Bone anatomy and physiology

Question 1

Identifying bone markings

Answer 1

• Bulges, depressions, and holes in bones serve as
- Sites of attachment for muscles, ligaments, and tendons
• Sites of muscle and ligament attachment
- Tuberosity = rounded projection
- Crest = narrow, prominent projection ridge
- Trochanter = large, blunt, irregular surface
- Tubercle = small, rounded projection
- Epicondyle = raised are above condyle
- Process = any bony prominence
• Depressions and openings
- Fissure = narrow opening
- Foramen = Round or oval openings through a bone
- Fossa = Shallow, basin-like depression

Question 2

What are the 5 bone shapes? functions and examples

Answer 2

1. long bones - bones of the limb eg. Femur, humerus, tibia
2. Irregular Bones - e.g: Vertebrae and facial bones
3. Flat bones: Protective bone
   e. g: Cranium, pelvis, shoulder blade, sternum
4. Short Bones - e.g: wrist, ankle bones
5. sesamoid bones - e.g: patella (knee cap)

Question 3

What are the 5 functions of Bone tissue?

Answer 3

1. Support – Skeleton is the structural framework for the body
2. Protection – The skeleton protects many internal organs
3. Movement – Together bones and muscles produce movement
4. Storage – Bone tissue stores minerals (Ca2+, phosphate) and fat
5. Blood cell production – Within certain bones

Question 4

What are the two macroscopic (visible) types of bone tissue

Answer 4

compact bone - hard, dense

spongy bone - sponge like framework to resist stress and strain

Question 5

what makes up the Compact Bone

Answer 5

compact bone - Haversian system = osteons is the structural unit, Lamellae = weight bearing bone matrix,
perforating volkmann’s canals, Lacunae= small cavities that contain osteocytes, • Canaliculi – Hair-like canals that connect lacunae to each other and the Haversian canal

Question 6

Spongy Bone

Answer 6

consists of trabeculae and does not contain osteons,
Irregularly arranged lamellae, osteocytes and canaliculi,
Red bone marrow often fills the spaces between the trabeculae

Question 7

Whats the difference between spongy bone and compact bone

Answer 7

compact bone consists of osteons, lamellae and canaliculi all structured whereas spongy bone consists of trabeculae and irregularly arranged lamellae canaliculi

Question 8

Microscopic anatomy of bone cells- what are the 4 cell types and what do they do?

Answer 8

Osteogenic (osteoprogenitor) cells - juvenile cells, stem cells in periostium and endosteum
Osteoblasts - Bone-forming cells
Osteocytes - Mature bone cells
Osterclasts - cells that break down (resorb) bone matrix

Question 9

what are the two different types of formation of bone?

Answer 9

Instramembranous ossification - bones which form directly with ossification, flat bones of the skull and mandible

Endochondral ossification - bone forms within hyaline cartilage that develops from mesenchyme

Question 10

how does a bone grow?

Answer 10

endochondral ossification Pre-existing hyaline cartilage is gradually destroyed and replaced by bone

Question 11

What is osteoporosis? what happens to the bone

Answer 11

disease - loss of bone mass and increased porosity of the bone

osteoblast activity (bone forming cells) < Osteocalst activity (cells that resorb bone matrix)

Question 12

What are some causes of osteoporosis?

Answer 12

Post menopausal, age, reduced physical activity, endocrine disorders, genetics, nutritional state, medications (steroids)

Question 13

what are some treatments/ preventions of osteoporosis

Answer 13

• Calcium, vitamin D, and fluoride supplements
• increase Weight-bearing exercise throughout life
• Hormone (estrogen) replacement therapy slows bone loss
• Some drugs increase bone mineral density