1. Skeletal System

2. What is the skeletal system?  Skeletal system consists of bones, teeth, joints, & structures that connect bones to other bones or muscles (ligaments, tendons, & cartilage).

3. Brainstorm … What are the functions of the skeletal system? (why is it important)

4. 1. Support  Many bones provide support, but long bones especially important  Acts as the frame for the rest of the body  long bones in legs help support the trunk  other than long bones  the first vertebra supports the skull

5. 2. Protection  Protect vital internal organs  skull ->the brain  rib cage ->heart, lungs, & abdominal organs

6. 3. Movement  Combination w/muscular system, the skeletal system aids in movement  Skeletal muscles are attached to bones by tendons that act as a lever to move bones.

7. 4. Mineral Storage  Outer layers of bony tissues are used for the storage of minerals (primarily calcium and phosphorus)

8. 5. Blood Cell Formation & Energy Storage  Inner core of bone ->bone marrow  Red marrow is a major site of blood cell & platelet formation.  Yellow marrow ->long bones & other mature bones  Yellow marrow consists mostly of fat & serves as an energy reserve.

9. What is the purpose? Why is it important?  Provides frame and support  Aids movement  Protects vital organs  Mineral storage  Blood cell formation

10. TURN AND TALK  Which of the 5 functions is the most important and why?

11. 3 cell types found in bones  1. Osteoblasts form a bone structure by secreting collagen, become enclosed in the matrix, & develop into osteocytes. (BUILD NEW BONE)  2. Osteocytes - exchange of nutrients & wastes with blood (SITE OF CYTE EXCHANGE)  3. Osteoclasts secrete enzymes that digest bone.  Bone is a living tissue that is continually remodeled in response to the body’s need for calcium  Osteoclasts are important in the development, growth, maintenance, & repair of bone (CLASH to break DOWN OLD BONE)

12.  Short bone – cube shaped, (think complex joins like the hock or knee) i.e. carpus and tarsus  Flat bone – plate of bone, (think thin and curved to protect organs) i.e. scapula, rib, skull  Irregular bone – complex shaped attached to muscles, i.e. vertebrae  Long bone – bone is longer that it is wide, i.e. femur, tibia, humerus, etc. (think legs/support)  NOT AS COMMON IN ANIMALS EXCEPT IN PAWS/HANDS  Sesamoid – small, seed-shaped bone, i.e. proximal and distal sesamoids, patella TYPES OF BONE

13. How are bones classified?  Long bones – femur  Short bones – knee  Flat bones – ribs, scapula  Irregular bones – vertebrae  Sesamoid bones –knee cap

14. Test Your Knowledge  Can you ID what “type” of bone each of these examples are?