The centrum is the main bony disk-shaped or spool-shaped portion of the vertebra; it forms around, and usually replaces, the notochord. On the dorsal side of the centrum is the neural arch, through which the nerve cord or spinal cord passes. The neural arch is often elongated into a neural spine,...
What is the lowest vertebrae?
The tailbone, or coccyx, is the lowest segment of the spinal column. The vertebrae in different sections of the spine have different structures and characteristics. The cervical spine forms the neck, the thoracic spine is in the region of the chest, and the lumbar spine supports the lower back.
How many bones are in the vertebrae?
The vertebral column is a series of approximately 33 bones called vertebrae, which are separated by intervertebral discs. The column can be divided into five different regions, with each region characterised by a different vertebral structure.
Where is the pedicle of vertebrae?
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Where is the thoracic and lumbar spine meet?
Lumbar Spine
- Body
- Spinous Process
- Articular Process
- Transverse Process
- Foramen
- Pedicle
- Body
What is the function of Centrum?
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What is the function of Centrum in lumbar vertebrae?
The lumbar vertebrae have a central body, also known as the centrum. This is large and mostly flattened, and it supports most of the body's weight.
What are types of vertebrae based on Centrum?
Opisthocoelous - centrum convex on anterior surface, concave on posterior surface, characteristic of some of the vertebrae of reptiles and mammals. Procoelous - centrum concave on anterior surface, convex on posterior surface, characteristic of some reptiles and amphibians.
What is Centrum in biology?
Medical Definition of centrum 1 : the center especially of an anatomical part. 2 : the body of a vertebra ventral to the neural arch.
Is laminectomy the same as decompression?
Cervical laminectomy Laminectomy is surgery that creates space by removing the lamina — the back part of a vertebra that covers your spinal canal. Also known as decompression surgery, laminectomy enlarges your spinal canal to relieve pressure on the spinal cord or nerves.
What causes pain in the lumbar vertebrae?
Common causes of low back pain (lumbar backache) include lumbar strain, nerve irritation, lumbar radiculopathy, bony encroachment, and conditions of the bone and joints.
What is Centrum and its types?
Centrum is the flat and thick portion of the vertebra which carries maximum load and pressure of the body. It is no doubt thick, and when we see the evolutionary line, we can see different types of centrum. The types of centrum are. Procoelous – concave in front and convex at back.
Which type of Centrum is found in vertebrae of mammals?
The vertebrae that have centrum with flat ends are called as acoelous, which is found in mammals. These flat ends of the centrum provide support and distribute forces as well as provides muscle attachment point.
Does axial vertebrae have Centrum?
The axis has an elongated centrum, the dens, which extends into the large neural canal of the atlas. The shape of the dens restricts motions between the first two vertebrae to rotations parallel to the long axis of the body.
Does sacral vertebrae have Centrum?
Development of the Sacrum By the eighth postovulatory week, five cartilaginous sacral vertebrae are evident. Each of these vertebrae goes on to form a centrum and bilateral neural processes.
What are the 5 parts of the vertebrae?
The spine is composed of 33 bones, called vertebrae, divided into five sections: the cervical, thoracic, and lumbar spine sections, and the sacrum and coccyx bones. The cervical section of the spine is made up of the top seven vertebrae in the spine, C1 to C7, and is connected to the base of the skull.
What is the neural arch of the vertebrae?
The neural arch is the bony structure that arises from the back of the vertebral body and encloses the spinal cord.
What is the name of the axis of the cervical vertebrae?
There are seven of these, and they are numbered C1 through C7. C1 is also dubbed the atlas, while C2 is the axis; both of these have more unique shapes—due to how they support the skull—in comparison with the other vertebrae.
What is the meaning of vertebrae?
Vertebrae Definition. Vertebrae are boneslocated within the vertebral column. In humans, they are a series of 33 bonesthat run from the base of the skull to the coccyx. The irregularly shaped bones form the roughly S-shape of the spinal cord. Between each vertebra is an intervertebral disc, which helps provide shock absorption and protect ...
How many lumbar vertebrae are there in chimpanzees?
They produce a natural curvature to the spine and support the greatest weight of the vertebrae. They allow for flexion, extension, and side-bending. Chimpanzees only have three lumbar vertebrae.
What is the bone that covers the vertebrae?
They are covered in cortical bone, which is denser, harder bone. The bodies have roughened attachment places for the intervertebral discs. The vertebrae have seven processes that jut out from their central body, including the main spinous process, four articular processes, and two transverse processes.
