query: the zygapophyseal joints of the vertebral column are classified as

pos: Facet joint the complex shape and deep location of the facet. Ancient Greek: ' ("yoke") + ' ("out/from") + "" ("grow") Facet joint The facet joints, (or zygapophysial joints, zygapophyseal, apophyseal, or Z-joints) are a set of synovial, plane joints between the articular processes of two adjacent vertebrae. There are two facet joints in each spinal motion segment and each facet joint is innervated by the recurrent meningeal nerves. The biomechanical function of each pair of facet joints is to guide and limit movement of the spinal motion segment. In the lumbar spine, for example, the facet joints function to protect the

pos: Facet joint Facet joint The facet joints, (or zygapophysial joints, zygapophyseal, apophyseal, or Z-joints) are a set of synovial, plane joints between the articular processes of two adjacent vertebrae. There are two facet joints in each spinal motion segment and each facet joint is innervated by the recurrent meningeal nerves. The biomechanical function of each pair of facet joints is to guide and limit movement of the spinal motion segment. In the lumbar spine, for example, the facet joints function to protect the motion segment from anterior shear forces, excessive rotation and flexion. Facet joints appear to have little influence on the

pos: Facet joint the complex shape and deep location of the facet. Ancient Greek: ' ("yoke") + ' ("out/from") + "" ("grow") Facet joint The facet joints, (or zygapophysial joints, zygapophyseal, apophyseal, or Z-joints) are a set of synovial, plane joints between the articular processes of two adjacent vertebrae. There are two facet joints in each spinal motion segment and each facet joint is innervated by the recurrent meningeal nerves. The biomechanical function of each pair of facet joints is to guide and limit movement of the spinal motion segment. In the lumbar spine, for example, the facet joints function to protect the

neg: Gaya Prasad Pal Medical College, Jamnagar in 1992. Later, he joined Modern Institute of Medical Sciences, Indore where he heads the department of anatomy and serves as the director. In between, he also worked as a visiting faculty at Medical College of Pennsylvania, Philadelphia during 1985–86 and 1987–90. Pal is married to Pushpa Verma and the couple has two children, Sandeep and Neeta. The family lives in Padmavaty Colony, Indore. Focusing his researches on the biomechanics of human spinal column, Pal elucidated the roles played by vertebral arches and their zygapophyseal joints in weight transmission along the vertebral column. These studies have assisted

neg: Saltoposuchus limbs, a slender body, and long legs. Paleontologists believe that with their body structures that "Saltoposuchus" were very fast and nimble. "Sphenosuchians are described as "greyhound dog[s] with scales and a long tail."" Early crocodylomorphs, such as "Saltoposuchus", have very long centra in their vertebrae, short vertebral processes, and medium-sized zygapophyseal joints. Molnar et Al. concluded that the average mediolateral range of motion in the early crocodylomorphs was greater than dorsoventral range of motion, and dorsoventral stiffness was estimated to be higher than mediolateral stiffness. In the wrists of "Saltoposuchus", the radiale and ulnare are elongated into rod shaped elements

neg: Luschka's joints Luschka's joints In anatomy, Luschka's joints (also called uncovertebral joints, neurocentral joints) are formed between uncinate processes above, and the uncus below. They are located in the cervical region of the vertebral column between C3 and C7. Two lips project upward from the superior surface of the vertebral body below, and one projects downward from the inferior surface of vertebral body above. They allow for flexion and extension and limit lateral flexion in the cervical spine. Pathological processes that can occur in these joints include degenerative changes or hypertrophic arthritis, resulting in foraminal stenosis and nerve compression. Foraminal stenosis at

neg: Luschka's joints this joint is the most common cause of cervical nerve root pressure. They were characterized by Hubert von Luschka in 1858. Luschka's joints In anatomy, Luschka's joints (also called uncovertebral joints, neurocentral joints) are formed between uncinate processes above, and the uncus below. They are located in the cervical region of the vertebral column between C3 and C7. Two lips project upward from the superior surface of the vertebral body below, and one projects downward from the inferior surface of vertebral body above. They allow for flexion and extension and limit lateral flexion in the cervical spine. Pathological processes that

neg: Digital motion X-ray 1, pp 10–13. 18. Occupational Medicine Practice Guide-lines, Second Edition, American College of Occupational and Environmental Medicine, 2004, Chapter 8. 19. Weiner RS, "Pain Management: A Practical Guide for Clinicians, Sixth Editi"on, DC Press, 2001. pp 395–396. 20. Dwyer A., et al., Cervical Zyagopophyseal Joint Pain Patterns. II: A Study in Normal Volunteers, Spine 15: 453-447, 1990. 21. Bogduk N, Marsland A: The Cervical Zygapophyseal Joints As a Source of Neck Pain. Spine 13: 610-617, 1988. 22. National Guideline Clearing House (NGC), [2]. Search video fluoroscopy, Select: Vertebral Subluxation in Chiropractic Practice, Council on Chiropractic Practice - Private Nonprofit Organization.

neg: Spondylitis joints, causing stiffness in the neck, jaw, shoulders, hips and knees. Spondylitis Spondylitis is an inflammation of the vertebra. It is a form of spondylopathy. In many cases spondylitis involves one or more vertebral joints as well, which itself is called spondylarthritis. Pott's disease is a tuberculous disease of the vertebrae marked by stiffness of the vertebral column, pain on motion, tenderness on pressure, prominence of certain vertebral spines, and occasionally abdominal pain, abscess formation, and paralysis. Ankylosing spondylitis is an inflammatory disease involving the spine and sacroiliac joints, and is therefore also a form of spondylarthritis. A combination of

neg: Spondylitis Spondylitis Spondylitis is an inflammation of the vertebra. It is a form of spondylopathy. In many cases spondylitis involves one or more vertebral joints as well, which itself is called spondylarthritis. Pott's disease is a tuberculous disease of the vertebrae marked by stiffness of the vertebral column, pain on motion, tenderness on pressure, prominence of certain vertebral spines, and occasionally abdominal pain, abscess formation, and paralysis. Ankylosing spondylitis is an inflammatory disease involving the spine and sacroiliac joints, and is therefore also a form of spondylarthritis. A combination of spondylitis and inflammation of the intervertebral disc space is termed a

neg: Back pain back pain, including blood vessels, internal organs, infections, mechanical, and autoimmune causes. The spinal cord, nerve roots, vertebral column, can all be sources of back pain, but primary muscle problems are rarely the cause. The anterior ligaments of the intervertebral disc are extremely sensitive, and even the slightest injury can cause significant pain. In osteoporosis, the bones become weaker and can develop small cracks, or fractures, in the bones, resulting in pain. Arthritis in the joints of the back can also result in discomfort. The synovial joints of the spine (e.g. zygapophysial joints/facet joints) have been identified as the primary

