FORENSIC ANTHROPOLOGY

The vertebral column

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)

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

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)

HOW TO ORIENT VERTEBRAE

Superior facets face posteriorly

Inferior facets face anteriorly

Spinous process points postero-inferiorly

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)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

THE SACRUM

Large, wedge-shaped Composed of 5 sacral vertebrae – fused

Articulates with L5, both innominates

Characteristics Large bodies Reduced spinous processes

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

http://www.back.com/images/sacrum-4-19.jpg

http://www.botany.uwc.ac.za/sci_Ed/grade10/manphys/images/man/sacrum.gif

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

THE SACRUM – USES IN FORENSICS Male vs female

Males sacrum curved

Females sacrum straight (WHY?)

Age

Transverse line between S1 – S2 closes mid twenties

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

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

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

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

THE INNOMINATE

FUNCTIONS:

Support internal organs

Changes in the human pelvis allow for bipedal locomotion

THE INNOMINATE

Each innominate articulates with

*sacrum (at the auricular surface)

*one femur (at the acetabulum)

*the other innominate (at pubic symph)

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

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)

THE INNOMINATE – WHAT TO KNOW The ischium and pubis – medially

Pubic ramus: anterior/superior, twists Pubic symphysis: most anterior point Ischiopubic ramus: flat Obturator foramen: big hole

The ischium and pubis – laterally Ischial spine: most inferior/posterior Lesser sciatic notch: inferior Ischial tuberosity: very thick Pubic tubercle: anterior, above symph

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)

THE INNOMINATE – FUSION AGES Ischiopubic ramus; 5-8 years

Acetabululm; 11-17 years

Ischial tuberosity; 16-20 years

Iliac crest; 17-23 years

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

THE INNOMINATE USES IN FORENSICSTO RECAP:

SEX: PUBIS AND ILIUM

AGE: FUSIONS, AURICULAR SURFACES, PUBIC SYMPHYSIS