Anth275 Mid-Term
Classify a set of skeletal remains as either human or bear paw and explain why each is classified as such.
knuckle joint (ball and socket joint); bear joints are v shaped in bear while human joints is U shaped thumb curves thumb joint is more rounded; bear is much more flatter bears phalanges are the same widths (human thumb bones are chunkier than the other bones) human hands tapper in the middle wrist bones are different
Define algor mortis.
cooling of the body
Define the tasks of a forensic anthropologists.
1. Humans from non-human remains 2. Determination of sex, age, race, stature 3. Other traits that lead to personal identification
Describe the 5 objectives FAs have if remains are of medico-legal significance.
1. Biological profile 2. Cause and manner of death 3. Time sense death 4. Scene recovery/mapping 5. Expert Testimony
What are the four types of bone cells? Define them.
1. Chondroblast: (high quantities of cartilage) cartilage forming cells that build a "model" of bone 2. Osteoblasts: bone forming cells; synthesize and secrete osteoid 3. Osteocytes: mature cells, non-dividing, maintain structure 4. Osteoclasts: bone erosion; lots of lysosomes
Describe the 5 stages of decomposition. Explain what may alter the time line of these processes.
1. Fresh: (1-7 days) Fresh appearance, no discoloration. 2. Early Decomposition: Some flesh relatively fresh, skin gray to green OR brown to black, skin slippage and hair loss, bloated or deflated, leathery skin. 3. Advanced Decomposition: Sagging flesh, caving of abdominal cavity, less than half of skeleton exposed, loss of internal organs, extensive maggot activity, mummification of outer tissue, adipocere may be present. 4. Skeletonization: Decomposing soft tissue with possible desiccation, more than half skeleton exposed, some body fluids present, greasy to dry bones. 5. Extreme Decomposition: Skeletonization with bleaching , exfoliation, and metaphysical loss, cancellous bone exposed in verts and long bones. Alter the time line: Affected by environment, i.e., temperature, humidity, accessibility; Exposure to wind, water, snow; Burial conditions; Presence/absence of clothing; Trauma and pre-existing disease, etc.
Discuss the contributions of the following: Thomas Dwight Ales Hrdlicka Earnest Hooton Thomas W. Todd Robert J. Terry Wilton Marion Krogman Charles E. Snow JPACIL Hawaii ... Defense POW/MIA Accounting Agency Mildred Trotter McKern and Stewart's Bill Bass Bill Maples
-Thomas Dwight: Harvard anatomy professor who was the first to extensively publish works on topics that would become the foundation of forensic anthropology, including methods of estimating sex, age, and stature from the skeleton. -Ales Hrdlicka: developed the theory that native Americans came from Asia across the Bering Strait. -Earnest Hooton: physical anthropologist known for his work on racial classification. -Thomas W. Todd: an orthodontist who is known for his contributions towards the growth studies of children during early 1900s. -Robert J. Terry: Terry Anatomical Skeletal Collection is a collection of some 1,728 human skeletons held by the Department of Anthropology of the National Museum of Natural History of the Smithsonian Institution, Washington, D.C., United States. -Wilton Marion Krogman: American anthropologist. that was a leader in the development of the field of physical anthropology, with an early and lasting interest in dental anthropology. -Charles E. Snow: American anthropologist studying growth patterns in young children. -JPACIL Hawaii ... Defense POW/MIA Accounting Agency: recover service members who became missing during their service. -Mildred Trotter: forensic anthropologist who discovered the structure and distribution of hair, and the growth, racial and sexual differences, and aging of the human skeleton -McKern and Stewart's: method constitutes one of the principal approaches towards pubic symphyseal age estimation. -Bill Bass: American forensic anthropologist, best known for his research on human osteology and human decomposition. -Bill Maples: traveled the world to examine and identify skeletons, including those of President Zachary Taylor, Czar Nicholas II of Russia and his family, and the Spanish explorer Francisco Pizarro, who conquered the Incas in 1532.
List and explain the three criteria for ML significant of a forensic anthropologist.
1. Skeletal or dental?- Identifying if the remains exhibit characteristics similar with bone or teeth in humans; can be hard to distinguish as sometimes other material looks like bone, ex. 9/11/2001 or Haut de la Garenne Children's Home. 2. Human or Non-human?- Identifying if the remains human or non-human; 20-30% reported are non-human, ex. bear paw vs human hand. 3. Contemporary vs Non-contemporary?-Identifying if the remains are recent or not; Contemporary <50 years (Assume it is until otherwise proven), Historic: >50, Prehistoric: very very old.