neg: Human skeletal changes due to bipedalism forward. The gluteus muscle helps to prevent the upper trunk of the body from "pitching forward" or falling over. Modern human hip joints are larger than in quadrupedal ancestral species to better support the greater amount of body weight passing through them, as well as having a shorter, broader shape. This alteration in shape brought the vertebral column closer to the hip joint, providing a stable base for support of the trunk while walking upright. Also, because bipedal walking requires humans to balance on a relatively unstable ball and socket joint, the placement of the vertebral column closer to the

neg: Fish anatomy vertebrae and spinal cord, but no gut. The defining characteristic of a vertebrate is the vertebral column, in which the notochord (a stiff rod of uniform composition) found in all chordates has been replaced by a segmented series of stiffer elements (vertebrae) separated by mobile joints (intervertebral discs, derived embryonically and evolutionarily from the notochord). However, a few fish have secondarily lost this anatomy, retaining the notochord into adulthood, such as the sturgeon. The vertebral column consists of a centrum (the central body or spine of the vertebra), vertebral arches which protrude from the top and bottom of the centrum,

neg: Nacholapithecus Nacholapithecus Nacholapithecus is a Middle Miocene genus of hominoid found in the Nachola formation in northern Kenya. It is a key genus in early hominid evolution. Similar in body plan to "Proconsul", it had a long vertebral column with six lumbar vertebrae, no tail, a narrow torso, large upper limbs with mobile shoulder joints, and long feet. Together with other Kenyapithecinae such as "Equatorius", "Kenyapithecus", and "Griphopithecus", "Nacholapithecus" displayed synapomorphies with "Anoiapithecus". Nacholapithecus was initially classified as belonging in "Kenyapithecus", then attributed to "Equatorius" (with "Equatorius" perhaps grouped into a sub-family "Equatorinae", instead of both species in "Afropithecini" ), finally

neg: Vertebral osteomyelitis Vertebral osteomyelitis Vertebral osteomyelitis (also termed spinal osteomyelitis, spondylodiskitis, or disk-space infection), is a type of osteomyelitis (infection and inflammation of the bone and bone marrow) that affects the vertebrae. It is a rare bone infection concentrated in the vertebral column. Cases of vertebral osteomyelitis are so rare that they constitute only 2%-4% of all bone infections. The infection can be classified as acute or chronic depending on the severity of the onset of the case, where acute patients often experience better outcomes than those living with the chronic symptoms that are characteristic of the disease. Although vertebral osteomyelitis is

neg: Costovertebral joints Costovertebral joints The costovertebral joints are the joints that connect the ribs to the vertebral column. The articulation of the head of the rib connects the head of the rib to the bodies of the thoracic vertebrae. The costotransverse joint connects the tubercle of the rib (costal tubercle) with the transverse process of the thoracic vertebra. Two convex facets from the head attach to two adjacent vertebrae, at the inferior costal facet of the superior vertebra, and the superior costal facet of the inferior vertebra respectively. This forms the synovial planar (gliding) joint, the articulation of the head of rib,

neg: Costovertebral joints which is strengthened by the ligament of the head and the intercapital ligament. Articulation of the tubercle is to the transverse process of the inferior vertebra. This articulation is reinforced by the dorsal costotransverse ligament. Costovertebral joints The costovertebral joints are the joints that connect the ribs to the vertebral column. The articulation of the head of the rib connects the head of the rib to the bodies of the thoracic vertebrae. The costotransverse joint connects the tubercle of the rib (costal tubercle) with the transverse process of the thoracic vertebra. Two convex facets from the head attach to two

neg: Vertebra the head of the rib. There are superior and inferior articular facet joints on each side of the vertebra, which serve to restrict the range of movement possible. These facets are joined by a thin portion of the vertebral arch called the "pars interarticularis". The transverse process of a lumbar vertebra is also sometimes called the costal or costiform process because it corresponds to a rudimentary rib ("costa") which, as opposed to the thorax, is not developed in the lumbar region. Vertebrae take their names from the regions of the vertebral column that they occupy. There are thirty-three vertebrae in

neg: Skeletal system of the horse to muscles. Synovial membranes are found in joint capsules, where they contain synovial fluid, which lubricates joints. Bones are covered by a tough membrane called periosteum, which covers the entire bone excluding areas of articulation. Ligaments attach bone to bone, and are vital in stabilizing joints as well as supporting structures. They are made up of fibrous material that is generally quite strong. Due to their relatively poor blood supply, ligament injuries generally take a long time to heal. Ligaments of the upper body include: Ligaments of the legs include: The axial skeleton contains the skull, vertebral column, sternum, and

neg: Vertebral column can be felt through the skin. Above and below each vertebra are joints called facet joints. These restrict the range of movement possible, and are joined by a thin portion of the neural arch called the "pars interarticularis". In between each pair of vertebrae are two small holes called intervertebral foramina. The spinal nerves leave the spinal cord through these holes. Individual vertebrae are named according to their region and position. From top to bottom, the vertebrae are: The upper cervical spine has a curve, convex forward, that begins at the axis (second cervical vertebra) at the apex of the

neg: Evolution of cetaceans joints of their ambulocetid relatives. The two tiny but well-formed hind legs of basilosaurids were probably used as claspers when mating. The pelvic bones associated with these hind limbs were not connected to the vertebral column as they were in protocetids. Essentially, any sacral vertebrae can no longer be clearly distinguished from the other vertebrae. Both basilosaurids and dorudontines are relatively closely related to modern cetaceans, which belong to parvorders Odontoceti and Mysticeti. However, according to a 1994 study done by Fordyce and Barnes, the large size and elongated vertebral body of basilosaurids preclude them from being ancestral to extant

neg: Vertebral column Vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton. 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. The vertebral column houses the spinal canal, a cavity that encloses and protects the spinal cord. There are about 50,000 species of animals that have a vertebral column. The human vertebral column is one of the most-studied examples. In a human's vertebral column there

neg: Human evolution also to the vertebral column, feet and ankles, and skull. The femur evolved into a slightly more angular position to move the center of gravity toward the geometric center of the body. The knee and ankle joints became increasingly robust to better support increased weight. To support the increased weight on each vertebra in the upright position, the human vertebral column became S-shaped and the lumbar vertebrae became shorter and wider. In the feet the big toe moved into alignment with the other toes to help in forward locomotion. The arms and forearms shortened relative to the legs making it

neg: Vertebral column skull which articulates with the first cervical vertebra. Vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton. 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. The vertebral column houses the spinal canal, a cavity that encloses and protects the spinal cord. There are about 50,000 species of animals that have a vertebral column. The human vertebral column is one of the

