ANTH 2014 Exam 1

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ANTH 2014 Exam 1
2012-02-14 23:55:29
forensic anth

Forensic Anthropology Exam 1
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  1. Factors that play a role in postmortem decomposition
    • Temperature
    • Clothing (cotten/linen vs. polyester)
    • Insect Activity
    • Trauma
    • Surface/Burial/Water
    • Predators
  2. Cooling of the body
    • Deep organs cool slower
    • Gross errors can occur (especially in countries like Saudi Arabi where ambient temperature exceeds 40C; body may "warm up")
    • On average, exposed skin feels warm to touch 6-8 hrs
    • For forensic anthropologists, no thermometer is going to help
  3. postmortem hypostasis
    • Lividity (settling of RBCs with discoloration)
    • Often called livor mortis
    • Supine position - seen on back, buttocks, thighs, and calves
    • Pressure from clothiing (like a strap) or lying on hard surface
    • Areas are pale - NOT trauma
  4. taphonomy
    • transition of a body from the time of death through decomposition, destruction, transport, or burial to fossilization
    • Fossilization is the exception, not the rule
  5. 5 Stages of Decay
    • Fresh: starts at death; ends with beginning of bloat
    • Putrefaction/Bloat
    • Decay
    • Dry: tough fibrous materials survive up to 6 mos (tendons, ligaments, uterus & prostate)
    • Skeletal
  6. PMI
    • Postmortem Interval
    • Time since death
    • Different "causes" of death but death occurs after irreversible cardiac arrest
  7. irreversible cardiac arrest
    • cardiorespiratory function fails
    • collapse of blood pressure
    • supply of oxygenated blood to brain gone
    • loss of cerebral function
  8. Forces that promote decay: insect activity
    • Flies don't lay eggs in rain
    • Generally insects (typically secondary screw worms) lay eggs within minutes (at temperatures above 50F)
    • Eggs hatch within 8-18hrs (from time insects have access to the remains)
  9. Decay in Louisiana
    • Within 24 hrs, a body can be swollen beyond recognition
    • Within 2 weeks (in extreme cases), body skeletalized
    • Within 6-8 mos (rule of thumb), tendon and ligamentous attachments still in place
    • By one year after death, typically clean bone
  10. Mummification
    • Occurs occasionally
    • Dessication - drying out of skin and organs or just outer skin
    • Desert-like conditions (Egypt, S. America - Andes)
    • More often seen in newborn infants (virtually "sterile" emerging from uterus and may "dry up" before bacterial action occurs)
    • Cool dry conditions (hay lofts, barns) - partial mummification
  11. Insects of Special Interest
    • Non-native to LA
    • Hairy Maggot Blowfly: cannibalistic; will eat other insect larva
    • Fire Ants: eat larva and eggs
  12. Cadaver dogs
    • Potential use
    • Must be careful
    • Worst part: trainers/owners
  13. Putrefaction/Bloat
    • Usual course of decomposition
    • Moist degeneration leading to liquefaction of soft tissues
    • In temperate climates, usually seen on 3rd or 4th day
    • In tropics, subtropics (LA), or summer in temperate climates, may start within hours after death
  14. Putrefaction/ Bloat breakdown
    • abdominal wall where gut bacteria proliferate and decompose hemoglobin into green compounds - stains skin
    • gas forms
    • body swells
    • progressive bloating of face, abdomen, breasts, and genitals
    • superficial veins become outlined in red or green (marbled appearance)
    • skin blisters as epidermis peels off
    • tongue & eyes protrude due to internal gas pressure
    • bloody fluid squeezed up from decomposing lungs
    • air passages leak or "purge" out of mouth & nostrils
  15. Insect Life Cycle
    • Adult
    • Eggs
    • Larva (maggots) - go through instar (stages of growth)
