Module 1: Bone Biology, Skeletal Development & Anatomical Terms Flashcards
What is the structure of bone?
90% Protein (Collagen) and Mineral (hydroxyapatite)
How are bones formed?
Osteoblasts
Where are osteoblasts found?
Underneath the periosteum of bone
Periosteum
Thin membrane on the outer surface of bone
Osteoclasts
Resorb or remove bone that is unnecessary
Wolff’s Law
Bone is laid down where it is needed and resorbed where it is not
What is the first step in a forensic investigation?
Determining remains are bone vs other material
What is the second step in a forensic investigation?
Determining animal vs human bone
How do you differentiate bone from non-bone?
Gross inspection, screening with 1/4” mesh, flotation, etc.
Taphonomy
Environmental or human changes after death
Radiography
Bone is usually more radio-opaque than sticks, plastic, other materials, so x-raying remains is a good way to sift through remains
General microscopic analysis
Demonstrates texture and structure of bone that can be useful in ID
ALS (Alternative light source)
Using shortwave light to ID bone-bone fluoresces
Histological analysis
Can show microstructures which can help identify bone and tooth. Requires thin sectioning of bone.
Elemental analysis
SEM/EDS or XRF to assess calcium and phosphorus content of materials
Human bone
Textured, concentrated trabecular structures at ends of bones
Mammal bone
Smooth in appearance, slight wood grain pattern, more homogeneous trabecular distribution
Bird bone
smooth appearance, thin/less dense trabeculae
Reptile bone
Smooth appearance, little to no trabecular bone, dense cortical bone
When remains are fragmentary, what is the most helpful way to analyze materials?
Microscopic analysis
Non-human bone
Usually non-Haversian and more linear. Fibrolamellar, laminar, or plexiform bone.
How do mammal bones grow
In diameter very rapidly, as opposed to in length slowly
Plexiform bone
Brick-like appearance or linear
Haversian systems
Near muscle attachment sites in large mammals, consist of concentric rings oriented along the long axis of the bone
Fibrolamellar bone
Layered/sandwiched and consisting of alternating Haversian and lamellar banding patterns, rarely in humans