Which vertebrae do not have discs?
The sacral and coccygeal vertebrae do not have intervertebral discs. These bones are sometimes referred to as the caudal vertebrae and have the most variation in number, with some species having a few and others having 50caudal vertebrae.
Why are vertebrae important?
Vertebrae are important structurally in vertebrates. They support the head and neck, allowing movements such as turning the neck. The vertebrae also provide attachment points for muscles and ligaments, allowing many of the motions that the body is able to go through, such as bending and twisting. The vertebrae also protect ...
What are the two parts of the vertebrae?
The main portion of the vertebra is the body, which is divided into two parts: the centrum and the posterior vertebral arch (also called the neural arch).
How many somites are there in the human embryo?
Their number varies between species: there are 42 to 44 somites in the human embryo and around 52 in the chick embryo. The somites are spheres, formed from the paraxial mesoderm that lies at the sides of the neural tube and they contain the precursors of spinal bone, the vertebrae ribs and some of the skull, as well as muscle, ligaments and skin. Somitogenesis and the subsequent distribution of somites is controlled by a clock and wavefront model acting in cells of the paraxial mesoderm. Soon after their formation, sclerotomes, which give rise to some of the bone of the skull, the vertebrae and ribs, migrate, leaving the remainder of the somite now termed a dermamyotome behind. This then splits to give the myotomes which will form the muscles and dermatomes which will form the skin of the back. Sclerotomes become subdivided into an anterior and a posterior compartment. This subdivision plays a key role in the definitive patterning of vertebrae that form when the posterior part of one somite fuses to the anterior part of the consecutive somite during a process termed resegmentation. Disruption of the somitogenesis process in humans results in diseases such as congenital scoliosis. So far, the human homologues of three genes associated to the mouse segmentation clock, (MESP2, DLL3 and LFNG), have been shown to be mutated in cases of congenital scoliosis, suggesting that the mechanisms involved in vertebral segmentation are conserved across vertebrates. In humans the first four somites are incorporated in the base of the occipital bone of the skull and the next 33 somites will form the vertebrae, ribs, muscles, ligaments and skin. The remaining posterior somites degenerate. During the fourth week of embryogenesis, the sclerotomes shift their position to surround the spinal cord and the notochord. This column of tissue has a segmented appearance, with alternating areas of dense and less dense areas.
How are the sides of the vertebrae separated?
The sides of the vertebral column are separated from the posterior surface by the articular processes in the cervical and thoracic regions and by the transverse processes in the lumbar region . In the thoracic region, the sides of the bodies of the vertebrae are marked in the back 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 special spinal nerves and are situated between the transverse processes in the cervical region and in front of them, in the thoracic and lumbar regions.
What is the defining characteristic of a vertebrate in which the notochord (a flexible rod of
The vertebral column is the defining characteristic of a vertebrate in which the notochord (a flexible rod of uniform composition) found in all chordates has been replaced by a segmented series of bone: vertebrae separated by intervertebral discs.
What is abnormal curvature?
Excessive or abnormal spinal curvature is classed as a spinal disease or dorsopathy and includes the following abnormal curvatures: 1 Kyphosis is an exaggerated kyphotic (convex) curvature of the thoracic region in the sagittal plane, also called hyperkyphosis. This produces the so-called "humpback" or "dowager's hump", a condition commonly resulting from osteoporosis. 2 Lordosis is an exaggerated lordotic (concave) curvature of the lumbar region in the sagittal plane, is known as lumbar hyperlordosis and also as "swayback". Temporary lordosis is common during pregnancy. 3 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, so that they do not fuse properly. It can also be caused by pulmonary atelectasis (partial or complete deflation of one or more lobes of the lungs) as observed in asthma or pneumothorax. 4 Kyphoscoliosis, a combination of kyphosis and scoliosis.
What are the vertebrae in the human vertebral column?
Main article: Vertebra. The vertebrae in the human vertebral column are divided into different regions, which correspond to the curves of the spinal column. The articulating vertebrae are named according to their region of the spine. Vertebrae in these regions are essentially alike, with minor variation.
How many vertebrae are there in the human body?
In a human's vertebral column, there are normally thirty-three vertebrae. The upper 24 pre-sacral vertebrae are articulating and separated from each other by intervertebral discs, and the lower nine are fused in adults, five in the sacrum and four in the coccyx, or tailbone. The articulating vertebrae are named according to their region ...