    • Pupa
  16. rigor mortis
    • most dead bodies become stiff
    • occurs at variable times after death
    • rigor passes, body becomes limp again
    • only practical use - to estimate time of death
    • absent or hardly detectable in infants & the old and feeble
  17. Why does rigor mortis appear more quickly in persons who die during or soon after physical exertion or exhaustion?
    • Glycogen (energy source) is depleted at this time
    • speeds up the physiochemical process of rigor
  18. How to find a buried body
    • Informant/Accident
    • Probing: use of metal rod to determine outline/area of burial pit
    • Depression: evidence that soil has been overturned
    • Vegetation: organic matter from decomposition provides nutrients for vegetation ("grass is greener over the septic tank")
  19. Field Recovery: Unit Set-up
    • 10' square: use feet/inches when working with law enforcement; other scenaries use metric
    • Back Hoe: depth of burial may indicate premeditation
    • Shovel Skimming
  20. adipocere
    • hydrolysis of adipose tissue
    • decomposition of fatty tissue
    • "grave wax"
  21. True or False: All bone is ivory colored
    • Bone is porous and will take on the color of the environment around it after it has been there for a while (i.e. red Native American bones)
    • All bone is ORIGINALLY ivory colored
  22. general rule of body dumping
    As a general rule, killers do not take bodies further than 1/4 mile from the nearest road access by vehicle
  23. Field Recovery: Equipment Needed
    • Portable Field Kit
    • Metal Detector
    • Shovels
    • GPS
    • Camera
  24. Field Kit Materials
    • Multiple tape measures (10m and 100m)
    • Wooden stakes, string
    • Line level, plumb bob
    • Flags
    • Trowels
    • Perino picks - piece of cane stripped and rounded off (soft touch; will not damage bone)
    • Brushes
    • Dust pans, whisk brooms
    • Bags - paper, plastic (assorted sizes)
    • Body bag
    • Pencils and Sharpies
    • Graph paper
    • Eye protection, Gloves, Insect Repellent
  25. Partially Decomposed Remains
    • Munsell chart - soil chart
    • Generally can find original position of body because of a stain left by body decomposition
  26. Scene Presevation
    • Use caution tape
    • Make a standard path and stick to it
  27. Plan view
    map as though you were looking at the scene from above
  28. Field Recovery Map
    • North arrow
    • Anchor the map (link to a datum point)
    • Scale
  29. Post-Cranial Skeletal Positional Terms
    • Proximal: the part of the bone closest to the skull
    • Distal: the part of the bone furthest from the skull
    • Medial: part of bone closest to the midline of the body
    • Lateral: part of bone furthest from the midline of the body
  30. Cortical Bone
    dense, outer layer of bone
  31. Trabecular (Spongy) Bone
    • Made of same material as cortical, but loosely packaged/organized
    • Seen especially on the ends of long bones
  32. Periosteum
    • thin organic sheath covering all bone (especially long bone) but sub-chondral
    • Osteogenic: bone cell forming
  33. Chondral
    all bone with periosteum
  34. Subchondral
    • bone at joints (knee, shoulder, hip, etc.) nourished by synovial fluid
    • Cartilagenous joints to NOT have periosteum
  35. Synovial fluid
    • Lubricant which helps to cushion (along with cartilage) and absorb pressures placed on knee, shoulder, hip, etc.
    • Helps to nourish non-vascular cartilage
  36. Foramen magnum
    hole where spinal cord enters brain
  37. Layers of teeth
    • Enamel
    • Dentin
    • Pulp - organic material (nerve endings) and DNA
  38. Baby Dental Formula
    • 2102/2102
    • 2 incisors, 1 canine/cuspid, 1 premolars, 2 baby molars
    • 20 teeth
  39. Adult Dental Formula
    • 2123/2123
    • 2 incisors, 1 canine/cuspid, 2 premolars/bicuspids, 3 molars
    • 32 teeth
  40. Central & lateral incisors function
    grabbing and holding
  41. Canines function
    nipping & holding
  42. Premolars function
    grinding & chewing
  43. Molars function
    grinding and chewing
  44. deciduous teeth
    • Baby teeth
    • 20
    • Born with tooth buds
  45. Types of Sutures
    • Coronal suture: separates the front of the skull from the back ("crown")
    • Sagittal suture: separates the skull from left to right
    • Lambdoidal suture: runs along the back of the skull
    • Squamosal suture: NOT interlocking; two bones rest against one another; temporal bone & parietal bone (like a bevel mirror); WEAK
    • Basilar suture: completely fuses around the age of 18
  46. Cranial deformation
    • Skulls of children are more malleable than those of adults
    • Deforming the shape of a skull
    • Reflects social status
  47. 4 factors that lead to variation in human skeleton
    • Ontogeny: growth
    • Sexual dimorphism: differences in the sizes between the sexes
    • Geographic location: where the person grew up
    • Normal variation between or among individuals
  48. Hydroxyapatite
    • Mineral in bone
    • Gives bone its toughness
    • Makes the bone dynamic
    • If you put bone in a certain type of acid, it dissovles the hydroxyapatite, makes the bone rubbery
    • If you heat bone and dry it out, it becomes brittle (bone has been used as fuel)
