1. Chapter 7
Skeletal system

6. Skeletal system is made up of-
206 bones in the adult skeleton
Composed of cartilage and bone
Includes the joint, cartilage and ligament systems
Is the internal frame work of the body that allows for motion and protection
Always changing due to stress and blood calcium levels
Very active and alive tissue

8. Bone function: Support Protection Movement Storage-minerals and fat
Blood cell formation-within bone marrow

9. Bone types: compact-dense and smooth
Spongy-open and rough with many holes

10. osteoblasts
1. functions in bone deposition by secreting collagen,
2. cannot undergo mitosis
osteocytes mature bone cells derived from osteoblasts;
2. principle bone cell,
3. cannot undergo mitosis,
4. maintain daily cellular activities (i.e. exchange of nutrients & wastes with blood)
osteoclasts
1. functions in bone resorption (i.e. destruction of bone matrix),
2. important in development, growth, maintenance & repair of bone

12. Bone classification:
Long bones-long and thin with mostly compact bone-femur
Short bones-cube shaped and mostly spongy bone-wrist and ankle
Flat bones-thin, flattened and curved-spongy bone sandwiched between two layers of compact bone-skull and ribs
Irregular bones-do not fit into any of the above categories-vertibra

13. Bone markings:
The ridges, holes and bumps on the bone-where tendons, muscles and ligaments attach along with where nerves and blood vessels pass through the bone

14. Two major types of bone markings:
Projections or processes-growth is outward-words that start with a “T”
Depressions or cavities-grooves or indentations-words with a “F” except for facets

15. Site of muscle attachment-projections:
Tuberosity-large rounded projection
Trochanter-very large, blunt irregular shaped projection-found on femur only
Tubercle-small rounded projection
Epicondyle-raised area above a condyle
Crest-ridge of bone, very prominent
Line-ridge of bone, less prominent
Spine-sharp, slender, pointed projection

17. Joint projections: Condyle-rounded articular projection
Ramus-armlike bar of bone
Head-bone expansion with narrow neck
Facet-smooth, flat-like surface

18. Bone depressions: Fissure-narrow, slit-like opening
Foramen-round or oval opening in bone
Groove-furrow
Fossa-shallow, basin like depression-on atricular surface
Meatus-canal-like passage
Sinus-cavity within a bone, filled with air and lined with mucous membrane