neg: Specified risk material attached to brain and close to the skull exterior), eyes, spinal cord, distal ileum (a part of the small intestine), and the dorsal root ganglia (nerves attached to the spinal cord and close to the vertebral column) of cattle aged 30 months or older. On January 12, 2004, the Food Safety and Inspection Service of the USDA published new rules banning such materials from the human food supply. In countries classified as undetermined risk, the OIE code recommends SRM removal as follows: tonsils and intestines in cattle at all ages; brains, eyes, spinal cord, skull and vertebral column from animals

neg: Anatomical terminology the skeleton. Together, these fibrous layers, along with tendons and ligaments, constitute the deep fascia of the body. Movement is not limited to only synovial joints, although they allow for most freedom. Muscles also run over symphysis, which allow for movement in for example the vertebral column by compression of the intervertebral discs. Additionally, synovial joints can be divided into different types, depending on their axis of movement. A serous membrane (also referred to as a serosa) is a thin membrane that covers the walls of organs in the thoracic and abdominal cavities. The serous membranes have two layers; "parietal"

neg: Pelvis joints or adding torsion to the vertebral column. In ambulatory mammals the acetabula are shallow and open to allow a wider range of hip movements, including significant abduction, than in cursorial mammals. The lengths of the ilium and ischium and their angles relative to the acetabulum are functionally important as they determine the moment arms for the hip extensor muscles that provide momentum during locomotion. In addition to this, the relatively wide shape (front to back) of the pelvis provides greater leverage for the gluteus medius and minimus. These muscles are responsible for hip abduction which plays an integral role

neg: Puertasaurus exceed the length of the centrum. This would make it have one of the proportionately largest neural spines of any titanosaur. The apex of the neural spine was positioned on the posterior side of the vertebral midline. The spinoprezygapophyseal laminae (the spike-like projection in front of the neural spine) are separated from each other and only touch the middle of the neural spine. The zygapophyseal articulations, which connect two adjacent vertebrae, are located on the lower part the neural arch. The diapohyses and parapohyses (processes on the side of the vertebra) are strongly laterally projected. The cervical vertebra lacks pleurocoels

neg: Spondylosis spinal instability or mal-alignment. Use of instrumentation (such as pedicle screws) in fusion surgeries varies across studies. Spondylosis Spondylosis is the degeneration of the spinal column from any cause. In the more narrow sense it refers to spinal osteoarthritis, the age-related wear and tear of the spinal column, which is the most common cause of spondylosis. The degenerative process in osteoarthritis chiefly affects the vertebral bodies, the neural foramina and the facet joints (facet syndrome). If severe, it may cause pressure on the spinal cord or nerve roots with subsequent sensory or motor disturbances, such as pain, paresthesia, imbalance, and

neg: Spondylosis Spondylosis Spondylosis is the degeneration of the spinal column from any cause. In the more narrow sense it refers to spinal osteoarthritis, the age-related wear and tear of the spinal column, which is the most common cause of spondylosis. The degenerative process in osteoarthritis chiefly affects the vertebral bodies, the neural foramina and the facet joints (facet syndrome). If severe, it may cause pressure on the spinal cord or nerve roots with subsequent sensory or motor disturbances, such as pain, paresthesia, imbalance, and muscle weakness in the limbs. When the space between two adjacent vertebrae narrows, compression of a nerve

neg: Nemegtomaia a crouching position. The vertebral column, neck, and hips deteriorated during burial, and much of the damage to the skeleton is thought to have been caused by the activity of invertebrates. Borings in the bones, burrows, and reworked sediments (perhaps caused by the construction of pupal chambers) in the specimen indicate it was scavenged upon by colonies of skin beetles (Dermestidae) and perhaps other scavenging insects. There are many feeding traces in the joints of the skeleton, and almost all the surfaces where the bones articulated have been obliterated. There are also tunnels in the nest under the neck and

neg: Synapomorphy and apomorphy mammals in relation to tetrapods but is a symplesiomorphy for mammals in relation to one another—rodents and primates, for example. So the concept can be understood as well in terms of "a character newer than" (autapomorphy) and "a character older than" (plesiomorphy) the apomorphy: mammary glands are evolutionarily newer than vertebral column, so mammary glands are an autapomorphy if vertebral column is an apomorphy, but if mammary glands are the apomorphy being considered then vertebral column is a plesiomorphy. Cladograms are diagrams that depict evolutionary relationships within groups of taxa. These illustrations are accurate predictive device in modern genetics. They

neg: Neuromere spinal cord segments are found between vertebral levels T9 and L2, and the spinal cord ends around the L1/L2 vertebral level, forming a structure known as the conus medullaris. Although the spinal cord cell bodies end around the L1/L2 vertebral level, the spinal nerves for each segment exit at the level of the corresponding vertebra. For the nerves of the lower spinal cord, this means that they exit the vertebral column much lower (more caudally) than their roots. As these nerves travel from their respective roots to their point of exit from the vertebral column, the nerves of the lower

neg: Metoposaurus they were present as cartilages. The atlas, axis, and third and fourth cervical vertebrae are characteristic and similar to those in other stereospondyls. The morphology of the atlas, axis, and third and fourth vertebrae suggests that the neck of "Metoposaurus" was relatively flexible. The intercentra of the region where the vertebral column contacts the shoulder girdle are flat anteriorly and posteriorly. The neural arches have almost vertically set prezygapophyses (vide postcervical vertebrae). This suggests that in this region the lateral bending of the vertebral column was very limited. It was probably connected through articulation of the vertebral column with the

neg: Muscle muscular "slip" is a narrow length of muscle that acts to augment a larger muscle or muscles. The muscular system is one component of the musculoskeletal system, which includes not only the muscles but also the bones, joints, tendons, and other structures that permit movement. All muscles are derived from paraxial mesoderm. The paraxial mesoderm is divided along the embryo's length into somites, corresponding to the segmentation of the body (most obviously seen in the vertebral column. Each somite has 3 divisions, sclerotome (which forms vertebrae), dermatome (which forms skin), and myotome (which forms muscle). The myotome is divided into

neg: Vertebral column front and the back, and in between the vertebrae joining the spinous processes, the transverse processes and the vertebral laminae. 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. These regions are called the cervical spine, thoracic spine, lumbar spine, sacrum and coccyx. There are seven cervical vertebrae, twelve thoracic vertebrae and five lumbar vertebrae. The number of vertebrae in a region can vary but overall

neg: Amargasaurus small head, and a barrel-shaped trunk supported by four column-like legs. The neck of "Amargasaurus" was shorter than in most other sauropods, a common trait within the Dicraeosauridae. Measuring in length, the neck corresponded to 136% of the length of the dorsal vertebral column. This is comparable to "Dicraeosaurus" (123%) but greater than in the extremely short-necked form "Brachytrachelopan" (75%). The neck consisted of thirteen cervical vertebrae, which were opisthocoelous (convex at the front and hollow at the back), forming ball-and-socket joints with neighboring vertebrae. The trunk was made out of nine dorsal and probably five fused sacral vertebrae. The

