THE BACK VERTEBRAE VERTEBRAL COLUMN TOPICS THE BONES and THE - - PowerPoint PPT Presentation
THE BACK VERTEBRAE VERTEBRAL COLUMN TOPICS THE BONES and THE JOINTS OF THE BACK THE TYPICAL VERTEBRA THE INTERVERTEBRAL DISC THE CERVICAL VERTEBRAE THE THORACIC VERTEBRAE THE LUMBAR VERTEBRAE THE SACRUM THE COCCYX
TOPICS
THE VERTEBRAE
THE BONES and THE JOINTS OF THE BACK
THE BACK
THE BACK - BONES & JOINTS
The back comprises the posterior aspect of the trunk, inferior to the neck and superior to the buMocks. The vertebral column extends from the cranium (skull) to the apex of the coccyx.
THE VERTEBRAE
THE BACK - BONES & JOINTS
The vertebral column in an adult consists of 33 vertebrae arranged in five regions:
THE VERTEBRAE
THE BACK - BONES & JOINTS
Significant mo]on occurs only between the 25 superior vertebrae. Of the 9 inferior vertebrae, the 5 sacral vertebrae are fused in adults to form the sacrum, and a`er approximately age 30, the 4 coccygeal vertebrae fuse to form the coccyx.
THE VERTEBRAE
THE BACK - BONES & JOINTS
THE TYPICAL VERTEBRA
THE VERTEBRAE
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A typical vertebra consists of a:
The vertebral body is the more massive, cylindrical, anterior part of the bone that gives strength to the vertebral column and supports body weight. The vertebral arch is posterior to the vertebral body and consists of 2 (right and le`) pedicles and 2 laminae. The vertebral arch and the posterior surface of the vertebral body form the walls of the vertebral foramen.
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The vertebral arch encloses the vertebral (foramen) canal that houses the spinal cord. THE VERTEBRAE The canal contains the spinal cord and the roots of the spinal nerves, along with the membranes (meninges), fat, and vessels that surround and serve them.
THE BACK - BONES & JOINTS
Vertebral notches of adjacent pedicles form intervertebral foramina that provide for the exit
THE VERTEBRAE The dorsal projec]ng spines and the lateral projec]ng transverse processes provide aRachment sites for muscles and ligaments.
THE BACK - BONES & JOINTS
Seven processes arise from the vertebral arch of a typical vertebra:
arch at the junc]on of the laminae.
junc]ons of the pedicles and laminae.
from the junc]ons of the pedicles and laminae, each bearing an ar]cular surface (facet). THE VERTEBRAE
THE BACK - BONES & JOINTS
The ar]cular processes are in apposi]on with corresponding processes of vertebrae adjacent (superior and inferior) to them, forming zygapophysial (facet) joints THE VERTEBRAE The intervertebral disks contribute to about 25% of the length of the vertebral column. They form the car]laginous joints between the vertebral bodies and provide limited movements between the individual vertebrae.
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THE INTERVERTEBRAL DISK
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Each intervertebral disk is numbered by the vertebral body above the disk. THE VERTEBRAE
THE BACK - BONES & JOINTS
Each intervertebral disk is composed of the following:
the outer concentric rings of fibrocar]lage and fibrous connec]ve ]ssue.
inner so`, elas]c, compressible material that func]ons as a shock absorber THE VERTEBRAE The hernia]on of a nucleus pulposus is most commonly in a posterolateral direcSon due to the strength and posi]on of the posterior longitudinal ligament
THE BACK - BONES & JOINTS
THE NECK 7 cervical vertebrae form the cervical region of the vertebral column, which encloses the spinal cord and meninges.
THE NECK - BONES & JOINTS
CERVICAL VERTEBRAE - CHARACTERISTICS
foramen transversarium (transverse foramen) in the transverse process
THE NECK - BONES & JOINTS
The most dis]nc]ve feature of each cervical vertebra is the oval foramen transversarium (transverse foramen) in the transverse process.
