Chapter 14 - Forensic Anthropology

More applications of forensic anatomy

forensic experts may be called upon to give more info about life and death of humans and animals in unique circumstances mass murder earlier man historical significance prehistoric animals

Why are teeth used for body identification?

hardest substances in the body (do not readily compose) unique to the individual X-rays are a good record of the persons teeth

What is osteoarthritic lipping

limits range of motion, tell how old

Rough estimate of body decomposition equation

1285 -------------------- average temp (c)

How many bones does a human have

206

Glastier Equation

98.4-measured rectal temperature/1.5 = approximate hours since death within the first 36 hours but most accurate within first 12

Algor Mortis

cooling rate of the body after death starts at 37 C and 98 F cools to reach equilibrium within the ambient temperature rate depends on many factors: victim's health and weight at time of death, degree of bacterial activity

Cold, stiff

dead 8-36 hours

Warm, stiff

dead between 3-8 hours

cold, not stiff

dead more than 36 hours

What makes up most of the bones length

diaphysis or shaft

Where are epiphyses found

ends of bones

Steps in facial reconstruction

establish age, sex, race plot landmarks for tissue thickness plot origin and insertion points for muscles plot landmars for facial features select a dataset and mount markers for tissue thickness mount the eyes model muscles on the skull add fatty tissue around the eyes and lacrimal glands add eyelids add the nose add the parotid gland cover all with layers of skin detail the face

Non union without separate epiphysis

male: 21 or younger female: 20 or younger

Time since death pt 4

mummification due to hydration --most common in dry, hot conditions and corpses with low body fat rate of decomposition depends on: temperature, scavengers, etc --body underwater decays 2x faster than a body underground

Stage 1: _____________ (the growth plate has not formed yet) baby

no epiphysis

Stage 2: __________ the epiphysis and bone are separate, toddler

non-union

Warm, not stiff

not dead more than 3 hours

Stage 3: ____________ the epiphysis is attached ,but a line is visible, late teens

partial union

What bone offers the most definitive traits to determine gender

pelvis comparison of three characteristics of the os pubis gives the information used to identify sex

Liver Mortis

pooling of the blood due to gravity after the heart stops purplish-red discoloration can help determine the position of the body at the time of death discoloration will not occur in places in contact with the ground or where capillaries are compressed most evident in first 12 hours dark purple = openings and no contact with object

what is most important when making a face

proportion

Estimating time since death

within 4 hours of death, decomposition occurs cells are deprived of oxygen, and carbon dioxide in the blood increases, pH decreases and wastes accumulate toxic enzymes dissolve cells - autolysis ---noticeable as fluid filled blisters on the skin and skin slippage

Time since death pt 3

Adipocere: forms months to years after death, gray wax formed from the saponification of fatty acids: break down formed most often in most burial sites, on people with excess body fat, on a body within a burial vault yellowish white color

Negroid

African, Aborigine, and Melanesian descent wide nasal aperture, rectangular palate, square orbits, more pronounced zygomatic arches long bones are longer, and have less curvature and greater density

Mongoloid

Asian, Native American, and Polynesian descent more rounded nasal aperture, parabolic palate, rounded orbits, wide zygomatic arches, more pointed mandibles

How can height be determined

Can be calculated by measure the length of certain long bones including the femur, tibia, humerus, and radius

Facial recognition materials

Erasers: make tissue depths at various points on a skull Clay: build around these markers and facial features are molded use about 21 markers

Caucasoid

European, Middle Eastern, and Indian descent long, narrow nasal aperture, triangular palate, oval orbits, narrow zygomatic arches, and narrow mandibles

Gender Identification

Female has a wider pubic body than the male The female has a wider subpubic concavity or subpubic angle most females hae a ventral arc present

How can osteon arrangement impact human vs non human animal

Human: no order to osteons NHA: osteon arrangement orderly

Cranial Sutures: Sagittal suture completely closed

Male - 26 or older Female - 29 or older

Cranial sutures: Sagittal suture completely open

Male - less than 32 Female - less than 35

Cranial sutures: Complete closure of all three major sutures

Male - over 35 Female - over 50

Non union with separate epiphysis

Male: 16-21 Female: 17-20

Partial union

Male: 17-30 Female: 17-33

Complete Union

Male: 21 or older female: 20 or older

What is the order of specialists?

Pathologist: determine cause, manner, mechanism, soft tissue Entomologist: determine how long body has been dead based on bugs Anthropology: boil body and get skeleton --exumed remains or bodies that have been out for a while

Body Farm

a research facility where human decomposition can be studied in a variety of settings Developed in 1980 observe and understand processes and timetable of postmortem decay has helped to improve the ability to determine "time since death"

What can be determined from a whole bone or a part of a bone

age range: 5-10 years sex - determined from pelvis, skull, tibia race - femur, skull approximate height cause of death, disease or anomaly (out of norm, six fingers, previous broken bone)

what is the function of the epiphyses

allow for growth good to look for changes in estimating age

Algor Mortis things to consider

ambient temperature type of clothing worn by victim: lots of clothing slow rate wetness of the clothing: increase temp layers of clothing amount of surface area to mass --- greater = faster cooling -----small children cool faster than large adults

Stage 4: ____________, the epiphysis is attached and a line is not visible, late 40s, faint

complete union

What are the functions of bones

provide structure and rigidity protect soft tissue and organs serve as an attachment for muscles produce blood cells: medullary capillary - red blood marrow make red blood cells serve as a storage area for minerals: calcium can detoxify the body by removing heavy metals and other foreign elements from the blood

Time since death continued

putrefaction: next step, body looks green includes destruction of soft tissue (mainly by bacterial activity) first evidenced by greenish cast to skin color: dead red blood cells bloating: caused by gases produced by bacteria ---black putrefaction

What does a forensic anthropologist provide information on

skeletonize or badly remains

What is forensic anthropology?

specializes in the changes and variations in the human skeleton for the purpose of legal inquiry

Male Skull

square mandible strong mastoid process (eyebrows) external occipital notch (back of head) wide ascendigranus heavy brow ridge

Rigor Mortis

stiffness, rigidity of the skeletal muscles after death begins in the smaller muscles first: face down to toes can occur within the first few (4) hours and is totally gone by approximately 30 hours rigor disappears in the same order that it began affected by: ambient temperature, dehydration, muscle condition prior to death, etc

What is a osteon

structural unit of compact bone

Osteology

study of bones

Odontology

study of teeth identity can be determined by comparing a persons teeth to dental records unusual features include the number and types of teeth and fillings, the spacing of teeth, and special dental work

How is age determined from bones

teeth epiphyses or growth plates pubic symphysis cranial sutures: the three major cranial sutures appear as distinct lines in youth and gradually close from the inside out - most reliable investigators always use an age range

Gender differences

the rib cage and shoulders of males are generally wider and larger in males, the index finger is sometimes shorter than the third finger in females, the index finger is sometimes longer than the third finger

Determining Time since death

usually determined by a pathologist best if determined within the first 24 hours ---can use algor, liver, and/or rigor mortis after 24 hours need to use other methods --environmental conditions, state of dress, coverage (trees, cars, etc) --animal activity