical region and what is unique about C1 and C2?
    There are 7 cervical vertebrae; C1 (atlas) supports the skull and lacks a body, C2 (axis) has the dens for head rotation.
  • Describe the characteristics of thoracic vertebrae.
    Thoracic vertebrae have heart-shaped bodies, long downward-pointing spinous processes, and circular vertebral foramina.
  • What distinguishes lumbar vertebrae from others?
    Lumbar vertebrae have large, kidney-shaped bodies, short blunt spinous processes, and triangular vertebral foramina.
  • What forms the sacrum and coccyx?
    The sacrum is formed by fusion of 5 sacral vertebrae; the coccyx is formed by fusion of 4 small coccygeal vertebrae.
  • What are the three parts of the sternum?
    The sternum consists of the manubrium, body, and xiphoid process.
  • Differentiate between true, false, and floating ribs.
    True ribs (1-7) attach directly to the sternum; false ribs (8-12) attach indirectly or not at all; floating ribs (11-12) do not attach anteriorly.
  • What are fontanelles and their function in the fetal skull?
    Fontanelles are soft spots of connective tissue between skull bones in infants that allow skull flexibility during birth and brain growth.