Download Vertebras and Pelvic Girdle

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….

Encircle vert foramen

(form vert canal)
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

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




C2 – called the axis

http://www.med.howard.edu/anatomy/gas/wk7/20-4_Spec_Cerv_vert.jpg
Occipital articulation
surface
Articular surface for dens
(p/i)
NO VERT BODY
Dens (odontoid process)
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/e
n/thumb/6/64/300pxGray91.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.maitriseorthop.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

Posteriorly –
Sacral promontory
 Posterior sacral
(sup/ant): central,
foramina
superior border of S1
 Superior articular facets:
 Anteriorly
articulation of L5-S1
 Anterior sacral
 Spinal canal
foramina
 Ala (wings)
 Transverse line of
 Laterally
fusion
 Auricular surface
 Spinous processes

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 





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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 FORENSICS
TO RECAP:


SEX: PUBIS AND ILIUM
AGE: FUSIONS, AURICULAR SURFACES,
PUBIC SYMPHYSIS