bones & skeletal tissue
Post on 23-Feb-2016
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• Support• Protection• Movement• Mineral storage• Blood cell formation
(hemopoiesis)• Triglyceride storage
Distalepiphysis
Proximal epiphysis
diaphysis
yellow marrow
epiphyseal line
periosteum
compact bone
spongy bone
Endosteum
hyaline cartilage
Sharpey’s fibers
spongybone
central canal
compact bone
Haversian system
osteocyte
periosteum
osteocytes osteocytes in lacunaein lacunae
central central canalcanal
canaliculi canaliculi in matrixin matrix
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
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- dwarfismHypersecretion of GH- gigantism
• Parathyroid hormoneParathyroid hormone- stimulates - stimulates osteoclastsosteoclasts
• CalcitoninCalcitonin- inhibits osteoclasts- inhibits osteoclasts
Maintains homeostasis
Osteoblast
Osteocyte
OsteoclastEats bone
Builds new bone
Mature bone cell
hematoma callus bony callusbone 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
29 40 84 92
• Rickets- vitamin D deficiency
• Osteomalacia- soft bones, inadequate mineralization in bones, lack of vitamin D
• Pagets Disease- spotty weakening in the bones, excessive and abnormal bone remodeling
• Rheumatoid arthritis- autoimmune reaction
INQUIRY
http://www.youtube.com/watch?v=DSHoonPWwXQ
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?
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