neg: Laminotomy Laminotomy A laminotomy is an orthopaedic neurosurgical procedure that removes part of the lamina of a vertebral arch in order to relieve pressure in the vertebral canal. A laminotomy is less invasive than conventional vertebral column surgery techniques, such as laminectomy because it leaves more ligaments and muscles attached to the vertebral column intact and it requires removing less bone from the vertebra. As a result, laminotomies typically have a faster recovery time and result in fewer postoperative complications. Nevertheless, possible risks can occur during or after the procedure like infection, hematomas, and dural tears. Laminotomies are commonly performed as

neg: Dinocephalosaurus The long, slender cervical ribs bear frontal projections free of the vertebral bodies, which are also unique to "Dinocephalosaurus". These ribs are aligned along the neck and bridge multiple consecutive vertebral joints, from two or three consecutive joints in the anterior the neck to five or six in the posterior neck. There appear to be no distinct processes on the vertebrae for articulation with the ribs. The trunk of "Dinocephalosaurus" has at least 26 vertebrae. In "Dinocephalosaurus", there appear to be no lumbar vertebrae, or vertebrae of the trunk lacking ribs. The ribs of the sacrum and tail also do

neg: Rib During adolescence secondary ossification centers are formed in the tubercles and heads of the ribs. In fish, there are often two sets of ribs attached to the vertebral column. One set, the dorsal ribs, are found in the dividing septum between the upper and lower parts of the main muscle segments, projecting roughly sideways from the vertebral column. The second set, the ventral ribs arise from the vertebral column just below the dorsal ribs, and enclose the lower body, often joining at the tips. Not all species possess both types of rib, with the dorsal ribs being most commonly absent.

neg: Laminotomy treatment for lumbar spinal stenosis and herniated disks. MRI and CT scans are often used pre- and post surgery to determine if the procedure was successful. The spinal cord is housed in a bony hollow tube called the vertebral column. The vertebral column is composed of many ring-like bones called vertebra (plural: vertebrae) and it spans from the skull to the sacrum. Each vertebra has a hole in the center called the vertebral foramen through which the spinal cord traverses. Laminae (singular: lamina) are the anatomical structures of primary importance in a laminotomy. Laminae are part of the vertebral arch

neg: Edmontosaurus part of the tail "ramrod" straight. The ossified tendons are interpreted as having strengthened the vertebral column against gravitational stress, incurred through being a large animal with a horizontal vertebral column otherwise supported mostly by the hind legs and hips. The shoulder blades were long flat blade-like bones, held roughly parallel to the vertebral column. The hips were composed of three elements each: an elongate ilium above the articulation with the leg, an ischium below and behind with a long thin rod, and a pubis in front that flared into a plate-like structure. The structure of the hip hindered the

neg: Spinal cord cord ends around the L1/L2 vertebral level, forming a structure known as the conus medullaris. Although the spinal cord cell bodies end around the L1/L2 vertebral level, the spinal nerves for each segment exit at the level of the corresponding vertebra. For the nerves of the lower spinal cord, this means that they exit the vertebral column much lower (more caudally) than their roots. As these nerves travel from their respective roots to their point of exit from the vertebral column, the nerves of the lower spinal segments form a bundle called the cauda equina. There are two regions where

neg: Invertebrate Crustacea from the Linnean Insecta, and Mollusca, Annelida, Cirripedia, Radiata, Coelenterata and Infusoria from the Linnean Vermes. They are now classified into over 30 phyla, from simple organisms such as sea sponges and flatworms to complex animals such as arthropods and molluscs. Invertebrates are animals "without" a vertebral column. This has led to the conclusion that "in"vertebrates are a group that deviates from the normal, vertebrates. This has been said to be because researchers in the past, such as Lamarck, viewed vertebrates as a "standard": in Lamarck's theory of evolution, he believed that characteristics acquired through the evolutionary process involved

neg: Vertebral column are different ligaments involved in the holding together of the vertebrae in the column, and in the column's movement. The anterior and posterior longitudinal ligaments extend the length of the vertebral column along the front and back of the vertebral bodies. The interspinous ligaments connect the adjoining spinous processes of the vertebrae. The supraspinous ligament extends the length of the spine running along the back of the spinous processes, from the sacrum to the seventh cervical vertebra. From there it is continuous with the nuchal ligament. The striking segmented pattern of the spine is established during embryogenesis when somites are

neg: Dorsal ramus of spinal nerve Intermediate branch supplies innervation to the spinalis muscle and the longissimus muscle. The medial branch supplies innervation to the rest of the epaxial derived muscles on the back (including the transversospinales, intertransversarii muscles, interspinalis muscles, suboccipital muscles, and splenius), and the zygapophyseal joints. Because each spinal nerve carries both sensory and motor information, spinal nerves are referred to as “mixed nerves." Posterior rami carry visceral motor, somatic motor, and sensory information to and from the skin and deep muscles of the back. The posterior rami remain distinct from each other, and each innervates a narrow strip of skin and muscle

neg: Vertebral column (both the cranial zygapophyses and the caudal zygapophyses). The centrum of the vertebra can be classified based on the fusion of its elements. In temnospondyls, bones such as the spinous process, the pleurocentrum and the intercentrum are separate ossifications. Fused elements, however, classify a vertebra as having holospondyly. A vertebra can also be described in terms of the shape of the ends of the centrum. Centra with flat ends are "acoelous", like those in mammals. These flat ends of the centra are especially good at supporting and distributing compressive forces. "Amphicoelous" vertebra have centra with both ends concave. This shape

neg: Vertebral column consisting of separate pieces of arch-shaped cartilage around the spinal cord in most parts of the body, changing to long strips of cartilage above and below in the tail region. Hagfishes lack a true vertebral column, and are therefore not properly considered vertebrates, but a few tiny neural arches are present in the tail. The general structure of human vertebrae is fairly typical of that found in mammals, reptiles, and birds. The shape of the vertebral body does, however, vary somewhat between different groups. In mammals, such as humans, it typically has flat upper and lower surfaces, while in reptiles

neg: Laminotomy average. During a laminotomy, the individual lies on his or her stomach with the back facing up towards the physician. An initial incision is made down the middle of the back exposing the vertebrae on which the laminotomy will be performed. In this procedure, the spinous process and the ligaments of the vertebral column are kept intact, but the muscles adjacent to the vertebral column known as the paraspinous muscles (Example:spinalis muscle) must be separated from the spinous process and vertebral arch. In a unilateral laminotomy, these muscles are only detached from the side on which the laminotomy is being

neg: Babakotia level of adaptations for suspensory behavior between the large sloth lemurs and the small sloth lemurs. This includes its highly mobile hip and ankle joints, as well as other specializations in the vertebral column, pelvis, and limbs. Its forelimbs were 20% longer than its hind limbs, giving it a higher intermembral index (~119) than "Mesopropithecus" (~97 to 113), suggesting that it was convergently similar to arboreal sloths. It had a reduced tarsus and curved, elongated digits, adapted for grasping and suggesting suspensory behavior. Its hind feet were reduced, making it well-adapted for climbing and hanging (like in other palaeopropithecids), but

neg: Vertebral column permanent. Excessive or abnormal spinal curvature is classed as a spinal disease or dorsopathy and includes the following abnormal curvatures: Individual vertebrae of the human vertebral column can be felt and used as surface anatomy, with reference points are taken from the middle of the vertebral body. This provides anatomical landmarks that can be used to guide procedures such as a lumbar puncture and also as vertical reference points to describe the locations of other parts of human anatomy, such as the positions of organs. The general structure of vertebrae in other animals is largely the same as in humans.