  49. Collagen
    • 90% of bone
    • Organic matter
    • Interwoven with many minerals to make it strong
    • Bones must deal with compression, tension, torsion
    • Bones are flexible in some ways to a certain point
  50. What is bone made of?
    • Both minerals and organic matter
    • 90% organic matter is a protein called collagen
    • Minerals - hydroxyapatite
  51. Osteoblasts
    • Form bone matrix
    • Blast - build
    • Constantly at work
  52. Osteocytes
    • Maintain bone tissue
    • Participate in mineralization
  53. Osteoclasts
    • Destroy bone tissue and calcified cartilage through resorption
    • Clastic activity is destructive activity
    • Histologically, osteoclasts are always associated with bone resorption at an existing bone surface
    • In a single day, an osteoclast can destroy what it took 100 osteoblasts to form in the same peroid
    • Most diseases result in osteoclastic activity (venereal syphilis starts in long bone, affects skull)
  54. What is responsible for the gross appearance of bone?
    Osteoclasts and osteoblasts
  55. 3 Types of Embryonic Tissue
    • Ectoderm: forms tooth enamel
    • Mesoderm: forms dentin, bone, cartilage
    • Endoderm: forms body organs, etc.
  56. Wolff's Law of Bone Transformation
    • Bone will restructure itself in order to optimally resist stress
    • Established by Dr. Wolff in 1862
    • Hormonal activity will instruct to build or destroy bones as necessary
  57. Death Investigation
    • Determines cause and manner of death
    • Cause: massive hemorrhage; car crush; blunt force trauma
    • Manner: accident, suicide, homicide, natural causes, unknown
  58. Forensic Anthropologists
    • Main job - indentification of individual
    • Secondary job - what happened to individual

    No putative ID - estimate PMI (postmortem interval), perform facial reconstruction, enter into databases
  59. Antemortem injury
    • before death
    • Ex - broken bones, prosthetics, etc.
  60. Perimortem trauma
    at or around the time of death
  61. Postmortem trauma
    • after death
    • Ex - animal marks, etc.
  62. Questions You Have to Ask
    • 1. Is it bone?
    • 2. If it is bone, is it human?
  63. What is the closest thing you will ever see to a human hand?
    Forepaw of a bear
  64. LA Coroner System
    • Not a medical examiner system
    • Elected position
    • Main job - mental health & unattended deaths
    • Typically medical doctors; only a few are pathologists
    • May not perform autopsies - hire forensic pathologists
    • If a medical doctor does not run, any citizen can
  65. Chief Medical Examiner
    • Typically a board-certified forensic pathologist (medical school plus advanced training)
    • May have pathologists working for him/her
  66. Pathologists
    • Perform autopsies
    • Can determine if death is from accident, suicide, homicide, natural causes, or is unknown (indeterminate)
  67. Attended death
    • Under care of physician
    • Extended illness
  68. Unattended death
    • Unexpected
    • Perhaps result of trauma
    • No physician present to render opinion
    • Accidents, homicides, sudden illness
  69. Skull Layers
    • Like a sandwich - outer layer, middle layer, inner layer
    • Called tables
    • Diploe: middle layer; spongy bone in between outer and inner layers
  70. Positions of the Skull
    • Superior: top
    • Anterior/Ventral: front
    • Posterior/Dorsal: back
    • Inferior: bottom
    • Lateral: side
  71. Fontanelles
    • Wide open
    • Malleable plates to allow for brain growth
    • Bregmatic
    • "Soft spot"
    • Last fontanelle closes between 20-24 mos
  72. Sutures
    • Skull joints
    • Most are interlocking (except squamousal - bevel)
    • Fuse at different times in our lives
    • Wide open at birth
    • Typically all closed by 35 yrs
    • Misleading in terms of determining age
  73. Extra bones
    Wormian (Native American)
