The Skeletal System

1. The Skeletal System

2. A. Functions • Support • Protection • Movement • Storage of Minerals • Manufactures Blood Cells

3. B. Exoskeleton vs. Endoskeleton • Exoskeleton • Hard, external body covering • (outer covering) • Made of chitin (protein/carbohydrate) • Found in Arthropods (invertebrates)

4. B. Exoskeleton vs. Endoskeleton • Exoskeleton d) Growth occurs through molting • Shedding of the exoskeleton e) Additional Functions: • Guards against water loss (only for terrestrial organisms)

5. B. Exoskeleton vs. Endoskeleton • Exoskeleton f) Disadvantages: • Limits size and movement of organism • Growth is limited • Size of the organism cannot change until it molts again

6. B. Exoskeleton vs. Endoskeleton • Endoskeleton • Lies within soft tissues of the body • Internal skeleton • Found in vertebrates • Additional function: • Blood cell formation • Disadvantage: • No external protection

7. What type of skeleton do humans have??? Endoskeleton

8. What makes up the endoskeleton??? Calcium, Bones

9. osteocytes blood vessel Haversian canals C. Bones • Bone is living tissue!

10. C. Bones 2. Development: • Most bones in the fetus of vertebrates begin as cartilage • As a fetus grows, osteoblasts replace cartilage with bone and add minerals ________ = calcification • Calcification completed around age 25 (Calcium)

12. Compact bone Spongy bone C. Bones 3. Bone Marrow • Red marrow • Produces red blood cells • Produces some white blood cells and platelets • Yellow marrow • Fat storage

13. C. Bones 4. Bones of Humans • 206 bones • Actual bones (see diagram)

14. Cranium Mandible Maxilla Vertebrae Cervical (C1-C7) Thoracic (T1-T12) Lumbar (L1-L5) Sacrum (5 fused) Coccyx/tailbone (3-5 fused) Ribs Sternum Clavicle (collar bones) Scapula (shoulder blade) Pelvis Illium (hip bones) Ischium (butt bones) Pubis Arm and Hand Bones Humerus Radius Ulna Carpels (wrist bones) Metacarpels Phalanges (fingers) Leg and Foot bones Femur Tibia Fibula Patella (knee cap) Tarsals (ankle bones) Metatarsals Phalanges (toes) C. Bones

16. C. Bones • Appendicular Skeleton • Includes legs, arms, feet and hands • Allows for movement • Axial Skeleton • Includes skull, rib cage, and vertebraae • Supports and protects body tissues • Limited movement

17. D. Joints (Articulations) • Site where two or more bones meet • Functions: • Hold bones together • Can provide mobility

18. 3. Types a) Gliding • Bones move over each other in a back and forth motion • Examples: • Wrist • ankle

19. 3. Types b) Pivot • Allows for rotation • Examples: • Radius/ulna • Neck • Vertebrate

20. 3. Types • Ball and Socket • Moves in many directions • Most flexible • Examples • Shoulder • Hip

21. 3. Types • Saddle • allows back and forth, and up and down movement • Examples: Thumb

22. 3. Types e) Hinge • Only moves in one direction • Examples: • Knee • elbow

23. 3. Types f) Fibrous • Does not move at all • Example: • Skull • Rib cage

24. E. Muscle & Bone Attachment • Cartilage • provides cushion • located between bones • Ligaments • Connect bone to bone • Examples: ACL, PCL • Tendons • Connect muscle to bone