ACTIVITY 1: BONY LANDMARK ANALYSIS

Transcription

1 Group members name and responsibilities (specifically): Must have all handwriting samples on project! ACTIVITY 1: BONY LANDMARK ANALYSIS 1. Help Tom McCune with this case by finding the bones that have all the landmarks described below. 2. Next identify the landmarks (A, B, C, etc.) on the bone described. 3. Then, write the name of the bone that you believe is appropriate and indicate how many of that same bone a complete skeleton should have (totals). 4. Finally, describe the location of this bone type in the body. Include other interesting features of each bone like what other bones does it articulate with? Is it part of the Appendicular or Axial skeleton? Is it a right or left appendage? Bone 1 contains: (A) olecranon fossa, (B) deltoid tuberosity, (C) head, and (D) medial epicondyle. Bone 2 contains: (A) long spinous processes, (B) transverse facets, and (C) vertebral foramen. Bone 3 contains: (A) medial malleolus, (B) lateral condyle, and (C) tuberosity. Bone 4 contains: (A) promontory, (B) superior articular process, and (C) foramina. Bone 5 contains: (A) acromion, (B) glenoid fossa, and (C) corocoid process. 1

2 Bone 6 contains: (A) linea aspera, (B) lateral epicondyle, and (C) greater trochanter. Bone 7 contains: (A) head, and (B) lateral malleolus. Bone 8 contains: (A) olecranon process, (B) head, and (C) styloid process. Bone 9 contains: (A) acromial end, and (B) sternal end. Bone 10 contains: (A) lamina, (B) square spinous processes, and (C) large body. Bone 11 contains: (A) apex, and (B) base. Bone 12 contains: (A) head, (B) neck, and (C) styloid process. Bone 13 contains: (A) transverse foramen, (B) bifid spinous process, and (C) small body. Bone 14 contains: (A) manubrium, (B) body, and (C) xiphoid process. Bone 15 contains: (A) costal groove, (B) shaft, and (C) head. 2

3 Bone 16 contains: (A) capitate, (B) pisiform, and (C) triquetral. Bone 17 contains: (A) proximal, (B) middle, and (C) distal pieces. Bone 18 contains: (A) cuboid, (B) talus, and (C) calcaneus. Bone 19 contains: (A) greater wings, (B) sella turcica, and (C) lesser wings. Bone 20 contains: (A) mastoid process, (B) styloid process, and (C) zygomatic process. Bone 21 contains: (A) mental foramen, (B) ramus, and (C) coronoid process. Bone 22 contains: (A) cribriform plate, (B) crista galli, and (C) perpendicular plate. Bone 23 contains: (A) acetabulum, (B) sciatic notch, and (C) ischial tuberosity. BONUS BONE #1 contains: (A) horizontal plate, (B) perpendicular plate. BONUS BONE #2 contains: (A) temporal process, (B) zygomaticofacial foramen 3

4 ACTIVITY 2: SEX DETERMINATION FROM PELVIC MORPHOLOGY * Morphological characteristics of the pelvis and skull are used in determining the sex of a skeleton. Pelvic differences are associated with adaptations for child bearing and the size of muscles. This activity also helps you to realize that pelvic girdles will not necessarily exhibit all female or all male characteristics because of normal variations. Help Tom McCune determine the sex of the skeleton by identifying the specific lettered parts of the pelvic girdle and circling their characteristics on the chart below; then answer the question that follows and provide your reasoning. Refer to handouts on pelvic measurements! Sex Characteristics of the Pelvis Feature Male Female A. obturator foramen shape large, ovoid triangular B. acetabulum size large small C. pubic angle (arch) < 90 ο > 90 ο D. sciatic notch shape Can t wiggle thumb Can wiggle thumb E. ilium shape high, vertical wide F. pelvic inlet shape heart-shaped circular G. sacrum shape long, narrow short, wide H. pubis body width mm ~ 40 mm Male control Female control Tom McCune s 1. What is the sex of the unknown pelvic bone? 2. Record observations that support this determination: How do you know (facts)? 4

5 ACTIVITY 3: SEX DETERMINATION FROM SKULL MORPHOLOGY * Verify the sex of the skeleton by identifying specific features of the skull and circling the characteristics that match their observations. Examine many skulls during this activity. Determinations cannot be made easily by observing one skull because of normal variations. Help Tom McCune determine the sex of the skeleton by identifying the specific parts of the skull and circling their characteristics on the chart below; then answer the question that follows and provide your reasoning. Refer to handouts on skull measurements! Sex Characteristics of the Skull Feature Male Female A. supra-orbital margin blunt slender B. occipital protuberance (nuchal crest) prominent (rough and bumpy) slender (smooth) C. mastoid process large and projecting small and non-projecting D. mandible shape (chin) somewhat square, U shape rounded, V-shaped E. shape of eye orbit somewhat square somewhat round F. supra-orbital ridge/glabella (a bump between the eyebrows) more expressed and pronounced less expressed or absent G. Mental eminence more expressed and pronounced less expressed or absent 1. What is the sex of the unknown skull? 2. Record observations that support this determination: How do you know (the facts)? 5

