Anatomy: week 3 Skeletal System

  1. The Skeletal System's functions are:
    • -Support
    • -Calcium & Phosphorus Storage
    • -Marrow Cavities- blood cell production
    • -Protection
  2. Has 2 Bone Forms:
    1. Compact Bone

    2. Spongy Bone
  3. Compact Bone:
    • -Osteon (ring structures)
    • -Central canal- parallel to bone
    • -Lamellae rings
    • -Lacuna with osteocytes inside them
    • -Canaliculi
    • -Perforating canals- running perpendicular to bone
  4. Spongy Bone:
    • -Also formed from Lamellae
    • -Found at the end of the bone- Epiphysis (head of the bone)
    • -Shaft of the bone is called- Diaphysis
    • -Red Marrow is where blood cell production occurs
  5. Facts about the bone:
    • -Prior to 6 weeks, there's no bone- its cartilage. Continues to age 25yr
    • -Loss of bone mass at age 30
    • -Bone loss in women can be up to 8% per decade
    • -Men lose up to 3% per decade
  6. Bone is classified based on shape:
    • 1. Long Bones- longer in length then width
    • 2. Flat Bones- thin; narrow; flat
    • 3. Sutural Bones/Wormian Bones- sutures
    • 4. Irregular Bones- random odd shapes; vertebra
    • 5. Short Bones- cuboidal shaped; make up carpals/tarsal bones, like the wrist/ankle
    • 6. Sesamoid Bone- form where you have joints; small/round; example is the patella-almost everyone has, but also can be found in some in the ankles and wrist
  7. AXIAL Skeleton:
    • -80 Bones
    • -Found along midline of body
    • -Make up skull-cranium & facial
    • -Vertebral column
    • -Thoracic cage
    • -Hyoid Bone- found in the neck (ligament); not connected to any other bone
    • -Ear ossicles- malleus, incus, stapes--these are the smallest in the body, found in the ear structure
  8. APPENDICULAR Skeleton:
    • -Remaining 126 bones
    • -Associated with appendages
    • -Includes:
    • 1. Pectoral Girdle-or shoulder girdle; consists of S shaped clavicle, and broad flat scapula-shoulder blade.
    • 2. Pelvic Girdle- support and protect the lower viscera, including reproductive organs; bones are more massive then Pectoral Girdle due to the stress in weight bearing and locomotion.
  9. Structures in Skull:
    -8 Bones make up the cranium

    • -Has 4 Suture Lines:
    • 1. Sagittal Suture- between parietals

    2. Coronal Suture- separates frontal from parietal

    3. Lambdoid Suture- separates occip. from parietals

    4. Squamous Suture- separates parietal from temperal
  10. Sphenoid Bone
    • -Butterfly shaped
    • -Contacts all other Cranial Bones
  11. Sella Turcica Bone:
    -(Saddle- looking) pituitary gland--aka the master gland
  12. Ethmoid Bone:
    • -Most secretive
    • -Hard to see
    • -Tucked away
  13. How many bones make up the Eye Socket?
    - 7 Bones
  14. How many bones make up the Vertebral Column?
    - 26 Bones

    • -Protects spinal cord
    • -Broken up into different regions
  15. How many Bones make up the Cervical Region (neck)?
    - 7

    • -C1- Atlas; holds up; flat; allows to move head in the "yes" motion (aka. the YES bone)
    • -C2- Axis; allows head to move in the "no" position (aka. the NO bone)
    • -C7- vertebra prominens; sticks out; can feel it on the back of neck; ligamentum nuchae
  16. How many Bones make up the Thoracic Region? (main back)
    • - 12 vertebra
    • - Rib artiulations
  17. How many Bones make up the Lumbar Region? ( lower back)
    - 5
  18. How many Bones make up the Sacrum Region?
    - 1 single bone-- actually 5 bones fussed together, only counted as 1
  19. How many Bones in the Coccyx?
    - 1 bone; actually 3-5 bones fussed together, only counted as 1
  20. How many Rib Bones?

    • -1 to 7- are true ribs
    • -8 to 10- are false ribs
    • -11 to 12- are floating ribs; not connected to sternum
  21. Clavicle Bone:
    -the Clavicle (collarbone) is the ONLY direct connection between the Axil skeleton, and the Pectoral Girdle.
Card Set
Anatomy: week 3 Skeletal System
Skeletal System