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THORACIC VERTEBRAE
THORACIC VERTEBRAE
General Features
• intermediate in size between cervical and lumbar vertebrae
• increase in size from above downward, the upper vertebrae being
smaller than those in the lower part of the region.
• The bodies are heart-shaped particularly in the middle of the thoracic
region, almost equal in the antero-posterior and in transverse
dimensions.
• The vertebral foramen is small, and of a circular form.
• The spinous process is long, triangular ,directed obliquely downward,
and ends in a tuberculated extremity
•
The transverse processes are thick, strong, of considerable length,
directed obliquely backward and laterally, and each ends in a clubbed
extremity
THORACIC VERTEBRAE
Distinguishing Features
• They present on either side, two costal demi- facets on the
sides of the bodies (one above, near the root of the pedicle,
the other below, in front of the inferior vertebral notch)for articulation
with the heads of the ribs (costovertebral joint)
• facets on the transverse processes for articulation with the tubercles
of the ribs (costotransverse joint)
ATYPICAL THORACIC VERTEBRAE
• The thoracic vertebrae which present certain
peculiarities, and must be specially considered
are:
• First
•
ninth
•
tenth
•
eleventh
• twelfth
ATYPICAL THORACIC VERTEBRA: FIRST
It has, on either side of the body,
• an entire articular facet for the head of the first rib, and
•
a demi-facet for the upper half of the head of the second rib
Atypical Thoracic Vertebra ninth & tenth
• The Ninth Thoracic Vertebra may have no demifacets below.
• The Tenth Thoracic Vertebra has an entire
articular facet on either side, which is placed partly
on the lateral surface of the pedicle.
Atypical Thoracic Vertebra
eleventh & twelfth
• The articular facets for the heads of the ribs are of large size,
circular, and placed chiefly on the pedicles
• The spinous process is short, and nearly horizontal in direction.
• The transverse processes are very short and have no articular facets
for tubercle of ribs
•
both approaches in its form and size to that of the lumbar vertebræ
ATTACHMENTS
• Anterior longitudinal ligament
• Posterior longitudinal ligament
• Ligamentum flavum
• Interspinous ligament
• Supraspinous ligament
ANTERIOR LONGITUDINAL LIGAMENT
 It runs down the anterior surface of the spine.
 It traverses all of the vertebral bodies and intervertebral discs.
POSTERIOR LONGITUDINAL
LIGAMENT
• It is situated within the vertebral canal, and extends
along the posterior surfaces of the bodies of the
vertebrae, from the body of the axis, where it is
continuous with the membrana tectoria, to the
sacrum
LIGAMENTA FLAVA
• ligamentum flavum (yellow ligament) are ligaments which connect the
laminae of adjacent vertebra, all the way from
the axis to the first segment of the sacrum (C2
to S1). They are best seen from the interior of
the vertebral canal;
• Their marked elasticity serves to preserve the
upright posture, and to assist the vertebral
column in resuming it after flexion.
INTERSPINOUS LIGAMENTS &SUPRASPINOUS LIGAMENT
• interspinous ligaments: thin and membranous, connect adjoining
spinous processes and extend from the root to the
apex of each process.
• supraspinous ligament is a strong fibrous cord,
which connects together the apices of the spinous
processes from the seventh cervical vertebra to
the sacrum
KYPHOSIS
• It is an exaggerated posterior) curvature in the
thoracic region.
• It produces the so-called "humpback", a condition
commonly observed in osteoporosis.
THORACIC DISC HERNIATION
• A tear in the outer, fibrous ring (annulus fibrosus) of an
intervertebral disc allows the soft, central portion
(nucleus pulposus) to bulge out.