1. Human Skeleton:
The human skeleton consists of over 200 bones of different sizes and shapes that play a variety of roles in maintaining our health and well-being.
Bones provide the basic structural framework for our muscles and allow us to stand upright and move about.
Bones also encase and protect sensitive organs of the body such as the brain, heart, spinal cord and eyes from injury from external forces.

3. Skeletal Problems Disease / genetics Osteoporosis (Type I)
Multiple myeloma
Metastatic bone cancer
Rheumatoid arthritis
Paget’s Disease
Hormone ablative therapy
Spinal cord or nerve injury
Surgery and rehabilitation
Aging (Type II Osteoporosis)
Bedrest
Microgravity

4. Structural Support Protection Movement Mineral Storage Calcium
Functions of Bone
Structural
Support
Protection
Movement
Mineral Storage
Calcium
Phosphate

5. Bone structure and composition

6. Types of bone Two major types of bones 1. Compact (cortical, i. e
Types of bone Two major types of bones 1. Compact (cortical, i.e., long bones) Mechanical and protective functions 2. Cancellous (spongy, i.e., vertebrae) Metabolic regulation of calcium

7. Bone composition 70% mineral (Ca2+ and PO4- as hydroxyapatitie)
22% protein (95% Type I collagen + 5% proteoglycans and other materials)
8% water
Bone is a connective tissue that consists principally of a mineralized extracellular matrix plus the specialized cells,
Osteoblasts
Osteocytes
Osteoclasts
Bone lining cells

9. Osteoblasts and osteocytes
Osteoblasts, the bone forming cells work in groups to secrete and then mineralize patches of new bone matrix.
Characteristics of Osteoblasts
Matrix formation
Secretes Type I collagen
Regulates mineralization
Positioned above osteoid matrix
Matrix usually polarized but can surround cells