Vertebral Column and Thoracic Cage Nestor T. Hilvano, M.D., M.P.H.

Learning Objectives You should be able to: Describe the general features and functions of the vertebral column. Identify and describe the special features of the vertebrae in different regions of the vertebral column and discuss the functional significance of the regional differences. Describe the anatomy of the sternum and ribs and how ribs articulate with the thoracic vertebrae. Compare and contrast scoliosis, kyphosis, and lordosis. Explain herniated disc of lower back as to structural and functional involvement.

Vertebral Column vertebrae and intervertebral discs vertebral groups 7 cervical in the neck 12 thoracic in the chest 5 lumbar in lower back 5 fused sacral 4 fused coccygeal Spine exhibits one continuous C-shaped curve, Known as primary curvature at birth

Adult Spinal Curvatures S-shaped vertebral column Secondary curvatures develop several months after birth lifting head as it begins to crawl develops cervical curvature. walking upright develops lumbar curvature.

Abnormal Spinal Curvatures ___ – abnormal lateral curvature of spine ___ - is a hump- backed, from osteoporosis or abnormal vertebral growth ___ - bending backward or swayback, from weak abdominal muscles a. kyphosis b. scoliosis c. lordosis d. stenosis

General Structure of Vertebra Vertebral Body Vertebral foramen Vertebral arch 2 lamina 2 pedicles Processes spinous, transverse and articular

Intervertebral Foramen and Discs _____ - passageway for nerves. _____ - absorb shock _____ - condition that caused pressures on spinal nerve or cord, may be due to sudden, traumatic injury or repeated minor injuries a. herniated disc b. intervertebral disc c. intervertebral foramen d. transverse foramen

Typical Cervical Vertebrae Body ___; Vertebral foramen ___; Spinous process (C2 to C6) ___; transverse processes short with ___ for protection of vertebral vessels. a. large b. small c.transverse foramen d. bifid/forked C7 is called vertebra prominens (spinous process ends in broad tubercle) ___ vertebrae have small bodies increasing the possibilities of dislocations and fractures. a. thoracic b. lumbar c. sacral d. cervical

The Unique Atlas and Axis Atlas (C1) supports the skull concave superior articular facet nod your head in “yes” movement vertebral foramen, with anterior and posterior arches no vertebral body and spinous process Axis (C2) Dens (odontoid process) is held in place inside the vertebral foramen of the atlas by transverse ligaments allows rotation of head -- “no”

Typical Thoracic Vertebrae Body ___; Vertebral foramen ___; Spinous process ___, not split, points inferiorly; Transverse processes with facets for ___ articulations, superior articular facets face posteriorly. a. small b. medium-sized c. rib articulations d. long/slender

Lumbar Vertebrae Body ___; Vertebral foramen ___; Spinous process ___, points posteriorly; Transverse processes short, ___. Superior articular processes face medially Lumbar region resistant to twisting movements a. smallest b. large c. no transverse foramen d. blunt/broad ___ vertebrae have massive bodies and are weight bearing which contribute to common site of ruptured disc.

Sacrum 5 sacral vertebrae fused Attaches the axial skeleton to the pelvic girdle Sacral promontory – landmark in females during pelvic exam and labor/delivery Anterior surface smooth and concave sacral foramina nerves and blood vessels 4 transverse lines indicate line of fusion of vertebrae Posterior surface - sacral crests provide attachment of muscles

Coccyx Single, small bone Attachment site for muscles of pelvic floor 4 vertebrae fused Co1 to Co4 Attachment site for muscles of pelvic floor Cornua hornlike projections on Co1 for ligaments attach coccyx to sacrum ___ What bone is fractured by fall or during childbirth? a. sacrum b. coccyx c. pelvis d. symphysis pubis

Thoracic Cage Consists of: sternum, ribs and thoracic vertebrae. Functions: attachment site for pectoral girdle and protects viscera. Sternum made up of: manubrium, body, and xiphoid process. 12 pairs of ribs: ___ true ribs; ___ false ribs; ___ floating ribs. a. 11th-12th pairs b. 8th-10th pairs c. 1st-7th pairs What bone is commonly fractured in doing a CPR? ___.

Rib Structure Flat blade called a shaft inferior margin has costal groove for nerves and vessels Proximal head and tubercle are connected by neck Articulation- head with body of vertebrae, tubercle with transverse process

Homework (Self- Review) Describe the distinctive characteristics of typical cervical, thoracic, and lumbar vertebrae as to location, vertebral body, vertebral foramen, spinous process, transverse processes, and functions. Compare and contrast spinal abnormalities in lordosis, kyphosis, and scoliosis. Identify specific bones associated with the following. a) vertebral prominens, b) dens, c) costal cartilages, d) xiphoid process, e) transverse foramina, e) tail bone 4. Explain why is the cervical vertebrae are more prone to fractures and dislocations rather than other regions of the vertebral column. 5. Discuss herniated disc of the lower back as to structural and functional involvement. 6. What is easily broken in doing a CPR and why?