Explain how bone is remodeled and repaired.
1. Woven bone is replaced by compact lamellar bone; osteoclasts eat away at the woven bone and from a tube around a the vessel. 2. Osteoblasts lay down osteoid in concentric rings. 3. Trap themselves in their boney nests and turn into osteocytes. 4. Next layer is laid down.
List and discuss the steps involved in the Death Investigation and its purpose.
1st: Death pronouncement: declaring person is dead (done by anyone: ME, Coroner, Paramedics, NOT time of death) 2nd: Scene Investigation 3rd: Establishing ML Jurisdiction 4th: Triage (body sits in ice before next course of action) → Autopsy/External Examination where they examine: ID; Toxicology, Histology, Serology; Trauma Assessment → No Autopsy where there is a Trauma Assessment (too); Medical History 5th: Additional Investigations 6th: Cause and Manner of Death; Death Certification
Explain why algor mortis, livor mortis, and rigor mortis happens physiologically. Explain why each of these is important and what it tell us about the post mortem and PMI.
Algor Mortis: Dead bodies cool to ambient temperature, rate influenced by factors (temperature, humidity, accessibility, etc.), like coverings, body build, and estimate elapsed time. Average adult corpse loses heat: 1.5 F/hour in temperate climates and 0.75 F/hour in tropical climates Useful up to about 18 hours after death Livor Mortis: When heart stops, blood stops flowing through body, deoxygenated blood pools to the lowest points; ½-4 hours post-mortem, peaks 8-12 hours; white=pressure points and purple=no pressure points; Position, pattern formed when individual dies is retained, even if the body is moved; Unfixed livor results in blanching of the coloration Livor is fixed; it will not shirt with movement of the body is non-blanchable. Blood is coagulated. Rigor Mortis: Pull toward each other for contraction-myosin (calcium and ATP) ATP is needed to unbind myosin heads from actin → At death: calcium leaches out of organelles opens binding sites; lack of ATP matins myosin/actin binding (contraction) after death; Begins in eyelids and face; Peaks 12 hours, dissipates 24-36 hours as proteins are broken down; Rigor mortis of the arrector pili muscles can result in postmortem "goose bumps"
What is the difference between algor mortis, livor mortis, and rigor mortis?
Algor mortis is the cooling of the body, livor mortis is the pooling of blood, and rigor mortis is the stiffening of the body.
How do bones grow?
All bones grow by deposition of osteoid onto a pre-existing surface of precursor. In-depth: Soft tissue model w/ osteoprogenitor cells → model becomes vascularized → osteoprogenitor cells differentiate into osteoblasts → osteoblasts deposit osteoid → osteoid becomes mineralized
Define forensic anthropology.
Application of anthropological methods and theory particularly relating to the recovery and analysis of human skeletal remains to resolve legal matters.
Define postmortem interval (PMI).
Asking: "how long has the body been dead for?" Time Since Death: Processes of Decomposition: timetables for estimating PMI Requires specialized approaches from other fields: forensic entomology Decomposition: varies with geography, temperature, environment (all prior depends on this; very important)
Describe some methods that an FA might use to determine if a case is historic or contemporary.
Biocultural modifications, context, taphonomic changes. Prehistoric: pottery, stone pints, antler tine points, worked bone, worked shell; biocultural modifications (trephination) Contextual clues: location: site registries, historical societies, churches; artifacts: personal effects, grave goods, recent and kinds of fillings/implants Taphonomy: Any process that can affect what occurs to the body between the time of death and recovery of a body
Describe and discuss the efficacy (usefulness), the advantages, and disadvantageous of methods used to estimate stature.
Biological stature: height of a person in anatomical position Reported Stature: drivers license missing person's report Forensic Stature: estimated, potentially to reported stature Cadaveric stature: length of corpse Potential problems?= Discrepancies between biological stature and reported stature create several issues: 1. Incorrect reporting, 2. Men overestimate, 3. Taller women underestimate Stature changes Biological stature: most accurate Stature fluctuates: within 1 inches Stature decreases after 45 years
Define antemortem.