What is the posterior of the vertebral arch?
The vertebral arch is posterior, meaning it faces the back of a person. Together, these enclose the vertebral foramen, which contains the spinal cord. Because the spinal cord ends in the lumbar spine, and the sacrum and coccyx are fused, they do not contain a central foramen.
What is the purpose of the centrum?
Centrum provides strength to vertebra and connects one vertebra with another. There are many types of centra in vertebrates. Amphicoelous vertebrae are found in fishes apoda and some urodela. These have concavities on anterior as well as posterior side of the centrum.
Which vertebrae have concavity?
Opisthocoelous vertebrae possess concavity on the posterior side while convexity on the anterior side, as found in salamanders, parrots and ungulates. Amphiplatyan vertebrae are flat on both sides as in mammals. Heterocoelous vertebrae are characteristic of birds neck.
What is the name of the vertebrae that are characteristic of birds neck?
Heterocoelous vertebrae are characteristic of birds neck. The centrum is saddle-shaped to provide high flexibility to the neck movement. Biconvex vertebra is the 9 th vertebra of frog, whose centrum has convexity on both anterior as well as posterior side.
How many cervical vertebrae are there in mammals?
MAMMALS. Mammals have 7 cervical vertebrae, except 6 in manatee, 8 in ant bear and 9 in sloth. Dorsal vertebrae are differentiated into thoracic and lumbar which vary in number. Sacral vertebrae are 2-5 and are fused to form a synsacrum. Sacrum is absent in whales and dolphins.
Which vertebrae are gasterocentrous?
Most of the vertebrae, except in the neck and tail region are fused together and are gasterocentrous. Cervical vertebrae are heterocoelous to provide flexibility to the neck. Thoracic vertebrae are fused and carry double-headed ribs with uncinate process. Foramen transversalia is characteristic of cervical vertebrae and also there are reduced cervical ribs. Synsacrum is made by the fusion of thoracic, lumbar, sacral and few caudal vertebrae. Free caudal vertebrae are amphicoelous and the terminal caudals are fused together to form pygostyle for giving support to rectrices.
Which vertebrae are bony and identifiable into trunk and caudal vertebrae?
Vertebrae are bony and identifiable into trunk and caudal vertebrae. Caudal vertebrae possess long neural and haemal spines. Centra are amphicoelous and notochord is extremely constricted in the middle of the centrum. Ribs are single headed attached to the trunk vertebrae.
What are the two types of vertebrae?
ELASMOBRANCHS. Vertebral column is cartilaginous and continuously wrapped around the notochord. There are only two types of vertebrae, namely trunk and caudal, the latter possess haemal arch and haemal spine. Vertebrae are diplospondylous type, having anterior hypocentrum and posterior pleurocentrum.
What is the structure of a vertebrae?
Vertebrae, apart from those that are atypical, have a similar basic structure which can be described as an anterior vertebral body and a posterior neural (or vertebral) arch. These basic characteristics vary depending on the function of each individual vertebra. The vertebral body is the large anterior cylindrical portion ...
What is the unit of the vertebra?
Vertebra. The vertebra (plural: vertebrae) is the fundamental segmental unit of the vertebral column (also known as the spine ).
How many secondary ossification centers are there in each vertebra?
During puberty, five secondary ossification centers develop in each vertebra. The secondary centers on the tips of the transverse and spinous processes contribute to the length of these. In the developing vertebral body, two ring or annular epiphyses form, one above and one below the ossifying centrum.
What is the neural arch?
The neural arch is comprised of the bone posterior to the vertebral body which has several individual components that are fused to form a ring (the vertebral foramen) that encloses the spinal canal. The components are: the pedicles which are short, thick bilateral processes that protrude posteriorly from the posterolateral corner ...
How many vertebrae are in the spine?
Spinal organization. There are 24 vertebrae stacked on top of each other separated by intervertebral discs . In addition, there are five sacral vertebrae which are fused into a single bone, the sacrum. Four small caudal rudimentary vertebrae fuse to form the coccyx.
Which part of the pedicle is slightly curved?
The superior and inferior margins of each pedicle are slightly curved and form the vertebral notches, which when an adjacent vertebra is joined, create the intervertebral (or neural) foramina which transmit the nerve roots and associated vessels.
What is the span of bone in the lumbar spine?
in the lumbar spine, a span of bone exists between the superior and inferior articular processes bilaterally, which is known as the pars interarticularis. In the axial plane, this lies between the pedicle and the lamina on each side.
