1. Skeletal System

3. Support All living organisms need a support structure
One-cell organisms have cytoskeleton
Arthropods have exoskeleton (exo = out) (i.e. insects, snails)
Vertebrates have endoskeleton (endo = in)

4. Skeletal System Parts
Bones and other connective tissues, such as cartilage and ligaments, form the skeletal system.

5. Functions Our skeletal system and its joints allows special movements
Hips allows us to walk upright on 2 legs
Hands allow us to have an opposable thumb = ability to grasp objects.
Size of skull says we have a well developed brain. (Remember evolution of late ancestors. Small skull, big jaw.)

6. Functions
The skeleton supports the body, protects internal organs, provides for movement, stores mineral reserves, and provides a site for blood cell formation.
Examples:
Skull protect brain
Ribs and sternum protects lungs, kidneys, liver, stomach, heart, etc.

7. Divisions There are 206 bones in 2 parts
Axial – supports the central axis of the
body
Skull, vertebrae and ribs

8. Divisions Appendicular Skeleton
The bones of the arms and legs, along with the bones of the pelvis and shoulder area, form the appendicular skeleton.

10. Structure
The bone is surrounded by a tough layer of connective tissue called the periosteum
Blood vessels pass through here to supply bone w/ oxygen and nutrients
Below periosteum is compact bone. (Really dense, but not solid)
Running through compact bone are tubes called Haversian canals that have blood vessels and nerves.
Spongy bone is less dense found inside the outer layer of compact bone.
Its not soft or spongy. Its pattern provides strong support without adding too much mass.

11. Structure
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12. Structure Osteocytes Osteoclasts Osteoblasts
Mature bone cells
Osteoclasts
Break down bone
Osteoblasts
Build up bone
Bone remodel even when we stop growing.
Example: Exercise puts stress on our bones and forces bone to become stronger. Broken bone need to rebuild. Also, if not used, bones become weaker and break down.

13. Structure Bone marrow are in cavities within our bones 2 types:
Yellow – made up of fat cells
Red – makes RBCs, WBCs and platelets

14. Bone Marrow

16. Bone Development Embryo is almost entirely cartilage.
Cartilage is replaced by bone by ossification
Starts 7 months before birth. Here’s where osteoblasts come into play.

18. Types Of Joints Pivot Hinge Ball & Socket Gliding Top of the neck
Elbow/Knee
Ball & Socket
Gliding
Intercarpal joints
Shoulder/Hip

19. Structure of Joints Cartilage covers surfaces where bone meet.
Bone on bone hurts!
A capsule surrounds the joint made of 2 layers
1. ligaments
2. cell that make synovial fluid (reduces friction)

20. Disorders Research and find a disorder of the skeletal system.
Name, how it affects a person and how to treat it.Write 1 paragraph about it. Will count as 1 homework and 1 project grade.

21. Cranium
Mandible
Clavicle
Scapula
Sternum
Humerus
Rib
Vertebral Column
Ulna
Pelvis
Radius
Sacrum
Carpals
Coccyx
Metacarpals
Phalanges
Femur
Patella
Tibia
Fibula
Tarsals
Metatarsals
Phalanges