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Encyclopedia > Vertebral column
The vertebral column seen from the side
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The vertebral column seen from the side
Different regions (curvatures) of the vertebral column
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Different regions (curvatures) of the vertebral column

The vertebral column (backbone or spine) is a column of vertebrae situated in the dorsal aspect of the abdomen. It houses the spinal cord in its spinal canal. Image File history File links Download high resolution version (233x800, 27 KB) File links The following pages link to this file: Vertebral column Deadlift ... Image File history File links Download high resolution version (233x800, 27 KB) File links The following pages link to this file: Vertebral column Deadlift ... Image File history File links 385px-Spinal_column_curvature. ... Image File history File links 385px-Spinal_column_curvature. ... A diagram of a thoracic vertebra. ... In anatomy, the abdomen is a part of the body, In humans, it is the region between the thorax and the pelvis. ... The spinal cord is a part of the vertebrate nervous system that is enclosed in and protected by the vertebral column (it passes through the spinal canal). ... The spinal canal is the space in vertebrae through which the spinal cord passes. ...

Contents


Curves

Viewed laterally the vertebral column presents several curves, which correspond to the different regions of the column, and are called cervical, thoracic, lumbar, and pelvic. The cervical curve, convex forward, begins at the apex of the odontoid (tooth-like) process, and ends at the middle of the second thoracic vertebra; it is the least marked of all the curves. The thoracic curve, concave forward, begins at the middle of the second and ends at the middle of the twelfth thoracic vertebra. Its most prominent point behind corresponds to the spinous process of the seventh thoracic vertebra. The lumbar curve is more marked in the female than in the male; it begins at the middle of the last thoracic vertebra, and ends at the sacrovertebral angle. It is convex anteriorly, the convexity of the lower three vertebrae being much greater than that of the upper two. The pelvic curve begins at the sacrovertebral articulation, and ends at the point of the coccyx; its concavity is directed downward and forward. The thoracic and pelvic curves are termed primary curves, because they alone are present during fetal life. In the early embryo, the vertebral column is C-shaped, and the cervical and lumbar curvatures are not yet present in a newborn infant. The cervical and lumbar curves are compensatory or secondary, and are developed after birth, the former when the child is able to hold up its head (at three or four months), and to sit upright (at nine months), the latter at twelve or eighteen months, when the child begins to walk. A cervical vertebra Cervical vertebrae (Vertebrae cervicales) are the smallest of the true vertebrae, and can be readily distinguished from those of the thoracic or lumbar regions by the presence of a foramen (hole) in each transverse process. ... A typical thoracic vertebra The thoracic vertebrae (vertebrae thoracales) compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. ... Categories: Anatomy stubs | Anatomy ... Female symbol Female is the sex of an organism, or a part of an organism, which produces egg cells. ... Male symbol Male is the sex of an organism, or a part of an organism, which produces sperm. ... The coccyx is formed of four fused vertebrae. ... Fetus at eight weeks Foetus redirects here. ... Embryos (and one tadpole) of the wrinkled frog (Rana rugosa). ... A human infant The word Infant derives from the Latin in-fans, meaning unable to speak. ... Birth is the process in animals by which an offspring is expelled from the body of its mother. ... A male toddler A child (plural: children) is a young human. ... For other uses of the word head, see head (disambiguation). ... Walking is the main form of animal locomotion on land, distinguished from running and crawling. ...


The vertebral column also has a slight lateral curvature, the convexity of which is directed toward the right side. This may be produced by muscular action, most persons using the right arm in preference to the left, especially in making long-continued efforts, when the body is curved to the right side. In support of this explanation it has been found that in one or two individuals who were left-handed, the convexity was to the left side. This curvature is regarded by others as being produced by the aortic arch and upper part of the descending thoracic aorta – a view which is supported by the fact that in cases where the viscera are transposed and the aorta is on the right side, the convexity of the curve is directed to the left side. ARM may stand for: Most likely: ARM Ltd (originally Advanced RISC Machines) ARM architecture CPU design or one of its derivatives developed by ARM Ltd (originally called The Acorn RISC Machine) Adjustable rate mortgage Annotated Reference Manual (C++) Artificial rupture of membranes (see amniotic sac) the ISO 3166-1 3... The largest artery in the human body, the aorta originates from the left ventricle of the heart and brings oxygenated blood to all parts of the body in the systemic circulation. ... In anatomy, the viscera are the internal organs of an animal, in particular the internal organs of the head, thorax and abdomen. ...


Surfaces

Anterior surface

When viewed from in front, the width of the bodies of the vertebrae is seen to increase from the second cervical to the first thoracic; there is then a slight diminution in the next three vertebrae; below this there is again a gradual and progressive increase in width as low as the sacrovertebral angle. From this point there is a rapid diminution, to the apex of the coccyx.