Birth to Perimortem.
Define osteogenesis.
Bone growth
What are the 3 types of connective tissue in a skeletal system? Define them.
Bone: hard tissue Ligaments: bones to bones, strengthens joints, enable movement "tying bones together" Cartilage: support under pressure, between two bones
Define osteoid.
Boney glue, collagen fibrils form frame-work for calcium and phosphate
Explain the difference between "Cause" and "Manner" of Death.
Cause is the medical reason as to how someone died while Manner determines the "legal" reason why they died.
Explain remodeling in bone.
Changes in shape, size, strength; Dependent on diet, exercise, and age.
What is the difference between cranial and post-cranial?
Cranial (just head) vs Post Cranial (neck down) Cranial: skull→cranium(everything minus mandible) → calvaria (face removed; all bones surrounding) → calotte (not bottom half) Axial: bones of the trunk; skull (cranium-8, face-20, mandible), vertebral column (26), sternum and ribs (24) Appendicular: limb bones and girdles; pectoral girdle, pelvic girdle, limbs
What is the American Board of Forensic Anthropologists definition of Forensic Anthropology? What are their tasks?
Definition: The application of the science of physical or biological anthropology to the legal process; analysis of skeletal, badly decomposed, or otherwise unidentified human remains is important in both legal and humanitarian contexts. Tasks: FAs apply standard scientific techniques developed in physical anthropologists to analyze human skeletal remains and aid the detection of crime; assisting in location and recovering human skeletal remains; work in conjunction with forensic pathologists
Identify the structure of a long bone.
Diaphysis (shaft): middle of long bone. Metaphysis: top and bottom of diaphysis, where bone grows; aka growth plate of bone. Epiphysis: very top and bottom of bone, where joints are going to be. Medullary cavity: yellow bone marrow (adults), red bone marrow (in children). Spongy bone: located in epiphysis. Compact bone: all around bone. Periosteum: (soft tissue structure next bone) thin layer that covers the whole bone, allowing soft tissue structure to attach to bone (velcro but better). Red bone marrow: produces blood cells, all juvenile/infant bones, adults (in epiphyses; adults lose and replaced by yellow)-ribs, vert bodies, humerus, pelvis, femur, Yellow bone marrow (in medullary cavity): replaces red with age, cells become saturated with fat and are no longer active in blood cell production, can revert to red
Define woven bone (fibrous bone).
Haphazard organization of collagen fibers is mechanically weak.
Describe the role of a forensic anthropologist (FA) within the medico-legal system.
Do remains need to be processed through the medicolegal system for a death investigation, Determines cause and manner of death, Lead to victim identification
Discuss the significance of the Parkman murder for forensic anthropology.
Due to the body being dismembered and partially burned, the need for forensic anthropology came in. The decedent was identified to be 5'10 by Wyman, the cause and manner of death was identified by Holmes, the use of dentition determined identity by Dr. Parkman's dentist, and Mrs. Parkman identified the body based on birthmarks on lower back and genitals.
Define postmortem.
End of perimortem until the body is discovered.
Explain what the medicolegal system is and its functions.
Explain: Formal mechanism for death investigation and death certification; headed by a coroner or medical examiner (qualifications for the jobs are are different; jobs are the same) Functions: It provides legal evidence based on biological data/evidence found by coroners/medical examiners to utilize during legal cases.
Explain the types of cases that are accepted by the MEs office, plus examples.
Explain: Non-Natural Deaths (unexplained): Homicides, Infants, Child Deaths, Suicides, Accidents (drowning, MVAs, Falls, work related deaths, etc.), Drug Abuse. Suspicious: Decomposed remains, deaths in custody (Nursing homes), Medically Unattended Deaths, sudden death of individuals <50 years, no one to make arrangements.
Define fontanels and sutures. Give their function.
F: Unique features of fetal skull. S: Immovable cranial joints (is a good indicator of age; ex. if suture is not visible, individual is older). Newborn has soft spots to get through vaginal birth; molding of the head to shape of birth canal reducing head circumference.
Compare and contrast the growth patterns in males and females.
Females mature earlier than males as they achieve adult size earlier and stop growing earlier. Males mature later as they achieve adult size later and grow for longer periods of time resulting in larger size.
Explain histological differences between human and nonhuman remains (and use these methods to differentiate between several picture examples).
