Maria Kais-
-what is the total number of vertebrae during early development?-what happens to several vertebrae in the sacral and coccygeal regions?-how many vertebrae does the adult vertebral column have?The total number of vertebrae during early development is 33. Then, several vertebrae in the sacral and coccygeal regions fuse. As a result, the adult vertebral column typically contains 26 vertebrae.
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how are the 26 vertebrae distributed?■7 cervical vertebrae in the neck region. ■ 12 thoracic vertebrae posterior to the thoracic cavity. ■ 5 lumbar vertebrae support the lower back. ■ 1 sacrum consists of five fused sacral vertebrae. ■1 coccyx usually consists of four fused coccygeal vertebrae.
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when viewed from the side, what does the vertebral column show?When viewed from the side, the vertebral column shows four slight bends called normal curves.
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relative to the front of the body, describe the cervical and lumbar curves, the thoracic and sacral curves.Relative to the front of the body, the cervical and lumbar curves are convex (bulging out), and the thoracic and sacral curves are concave (cupping in).
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what are the functions of the curves of the vertebral column? (4)The curves of the vertebral column increase its strength, help maintain balance in the upright position, absorb shocks during walking and running, and help protect the vertebrae from breaks .
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whuch vertebrae are movable and which are immovable?The cervical, thoracic, and lumbar vertebrae are movable, but the sacrum and coccyx are immovable.
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what is between adjacent vertebrae from the 2nd cervical vertebra to the sacrum?Between adjacent vertebrae from the second cervical vertebra to the sacrum are intervertebral discs.
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what does each disc have on the outer and on the interior?Each disc has an outer ring of fibrocartilage and a soft, pulpy, highly elastic interior.
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what are the functions of the discs? (3)The discs form strong joints, permit various movements of the vertebral column, and absorb vertical shock.
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describe the vertebral column in the fetus.In the fetus, there is a single concave curve.
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what happens at the 3rd month after birth?At about the third month after birth, when an infant begins to hold its head erect, the cervical curve develops.
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when does the lumbar curve develop?Later, when the child sits up, stands, and walks, the lumbar curve develops.
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what is the body and describe its shape?The body, the thick, disc-shaped front portion, is the weight-bearing part of a vertebra.
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-how does the vertebral arch extend?-it is formed by what? how does the pedicles project from the body?-what are the laminae and how do they end?-what does the hole between the vertebral arch and body contain and what is it known as?-together, what do the vertebral foramina of all vertebrae form?-there is what when the vertebrae are stacked on top of one another?-what is each opening called and what does it permit?-The vertebral arch extends backwards from the body of the vertebra.-It is formed by two short, thick processes, the pedicles, which project backward from the body to unite with the laminae.-The laminae are the flat parts of the arch and end in a single sharp, slender projection called a spinous process.-The hole between the vertebral arch and body contains the spinal cord and is known as the vertebral foramen.-Together, the vertebral foramina of all vertebrae form the vertebral cavity.-When the vertebrae are stacked on top of one another, there is an opening between adjoining vertebrae on both sides of the column.-Each opening, called an intervertebral foramen, permits the passage of a single spinal nerve.
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-how many processes arise from the vertebral arch?-at the point where a lamina and pedicle join, what extends laterally on each side?-what projects from the junction of the laminae?-what do these 3 processes serve as?-what do the remaining 4 processes form with other vertebrae above or below?-what do the 2 superior articular processes of a vertebra articulate with?-what do the 2 inferior articular processes of a vertebra articulate with?-what are facets and with what are they covered?-Seven processes arise from the vertebral arch.-At the point where a lamina and pedicle join, a transverse process extends laterally on each side.-A single spinous process (spine) projects from the junction of the laminae.-These three processes serve as points of attachment for muscles.-The remaining four processes form joints with other vertebrae above or below.-The two superior articular processes of a vertebra articulate with the vertebra immediately above them.-The two inferior articular processes of a vertebra articulate with the vertebra immediately below them.-The smooth articulating surfaces of the articular processes are called facets, which are covered with hyaline cartilage.
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how are the vertebrae in each region numbered?Vertebrae in each region are numbered in sequence from top to bottom.
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what are the 7 cervical vertebrae termed?The seven cervical vertebrae are termed C1 through C7.