neg: Brachiosaurus belonging to "Brachiosaurus" had identical proportions. Unlike "Giraffatitan" and other sauropods, which had vertically oriented forelimbs, the arms of "Brachiosaurus" appear to have been slightly sprawled at the shoulder joints, as indicated by the sideward orientation of the joint surfaces of the coracoids. The humerus was less slender than that of "Giraffatitan", while the femur had similar proportions. This might indicate that the forelimbs of "Brachiosaurus" supported a greater fraction of the body weight than is the case for "Giraffatitan". Though the vertebral column of the trunk or torso is incompletely known, the back of "Brachiosaurus" most likely comprised twelve

neg: Human skeleton human males do not have penile bones. The axial skeleton (80 bones) is formed by the vertebral column (32–34 bones; the number of the vertebrae differs from human to human as the lower 2 parts, sacral and coccygeal bone may vary in length), a part of the rib cage (12 pairs of ribs and the sternum), and the skull (22 bones and 7 associated bones). The upright posture of humans is maintained by the axial skeleton, which transmits the weight from the head, the trunk, and the upper extremities down to the lower extremities at the hip joints. The bones

neg: Spinal muscular atrophy and pain. Weak muscles that normally stabilize joints such as the vertebral column lead to development of kyphosis and/or scoliosis and joint contracture. Spine fusion is sometimes performed in people with SMA I/II once they reach the age of 8–10 to relieve the pressure of a deformed spine on the lungs. Furthermore, immobile individuals, posture and position on mobility devices as well as range of motion exercises, and bone strengthening can be important to prevent complications. People with SMA might also benefit greatly from various forms of physiotherapy, occupational therapy and physical therapy. Orthotic devices can be used to support

neg: Sclerothorax the vertebral column and the lower jaw. It was described in 2004 by Michael Fastnacht, who also reported that the specimen had an impression of the palate. The palate seemed to be long and narrow like that of another German temnospondyl called "Trematosaurus". Fastnacht therefore concluded that Huene's two specimens belonged to different species, with the first high-spined specimen referable to "Sclerothorax". However, three more specimens were uncovered in German museum collections with nearly complete skulls attached to vertebral columns. These specimens had broad heads, proving that Huene's second specimen also belongs to "Sclerothorax". Huene originally classified "Sclerothorax" within the

neg: Vertebra are essentially alike across the vertebrate species, with the greatest difference seen between an aquatic animal and other vertebrate animals. As such, vertebrates take their name from the vertebrae that compose the vertebral column. Each vertebra is an irregular bone. The size of the vertebrae varies according to placement in the vertebral column, spinal loading, posture and pathology. Along the length of the spine the vertebrae change to accommodate different needs related to stress and mobility. Every vertebra has a body, which consists of a large anterior middle portion called the centrum (plural "centra") and a posterior vertebral arch, also

neg: Tiludronic acid the distal hock joints (bone spavin) and vertebral column. Tildren is administered intravenously. It is labeled for 0.1 mg/kg dosing, once daily for 10 days by slow intravenous injection, which for a 500 kg horse works out to be 1 vial per day. However, one study giving all 10 doses at once (1 mg/kg IV as a single CRI) was found to have the same pharmacological effects, and is used clinically. It may be given systemically or locally, by regional limb perfusion. Although RLP is thought to have certain benefits, including decreased cost and reduced risk of adverse effects, some

neg: Scipionyx the ninth cervical vertebra to the back, the vertebral joints show the remains of articular capsules. Between the spines at places very thin interspinal and supraspinal ligaments are visible. Six vertebrae are visibly capped by cartilaginous synchondroses, a typical juvenile feature. Cartilaginous caps are also present on all limb joints, even the smallest, and are especially thick in the shoulder, elbow and wrist joints. Also the pubic foot is capped and the ilium and pubic bone are separated by cartilage. Of the respiratory system little has been preserved. No traces of the lungs have survived, nor of any air sacks.

neg: Joint tooth and the jawbone is also called a joint, and is described as a fibrous joint known as a gomphosis. Joints are classified both structurally and functionally. Joints are mainly classified structurally and functionally. Structural classification is determined by how the bones connect to each other, while functional classification is determined by the degree of movement between the articulating bones. In practice, there is significant overlap between the two types of classifications. Structural classification names and divides joints according to the type of binding tissue that connects the bones to each other. There are three structural classifications of joints: Joints

neg: Back injury be classified using the AO spine injury classification system. The three categories - A, B, and C - are based on the location of damage on the vertebra (either on the anterior or posterior segment) and by the direction of the applied injurious force. This classification system can be used to classify injury to the cervical, thoracolumbar, and sacral regions of the spinal column. Herniated discs can be graded based on the size and location of the herniation as seen on an MRI. The size of the herniation is the extent to which it protrudes into the vertebral foramen. The

neg: Vertebral column the Arabian (breed) can have one less vertebrae and pair of ribs. This anomaly disappears in foals that are the product of an Arabian and another breed of horse. Vertebrae are defined by the regions of the vertebral column that they occur in, as in humans. Cervical vertebrae are those in the neck area. With the exception of the two sloth genera ("Choloepus" and "Bradypus") and the manatee genus, ("Trichechus"), all mammals have seven cervical vertebrae. In other vertebrates, the number of cervical vertebrae can range from a single vertebra in amphibians, to as many as 25 in swans or

neg: Vertebrate anterior end of the animal, while the anus opens to the exterior before the end of the body. The remaining part of the body continuing after the anus forms a tail with vertebrae and spinal cord, but no gut. The defining characteristic of a vertebrate is the vertebral column, in which the notochord (a stiff rod of uniform composition) found in all chordates has been replaced by a segmented series of stiffer elements (vertebrae) separated by mobile joints (intervertebral discs, derived embryonically and evolutionarily from the notochord). However, a few vertebrates have secondarily lost this anatomy, retaining the notochord into

neg: Vertebral column the number remains the same. The number of those in the cervical region however is only rarely changed. The vertebrae of the cervical, thoracic and lumbar spines are independent bones, and generally quite similar. The vertebrae of the sacrum and coccyx are usually fused and unable to move independently. Two special vertebrae are the atlas and axis, on which the head rests. A typical vertebra consists of two parts: the vertebral body and 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.