Haversian systems and secondary osteons: common in remodeled human bone; Macrostructure Dissimilarities: Shape, Rugosity, and Texture; Human cross-sections: more porous compact bone, diaphyseal trabecula present, ¼ thickness of diameter of long bone (less thickness in compact vs spongy), thick dipole in cranial vault bones while Other animals' cross sections: less porous, birds have structs, diaphyseal trabecula absent, ½ thickness of diameter of long bone, birds thin wall, more compact cranial vault bone
Describe the three main methods used to distinguish between human and nonhuman remains.
History and Microstructures: osteon vs banding and microanatomy Maturity: Size, development, and fusion → Epihesis present or not for development; Throw it under the microscope if cannot tell to determine osteons Morphology: shape
Given a set of pictures (representing cross-sectional long bones, vertebrae, skulls, pelvis, and long bones) used methods to discriminate between human and nonhuman remains and characterize the difference in anatomy (i.e. identify the traits you used to determine if they were human or nonhuman).
Human Skull: have foramen on either side of the sutures; Interdigitation at sutures. Distinct inner and outer cortical tables separated by dipole, thinner than shells, fewer sutures, smoother surface, endocranial and ectocranial surfaces will look different Turtle Shell: Shells generally flatter, Endocranial/ectocranial surface will look smaller; Lines on the inside resemble lines on the outside, more sutures, thicker than cranial bones, rougher surface Is it a bipedal primate: A habitual biped has structurally changed the skeleton so that the center of gravity falls between the two feet when standing with legs extended; S-shaped keeps feet directly under the center of gravity; Becoming a piped changes the way an animal balances; The vert increase as the direction heads inferiorly; Spikes in vert are short while in other animals vary Human vs Non-Human Pelvis: To maintain balance, the bipedal pelvis has a foreshortened ilium and it is broader and bowl-shaped. The quadruped pelvis has a long ilium positioned on the back, not the side. Human vs Non-Human Long Bones: Humans: small, gracile, smoother, less complex joint surfaces; Non-Humans: complex joint surfaces for increased stability in quadrupedal locomotion Femur: Human Femur: small processes of bone, smaller cross-sections, rounded head, long neck; Non-Human Femur: larger processes of bone, larger cross-sections, oblong heads, short necks Tibia: Human Tibia: Tibia and fibula are unfused, triangular cross section, flat talar surface; Non-Human Tibia: (sometimes depend on taxa) tibia and fibula are fused, square cross section, undulating surface Humerus: Human humorous: gracile/smooth, small cross section, rounded enlarged head, head is medial; Non-Human humorous: robust weight-bearing, large cross section, had posteriorly placed Radius and Ulna: Human: gracile/smooth, unfused, pronating, rounded radial head, small cross-sections; Non-Human: robust/weight-bearing, fused, non-pronating, large cross-section
Assess the ML significance of an unexplained/unnatural or suspicious case, if an FA is given one.
If determined to be of ML significance, the FA will 1. Biological profile 2. Cause and manner of death 3. Time sense death 4. Scene recovery/mapping 5. Expert Testimony
Describe and discuss the efficacy (usefulness), the advantages, and disadvantageous of methods used to estimate sex.
Issue in Sex Estimation: Large range of variation: Sexual dimorphism Within populations age Between populations regional variation Idiosyncrasies Mechanisms and processes that produce variations Growth and development Genetics Sexual selections Health diet and disease
Explain why it is important for the FA to be able to determine the difference between human and non-human remains.
It is important for an FA to be able to determine the difference between human and non-human remains due to the fact that: 1. Mammals have roughly the same number of bones (and same types of bones) and are can be easily misleading. 2. If the FA launches an investigation into non-human remains, it is a major waste of time and money.
Define manner of death and give an example.
Legal type of death; ex. homicide, suicide, accident, natural, undetermined
Determine different types of bone.
Long bone Short bone Irregular bone (vertebra) Sesamoid bone (grows/lives inside tendon; knee cap) Flat bone (sternum)
Review Lab 1
Look back on lab.
Define cause of death and give an example.
Medical reason why they died; Ex. disease/injury initiating sequence of events resulting in death
Discuss the difference between interpretation/opinion and data/evidence.
