MSK2 axial & appendicular

• What are the two types of bone?


  Compact bone and spongy bone
• What are the two skeletal systems in the human body?


  The axial skeleton and the appendicular skeleton
• How many bones does the average baby have at birth?


  Approximately 300 bones
• How many bones does the average adult have?


  Approximately 206 bones
• Why does the number of bones decrease from infancy to adulthood?


  Because some bones fuse together as a person grows
• What is the purpose of the unfused bones in a baby's cranium?


  To allow flexibility during birth and growth
• At what age do the bones of the cranium typically fuse?


  About 1 to 2 years
• When do the cartilaginous growth plates typically fuse and calcify?


  Between 14 to 16 years
• What are the two principal skeletal groups in the adult human skeleton?


  1. The Axial skeleton: 80 bones
  2. The Appendicular skeleton: 126 bones
• What is the composition of compact bone?


  It consists of closely packed osteons or Haversian systems
• What is the central canal in an osteon called?


  The Osteonic (Haversian) Canal
• What are the concentric rings of matrix in compact bone called?


  Lamellae
• What are osteocytes and where are they located?


  Osteocytes are maintenance cells located in spaces called lacunae
• What is the function of canaliculi in compact bone?


  They provide passageways for blood vessels and nerves
• Why is compact bone stronger than spongy bone?


  Because it consists of tightly packed osteons
• What is spongy bone composed of?


  Plates (trabeculae) and bars of bone adjacent to small cavities containing red bone marrow
• How do trabeculae in spongy bone provide strength?


  They are arranged to follow lines of stress
• How many bones are in the axial skeleton?


  80 bones
• What structures make up the rib cage?


  The rib cage consists of 12 pairs of ribs, the sternum, and the xiphoid process
• What are the two types of ribs in the rib cage?


  True ribs and false ribs
• How many pairs of true ribs are there?


  7 pairs
• How many pairs of false ribs are there?


  5 pairs
• How many pairs of floating ribs are there?


  2 pairs
• What is the sternum also known as?


  The breastbone
• What are the three sections of the sternum?


  The manubrium, body, and xiphoid process
• What are the key landmarks of the sternum?


  Jugular notch, sternal angle, and xiphisternal joint
• How many cranial bones are there?


  8 bones
• What are the paired cranial bones?


  Parietal and temporal bones
• What are the unpaired cranial bones?


  Frontal, occipital, sphenoid, and ethmoid bones
• How many facial bones are there?


  14 bones
• What are the two unpaired facial bones?


  Mandible and vomer
• What are the six paired facial bones?


  Nasal, inferior nasal concha, palatine, maxillae, zygomatic, and lacrimal bones
• How many individual vertebrae are in the vertebral column?


  33 individual vertebrae
• How many cervical vertebrae are there?


  7 cervical vertebrae
• How many thoracic vertebrae are there?


  12 thoracic vertebrae
• How many lumbar vertebrae are there?


  5 lumbar vertebrae
• How many sacral vertebrae are there?


  5 sacral vertebrae
• How many coccygeal vertebrae are there?


  4 coccygeal vertebrae
• What are the common structures of all vertebrae?


  1. Body
  2. Vertebral foramen
  3. Vertebral arch
  4. Spinous process
  5. Laminae
  6. Transverse process
  7. Superior and inferior articular processes
  8. Pedicles

  
• What is the function of the anterior and posterior longitudinal ligaments?


  They run from the occiput to the sacrum and prevent hyperextension and hyperflexion