Posterior surface

The posterior surface of the vertebral column presents in the median line the spinous processes. In the cervical region (with the exception of the second and seventh vertebrae) these are short and horizontal, with bifid extremities. In the upper part of the thoracic region they are directed obliquely downward; in the middle they are almost vertical, and in the lower part they are nearly horizontal. In the lumbar region they are nearly horizontal. The spinous processes are separated by considerable intervals in the lumbar region, by narrower intervals in the neck, and are closely approximated in the middle of the thoracic region. Occasionally one of these processes deviates a little from the median line — a fact to be remembered in practice, as irregularities of this sort are attendant also on fractures or displacements of the vertebral column. On either side of the spinous processes is the vertebral groove formed by the laminae in the cervical and lumbar regions, where it is shallow, and by the laminae and transverse processes in the thoracic region, where it is deep and broad; these grooves lodge the deep muscles of the back. Lateral to the vertebral grooves are the articular processes, and still more laterally the transverse processes. In the thoracic region, the transverse processes stand backward, on a plane considerably behind that of the same processes in the cervical and lumbar regions. In the cervical region, the transverse processes are placed in front of the articular processes, lateral to the pedicles and between the intervertebral foramina. In the thoracic region they are posterior to the pedicles, intervertebral foramina, and articular processes. In the lumbar region they are in front of the articular processes, but behind the intervertebral foramina.


Lateral surfaces

The lateral surfaces are separated from the posterior surface by the articular processes in the cervical and lumbar regions, and by the transverse processes in the thoracic region. They present, in front, the sides of the bodies of the vertebrae, marked in the thoracic region by the facets for articulation with the heads of the ribs. More posteriorly are the intervertebral foramina, formed by the juxtaposition of the vertebral notches, oval in shape, smallest in the cervical and upper part of the thoracic regions, and gradually increasing in size to the last lumbar. They transmit the spinal nerves and are situated between the transverse processes in the cervical region, and in front of them in the thoracic and lumbar regions.


Vertebral canal

The vertebral canal follows the different curves of the column; it is large and triangular in those parts of the column which enjoy the greatest freedom of movement, such as the cervical and lumbar regions; and is small and rounded in the thoracic region, where motion is more limited.


Abnormalities

Occasionally the coalescence of the laminae is not completed, and consequently a cleft is left in the arches of the vertebrae, through which a protrusion of the spinal membranes (dura mater and arachnoid), and generally of the spinal cord (medulla spinalis) itself, takes place, constituting the malformation known as spina bifida. This condition is most common in the lumbosacral region, but it may occur in the thoracic or cervical region, or the arches throughout the whole length of the canal may remain incomplete. The dura mater (from the Latin hard mother), or pachymeninx, is the tough and inflexible outermost of the three layers of the meninges surrounding the brain. ... The arachnoid layer is the second or middle layer of the meninges, the membranes surrounding the brain. ... The spinal cord is a part of the vertebrate nervous system that is enclosed in and protected by the vertebral column (it passes through the spinal canal). ...


The following abnormal curvatures may occur in some people:

  • Kyphosis is an exaggerated posterior curvature in the thoracic region. This produces the so-called "humpback".
  • Lordosis is an exaggerated anterior curvature of the lumbar region, "swayback". Temporary lordosis is common among pregnant women.
  • Scoliosis, lateral curvature, is the most common abnormal curvature, occurring in 0.5% of the population. It is more common among females and may result from unequal growth of the two sides of one or more vertebrae.

The medical term kyphosis has several meanings. ... Lordosis is a term used to describe the direction of the curvature of the five lumbar and seven cervical vertebrae of the vertebral column. ... A pregnant woman Pregnancy is the process by which a mammalian female carries a live offspring from conception until it develops to the point where the offspring is capable of living outside the womb. ... Image of a woman on the Pioneer plaque sent to outer space. ... Female symbol Female is the sex of an organism, or a part of an organism, which produces egg cells. ...

References

1917 (MCMXVII) was a common year starting on Monday of the Gregorian calendar (see link for calendar) or a common year starting on Tuesday of the Julian calendar. ... Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ... Anatomical drawing of the human muscles from the Encyclopédie. ... The 1989 movie Gross Anatomy stars Matthew Modine and Daphne Zuniga. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ...

Links

  • Osteopathy and the Spine
  • North American Spine Society is a multidisciplinary medical organization that advances quality spine care through education, research and advocacy.

  Results from FactBites:
 
II. Osteology. 3b. The Vertebral Column as a Whole. Gray, Henry. 1918. Anatomy of the Human Body. (1077 words)
The vertebral column is situated in the median line, as the posterior part of the trunk; its average length in the male is about 71 cm.
111), the vertebral column presents several curves, which correspond to the different regions of the column, and are called cervical, thoracic, lumbar, and pelvic.
On either side of the spinous processes is the vertebral groove formed by the laminæ in the cervical and lumbar regions, where it is shallow, and by the laminæ and transverse processes in the thoracic region, where it is deep and broad; these grooves lodge the deep muscles of the back.
Vertebral column Summary (1754 words)
In human anatomy, the vertebral column (backbone or spine) is a column of vertebrae situated in the dorsal aspect of the abdomen.
It houses the spinal cord in its spinal canal.
In the early embryo, the vertebral column is C-shaped, and the cervical and lumbar curvatures are not yet present in a newborn infant.
  More results at FactBites »

 
 

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