cervical vertebrae 1

8/6/2019 Cervical Vertebrae 1

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Cervical vertebrae



The first cervical vertebra.

� General features: The first cervical vertebra) isnamed the Atlas, because it supports the globe of the head.

� It differs from all the other vertebra in having nobody.

� In addition, it has no spine.

� The atlas consists of two bulky lateral masses,connected to each other in front by a shortanterior arch, and behind by a long, curved,

posterior arch. It therefore forms a ring of bone.� When the atlas and the second cervical vertebra

are articulated together, an upward projectionfrom the latter, which is termed the odontoid

process.



Axis (anatomy)

� The second cervical vertebra.

� It forms the pivot upon which the first cervical

vertebra (the atlas), which carries the head,rotates.

� The most distinctive characteristic of this bone

is the strong odontoid process ("dens") which

rises perpendicularly from the upper surface

of the body



The body

� The body is deeper in front than behind, andprolonged downward anteriorly so as tooverlap the upper and front part of the third

vertebra.

� It presents in front a median longitudinalridge, separating two lateral depressions forthe attachment of the longuss colli muscles.

� Its under surface is concave from beforebackward and convex from side to side.



Other features

� The dense, or odontoid process , exhibits a slightconstriction or neck where it joins the body.

� The pedicles are broad and strong, especially in front,where they coalesce with the sides of the body and theroot of the odontoid process. They are covered above by

th

e superior articular surfaces.� The laminae are thick and strong, and the vertebral

foramen large, but smaller than that of the atlas.

� The transverse process are very small, and each ends in asingle tubercle; each is perforated by the transverse

foramen , which is directed obliquely upward and laterally.� The spinous process is large, very strong, deeply

channelled on its under surface, and presents a bifid,tuberculated extremity.



The seventh cervical vertebra

� General features:� The seventh cervical vertebra:

� is named the vertebra prominens because of itslong spine, the tip of which can be felt through the

skin at the lower end of the furrow.� This process is thick and nearly horizontal in

direction; it is not bifurcated but ends in a tubercle.

� The transverse processes are of considerable size.

� The anterior parts are usually slender, but they mayform separate bones, which are then known ascervical ribs.

� The foramen transversarium is relatively small;



A typical cervical vertebra.

� General features.-

� The body is small and is broader from side to side thanfrom before backwards.

� The vertebral foramen is large in proportion to the size of the body and it is triangular in outline.

� The pedicles, which project laterally as well as backwards.

� The superior and inferior vertebral notches are almostequal,

� The laminae are relatively long and narrow, and are thinnerabove than below.

� The spine (spinous process) is s

hort and bifid.

� The superior and inferior articular processes processesform an articular pillar, which projects laterally at the

junction of the pedicle and lamina.

� The transverse process is pierced by the foramen.

cervical vertebrae 1

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