THE CERVICAL VERTEBRAE
THE NECK
THE NECK - BONES & JOINTS
THE CERVICAL VERTEBRAE
The four typical cervical vertebrae C3–C6 have the following characteris]cs:
anteroposteriorly; the superior surface is concave, and the inferior surface is convex.
atypical) include foramina transversaria for the vertebral vessels (the vertebral veins and, except for vertebra C7, the vertebral arteries).
projec]ons: an anterior tubercle and a posterior tubercle. The anterior rami of the cervical spinal nerves course ini]ally on the transverse processes in grooves for spinal nerves between the tubercles.
THE NECK - BONES & JOINTS
THE CERVICAL VERTEBRAE
The first (atlas), second (axis) and seventh (vertebra prominens) cervical vertebrae are ATYPICAL. Vertebrae C3–C6 are the typical cervical vertebrae.
THE NECK - BONES & JOINTS
THE CERVICAL VERTEBRAE
There are three atypical cervical vertebrae (C1, C2, and C7):
spinous process or body and consis]ng of two lateral masses connected by anterior and posterior arches. Its concave superior ar]cular facets receive the occipital condyles.
projects superiorly from its body. The dens is embryologically the vertebral body of the atlas (C1).
THE NECK - BONES & JOINTS
THE CERVICAL VERTEBRAE
The axis has two large, flat bearing surfaces, the superior ar]cular facets, on which the atlas rotates. The dens lies anterior to the spinal cord and serves as the pivot about which the rota]on of the head occurs. The dens is held in posi]on against the posterior aspect of the anterior arch of the atlas by the transverse ligament of the atlas.
THE NECK - BONES & JOINTS
THE CERVICAL VERTEBRAE
There are three atypical cervical vertebrae (C1, C2, and C7):
spinous process, which is not bifid. Its transverse processes are large, but its foramina transversaria are small.
THE NECK - BONES & JOINTS
THE CERVICAL VERTEBRAE
There are three atypical cervical vertebrae (C1, C2, and C7):
spinous process or body and consis]ng of two lateral masses connected by anterior and posterior arches. Its concave superior ar]cular facets receive the occipital condyles.
projects superiorly from its body.
spinous process, which is not bifid. Its transverse processes are large, but its foramina transversaria are small.
CERVICAL VERTEBRAE - CHARACTERISTICS
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C7 is a prominent vertebra that is characterized by a long spinous process - vertebra prominens
CERVICAL VERTEBRAE - CHARACTERISTICS
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body nor a spinous process
in the center of its external aspect
CERVICAL VERTEBRAE - CHARACTERISTICS
THE BACK - BONES & JOINTS
vertebrae
(odontoid process), which projects superiorly from its body
facets, on which the atlas rotates
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THORACIC VERTEBRAE - CHARACTERISTICS
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The thoracic vertebrae provide aMachment for the ribs the primary characteris]c features of thoracic vertebrae are the costal facets for ar]cula]on with ribs The primary characteris]c features of thoracic vertebrae are the costal facets for arSculaSon with ribs.
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LUMBAR VERTEBRAE - CHARACTERISTICS
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The lumbar vertebrae have massive bodies, accoun]ng for much of the thickness of the lower trunk in the median plane Are dis]nguished by their large bodies, sturdy laminae, and absence of costal facets. The fi`h lumbar vertebra has the largest body of the vertebrae. Are characterized by a strong, massive transverse process and have mamillary and accessory processes.
THE BACK - BONES & JOINTS
SACRUM - CHARACTERISTICS
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The wedged-shaped sacrum is usually composed of five fused sacral vertebrae in adults. The sacral canal is the con]nua]on of the vertebral canal in the sacrum Typically four pairs of sacral foramina for the exit of the posterior and anterior rami of the spinal nerves The base of the sacrum is formed by the superior surface
The anterior projec]ng edge of the body of the S1 vertebra is the sacral promontory. The apex of the sacrum, its tapering inferior end, has an oval facet for ar]cula]on with the coccyx.
