Analyzing bones is important to identify a victim or suspect.

You can find: IdentityGenderAgeHeightRaceBackground

Forensic Anthropology

HOW?

Characteristics of Bone 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 marrow4. 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make measurements from a microscope using an “ocular Micrometer” (the eyepiece lens in the microscopes in the back have been replaced by this “ocular micrometer lens).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 Measurement from slide1.0 mm = 5 micrometers

Use a consistent magnification….use 100XYou 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?

OsteobiographyA story of a life told by the bones

Examples: GenderAgeHeightRaceright or left handeddiet and nutrition (esp. lack of vitamin D and

calcium)diseases and genetic disorders (arthritis,

osteoporosis, scoliosis)previous injuriessurgical implantschildbirth

b. Skull differences

C. What bones can tell us 1. Gender

a. Overall appearanceFemale–“gracile”– smootherMale – “robust” – thicker, rougher and more bumpy

c. pelvis differencesYou would compare the following:

subpubic anglelength, width, shape, angle of sacrumwidth of the ileumangle of the sciatic notch

*surface has scars if female has borne children

Male Female

Subpubic Angle

Shape of Pubis

Shape of Pelvic cavity

Sacrum

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 socketsabsence or presence of a nasal spinemeasurements 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 jawwidth of the faceAngle of the jaw and face

Caucasoid Negroid Mongoloid

Shape of EyeOrbits

Nasal Spine

Nasal Index

Prognathism

Femur