1. Skeletal System
No bones about it!!!

2. What does the skeletal system do?
Support, Protection, Movement, Storage, Hemopoiesis

3. Types of bones in body
Long (most bones of limbs (humerus, femur, fingers, toes except wrist, ankle, knee cap) - shaft is greater in length than width, mostly compact bone),
short (carpals, tarsals-cube shaped, small layer of compact bone ),
flat (skull, sternum or scapula-flat, thin, curved and generally 2 layers of compact bone sandwiching spongey bone)
irregular (spine, pelvis) thin layers of compact bone surrounding a spongy interior
Sesamoid bones are bones embedded in tendons. Since they act to hold the tendon further away from the joint, the angle of the tendon is increased and thus the leverage of the muscle is increased. Examples of sesamoid bones are the patella

4. Structure of long bone Diaphysis - shaft of long bone
Medullary cavity - hollow tube
Epiphyses - ends
Articular cartilage - covering epiphysis

5. Microscopic structure of bone
Two types of connective tissue - _________ & ________.
Outer layer of bone is _______, _______
Porous bone on ends are _________ bone
Needlelike threads of spongy bone surround a network of spaces called _____________.
Bones, tendons
dense, compact
Spongy
trabeculae

6. Matrix of Bone Osteon/Haversian System Concentric Lamella Osteocytes
Lacunae
Canaliculi
Periosteum
Osteons/haversian systems -structural unit of bone
Concentric lamella - Calcified layers that surround central canal where blood vessels are found
Bone cells - osteocytes
Lacunae - hard layers where bone cells are found
Canaliculi - tiny canals b/t lacunae and haversian system. Nutrients pass thru here.
Periosteum - outer layer of bone

7. Internal Bone Structure
Haversian System
Osteon
Concentric Lamellae

9. Bone Formation Osteoblasts - Osteoclasts -
Combined efforts of ____________ & __________ sculpts bones into adult shapes
Calcium salts -
Osteoblasts - bone forming cells
Osteoclasts - bone reabsorbing cells
Combined efforts of cells sculpts bones into adult shapes
Laying down of calcium salts is ongoing process for strength

10. Osteoblasts - bone forming cells
Osteoclasts - bone reabsorbing cells

11. Echondral Ossification “Formed in cartilage”
Cartilage in epiphyseal plate leads to growth
Growth ceases when all epiphyseal cartilage is transformed to bone
Growth plate determines growth in children to adult

12. Axial division of skeleton
center axis of body
Skull, ribs, vertebrae

13. Appendicular division of skeleton
Upper and lower extremities
Shoulder, arm, wrists, hands
Hip girdle, legs, ankles, feet

14. Articulations (joints)
3 main types according to degree of movement
Synarthroses (no movement) - cranial bones, commonly called “sutures”, fibrous tissue grows b/t holding close together
Amphiarthroses (slight movement) - connected by cartilage, ex. Symphysis pubis where pubic bones connect
Diarthroses (free movement) see next slides

15. Diathrotic types

16. Diathrotic types cont’d

17. Movement of joints Flexion - reduces angle of joint
Extension - increases angle of joint
Rotation - spins one bone relative to another
Circumduction - moves distal end in a circle while keeping proximal end relatively stable
Abduction - increase angle of joint to move away from midline
Adduction - decrease angle of joint to move toward midline

18. Flexion & Extension

19. Rotation & Circumduction

20. ABduction & ADduction