Chapter 6

Question 1

functions of skeletal system

Answer 1

Support or framework
Protection
Movement (anchorage)
Mineral storage
Blood formation
Red marrow
Triglyceride Storage
Hormone Production
Osteocalcin

Question 2

Types of bones:

Answer 2

SHORT BONES:

ie) carpals
- cube shaped

FLAT BONES:

ie) scapula
- protects organs and provides surfaces for muscle and ligament attachments.

IRREGULAR BONES:

ie) Vertebrae
- Different shapes to fulfill special functions in the human body

LONG BONES:

ie) Femur
- Form the framework of the appendicular skeleton

Question 3

Axial and appendicular skeleton:

Answer 3

Axial skeleton: The skull, vertebrae, sternum, and ribs

Appendicular skeleton: bones composing the body appendages

Question 4

Bone is 2/3 inorganic (minerals) and 1/3 organic (cells + osteoid)

Answer 4

:) Organic:
CELLS:
- Osteoblasts, osteocytes, osteoclasts, osteogenic, bone lining cells

OSTEOID:

• Synthesized by osteoblasts
• Proteoglycans/glycoproteins
• Collagen fibers (for tensile strength)

Inorganic:
Minerals:
- 65% by mass
- Mineral salts: hydroxyapatites (crystals) of calcium & phosphate
- Surround collagen fibers
- Hardness
- Resists compression

Question 5

Types of bone cells

Answer 5

Osteoblasts: bone forming cells, synthesize matrix

Osteocytes: maintain matrix, had been osteoblasts

Osteoclasts: degrade matrix (bone resorption)

Osteogenic cells: mitotically active stem cells; when stimulated can become osteoblasts or bone lining cells

Bone lining cells: on surface where no remodeling is occurring

Question 6

What is Osteon:

Answer 6

• Weight-bearing pillars
• Collagen runs in different directions in matrix of different lamellae
• Resist tension and twisting
• Collagen gives bone its flexibility
• Haversion canal or central canal

Question 7

Spongy Bone;

Answer 7

• Trabeculae have no osteons
• Have irregular lamellae
• Organized along stress lines

Question 8

Parts of bones:

Answer 8

DIAPHYSIS - LONG AXIS OF BONE

• Collar of compact bone surrounding central medullary cavity
• Thin layer of spongy bone found between marrow and compact bone

EPIPHYSES - BONE ENDS

• Compact bone forms exterior, interior is spongy bone
• Covered by thin layer of articular cartilage on joint surface
• Epiphyseal line is remnant of epiphyseal plate (growth plate)

Question 9

Bone membranes:

Answer 9

PERIOSTEUM:

• On outside, 2 parts:
• Outer fibrous layer: dense irregular CT
• Inner layer: delicate CT, osteoblasts & osteoclasts

ENDOSTEUM:

• Delicate CT
• Lines inside surfaces
• Osteoblasts & osteoclasts