1. Skeletal System Monday, October 12, 2015
Get out your leg bone diagrams
Get out paper
Get out something to write with

2. Get out your skeletal system diagrams
Using p. 144 as a guide, color code the axial and appendicular skeleton
Do anterior & posterior
Use same color front & back
Create a key / legend to go with your color codes

7. Tomorrow Have hand & foot diagrams labeled
Majority of class will be work day
Wed. – Mrs. Glisson will not be here till 11 or 12; no office hours Wed. morning;
Get out paper to take notes

8. Skeletal System Notes

9. Skeletal System Functions
Muscle attachment
Protection & support
Blood cell production
Storage of minerals

10. Structure
A bone’s shape make possible its function; bony processes or grooves indicate places of attachment for muscles
Compact bones makes up the wall of the diaphysis; the epiphyses are filled w/ spongy bone
Diaphysis also contains a hollow medullary cavity that is lined w/ endosteum & filled w/ marrow

12. Microscopic structure
Osteocytes are located within lacunae that lie in concetric circles around osteonic canals
Osteocytes pass nutrients & gasses in the matrix through canaliculi
Intercellular material consists of collagen & inorganic salts
Osteonic canals contain blood vessels & nerves fibers, and extend longitudinally through bone
In spongy bone, osteocytes & intercellular material NOT arranged around osteonic canals

14. Bone Development & Growth
Bones form by replacing connective tissue in the fetus
Some form within sheet-like layers of connective tissue (intramembranous bones) while others replace masses of cartilage (endochondral bones)

16. Bone Development & Growth
Intramembranous Bones = flat bones of the skull; osteoblasts deposit bony tissue around themselves
Endochondral bones = most bones; first develop as hyaline cartilage models & then are replaced w/ bone

17. Homeostasis of Bone Tissue
Osteoclasts tear down
Osteoblasts build bone
Happens throughout lifespan
An average of 3%-5% of bone calcium exchanged annually

18. Specific Functions Support & Protection
Give shape to head, thorax & limbs
Provide support for body (i.e. pelvis & lower limbs)
Skull protects brain, ears, & eyes
Body Movement
Bones can act as levers

19. Specific Functions Blood cell formation
2 kinds of marrow occupy the medullary cavities of bone
Red marrow functions in the formation of red blood cells, white blood cells, and platelets, and is found in the spongy bone of the skull, ribs, sternum, clavicles, vertebrae, and pelvis
Yellow marrow occupies the cavities of most bones & stores fat

20. Specific Functions Storage of Inorganic Salts
The inorganic matrix of bone stores inorganic mineral salts in the form of calcium phosphate; it is important in many metabolic processes
Calcium in bone is a reservoir for body calcium; when blood levels are low, osteoclasts release calcium from bone
Calcium is stored in bone under the influence of calcitonin when blood levels of calcium are high
Bone also stores magnesium, sodium, potassium & carbonate ions
Bones can also accumulate harmful elements such as lead, radium and strontium

21. Organization
Axial skeleton = skull, hyoid bone, vertebral column (vertebrae & intervertebral disks), and thorax (ribs & sternum)
Appendicular skeleton = pectoral girdle (scapulae & clavicles), upper limbs (humerus, radius, ulna, carpals, metacarpals, & phalanges), pelvic girdle (coxal bones articulating w/ the sacrum), and lower limbs (femur, tibia, fibula, patella, tarsals, metatarsals, phalanges).

22. For remainder of class…
Work on skeletons