neg: Facet joint range of side bending (lateral flexion). These functions can be disrupted by degeneration, dislocation, fracture, injury, instability from trauma, osteoarthritis, and surgery. In the thoracic spine the facet joints function to restrain the amount of flexion and anterior translation of the corresponding vertebral segment and function to facilitate rotation. Cavitation of the synovial fluid within the facet joints is responsible for the popping sound (crepitus) associated with manual spinal manipulation, commonly referred to as "cracking the back." The facet joints, both superior and inferior, are aligned in a way to allow flexion and extension, and to limit rotation. This is

neg: Vertebral column bone below the vertebral arch, with no trace of the separate elements present in the early tetrapods. In cartilaginous fish, such as sharks, the vertebrae consist of two cartilaginous tubes. The upper tube is formed from the vertebral arches, but also includes additional cartilaginous structures filling in the gaps between the vertebrae, and so enclosing the spinal cord in an essentially continuous sheath. The lower tube surrounds the notochord, and has a complex structure, often including multiple layers of calcification. Lampreys have vertebral arches, but nothing resembling the vertebral bodies found in all higher vertebrates. Even the arches are discontinuous,

neg: Vertebra anterior and posterior tubercles are on either side of the transverse foramen on each transverse process. The anterior tubercle on the sixth cervical vertebra is called the carotid tubercle because it separates the carotid artery from the vertebral artery. There is a hook-shaped uncinate process on the side edges of the top surface of the bodies of the third to the seventh cervical vertebrae, and also of the first thoracic vertebra. Together with the vertebral disc, this uncinate process prevents a vertebra from sliding backwards off the vertebra below it and limits lateral flexion (side-bending). Luschka's joints involve the vertebral

neg: Thoracic vertebrae the inferior vertebral notches are of large size, and deeper than in any other region of the vertebral column. The laminae are broad, thick, and imbricated – that is to say, they overlap those of subjacent vertebrae like tiles on a roof and connect with the pedicles to surround and protect the spinal cord. The intervertebral foramen is small, and circular, with two at each intervertebral level, one for the right and one for the left exiting nerve roots. The vertebral foramen is the large opening posterior to the vertebral body also known as the "spinal canal". It contains and

neg: Neuromere medullaris. The pia mater continues as an extension called the filum terminale, which anchors the spinal cord to the coccyx. The cauda equina (“horse’s tail”) is the name for the collection of nerves in the vertebral column that continue to travel through the vertebral column below the conus medullaris. The cauda equina forms as a result of the fact that the spinal cord stops growing in length at about age four, even though the vertebral column continues to lengthen until adulthood. This results in the fact that sacral spinal nerves actually originate in the upper lumbar region. The spinal cord

neg: Vertebral column notochord. This column of tissue has a segmented appearance, with alternating areas of dense and less dense areas. As the sclerotome develops, it condenses further eventually developing into the vertebral body. Development of the appropriate shapes of the vertebral bodies is regulated by "HOX genes". The less dense tissue that separates the sclerotome segments develop into the intervertebral discs. The notochord disappears in the sclerotome (vertebral body) segments, but persists in the region of the intervertebral discs as the nucleus pulposus. The nucleus pulposus and the fibers of the anulus fibrosus make up the intervertebral disc. The primary curves (thoracic

neg: Brachylophosaurus tended to follow the curvature of the vertebral column, and filling much of the bend between the front back and the head. On the snout, the remains of a broad keratinous beak are visible. The skin impressions show many folds and a structure of small polygonal scales. On the back a midline frill formed by triangular or hatchet-shaped projections is present. These seem to be individually separated and are placed as extensions of each neural spine of the vertebral column. The second, third and fourth finger of the hand are contained in a shared soft tissue "mitten". Examination of the

neg: Basivertebral veins vertebral plexuses. The basivertebral veins become greatly enlarged in advanced age. Basivertebral veins The basivertebral veins are veins within the vertebral column. They are contained in large, tortuous channels in the substance of the bones, similar in every respect to those found in the diploë of the cranial bones. They emerge from the foramina on the posterior surfaces of the vertebral bodies. They communicate through small openings on the front and sides of the vertebral bodies with the anterior external vertebral plexuses, and converge behind to the principal canal, which is sometimes double toward its posterior part, and open by

neg: Laminotomy needs to be removed in order to relive certain symptoms. Laminotomy A laminotomy is an orthopaedic neurosurgical procedure that removes part of the lamina of a vertebral arch in order to relieve pressure in the vertebral canal. A laminotomy is less invasive than conventional vertebral column surgery techniques, such as laminectomy because it leaves more ligaments and muscles attached to the vertebral column intact and it requires removing less bone from the vertebra. As a result, laminotomies typically have a faster recovery time and result in fewer postoperative complications. Nevertheless, possible risks can occur during or after the procedure like

neg: Laminotomy are pain, fatigue, weakness of the muscle and numbness. Stenosis can be caused by old age or an injury to the vertebral column and usually requires a CT scan or MRI to diagnose. Performing a laminotomy can relieve pressure in the spinal canal caused by lumbar stenosis and therefore alleviate symptoms. Laminotomies are also performed to create a window into the spinal canal in order to fix a problem that is within the spinal canal. Laminotomies are frequently used as a way to surgically repair a spinal disc herniation at any level of the vertebral column (cervical, thoracic, lumbar). A

neg: Neuromechanics of idiopathic scoliosis brace and because after spinal arthrodesis surgery, idiopathic scoliotic people showed a significant decrease in paravertebral muscle activity on the convex side but not on the concave side, the muscular asymmetry in idiopathic scoliosis is thought to be a biomechanical consequence of the scoliotic curvature rather than its cause. Since idiopathic scoliosis and its surgery affect the vertebrae and the joints along the spine, the range of motion is expected to be different between patients and non-scoliotic people. There is a hypothesis that states that the vertebral column behaves like a torsional spring: while walking, the angular momentum of the

neg: Basilosaurus and several attempts have been made to reconstruct the vertebral column from partial skeletons. estimated a total of 58 vertebrae, based on two partial and nonoverlapping skeletons of "B. cetoides" from Alabama. More complete fossils uncovered in Egypt in the 1990s allowed a more accurate estimation: the vertebral column of "B. isis" has been reconstructed from three overlapping skeletons to a total of 70 vertebrae with a vertebral formula interpreted as seven cervical, 18 thoracic, 20 lumbar and sacral, and 25 caudal vertebrae. The vertebral formula of "B. cetoides" can be assumed to be the same. "Basilosaurus" has an anguilliform

