Analyzing bones is important to identify a victim or suspect.
You can find:
Identity
Gender
Age
Height
Race
Background
A. Bones are alive
1. they grow and can
repair themselves
2. they are made of cells
that go through
cellular respiration.
3. blood cells are made in
the bone marrow
4. bones are regulated by
hormones
B. The cells of bone…four to consider
1. Osteoprogenitor cells
a. Stem cells of bone
b. divide and make more of these cells
c. they are the least differentiated…they have the potential to be any kind
of cell.
2. Osteoblasts
a. bone forming cells…make bone by producing extracellular matrix
(secreting minerals) around themselves.
3. Osteocytes
a. these are osteoblasts that cannot make any more matrix so they
differentiate into a cell that can maintain it
4. Osteoclast
a. break down bone matrix to repair it, or release the minerals we store in
the bone if they are needed in the body
C. You can determine the age of a bone as well as what the bone
came from by analyzing the Haversian systems (aka…Osteon) in
bone.
1. Functional unit of compact bone (hard bone)
2. Osteocytes are arranged in concentric layers around a central
canal that contains one or more blood vessels.
3. In animals, osteons are arranged in a pattern. In humans, they
are more chaotically arranged.
This Old Bone Lab Introduction:
Can make measurements from a microscope using an “ocular Micrometer” (the
eyepiece lens in the microscopes in the back have been replaced by this “ocular
micrometer lens). What you will see:
Measurement from microscope
1.0 mm = 5 micrometers
Measurement from
slide
Use a consistent magnification….use 100X
You will analyze bone fragments to determine the age
The younger you are, the larger the Haversian system.
With age, the Haversian systems and canals get smaller.
Calculate the average number of concentric lamellae in a given bone
sample to determine the age of the person at death.
This Old Bone Lab Introduction:
How many Osteons (Haversian systems) are shown
here?
You will be measuring the Haversian CANAL. From this
picture, what will you measure?
A story of a life told by the bones
Examples:
Gender
Age
Height
Race
right or left handed
diet and nutrition (esp. lack of vitamin D and
calcium)
diseases and genetic disorders (arthritis,
osteoporosis, scoliosis)
previous injuries
surgical implants
childbirth
C. What bones can tell us
1. Gender
a. Overall appearance
Female–“gracile”– smoother
Male – “robust” – thicker, rougher and more bumpy
b. Skull differences
c. pelvis differences
You would compare the following:
subpubic angle
length, width, shape, angle of sacrum
width of the ileum
angle of the sciatic notch
*surface has scars if female has borne children
Male
Subpubic
Angle
Shape of
Pubis
Shape of
Pelvic cavity
Sacrum
Female
d. Thigh bones (femur)
• angle of the femur with respect to the pelvis is
greater in females and straighter in males.
• the femur is thicker in males than females
2. Age
a. analysis of Haversian system (Osteon)
b. Suture marks – where bones fuse (skull)
-- disappear as bones mature (smoother look)
c. Cartilaginous lines – where cartilage is replaced by bone as
a human grows. The line is called an epiphysis. When the
replacement is complete, a line is no longer present. Age for
completion for each bone varies.
d. Long bones – femur (thigh) and humerus (upper arm)
-- when the long part of the bone has
completely fused to the rounded end part.
Epiphyseal
Plate
3. Height
a. measure femur and/or humerus
b. refer to databases (separate tables for males/females and
different races)
4. Race
a. difficult (intermarriages)
b. skull
shape of eye sockets
absence or presence of a nasal spine
measurements of the nasal index (ratio of the width of
the nasal opening to the height of the opening,
times 100)
projection of the upper jaw (maxilla) beyond the lower
jaw
width of the face
Angle of the jaw and face
Caucasoid
Shape of Eye
Orbits
Nasal Spine
Nasal Index
Prognathism
Femur
Negroid
Mongoloid