Opinions (subjective interpretation) vs evidence (objective). Differentiate between objective observation (evidence/data) and subjective interpretation (opinion).
Describe the bone matrix.
Organic component: what your body is making; ex. collagen and protein, strength and resilience Inorganic component: comes into system; ex. hydroxyapatite: inorganic salts of calcium and phosphate, hardness
Define Wolf's Law.
Osteoblasts deposit more bone where stress is applied to ensure that even pressure is being applied to all sides.
Give a set of skeletal remains, determine which methods should be used to estimate sex.
Pelvis: Phenice Method ← best method to use as it is 96% accurate from the pubic bone; Based off of ventral arc, sub-pubic concavity of ischiopubis ramus, medial aspect of ischiopubis ramus is sharp and narrow Skull: Mastoid Process: Behind ear; Short/Narrow → Long/Wide (1→5) Female: Short and Narrow Male: Long and Wide Suborbital Ridge/Glabella: Smooth → Pronounced (1→5) Female: Smooth Male: Pronounced The following practices are recommended for sex assessment: -Sex assessment should be made independently of suspected or presumptive identification to avoid bias. -When appropriate, use population- and period-specific standards. -Assess and measure the maximum number of age-appropriate cranial and postcranial variables, emphasizing the most dimorphic elements present, especially in the case of fragmentary remains. -Document and describe the location of any inconsistent indicators. -If an observation cannot be made or a measurement cannot be taken, explain its absence: missing, broken, fractured, congenital, pathological, or anomalous. -Sex assessment, as well as assessments of other skeletal parameters, should be performed, even if samples for DNA analyses will be taken. -Express degree of certainty when reporting sex assessments, especially when a sex assessment is less than certain, e.g. "male?" -When an assessment of skeletal sex is not possible (e.g. partial remains or those of subadults), sex assessment by DNA analysis may be helpful. Post Crainial: Metric Methods - Humerus Humeral head diameter: 42 Certainly female 43, 44 Probably female 45 46, 47 Probably male 48 Certainly male Almost any joint surface to distinguish male vs female
Describe and identify features on the crania and post crania that would indicate you are dealing with female or male remains.
Pelvis: Phenice Method ← best method to use as it is 96% accurate from the pubic bone; Based off of ventral arc, sub-pubic concavity of ischiopubis ramus, medial aspect of ischiopubis ramus is sharp and narrow; Greater sciatic notch; Preauricular sulcus; Pits of parturition; Subpubic angle; Sacral curvature Skull: Sexual differentiation of the skill reflects differences in size and robusticity; Accuracy 80-90% and Population specific Frontal Shape: Difficult to tell; have to be side by side Female (higher frequency): Vertical Male (higher frequency): Sloping Nuchal Crest: Neck muscles; Smooth → rugged (1→5) Females: smooth Males: rugged ***Mastoid Process: Behind ear; Short/Narrow → Long/Wide (1→5) Female: Short and Narrow Male: Long and Wide Suborbital Margin: Sharp → Blunt (1→5) ***Suborbital Ridge/Glabella: Smooth → Pronounced (1→5) Female: Smooth Male: Pronounced Chin: Flat → Projecting (1→5) Female: Flat Male: Projecting
Explain the physiological and developmental reasons why humans exhibit sexual dimorphism.
Physiological: Population differences, Sex chromosomes directly/indirectly (via hormone regulation) contribute to the development of other sex trains, including the sex differences that anthropologists observe in the skeleton. These traits are not binary. Developmental: Females mature earlier than males as they achieve adult size earlier and stop growing earlier. Males mature later as they achieve adult size later and grow for longer periods of time resulting in larger size.
Define livor mortis.
Post-mortem intravascular red-blue discoloration resulting from hypostasis of blood
List and describe the different types of bone growth.
Primary Ossification center: first place where bone is developed (main shaft of the bone). During course of fetal development: bone gets longer and slightly wider (metaphysis). Secondary Ossification Center: Epiphysis do not show up until your 6-7 years of age. NOTE: All keep growing until teenage years, until cartilage form and bone stops growing!
What are the important functions of bone?
Protects internal organs, stores and releases fat, produces blood cells, stores and releases minerals, facilitates movement, and supports body.
Define lamellar bone.
Regular parallel alignment of collagen into sheets ("lamellae") is mechanically strong.
Discuss the components of professional ethics for forensic scientists.