neg: Axial skeleton the coccyx, formed from 3-5 fused vertebrae. If you count the coccyx and sacrum each as one vertebra, then there are 26 vertebrae. If the fused vertebrae are all counted separately, then the total number of vertebrae comes to between 32 and 34. The vertebral column consists of 5 parts. The most cranial (uppermost) part is made up by the cervical vertebrae (7), followed by thoracic (12), lumbar (5), sacral (4–5) and coccygeal vertebrae (3–4). Cervical vertebrae make up the junction between the vertebral column and the cranium. Sacral and coccygeal vertebras are fused and thus often called "sacral bone"

neg: Gobipteryx has a large, uniform, and sutureless braincase. The vertebral column consists of at least 19 presacral vertebrae, the last 6 of these being dorsals. The neural spines of the twelfth and thirteenth vertebrae form the nuchal blade, which represents the point of greatest elevation in the vertebral column. The scapula contains a prominent glenoid labrum and tapers backward, ending as thin rods. The coracoids are slightly concave anteriorly and are separate from the scapulae dorsally. They also stick out from the neck on either side. "Gobipteryx's" clavicles curve in a way that is consistent with that of other birds. The

neg: Vertebral column by around twenty or so further vertebrae, divided between the thoracic and lumbar forms, depending on the number of ribs. There are generally three to five vertebrae with the sacrum, and anything up to fifty caudal vertebrae. The vertebral column in dinosaurs consists of the cervical (neck), dorsal (back), sacral (hips), and caudal (tail) vertebrae. Saurischian dinosaur vertebrae sometimes possess features known as pleurocoels, which are hollow depressions on the lateral portions of the vertebrae, perforated to create an entrance into the air chambers within the vertebrae, which served to decrease the weight of these bones without sacrificing strength. These

neg: Spinal cord spinal nerves originating in the upper lumbar region. Within the CNS, nerve cell bodies are generally organized into functional clusters, called nuclei. Axons within the CNS are grouped into tracts. There are 31 spinal cord nerve segments in a human spinal cord: In the fetus, vertebral segments correspond with spinal cord segments. However, because the vertebral column grows longer than the spinal cord, spinal cord segments do not correspond to vertebral segments in the adult, particularly in the lower spinal cord. For example, lumbar and sacral spinal cord segments are found between vertebral levels T9 and L2, and the spinal

neg: Neuromere segments forming 5 pairs of lumbar nerves (exit spinal column through IVF, below corresponding vertebra L1-L5) 5 sacral segments forming 5 pairs of sacral nerves (exit spinal column through IVF, below corresponding vertebra S1-S5) 3 coccygeal segments joined up becoming a single segment forming 1 pair of coccygeal nerves (exit spinal column through the sacral hiatus). In the fetus, vertebral segments correspond with spinal cord segments. However, because the vertebral column grows longer than the spinal cord, spinal cord segments do not correspond to vertebral segments in the adult, particularly in the lower spinal cord. For example, lumbar and sacral

neg: Xenarthra extinct at the end of the Pleistocene. Xenarthrans share several characteristics not present in other placental mammals, and are often considered to be among the most primitive order of placental mammals. The name Xenarthra, which means "strange joints", was chosen because their vertebral joints have extra articulations unlike other mammals. This trait is referred to as "xenarthry". Also, unlike other mammals, the ischium and sacrum are fused. The males have internal testicles, which are located between the bladder and the rectum. Xenarthra have been determined to have single-color vision. Through PCR analysis, it was discovered that a mutation in a

neg: Vertebral column the coccyx. From behind, 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, horizontal and bifid. 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.

neg: Megalodon a partially preserved vertebral column of a single specimen, excavated in the Antwerp Basin, Belgium, in 1926. It comprises 150 vertebral centra, with the centra ranging from to in diameter. The shark's vertebrae may have gotten much bigger, and scrutiny of the specimen revealed that it had a higher vertebral count than specimens of any known shark, possibly over 200 centra; only the great white approached it. Another partially preserved vertebral column of a megalodon was excavated from the Gram Formation in Denmark in 1983, which comprises 20 vertebral centra, with the centra ranging from to in diameter. The coprolite

neg: Vertebral column 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. 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

neg: Basivertebral veins Basivertebral veins The basivertebral veins are veins within the vertebral column. They are contained in large, tortuous channels in the substance of the bones, similar in every respect to those found in the diploë of the cranial bones. They emerge from the foramina on the posterior surfaces of the vertebral bodies. They communicate through small openings on the front and sides of the vertebral bodies with the anterior external vertebral plexuses, and converge behind to the principal canal, which is sometimes double toward its posterior part, and open by valved orifices into the transverse branches which unite the anterior internal

neg: Bowfin able to mechanical catch, and digest it. The vertebral column in bowfin is ossified and in comparison to earlier fishes, the centra are the major support for the body, whereas in earlier fish the notochord was the main form of support. Neural spines and ribs provide additional support and help stabilize unpaired fins. In bowfin neural spines and ribs also increase in prominence, an evolutionary aspect that helps them stabilize unpaired fins. The evolution of the vertebral column allows the bowfin to withstand lateral bending that puts the column under compression without breaking. This, in turn, allows the bowfin to

neg: Posterior ramus syndrome This diagnostic procedure can also be therapeutic; the injection of steroids or radiofrequency denervation of the medial branch can be added for refractory cases. Essential to remember is that the pattern of referred pain in no way hints at the spinal level involved. Multiple studies confirm that there is considerable overlap in the distribution of pain stemming from the zygapophyseal joints, including anterior, lateral or posterior thigh, groin, lumbar spine region, and trochanter region. This overlap of innervation is poorly handled by the standard dermatome map which physicians rely on to trace pain back to its source. Posterior ramus syndrome

neg: Craniate skull developed before the vertebral column. The clade was thus composed of the Myxini and the vertebrates, and any extinct chordates with skulls. However recent studies using molecular phylogenetics has contradicted this view, with evidence that the Cyclostomata (Hyperoartia and Myxini) is monophyletic; this suggests that the Myxini are degenerate vertebrates, and therefore the vertebrates and craniates are cladistically equivalent, at least for the living representatives. The placement of the Myxini within the vertebrates has been further strengthened by recent anatomical analysis, with vestiges of a vertebral column being discovered in the Myxini. In the simplest sense, craniates are chordates

neg: Pachyophis almost horizontal in the middle and then reobtaining their inclination anteriorly. Postzygapophyses width is slightly larger than that of the prezygapophyses. Both do not project very far laterally, with the anterior being more elongated that the posterior. The ribs are characterized by their needle like shape. Generally associated with the vertebrae, the ribs are technically not articulated to them. The upper third along the vertebral column are straight in shape, followed by a section of distinctive 120 degree bending, and then a return to the original straight form. The length of the ribs increases through the vertebral column. Pchyostosis also