  74. How many bones are in the human skull?
    27 if you count the hyoid
  75. Shrunken skulls
    • You cannot shrink a skull... but you can shrink a head
    • No skull... soft tissue has been shrunken
    • Jivaro skull
    • War trophy
  76. Skull
    cranium + lower jaw
  77. Cranium
    • Everything on the skull except mandible
    • Face, top (calotte), back, posterior, inferior portion
  78. Occipital condyles
    points of articulation with post-cranial skeleton
  79. Post-cranial skeleton
    Any bone inferior to the skull
  80. How many vertebra are in the vertebral column?
    • 24 vertebra
    • 7 cervical vertebra (lack foramen)
    • 12 thoracic vertebra (articulate with ribs)
    • 5 lumbar vertebra
  81. How many bones in the human hand?
  82. How many bones in the human foot?
  83. Insect Activity as a Force that Promotes Decay
    • Flies don't lay eggs in the rain
    • Generally insects (typically secondary screw worms) lay eggs within minutes at temperatures above 50F
    • Insects will not lay eggs at colder temperatures
    • Eggs hatch within 8-18 hrs of insect access to the remains
  84. Air Decomposition vs. Water Decomposition
    • Generally speaking, bodies decompose in air twice as fast as in water.
  85. Death Time Clock - Gloving
    • Epidermis sloughs/peels off
    • Fingerprints on outer skin
  86. Factors that play a role in postmortem decomposition in water
    • Environment: temperature, depth, current, marine life, obstructions/debris
    • Body: clothing, submerged vs. floating, type of joint, position of joint, amount of surrounding tissue, trauma
  87. Lacey Peterson Case
    • Mother & baby; husband convicted of killing them
    • Baby washed ashore; only part of mother found
    • Gases in body expelled the baby after the mother was dead
    • In water, 50F or below, bacterial breakdown is retarded
    • Also retarded by salinity of water (salt content)
    • Body will surface when putrefaction makes it bouyant
  88. Determining Sex from a Skull: Chin
    • Male - square
    • Female - rounded/pointed
  89. Determining Sex from a Skull: Mastoid Process
    • Male - large
    • Female - small
  90. Determining Sex from a Skull: External Occipital Protuberance
    • Male - large
    • Female - poorly developed
  91. Determining Sex from a Skull: Forehead
    • Male - retreating
    • Female - vertical; biparietal bossing (spreading/flare of parietal bones)
  92. Determining Sex from a Skull: Orbital Margin
    • Male - rounded
    • Female - sharp
  93. Determining Sex from a Skull: Supraorbital Ridge
    • Male - prominent
    • Female - absent or small (gracile)
  94. Determining Sex from a Skull: Muscle lines
    • Male - prominent
    • Female - poorly developed
  95. Determining Sex from a Skull: Ascending Ramus of Mandible
    • Gonion
    • Male - close to 90° angle
    • Female - obtuse angle
  96. Determining Sex from a Skull: Root of Zygoma
    • Male - extends beyond auditory meatus
    • Female - does not extend beyond auditory meatus
  97. Sexual Dimorphism
    difference in features (usually size) between sexes
  98. Tools to Measure Bones
    • Calipers
    • Sliding calipers - calibrated in mm & cm; used on the skull
    • Spreading calipers
    • Osteometric board - measures long bones to determine height
  99. What is the best bone in the body for determining sex?
    hip bone (innominate)
  100. Fordisc
    Software package used to determine whether skull measurements indicate sex (male or female)
  101. 3 pieces of hip bone
    • ilium
    • ischium
    • pubis
  102. parts of the pelvis
    • right innominate
    • left innominate
    • sacrum
  103. obturator foramen
    • oval in males
    • triangular in females
  104. pubic symphysis
    where the pubis bones fuse
  105. sacro-iliac joint
    where sacrum and hip bones fuse; changes throughout lifetime
  106. greater sciatic notch
    • narrow in males
    • wide in females
  107. Phenice method
    • Female pubic bone is longer than a male's - continues to grow
    • Region directly below pubic bone will be concave in females
    • Pubic bone on inferior border of male hip bone will be convex
    • Subpubic area (medial aspect of the ischiopubic ramus) is wider in a male than it is in a female
    • Females have very broad muscle attachment line (rough) called the ventral arc that appears after 25 years of age
    • Males do not have a ventral arch