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describe the spinous processes of the 2nd through 6th cervical vertebrae.The spinous processes of the second through sixth cervical vertebrae are often bifid, or split into two parts.
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how many foramina do all cervical vertebrae have? name themAll cervical vertebrae have three foramina: one vertebral foramen and two transverse foramina.
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what does each cervical transverse process contain? what passes through the transverse foramen?Each cervical transverse process contains a transverse foramen through which blood vessels and nerves pass.
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do the 1st 2 cervical vertebrae differ from the others?The first two cervical vertebrae differ considerably from the others.
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what is the 1st cervical vertebra called and what does it support and why is it named atlas?The first cervical vertebra (C1), the atlas, supports the head and is named for the mythological Atlas who supported the world on his shoulders.
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what does the atlas lack?The atlas lacks a body and a spinous process.
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what does the upper surface of C1 contain and what does it articulate? what does this articulation permit?The upper surface contains superior articular facets that articulate with the occipital bone of the skull. This articulation permits you to nod your head to indicate “yes.”
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what does the inferior surface of C1 contain? what does it articulate with?The inferior surface contains inferior articular facets that articulate with the second cervical vertebra.
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-what is the 2nd cervical vertebra called and what does it have?-what is the dens and where does it projects?-what is the dens considered as?-The second cervical vertebra (C2), the axis, does have a body and a spinous process.-A tooth-shaped process called the dens projects up through the vertebral foramen of the atlas.-The dens is a pivot on which the atlas and head move, as in side-to-side movement of the head to signify “no.”
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-what do the 3rd through 6th cervical vertebrae correspond to?-what is the 7th cervical vertebra called and is it different?-by what is it marked?-The third through sixth cervical vertebrae (C3 through C6), represented by the vertebra, correspond to the structural pattern of the typical cervical vertebra.-The seventh cervical vertebra (C7), called the vertebra prominens, is somewhat different.-It is marked by a single, large spinous process that can be seen and felt at the base of the neck.
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-what are the thoracic vertebrae termed as, describe their size and strength in comparison to the cervical vertebrae?-what are the distinguishing features of the thoracic vetebrae?-by what are movements of the thoracic region limited?-Thoracic vertebrae (T1 through T12) are considerably larger and stronger than cervical vertebrae.-Distinguishing features of the thoracic vertebrae are their facets for articulating with the ribs.-Movements of the thoracic region are limited by the attachment of the ribs to the sternum.
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-what are the lumbar vertebrae termed as? describe their size and strength.-describe their various projections and the spinous processes.-The lumbar vertebrae (L1 through L5) are the largest and strongest of the unfused bones in the vertebral column.-Their various projections are short and thick, and the spinous processes are well adapted for the attachment of the large back muscles.
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-what is the sacrum and by what is it formed? what are the sacral vertebrae termed as?-when does the fusion of the sacral vertebrae begin and when is it complete?-what does the sacrum serve as?-where is it positioned? what do the lateral surfaces of the pelvic cavity fuse to?-The sacrum is a triangular bone formed by the fusion of five sacral vertebrae, indicated in as S1 through S5.-The fusion of the sacral vertebrae begins between ages 16 and 18 years and is usually completed by age 30.-The sacrum serves as a strong foundation for the pelvic girdle.-It is positioned at the back of the pelvic cavity where its lateral surfaces fuse to the two hip bones.
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-what do the anterior and posterior sides of the sacrum contain?-nerves and blood vessels pass through what?-what is the sacral canal?-what is the lower entrance of the canal called?-what does the anterior top border of the sacrum have? what is this projection used as?-The anterior and posterior sides of the sacrum contain four pairs of sacral foramina.-Nerves and blood vessels pass through the foramina.-The sacral canal is a continuation of the vertebral cavity.-The lower entrance of the canal is called the sacral hiatus.-The anterior top border of the sacrum has a projection, called the sacral promontory, which is used as a landmark for measuring the pelvis prior to childbirth.
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-what is the shape of the coccyx and by what is it formed?-what is it termed as?-what does the top of the coccyx articulate with?-The coccyx, like the sacrum, is triangular in shape and is formed by the fusion of the four coccygeal vertebrae.-These are indicated in as Co1 through Co4.-The top of the coccyx articulates with the sacrum.
