Bone development and maturation
Immature bone that is formed during fetal development and bone healing is called what?
Woven bone
What cells are involved in degrading bone tissue?
Osteoclasts
Secrete collagenase and hydrogen ions
Are physicians mandated reporters of child abuse in the state of Florida?
yes
What are the 3 main amino acids in collagen?
Glycine
Lysine
Proline
Mature bone formed by remodeling of woven bone is called what?
Lamellar Bone
What cells are involved in building bone tissue and what do they secrete?
Osteoblasts
Secrete type 1 collagen
What are patterns suspicious for non accidental injuries in children?
Evenly distributed
Multiple injuries of different ages and localizations
Describe where each type of collagen (I-V) is most commonly found in the body
Type I - bone, skin, tendons, ligaments
Type II - Cartilage, nucleus pulposus
Type III - blood vessels
Type IV - basement membranes
Type V - Bone, skin, fetal tissue, placenta
What type of ossification is defined by bone being indirectly formed from mesenchymal cells via the cartilaginous model in the diaphysis of bone?
Endochondral ossification
Osteoblast activity is assessed by an increase in what?
Bone alkaline phosphatase
osteocalcin
type 1 pro collagen propeptides
What are unsuspicious locations of injuries that wouldn't suggest child abuse?
Front of the extremities
Knees, elbows, hands
During hydroxylation of proline to hydroxyproline, what vitamin is necessary for proper enzymatic function?
Vitamin C
Laboratory quantification of collagen is performed via measurement of hydroxyproline
Explain the steps of membranous ossification
Bone matrix formed directly and not from cartilage
Osteoblasts lay down woven bone that is later remodeled to lamellar bone
This is how most flat bones are formed (skull, facial bones)
What are the 3 main proteins involved in regulation of bone remodeling?
RANKL
Osteoprotegerin (OPG)
M-CSF
What are ways that you can manage child abuse or neglect?
Always notify CPS
Interview child and parent/caregiver separately if possible
Keep verbatim record
A requirement for fibril formation includes the formation of a triple helix. What bonds are created between 3 alpha chains to form the triple helix?
Disulfide bonds
Hydrogen bonds
Explain the main steps of endochondral ossification
hyaline cartilage secreted by chondroblasts and chondrocytes to from a mold (anlagen)
As mold grows chondrocytes die
Osteoblasts are delivered from blood and turn cartilage mold into bone
What two hormones are involved in regulation of bone remodeling?
PTH
Estrogen
What are suspicious locations of injuries that may suggest physical abuse of a child?
Buttocks
Posterior side of extremities
Back (posterior rib fractures)
Upper arms
Multiple complicated skull fractures
A key step in collagen synthesis is cross linking of lysine-hydroxylysine residues. What enzyme is involved in this process and what is it dependent on?
Copper dependent lysyl oxidase