1. Skeletal System

2. The Skeletal System Parts of the skeletal system
Bones (skeleton)
Joints
Cartilages
Ligaments
Divided into two divisions
Axial skeleton- Skull and Spinal Column
Appendicular skeleton- Limbs and Girdle

3. Functions of Bones Support of the body Gives shape
Protection of soft organs
Movement due to attached skeletal muscles
Storage of minerals and fats- calcium, phosphate, magnesium ect…
hematopoesis

4. Bones of the Human Body The Skeleton has 206 bones
Two basic types of bone tissue
Compact bone
- Homogenous
Spongy bone
- Small needle-like
pieces of bone.
- Many open canals.

5. Compact Vs. Spongy Bone

6. Classification of Bones
Long bones: have longitudinal axes and expanded ends. Ex. Radius/Ulna and the Femur
Short: are somewhat cubelike, with their lengths and width roughly equal. Ex. Bones of the wrist and ankle
Flat: are platelike structures with broad surfaces, such as ribs, scapulae, and some bones of the skull.
Irregular: have a variety of shapes and are usually connected to several other bones. Ex. Vertebrae of the spinal column and many facial bones.
Sesamoid: usually small and nodular and are embedded within tendons adjacent to joints. Ex. Patella

7. Classification of Bones on the Basis of Shape

8. Gross Anatomy of a Long Bone
Diaphysis
Shaft
Epiphysis
Ends
Blood cells made here as adults

10. Structures of a Long Bone
Periosteum
Outside covering of the diaphysis
Sharpey’s fibers
Secure periosteum to underlying bone

11. Structures of a Long Bone
Articular cartilage
Covers the epiphyses
Made of hyaline cartilage
Decreases friction

12. Structures of a Long Bone
Medullary cavity
Cavity of the shaft
Contains yellow marrow (mostly fat) in adults
Contains red marrow (for blood cell formation) in infants

13. Bone Markings Sites of attachments for muscles, tendons, and ligaments
Passages for nerves and blood vessels

15. Microscopic Anatomy of Bone
Osteon: the fundamental functional unit of compact bone. Each osteon consists of concentric layers, or lamellae, of compact bone tissue that surround a central canal, the haversian canal. The boundary of an osteon is the cement line.
Central (Haversian) canal: The haversian canal contains the bone's nerve and blood supplies.
Perforating (Volkman’s) canal: Volkmann canals are any of the small channels in the bone that transmit blood vessels from the periosteum into the bone and that communicate with the Haversian canals. The perforating canals provide energy and nourishing elements for osteons.

16. Microscopic Anatomy of Bone

17. Microscopic Anatomy of Bone
Lacunae: a small space containing an osteocyte in bone or chondrocyte in cartilage. Situated between the Lamella. Lacunae are connected to one another by small canals called canaliculi.
Lamellae: a thin plate-like structure, often one amongst many lamellae very close to one another, with open space between.

18. Microscopic Anatomy of Bone
Canaliculi: canals between the lacunae of ossified bone. The radiating processes of the osteocytes (called filopodia) project into these canals.
Tiny canals

20. Changes in the Human Skeleton
In embryos, the skeleton is primarily hyaline cartilage
During development, much of this cartilage is replaced by bone
Cartilage remains in isolated areas
Bridge of the nose
Parts of ribs
Joints

22. Bone Growth
Epiphyseal plates allow for growth of long bone during childhood
New cartilage is continuously formed
Older cartilage becomes ossified
Cartilage is broken down
Bone replaces cartilage

23. Long Bone Formation and Growth

24. Long Bone Formation and Growth

25. Bone Formation Video
Bone Formation Video is embedded.

26. Types of Bone Cells Osteocytes Osteoblasts Osteoclasts
Bone-forming cells
Osteoclasts
Break down bone matrix for remodeling and release of calcium
Bone remodeling is a process by both osteoblasts and osteoclasts

27. Bone Remodeling and Modeling Video

28. Factors Affecting Bone Development, Growth, and Repair
Deficiency of Vitamin A – retards bone development
Deficiency of Vitamin C – results in fragile bones
Deficiency of Vitamin D – rickets, osteomalacia
Insufficient Growth Hormone – dwarfism
Excessive Growth Hormone – gigantism, acromegaly
Insufficient Thyroid Hormone – delays bone growth
Sex Hormones – promote bone formation; stimulate ossification of epiphyseal plates
Physical Stress – stimulates bone growth

30. Bone Fractures Types of bone fractures Closed (simple) fracture
Open (compound) fracture

31. Common Types of Fractures

33. Stages in the Healing of a Bone Fracture