Download - Bones & Skeletal Tissue
• Support
• Protection
• Movement
• Mineral storage
• Blood cell formation (hemopoiesis)
• Triglyceride storage
Distal
epiphysis
Proximal
epiphysis
diaphysis
yellow marrow
epiphyseal line
periosteum
compact bone
spongy bone
Endosteum
hyaline cartilage
Sharpey’s fibers
periosteum
Haversian system
spongybone
Lamellae
osteocyte
Lamellae
osteocytes osteocytes in lacunaein lacunae
central central canalcanal
275 bones12 weeks (6-9 inches long)
Fig. 06.13
cartilagecalcified cartilage
bone
epiphyseal plate
epiphyseal line
Endochondral Ossification
2o ossification
center
Fetus: 1st 2 months
AdultChildhood
Just before birth
1o ossification
center
Fig. 06.08
• GH from anterior pituitary, which is regulated by T3 and T4 of the thyroid
• During puberty- sex hormones: estrogen and testosterone
Hyposecretion of GH- dwarfism
Hypersecretion of GH- gigantism
Sultan Kosen (R) 8 ft 1 in
He Pingping 2 ft 5.37 in
• Parathyroid hormone- stimulates osteoclasts
• Calcitonin- inhibits osteoclasts
• Parathyroid hormone- stimulates osteoclasts
• Calcitonin- inhibits osteoclastsMaintains homeostasis
Osteoblast
Osteocyte
OsteoclastEats bone
Builds new bone
Mature bone cell
hematomacallus bony callus
bone remodeling
Usually treated by realignment
• Simple- closed fracture (8-12 wks to heal) bone breaks cleanly; no penetration
• Compound- bone penetrates through skin
• Comminuted- bone fragments into many pieces; aged or brittle bones
• Compression- bone is crushed
• Depressed- broken bone portion is depressed inward
• Impacted- broken bone ends are forced into each other
• Spiral- excessive twisting of bone
• Greenstick- bone breaks incompletely
Oblique Comminuted Spiral Compound
1. Electrical stimulation of the fracture site:• Increases speed and completeness of healing• The e- stimulation inhibits PTH and slow osteoclasts
down from reabsorbing bone2. Ultrasound treatment:• Daily treatments reduce healing time of broken bones
by 25-35%3. Free vascular fibular graft technique:• Transplant fibula in arm• Gives good blood supply not available in other
treatments4. Bone substitutes:• Crushed bone from cadaver- but risk of HIV and
hepatitis• Sea bone- coral• Artificial bone- ceramic
Osteoporosis- bone reabsorption outpaces bone deposit; bones become lighter and fracture easier
Factors: • age, gender (more in women)• estrogen and testosterone decrease• insufficient exercise (or too much)• diet poor in Ca++ and protein• abnormal vitamin D receptors• smoking
2929 4040 8484 9292
Rickets- vitamin D deficiency
Osteomalacia- soft bones, inadequate mineralization in bones, lack of vitamin D
Rheumatoid arthritis- autoimmune reaction
1. What does the secondary site of ossification produce?
2. What is an epiphyseal line?3. Provide an example of a flat bone?4. How does PTH effect bone
development?5. How many bones in the adult
skeleton?6. What does an osteoblast do and
where are they primarily found?
INQUIRY