Chapter 9: Lumbar Spine, Sacrum, and
Coccyx
Lumbar Vertebrae (L1-L5) Anatomy Lateral View
transverse processes= fairly small on lumbar vertebrae
spinous process=bulky and blunt on lumbar vertebrae
Lumbar Vertebrae (L1-L5) Anatomy Superior View
Lumbar Vertebrae (L1-L5) Anatomy Anterior & Posterior View
Lumbar vertebrae: intervertebral foramina
superior vertebral notch=half-moon shaped area along upper surface of each pedicle
inferior vertebral notch=half-moon shaped area along the lower surface of each
pedicle.
when vertebrae are stacked, the superior & inferior notches line up and form the
intervertebral foramen
Therefore, between every two vertebrae are two intervertebral foramina, one on each
side, through which spinal nerves & blood vessels pass
Seen OPEN on lateral lumbar spine
,lumbar vertebrae: zygapophyseal joints
superior articular processes= the processes that project upward from the junction of the
pedicles & laminae
inferior articular processes= the processes that project downward from the junction of
the pedicles & laminae
zygapophyseal joints form an angle 30 to 50 degrees to the MSP between the
articular process of two adjacent vertebrae
L1-L2= 50 degree rotation
L4-L5= 30 degree rotation
Posterior Oblique= side that is down
RPO=right open
LPO= left open
Alternate Anterior Oblique= side away
RAO (alternate)= left open
LAO (alternate)= right open
pars interarticularis
-The portion of each lamina between the superior and inferior articular processes
-demonstrated on the oblique lumbar image
sacrum anterior view anatomy
-The bodies of the original five segments fuse into a single bone in the adult
-Sacrum is convex (outward) =cephalad angle
- shovel shaped with apex pointed inferiorly & anteriorly
-four sets of pelvic (anterior) sacral foramina transmit blood vessels & nerves
-the alae or wings are large masses of bone lateral to the first sacral segment
, -the two superior articular processes of sacrum form z joints with inferior articular
processes of L5
median sacral crest
ridge formed by the fused spinous processes of the sacral vertebrae.
sacrum posterior view anatomy
A. wedge shaped auricular surface, articulates with ilium to form sacroiliac joint
B. articulating facets of the superior articular processes
C. Posterior sacral foramina (8 total)
D. Sacral horns
E. enclosed sacral canal
sacral promontory
anterior ridge of body of the first sacral segment form posterior wall of inlet
auricular surface
region on the ilium of pelvis for articulation with the sacrum to form sacroiliac joint
Coccyx
Lumbar Vertebrae (L1-L5) Anatomy Lateral View
transverse processes= fairly small on lumbar vertebrae
spinous process=bulky and blunt on lumbar vertebrae
Lumbar Vertebrae (L1-L5) Anatomy Superior View
Lumbar Vertebrae (L1-L5) Anatomy Anterior & Posterior View
Lumbar vertebrae: intervertebral foramina
superior vertebral notch=half-moon shaped area along upper surface of each pedicle
inferior vertebral notch=half-moon shaped area along the lower surface of each
pedicle.
when vertebrae are stacked, the superior & inferior notches line up and form the
intervertebral foramen
Therefore, between every two vertebrae are two intervertebral foramina, one on each
side, through which spinal nerves & blood vessels pass
Seen OPEN on lateral lumbar spine
,lumbar vertebrae: zygapophyseal joints
superior articular processes= the processes that project upward from the junction of the
pedicles & laminae
inferior articular processes= the processes that project downward from the junction of
the pedicles & laminae
zygapophyseal joints form an angle 30 to 50 degrees to the MSP between the
articular process of two adjacent vertebrae
L1-L2= 50 degree rotation
L4-L5= 30 degree rotation
Posterior Oblique= side that is down
RPO=right open
LPO= left open
Alternate Anterior Oblique= side away
RAO (alternate)= left open
LAO (alternate)= right open
pars interarticularis
-The portion of each lamina between the superior and inferior articular processes
-demonstrated on the oblique lumbar image
sacrum anterior view anatomy
-The bodies of the original five segments fuse into a single bone in the adult
-Sacrum is convex (outward) =cephalad angle
- shovel shaped with apex pointed inferiorly & anteriorly
-four sets of pelvic (anterior) sacral foramina transmit blood vessels & nerves
-the alae or wings are large masses of bone lateral to the first sacral segment
, -the two superior articular processes of sacrum form z joints with inferior articular
processes of L5
median sacral crest
ridge formed by the fused spinous processes of the sacral vertebrae.
sacrum posterior view anatomy
A. wedge shaped auricular surface, articulates with ilium to form sacroiliac joint
B. articulating facets of the superior articular processes
C. Posterior sacral foramina (8 total)
D. Sacral horns
E. enclosed sacral canal
sacral promontory
anterior ridge of body of the first sacral segment form posterior wall of inlet
auricular surface
region on the ilium of pelvis for articulation with the sacrum to form sacroiliac joint
