Forensic Anthropology

1. Forensic Anthropology The vertebral column

2. The Vertebral Column • Functions: support, movement of trunk • Total of 33 (usually) individual vertebra • 5 types of vertebrae (plural) • Cervical (5) • Thoracic (12) • Lumbar (5) • Sacral (5) • Coccygeal (4)

3. http://webschoolsolutions.com/patts/systems/vertebra.gif

4. General morphology – need to know • Vertebral body (ant) • Vertebral arch (post) • On each arch…. • 2 pedicles – attach arch to body • 2 transverse processes – lateral projections • 2 lamina – posterior surface of arch • Spinous process – points postero-inferiorly • 2 articulations for each adjacent vertebra • 2 superior • 2 inferior • Encircle vert foramen • (form vert canal)

5. How to orient vertebrae • Superior facets face posteriorly • Inferior facets face anteriorly • Spinous process points postero-inferiorly

6. Articulations • Each vertebra articulates with 2 other vertebrae (superior and inferior) • Other articulations in…. • The cervical vertebra: C1 articulates with the occipital • The thoracic vertebra: 2 ribs with EACH vert • Lumbar (NONE) • Sacrum: ilium of the innominate (x2)

7. http://www.med.howard.edu/anatomy/gas/wk7/20-2_CervVert.jpg

8. http://www.kent.ac.uk/anthropology/department/research/images/vertebra2.jpghttp://www.kent.ac.uk/anthropology/department/research/images/vertebra2.jpg

9. Vertebral growth areas • 3 growth centers for each vertebra • Centrum (body) and 2 arches • Arches fuse first • T spine <1 year old • C spine 2 years old • L spine 5 years old • Arches (at the pedicles) fuse to the centrum between 2 – 5 years of age • 5 secondary growth centers at the transverse processes, spinous process, and superior and inferior vertebral bodies appear in teens, fuse in early adulthood

10. The C spine – unique characters • C1 – call the atlas • Occipital articulation surface • Articular surface for dens (p/i) • NO VERT BODY • C2 – called the axis • Dens (odontoid process) http://www.med.howard.edu/anatomy/gas/wk7/20-4_Spec_Cerv_vert.jpg

11. Typical C spine • C3 – C7 • Bifid spinous process • “Square-shaped” bodies • C7 has the longest spinous process and forms the vertebral prominence http://www.clinicalexams.co.uk/images/Cervical_vertebrae.jpg

12. http://www.hughston.com/hha/spine.jpg

13. The T spine • 12 vertebrae (pair with 12 pairs of ribs) • Rib facets/costal pits – articular area of each • T2-T8 typically have 2 rib demi-facets on each lateral side of the vertebral body (4 total) • T1-T10 typically have 1 rib facet on each transverse process (2 total) http://www.frca.co.uk/images/epidural-anatomy1.gif

14. The T spine • T1 1 full facet (superior) on each side 1 demi facet (inferior) on each side 1 facet on each transverse process • T2-T8 2 demi facets on each side 1 facet on transverse process • T10 1 facet on each side of body 1 facet on each transverse process • T11 1 facet on each side of the body 1 facet on each transverse process • T12 same as T11, but with widened inferior body to meet with L1

15. http://content.answers.com/main/content/wp/en/thumb/6/64/300px-Gray91.pnghttp://content.answers.com/main/content/wp/en/thumb/6/64/300px-Gray91.png

16. The L spine • Notice it for what it is missing – No transverse foramena OR rib facets • Typically large bodied • Short stunted spinous process • S/I articular facets curved in (U-shaped) in order to increase stability

17. http://www.sandiego-spine.com/photos/vertebrae-lumbar.gif

18. http://www.maitrise-orthop.com/corpusmaitri/orthopaedic/mo70_maigne_thoracolumbar/fig2.GIFhttp://www.maitrise-orthop.com/corpusmaitri/orthopaedic/mo70_maigne_thoracolumbar/fig2.GIF

19. Sorting the vertebrae • There should be a logical progression as the descend • Body size increases • Spinous process size changes • Increase in C spine • Decreases through T and L spine • Articular surface shape and position should match

