Page 267 - Fundamentals of anatomy physiology

254 Unit 2 Support and Movement
Figure 7–18 Vertebral Anatomy.

Vertebral arch Articular processes Superior articular Pedicle
process Vertebral body

Transverse
process

Pedicle Spinous
process
Vertebral body
7 Inferior articular Arrow passing
a The major components of a facet through vertebral
typical vertebra
Inferior articular foramen
process

b A lateral and slightly inferior view of
a vertebra

Spinous Superior articular facets
process
Superior articular process
Superior Inferior
articular articular Lamina of
process process vertebral arch
Intervertebral
Transverse
process foramen
Intervertebral
Inferior Pedicle
articular disc
Vertebral
facet body Spinous process
Intervertebral
Vertebral disc
foramen Transverse process

c An inferior view of a vertebra

Vertebral body Vertebral body

Inferior Inferior
articular
d A posterior view of process articular Arrow passing
three articulated facet through vertebral
vertebrae
canal

e A lateral and sectional view of

three articulated vertebrae

7-6 The five vertebral regions are extend inferiorly to the trunk. Twelve thoracic vertebrae (T1–
T12) form the superior portion of the back. Each articulates with
the cervical, thoracic, lumbar, sacral, one or more pairs of ribs. Five lumbar vertebrae (L1–L5) form
and coccygeal regions the inferior portion of the back. The fifth articulates with the
sacrum, which in turn articulates with the coccyx.
Learning Outcome Identify the vertebral regions, and describe the
distinctive structural and functional characteristics of vertebrae in each During development, the sacrum originates as a group of
region. five vertebrae, and the coccyx begins as three to five very small
vertebrae. In general, the vertebrae of the sacrum are com-
As Figure 7–17 shows, the vertebral column is divided into cer- pletely fused by age 25–30. Ossification of the distal coccygeal
vical, thoracic, lumbar, sacral, and coccygeal regions. The cer- vertebrae is not complete before puberty. Thereafter fusion
vical, thoracic, and lumbar regions consist of individual verte- takes place at a variable pace. ATLAS: Embryology Summary 7: The
brae. Seven cervical vertebrae (C1–C7) constitute the neck and
Development of the Vertebral Column