Vertebras and Pelvic Girdle
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Transcript 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
Occipital articulation
surface
Articular surface for dens
(p/i)
NO VERT BODY
C2 – called the axis
http://www.med.howard.edu/anatomy/gas/wk7/20-4_Spec_Cerv_vert.jpg
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
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