20. Sorting the vertebrae • Make three piles • Orient each with spinous process away, superior surface up • Begin at top and work way down matching inferior surface of upper with superior surface of next one down

21. The sacrum • Large, wedge-shaped • Composed of 5 sacral vertebrae – fused • Articulates with L5, both innominates • Characteristics • Large bodies • Reduced spinous processes

22. http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/19464.jpghttp://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/19464.jpg

23. http://www.back.com/images/sacrum-4-19.jpg http://www.botany.uwc.ac.za/sci_Ed/grade10/manphys/images/man/sacrum.gif

24. The sacrum – need to know • Superiorly • Sacral promontory (sup/ant): central, superior border of S1 • Superior articular facets: articulation of L5-S1 • Spinal canal • Ala (wings) • Laterally • Auricular surface • Spinous processes • Posteriorly – • Posterior sacral foramina • Anteriorly • Anterior sacral foramina • Transverse line of fusion

25. The sacrum – uses in forensics • Male vs female • Males sacrum curved • Females sacrum straight (WHY?) • Age • Transverse line between S1 – S2 closes mid twenties

26. The coccyx • Coccyx – group of fused bones vs coccygeal vertebra (individual bone) • Usually 4 segments fused – variation 3-5 • CV1 had transverse processes and horns (cornua) • CV2+ are variable, small, frequently lost • Typically all fuse together and frequently to sacrum

27. http://content.answers.com/main/content/wp/en/thumb/6/62/200px-Gray100.pnghttp://content.answers.com/main/content/wp/en/thumb/6/62/200px-Gray100.png

28. THE PELVIS • The many names for this region • Pelvis: composed of 2 innominate bones and the sacrum • Innominate (or Os Coxae): each half of the “pelvic bowl” formed by the fusion of • Ilium • Ischium • Pubis

29. THE INNOMINATE • ILIUM – most superior of the 3 the blade • ISCHIUM - most inferior of the 3 the ‘sit bone’ • PUBIS – most anterior of the 3 forms the symphysis

30. THE INNOMINATE • FUNCTIONS: • Support internal organs • Changes in the human pelvis allow for bipedal locomotion

31. THE INNOMINATE Each innominate articulates with *sacrum (at the auricular surface) *one femur (at the acetabulum) *the other innominate (at pubic symph)

32. THE INNOMINATE – what to know • The ilium: medially - • Iliac crest – superior rim • Iliac fossa – superior depression under rim • ASIS and AIIS • Arcuate line – midline inferior ridge • Iliac tuberosity – posterior rugosity • Auricular surface - posterior (art.w/ sacrum) • Preauricular sulcus

33. THE INNOMINATE – what to know • The ilium: laterally – • Iliac crest • Iliac pillar – ridge on midline of blade • PSIS and PIIS • Greater sciatic notch • Acetabulum (actually the point where all three bones fuse together, art. w/femur)

34. THE INNOMINATE – what to know • The ischium and pubis – medially • Pubic ramus: anterior/superior, twists • Pubic symphysis: most anterior point • Ischiopubicramus: flat • Obturator foramen: big hole • The ischium and pubis – laterally • Ischial spine: most inferior/posterior • Lesser sciatic notch: inferior • Ischialtuberosity: very thick • Pubic tubercle: anterior, above symph

35. THE INNOMINATE – L from R • Orient ilium (crest and blade) superior • Orient the pubic symphysis anteriorly and medially, ischium posterior and inferior • The acetabulum is on the side of origin (lateral)

36. THE INNOMINATE – fusion ages • Ischiopubic ramus; 5-8 years • Acetabululm; 11-17 years • Ischial tuberosity; 16-20 years • Iliac crest; 17-23 years

37. THE INNOMINATE uses in forensics • The pelvis is best for sex – due to changes in the pelvis for childbirth, there are numerous, easy to distinguish features that help differentiate males from females in both the PUBIS and the ILIUM • ALSO, well developed methods for aging adults based on changes in the PUBIC SYMPHYSIS

38. THE INNOMINATE uses in forensics TO RECAP: • SEX: PUBIS AND ILIUM • AGE: FUSIONS, AURICULAR SURFACES, PUBIC SYMPHYSIS