6 ACTIVITY 4: HEIGHT ESTIMATION * Another key question that the anthropologist tries to answer is, "What was the height of the individual?" The height is determined by measuring specific bones and comparing their length to chart measurements based on regression formula (statistical analysis). Anthropologists estimate the height of individuals by measuring specific bones. Measure the length of the femur and humerus from tip to tip and, using the height estimation data given below (Bass 1987), provide a range of estimated height in feet: Note: one must determine the sex and ethnicity in order to use the appropriate formula below! 6

7 ACTIVITY 5: AGE ESTIMATION *Only estimated ranges are possible in determining the age of a skeleton (Pickering and Bachman 1997); for example, between 0 and 5 years, 18 and 23 years, 30 to 45 years, and 60+ years of age. Clues are derived from the fusion of the epiphyses of long bones, closure of endocranial sutures, and ossification of the sutures. In pre-adult individuals, the epiphyses and diaphysis union will be incomplete with clear growth plates present. In old age, the cranial sutures are less distinct and become smooth, and the mandible height and thickness diminish and begin to appear more infantile. Skull Evidence: In the 0-5 year range, sutures will be open with fontanels between the cranial bones. The year range skulls will have rough suture lines compared to the 60+ age range, which will begin to display fading of sutures. Refer to suture closure handout for age ranges! Dental evidence: In the 0-2 year range no teeth are present. The 2-7 year range show all deciduous milk teeth have erupted (20 teeth). The 18+ age range displays permanent adult teeth (28-32 teeth). Also, the type and amount of dental work is characteristic of a particular age, for example a full set of healthy teeth is indicative of a year old individual. Refer to dental handout for age ranges! Degeneration: Evidence of aged skeletons is often determined by degenerative changes. Many vertebrae exhibit evidence of lipping (bone spurs) and signs of porosity. Reduced joint space in the knees and hips is also indicative of an older person 50+ age range. You can also see scapulae with atrophic or translucent spots thinning of bone due to lack of ossification and bone density. Estimate the age of the skeleton from any four of your bones and X-rays you choose. State the age range, name of specimen, and record observations that support your analysis, i.e. the facts ( #5 Tom McCune s case - see Skull and Humerus to determine relative age) 7

8 ACTIVITY 6: ANALYSIS FOR PATHOLOGICAL AND PHYSIOLOGICAL CHANGES * Skeletons may exhibit arthritic changes such as lipping (bone spurs) of the vertebrae or compression of the vertebral bodies. Signs of bone thinning or looking transparent due to bone loss and osteoporosis. Bone growths or tumors may be apparent. Also, bone spurs of the calcaneus (heel bone). Occasionally deformities from healed fractures are seen. Empty alveoli sockets may be the result of prior tooth loss or loss due to rough handling in the lab. Are there any missing appendages? Examine any four of the bones and X-rays in the lab and list any observable signs of trauma or pathology (disease). * For example, in forensic pathology, a broken hyoid bone suggests strangulation. If there is a crack in the calvaria (brain case), did it occur as a result of a fall off the lab bench or is it evidence of a fatal blow? The cracks of a deadly blow will look like a cracked hard-boiled eggshell while that postmortem fall from the lab bench will yield a linear line (crack). Give the trauma or disease of the skeleton from any four of your bones and X-rays you choose. State trauma or disease, name of specimen, and record observations that support your analysis, i.e. the facts ( #5 Tom McCune s case see the Hyoid bone) 8

9 ACTIVITY 7: RACE DETERMINATION It can be extremely difficult to determine the true race. Often times a skull will exhibit the characteristics of all three groups Caucasoid (European), Negroid (African), and Mongoloid (Asian/Amerindian) and not fit into the three-race model. The skull is considered to be the most important bone for race determination. Forensic anthropologists use lengths, widths, and shapes of skull features along with populationspecific dental traits to aid them in reaching a conclusion. For example, true Mongolian skulls tend to have cupped incisors on the inside surface. Analyze and compare the three groups of skulls. Choose Skull C to analyze. Circle the characteristics that apply to Skull C. Refer to yellow handout on skull measurements! Race Characteristics of the Skull Feature Caucasoid Mongoloid Negroid A. Nasal Index (see below) > 0.56 B. Nasal Spine prominent spine somewhat prominent spine very small spine C. Prognathism straight variable prognathic D. Shape of Orbital Opening rounded, somewhat square rounded, somewhat circular rectangular E. Nasal Silling/Guttering sharp ridge (silling) rounded ridge no ridge (guttering) F. Cupped or shovel-shaped incisors (tongue side) none present none Nasal Index = Nasal Width(mm) Nasal Height(mm) *Note use the inside scale on Vernier calipers! Race of Skull A ; nasal width mm ; nasal height mm Nasal Index for Skull A = (optional extra credit) Race of Skull B ; nasal width mm ; nasal height mm Nasal Index for Skull B = (optional extra credit) **Race of Skull C ; nasal width mm ; nasal height mm Nasal Index for Skull C = (Skull C: Tom McCune s case) 9