neg: Joint Types of articular surfaces include trochlear surfaces. Joints can also be classified based on their anatomy or on their biomechanical properties. According to the anatomic classification, joints are subdivided into "simple" and "compound", depending on the number of bones involved, and into "complex" and "combination" joints: The joints may be classified anatomically into the following groups: Damaging the cartilage of joints (articular cartilage) or the bones and muscles that stabilize the joints can lead to joint dislocations and osteoarthritis. Swimming is a great way to exercise the joints with minimal damage. A joint disorder is termed arthropathy, and when involving

neg: Vertebral column Because the spinal cord ends in the lumbar spine, and the sacrum and coccyx are fused, they do not contain a central foramen. The vertebral arch is formed by a pair of pedicles and a pair of laminae, and supports seven processes, four articular, two transverse, and one spinous, the latter also being known as the neural spine. Two transverse processes and one spinous process are posterior to (behind) the vertebral body. The spinous process comes out the back, one transverse process comes out the left, and one on the right. The spinous processes of the cervical and lumbar regions

neg: Xenarthra taxa are unrelated, and it was split up to reflect their true phylogeny. Aardvarks and pangolins are now placed in individual orders, and the new order Xenarthra was erected to group the remaining families (which are all related). The name "Xenarthra" means "strange joints", and was chosen because their vertebral joints have extra articulations and are unlike those of any other mammals. The morphology of xenarthrans generally suggests that the anteaters and sloths are more closely related to each other than either is to the armadillos; this is upheld by molecular studies. Since its conception, Xenarthra has increasingly come to

neg: Flexion teardrop fracture Flexion teardrop fracture A flexion teardrop fracture is a fracture of the anteroinferior aspect of a cervical vertebral body due to flexion of the spine along with vertical axial compression. The fracture continues sagittally through the vertebral body, and is associated with deformity of the body and subluxation or dislocation of the facet joints at the injured level. A flexion teardrop fracture is usually associated with a spinal cord injury, often a result of displacement of the posterior portion of the vertebral body into the spinal canal. The flexion teardrop fracture should not be confused with a similar-looking vertebral fracture

neg: Vertebral column the anterior surface commonly has a concave socket into which the expanded convex face of the next vertebral body fits. Even these patterns are only generalisations, however, and there may be variation in form of the vertebrae along the length of the spine even within a single species. Some unusual variations include the saddle-shaped sockets between the cervical vertebrae of birds and the presence of a narrow hollow canal running down the centre of the vertebral bodies of geckos and tuataras, containing a remnant of the notochord. Reptiles often retain the primitive intercentra, which are present as small crescent-shaped bony

neg: Antlerpeton company with an exploration office in Reno, Nevada) who discovered the holotype in 1990. The holotype of "Antlerpeton" consists of vertebrae, ribs, a pelvic girdle, two broken femora, and gastralia. All of the bones are articulated. With up to 28 vertebrae, the presacral vertebral column (the part of the column in front of the pelvic girdle) is long. Each vertebral segment is composed of a large principal centrum and a pair of two small bones that fit in front of it. The spinal cord passes through the larger bones, while the smaller bones are positioned to either side of the

neg: Spinal nerve the greater part of the fourth are connected together in this situation by anastomotic loops, and form the lumbar plexus. The smaller part of the fourth joins with the fifth to form the lumbosacral trunk, which assists in the formation of the sacral plexus. The fourth nerve is named the furcal nerve, from the fact that it is subdivided between the two plexuses. The sacral nerves are the five pairs of spinal nerves which exit the sacrum at the lower end of the vertebral column. The roots of these nerves begin inside the vertebral column at the level of the

neg: Cricosaurus an unusually large pelvic opening. The acetabulum, or femur articulation on the hip, is placed very far towards of the bottom of the body relative to the vertebral column, and the sacral ribs are angled downwards at 45°, further increasing the distance between the vertebral column and the pubis-ischium. The hip was effectively a vertical ellipse in cross-section, being tall and wide. In other pseudosuchians like "Steneosaurus", "Machimosaurus", and "Pelagosaurus", the sacral ribs are less angled and more horizontal; in this way, "Cricosaurus" is actually more similar to aquatic reptiles like "Chaohusaurus", "Utatsusaurus", and "Keichousaurus", the latter of which live

neg: Back injury Back injury Back injuries result from damage, wear, or trauma to the bones, muscles, or other tissues of the back. Common back injuries include sprains and strains, herniated discs, and fractured vertebrae. The lumbar spine is often the site of back pain. The area is susceptible because of its flexibility and the amount of body weight it regularly bears. It is estimated that low-back pain may affect as much as 80 to 90 percent of the general population in the United States. Muscle and soft tissue injuries can be classified using a graded system. Spinal column or vertebral injuries can

neg: Fish anatomy cord in an essentially continuous sheath. The lower tube surrounds the notochord, and has a complex structure, often including multiple layers of calcification. Lampreys have vertebral arches, but nothing resembling the vertebral bodies found in all higher vertebrates. Even the arches are discontinuous, consisting of separate pieces of arch-shaped cartilage around the spinal cord in most parts of the body, changing to long strips of cartilage above and below in the tail region. Hagfishes lack a true vertebral column, and are therefore not properly considered vertebrates, but a few tiny neural arches are present in the tail. Hagfishes do, however,

neg: Nacholapithecus recognised as a separate genus (Ishida "et al" 1999). Classified perhaps as a member of the family "Proconsulidae". "Nacholapithecus kerioi" is a hominoid known from the Aka Aiteputh Formation, in Nachola, Northern Kenya. The formation is largely part of the north-western rift "flank" overlying the Nachola Formation, part of the Neogene system (Samburu). Nacholapithecus Nacholapithecus is a Middle Miocene genus of hominoid found in the Nachola formation in northern Kenya. It is a key genus in early hominid evolution. Similar in body plan to "Proconsul", it had a long vertebral column with six lumbar vertebrae, no tail, a narrow torso,

neg: Pectodens neural spines, like "Tanystropheus". The cervical ribs are generally also long, having short forward processes and long rear processes that bridge two to three vertebral joints each. Meanwhile, the transverse processes of the dorsals are characteristically long and pronounced, terminating in sub-circular facet joints for the rounded heads of the ribs. Also like "Tanystropheus", the transverse processes of the tail become gradually reduced alongside the forward processes of the chevrons, disappearing by the 35th caudal vertebra. Like "Tanystropheus" and "Macrocnemus", the scapula is low. The long bones of the forelimbs have expanded and robust top ends; the deltopectoral crest on