Vertebral column 33 Vertebrae Inter-vertebral disc 7 12 5 4 Vertebral column 33 Vertebrae Inter-vertebral disc Form 1/4 of its length

Curvature of vertebral column Thoracic and sacral (primary) Concave anterior. Develop during fetal period, deference between ant and post Thickness of the vertebra. Cervical and lumbar : Concave posterior, develop during the fetal period, due to deference in IV disc thickness - Cervical - infant hold head - Lumber - infant walk and assume upright position, prominent in female.

Abnormal Vertebral column curvature Kyphosis: abnormal increase in thoracic curv. Erosion of anterior vertebral part. Lordosis: (hollow back) anterior rotation of pelvis. Abnormal increase in lumber curvature (pregnancy) Scoliosis: (Crooked or curved back) abnormal lateral curvature and rotation of the back (appears between ages of 10-15)

General Structure of Typical Vertebrae Body or centrum – disc- shaped, weight-bearing region Vertebral arch – composed of pedicles and laminae that along with the centrum, encloses the vertebral foramen Vertebral foramina – make up the vertebral canal through which the spinal cord passes

General Structure of typical Vertebrae cont. Spinous process project posterior and usually downward. Transverse processes project laterally Superior and inferior articular processes – protrude superiorly and inferiorly from the pedicle-lamina junctions Inter-vertebral foramina – lateral openings formed from notched areas on the superior and inferior borders of adjacent pedicles

Cervical Vertebrae Seven vertebrae (C1-C7) are the smallest & lightest vertebrae C3-C7 are distinguished with an oval body long spinous processes Large and triangular vertebral foramina Each transverse process contains a transverse foramen. Superior and inferior articular facets are oriented sup. and inf.

Atypical Cervical Vertebrae: The Atlas (C1) Has no body and no spinous process Consists of anterior and posterior arches, and two lateral masses The superior and inferior surface of lateral masses has articular surfaces to articulate with the occipital condyles and with the axis

Atypical Cervical Vertebrae: The Axis (C2) The axis has a body, spine, and vertebral arches as do other cervical vertebrae Unique to the axis is the dens, or odontoid process, which projects superiorly from the body and is attached to the anterior surface of the arch of the atlas. The dens is a pivot for the rotation of the atlas

Pivot Joint Projection of bone 1 articulates within ring of bone 2 Movements: Rotation Around one Axes

Thoracic Vertebrae There are twelve vertebrae (T1-T12) all of which articulate with ribs. Major markings include two demi-facets on the heart-shaped body for the head of the rib. Circular vertebral foramen, transverse processes with articular costal facets for the rib tubercles. Long biffed spinous process that is inclined downward. The location of the articulate facets prevent flexion and extension, but allow rotation of this area of the spine. Superior articular processes are oriented backward and laterally.

Thoracic Vertebrae

Lumbar Vertebrae The five lumbar vertebrae (L1-L5) are located in the small region of the back and have an enhanced weight-bearing function. Body is large and kidney-shaped. They have short, thick pedicles and lamina. Flat hatchet-shaped spinous processes. Triangular-shaped vertebral foramen. Orientation of the sup. articular facets face medially to lock the lumbar vertebrae together to provide stability

Vertebral characteristics

Inter-Vertebral Joints

Vertebral Column: Inter-vertebral Discs Cushion-like pad composed of two parts Nucleus pulposus – inner gelatinous nucleus that gives the disc is elasticity and compressibility Annulus fibrosus – surrounds the nucleus pulposus with a collar composed of collagen and Fibro cartilage.

Movements

Atlanto-occipital joints and ligaments Often considered to be a Hinge joint because of its primary uniaxial range of movement (as in shaking your head “yes”). The atlanto-occipital joints occur between the reciprocally curved surfaces of the two occipital condyles and the articular facets on the lateral masses of the atlas. Movements: While the primary axis of movement is the nodding movements (flexion and extension of the head) in the antero-posterior plane, a small amount of side to side bending (lateral flexion), and rotation is possible at this joint surface. Ligaments of the joint: Are the fibrous membrane of the joint capsule (Ant and Post), the anterior atlanto-occipital membrane, and the posterior atlanto-occipital membrane.

Cruciform ligament of atlas (cruciform): Alar ligaments: They connect the sides of the dens (on the axis, or the second cervical vertebra) to the tubercles on the medial side of the occipital condyle. Legamentum flavum: They connect the laminae of adjacent vertebrae, extending from the second thoracic vertebra, the axis, to the first segment of the sacrum Cruciform ligament of atlas (cruciform): is a cruciate ligament in the neck forming part of the atlanto-axial joint.

Cruciate ligament of atlas

Ligamentum flavum They connect the laminae of adjacent vertebrae,

Sacrum and Coccyx The sacrum Consists of five fused vertebrae (S1-S5), which shape the posterior wall of the pelvis It articulates with L5 superiorly, and with the auricular surfaces of the hip bones Major markings include the sacral promontory, transverse lines, alae, dorsal sacral foramina, sacral canal, and sacral hiatus

Coccyx S1 S2 S3 S4 S5 1 2 3 4 Coccyx (Tailbone) The coccyx is made up of four (in some cases three to five) fused vertebrae that articulate superiorly with the sacrum

Disc Problems Slipped (degeneration) disc vs. herniated disc Most common sites for disc problems: C5 - C6 L4 - L5 L5 - S1 Lumbago Laminectomy ( IS a surgical removal vertebral arch by shaving laminae to access disc)

Vertebral “Body” Fracture

Bony Thorax (Thoracic Cage) The thoracic cage is composed of the thoracic vertebrae dorsally, the ribs laterally, and the sternum and costal cartilages anteriorly Functions Forms a protective cage around the heart, lungs, and great blood vessels Supports the shoulder girdles and upper limbs Provides attachment for many neck, back, chest, and shoulder muscles Uses intercostal muscles to lift and depress the thorax during breathing

Bony Thorax (Thoracic Cage)

Sternum (Breastbone) A dagger-shaped, flat bone that lies in the anterior midline of the thorax Results from the fusion of three bones – the superior manubrium, the body, and the inferior xiphoid process Anatomical landmarks include the jugular (suprasternal) notch, the sternal angle, and the xiphisternal joint

Sternum

Structure of a Typical True Rib Bowed, flat bone consisting of a head, neck, tubercle, and shaft

Superior facet Inferior facet Articular facet of tubercle