Respect: Every individual has beliefs about how bones relate to once-living persons, beliefs of family should take precedence; Treat remains and families with respect and sensitivity. Confidentiality: Don't communicate case findings until they are officially made public! → Compromise integrity of the case finding; It is NOT your job! Honesty: Provide complete and accurate assessment of cases, without contributing information of opinions that cannot be substantiated by data.
Distinguish between skeletal remains that are of ML significance and those that are not of ML significance.
Skeletal remains that are of ML significance: suspicious deaths, unnatural deaths, Skeletal remains that are not of ML significance: non-bone remains, non-human remains, prehistoric and/or historic remains.
List the types of cases that a FA would be called in for.
Skeletonized remains, badly decomposed bodies, bodies found in water, burned remains, case in which the mechanism of trauma is questionable.
Give a set of skeletal remains, determine which methods should be used to estimate stature.
Skull, vertebrae, long bones.
Discuss the difference between estimating age in adults versus methods used for estimating age in sub adults.
Subadult methods are based on development: Dental development and eruption (babies, infants, kids) Dental development is highly precise Eruption is highly variable Primary ossification appearance and length (fetal, infant, children remains) Primary ossification: where bone first starts growing Bone length helps determine how old (fetus) Secondary ossification appearance and fusion (juveniles, teenagers) Teen years Adults Methods based on Breakdown/Degeneration: Dental wear (breaking down/wearing down enamel) population and diet dependant Cranial suture fusion (has a lot of error estimates) Joint surface breakdown (a lot of variables)--pubic symphysis joint (preferred joint)
Given a set of skeletal remains, determine which methods should be used to estimate age.
Subadult methods are based on development: Dental development and eruption (babies, infants, kids) Dental development is highly precise Eruption is highly variable Primary ossification appearance and length (fetal, infant, children remains) Primary ossification: where bone first starts growing Bone length helps determine how old (fetus) Secondary ossification appearance and fusion (juveniles, teenagers) Teen years Adults Methods based on Breakdown/Degeneration: Dental wear (breaking down/wearing down enamel) population and diet dependant Cranial suture fusion (has a lot of error estimates) Joint surface breakdown (a lot of variables)--pubic symphysis joint (preferred joint)
Given a set of skeletal remains, estimate age for that individual.
Subadult methods are based on development: Dental development and eruption (babies, infants, kids) Dental development is highly precise Eruption is highly variable Primary ossification appearance and length (fetal, infant, children remains) Primary ossification: where bone first starts growing Bone length helps determine how old (fetus) Secondary ossification appearance and fusion (juveniles, teenagers) Teen years Adults Methods based on Breakdown/Degeneration: Dental wear (breaking down/wearing down enamel) population and diet dependant Cranial suture fusion (has a lot of error estimates) Joint surface breakdown (a lot of variables)--pubic symphysis joint (preferred joint)
Define perimortem.
Surrounding death, Begins with the interaction between individuals and their cause of death, Ends at conclusion of the interaction between the individual and the causative agent (beginning to end of interaction with the agent of death); means different things to different practitioners.
Explain the difference between unexplained/non-natural and suspicious deaths.
The difference between unexplained and suspicious deaths are that one is unnatural in nature given that it doesn't occur normally while the other appears to have some kind of strange motive behind it worthy of investigation.
Describe other types of taphonomic processes and how they might influence the skeleton.
The other types of taphonomic process are invasion of cheatgrass, carnivore punctures on a scapula, sun-bleached mandibles; Antemortem injuries: healing happens to a bone
Define rigor mortis.
The stiffening of the body.
Explain why Non-Natural deaths and Suspicious deaths are accepted.
Why accepted: due to these deaths being unnatural in nature; i.e. no child should be dying so young. Why accepted: due to these deaths being suspicious in nature; i.e., if decomposed remains are found in the middle of nowhere, that is unnatural and should be investigated.
What are the two types of bone tissue? Describe them.
compact/lamellar: dense and made up of meller bone spongy/trabecular/cancellous: spongy in nature, holey, trabecula
Describe and discuss the efficacy (usefulness), the advantages, and disadvantageous of methods used to estimate age.
growth and development are better at estimating age, but gets harder to predict as the individual gets older.
Define osteology.
study of bone (human adult skeleton: 206 bones in adult)