SACRUM - CHARACTERISTICS
THE BACK - BONES & JOINTS
The sacrum is ]lted so that it ar]culates with the L5 vertebra at the lumbosacral angle, which varies from 130° to 160°. The pelvic surface of the sacrum is smooth and concave. The dorsal surface of the sacrum is rough, convex, and marked by five prominent longitudinal ridges
SACRUM - CHARACTERISTICS
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The clinically important features of the dorsal surface of the sacrum are the inverted U-shaped sacral hiatus and the sacral cornua The sacral hiatus leads into the sacral canal. In caudal epidural anesthesia or caudal analgesia, a local anestheSc agent is injected into the fat of the sacral canal that surrounds the proximal por]ons of the sacral nerves. Because the sacral hiatus is located between the sacral cornua and inferior to the S4 spinous process or median sacral crest, these palpable bony landmarks are important for loca]ng the hiatus. The anestheSc soluSon spreads superiorly and extradurally, where it acts on the S2–Co1 spinal nerves of the cauda equina.
LUMBAR PUNCTURE
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A lumbar puncture is used to inject anesthe]c material in the epidural space or to withdraw CSF from the subarachnoid space. A spinal tap is typically performed at the L4-L5 interspace. A horizontal line drawn at the top of the iliac crest marks the level of the L4 vertebra. When a lumbar puncture is performed in the midline, the needle passes through the interlaminar space of the vertebral column found between the laminae of the lumbar vertebrae. The interlaminar spaces are covered by the highly elas]c ligamentum flava.
LUMBAR PUNCTURE
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Clinical Correlate. During a lumbar puncture a needle is passed through the interlaminar space while the vertebral column is
THE BACK - BONES & JOINTS
COCCYX - CHARACTERISTICS
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a small triangular bone that is usually formed by fusion of the four coccygeal vertebrae the coccyx does not par]cipate with the other vertebrae in support of the body weight when standing
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VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
The vertebral column (spine) is an aggregate structure, normally made up of 33 vertebrae and the components that unite them into a single structural, func]onal en]ty - the “axis” of the axial skeleton.
VERTEBRAL COLUMN
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JOINTS OF VERTEBRAL COLUMN
VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
The joints of the vertebral column include the:
VERTEBRAL COLUMN
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The joints of the vertebral bodies are symphyses (secondary car]laginous joints) designed for weight-bearing and strength. The ar]cula]ng surfaces of adjacent vertebrae are connected by IV discs and ligaments. A typical vertebra has a total of six joints with adjacent vertebrae:
Each symphysis includes an intervertebral disc. INTERVERTEBRAL DISCS Stabilize and maintain spine by anchoring adjacent vertebral bodies. Allow flexibility and absorb/distribute energy. INTERVERTEBRAL DISCS The discs make up 25% of the spine height. Disc degenera]on with age results in loss of spinal column height.
VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
INTERVERTEBRAL DISCS Although the movement between any two vertebrae is limited, the summa]on of movement among all vertebrae results in a large range
The intervertebral disc consists of an outer anulus fibrosus, which surrounds a central nucleus pulposus.
VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
The anulus fibrosus consists of an outer ring of collagen. This arrangement of fibers limits rota]on between vertebrae. The nucleus pulposus fills the center of the intervertebral disc and absorbs compression forces between vertebrae.
VERTEBRAL COLUMN
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There is no IV disc between C1 and C2 vertebrae. The most inferior func]onal disc is between L5 and S1 vertebrae.
VERTEBRAL COLUMN
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Uncovertebral “joints” or cle`s (of Luschka) commonly develop between the unci of the bodies of C3 or 4–C6 or 7
the lateral and posterolateral margins of the IV discs. The uncovertebral “joints” are frequent sites of bone spur formaSon in later years, which may cause neck pain.
VERTEBRAL COLUMN
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The anterior longitudinal ligament is a strong, broad fibrous band that covers and connects the anterolateral aspects of the vertebral bodies and IV discs. The ligament extends longitudinally from the pelvic surface of the sacrum to the anterior tubercle of vertebra C1 and the occipital bone The anterior longitudinal ligament is the only ligament that limits extension. All other IV ligaments limit forms of flexion.
VERTEBRAL COLUMN
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The posterior longitudinal ligament is a much narrower, somewhat weaker band than the anterior longitudinal ligament. The posterior longitudinal ligament runs within the vertebral canal along the posterior aspect of the vertebral bodies. It is aMached mainly to the IV discs. Helps prevent or redirect posterior hernia]on of the nucleus pulposus.
VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
The joints of the vertebral column include the:
VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
The synovial joints between superior and inferior ar]cular processes on adjacent vertebrae are the zygapophysial joints. These ar]cula]ons are plane synovial joints between the superior and inferior arScular processes of adjacent vertebrae. A thin ar]cular capsule aMached to the margins
The zygapophysial joints permit gliding movements be tween the ar]cular processes.
VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
In cervical regions, the zygapophysial joints slope inferiorly from anterior to posterior. This orienta]on facilitates flexion and extension. In thoracic regions, the joints are oriented ver]cally and limit flexion and extension, but facilitate rota]on. In lumbar regions, the joint surfaces are curved and adjacent processes interlock, thereby limi]ng range of movement
THE LIGAMENTS OF VERTEBRAL COLUMN
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VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
The laminae of adjacent vertebral arches are joined by broad, pale yellow bands of elas]c ]ssue called the ligamenta flava. The thin interspinous ligaments connect adjoining spinous processes, aMaching from the root to the apex of each process. The cord-like band forming the supraspinous ligaments connects the ]ps of the spinous processes from C7 to the sacrum and merge superiorly with the nuchal ligament at the back of the neck. The strong, broad nuchal ligament is composed of thickened fibroelas]c ]ssue. The intertransverse ligaments, connec]ng adjacent transverse processes.
VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
The joints of the vertebral column include the:
VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
The atlantooccipital joints, formed between the atlas (C1 vertebra), and the occipital bone of the cranium. Atlanto-occipital Joints. The ar]cula]ons are between the superior ar]cular surfaces of the lateral masses of the atlas and the occipital condyles.
VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
Atlanto-occipital Joints. The main movement is fl exion, with a liMle lateral flexion and rota]on. The atlanto-axial joints, formed between the atlas and axis (C2 vertebra).
VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
Atlanto-axial Joints. There are three atlanto-axial ar]cula]ons. Atlanto-axial Joints. Two (right and le`) lateral atlanto-axial joints (between the inferior facets of the lateral masses of C1 and the superior facets of C2), and one median atlanto-axial joint (between the dens of C2 and the anterior arch of the atlas). The lateral atlanto-axial joints are gliding-type synovial joints, whereas the median atlantoaxial joint is a pivot joint.
THE CURVATURES OF VERTEBRAL COLUMN
THE BACK - BONES & JOINTS
CURVATURES OF VERTEBRAL COLUMN
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The vertebral column in adults has four curvatures that occur in the cervical, thoracic, lumbar, and sacral regions.
CURVATURES OF VERTEBRAL COLUMN
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thoracic kyphosis sacral kyphosis are concave anteriorly cervical lordosis lumbar lordosis are concave posteriorly
CURVATURES OF VERTEBRAL COLUMN
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The thoracic and sacral kyphoses are primary curvatures that develop during the fetal period. The cervical and lumbar lordoses are secondary curvatures that result from extension from the flexed fetal posi]on.
THE VASCULATURE OF VERTEBRAL COLUMN
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VASCULATURE OF VERTEBRAL COLUMN
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Vertebrae are supplied by periosteal and equatorial branches of the major cervical and segmental arteries and their spinal branches. Periosteal and equatorial branches arise from these arteries as they cross the external (anterolateral) surfaces of the vertebrae. Spinal veins form venous plexuses along the vertebral column both inside and outside the vertebral canal. Spinal veins form venous plexuses along the vertebral column both inside and outside the vertebral canal. The vertebral column is innervated by (recurrent) meningeal branches of the spinal nerves. The zygapophysial joints is innervated by ar]cular branches of the medial branches of the posterior rami.
LEVEL CORRESPONDING STRUCTURE
THE BACK - BONES & JOINTS
C2-C3 Mandible C3 Hyoid car]lage C4-C5 Thyroid car]lage C6 Cricoid car]lage C7 Vertebral prominens T3 Spine of scapula T7 Xyphoid, ]p of scapula T10 Umbilicus L1 Conus medullaris (end of cord) L3 Aorta bifurca]on L4 Iliac crest