Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

123 results found
Article

Accessory ossicle of the anterior arch of the atlas

The accessory ossicle of the anterior arch of the atlas is a normal variant and is best appreciated on a lateral cervical/sagittal study. It is observed as a circular and corticated osseous density that articulates with the inferior aspect of the anterior arch of the atlas.  It is not associate...
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Alar ligament

The alar ligaments join the lateral margins of the sloping upper posterior margin of the dens of C2 to the lateral margins of the foramen magnum (adjacent to the occipital condyles) and lie on either side of the apical ligament. The may be oblique or vertical and are thickest at the occipital at...
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Anatomy curriculum

The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists. General anatomy Neuroanatomy Head and neck anatomy Thoracic anatomy Abdominal and pelvic anatomy Spinal anat...
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Annulus fibrosus

The annulus fibrosus surrounds the nucleus polposus and together they form the intervertebral disc. Gross anatomy The annulus comprises 15 to 20 collagenous (type I) laminae which run obliquely from the edge of one vertebra down to the edge of the vertebra below. The direction of the fibres al...
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Anterior angulation of the coccyx

Anterior angulation of the coccyx may be a normal variant but poses a diagnostic challenge for those considering coccygeal trauma. Classification Four types of coccyx have been described: type I: the coccyx is curved slightly forward, with its apex pointing caudally (~70%) type II: the coccy...
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Anterior atlanto-occipital membrane

The anterior atlanto-occipital membrane is a thin membrane that joins the upper border of the anterior arch of the atlas (C1) to the anterior inferior surface of the foramen magnum. It is a continuation of the anterior longitudinal ligament above the C1 level. It is immediately posterior to the ...
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Anterior corticospinal tract

The anterior corticospinal tract is formed at the level of the of the medullary pyramids, where the majority (90%) of descending corticospinal tract fibres decussate to form the lateral corticospinal tract. The majority of the remaining non-decussating 10% of fibres form the much smaller anterio...
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Anterior longitudinal ligament

The anterior longitudinal ligament (ALL) arises from the anteroinferior basilar portion of occipital bone, traverses the entire length of the spine, and ends on the anteriosuperior portion of the sacrum. The ALL runs along the anterior surface of the vertebral bodies (firmly united to the perio...
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Anterior spinal artery

The anterior spinal artery supplies the anterior portion of the spinal cord and arises from the vertebral artery in the region of the medulla oblongata. The two vertebral arteries (one of which is usually bigger than the other) anastamose in the midline to form a single anterior spinal artery at...
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Anterior spinothalamic tract

The anterior spinothalamic tract, also known as the ventral spinothalamic fasciculus, is an ascending pathway located anteriorly within the spinal cord, primarily responsible for transmitting coarse touch and pressure.  The lateral spinothalamic tract (discussed separately), in contrast, primar...
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Apical ligament

The apical ligament is a small ligament that joins the apex (tip) of the dens of C2 to the anterior margin (basion) of the foramen magnum. It is the weak, fibrous remnant of the notochord and does not contribute significant stability. The more posterior alar and cruciate ligaments are stronger ...
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Arcuate foramen

The arcuate foramen (foramen arcuale atlantis, ponticulus posticus or posterior ponticle, or Kimerle anomaly) is a frequently encountered normal variant of the atlas and is easily appreciated on a lateral plain film of the cranio-cervical junction. It develops by calcification of the posterior ...
Article

Artery of Adamkiewicz

The artery of Adamkiewicz, also known as the great anterior radiculomedullary artery or arteria radicularis anterior magna, is the name given to the dominant thoracolumbar segmental artery that supplies the spinal cord. Gross anatomy Origin The artery of Adamkiewicz has a variable origin but ...
Article

Ascending lumbar vein

The ascending lumbar vein is a paired structure which forms a part of the venous drainage of the lumbar vertebral column. Summary location: near midline on the side of the vertebral column in the lumbar region origin and termination: continuation of the lateral sacral veins; joins the subcost...
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Atlanto-axial articulation

The atlanto-axial articulation is a complex of three synovial joints, which join the atlas (C1) to the axis (C2). Gross anatomy Articulations paired lateral atlanto-axial joints: classified as planar-type joint between the lateral masses of C1 and C2, though somewhat more complex in shape wit...
Article

Atlanto-occipital articulation

The atlanto-occipital articulation is comprised of a pair of condyloid synovial joints that connect the occiput (C0) to the first cervical vertebra (atlas/C1). Gross anatomy Articulations Each joint is comprised of two concave articular surfaces on the superior aspect of the lateral mass of a...
Article

Atlanto-occipital assimilation

Atlanto-occipital assimilation is the fusion of the atlas (C1) to the occiput and is one of the transitional vertebrae.  Epidemiology Atlanto-occipital assimilation occurs in approximately 0.5% (range 0.25-1%) of the population 2-4.  Clinical presentation Atlanto-occipital is typically asymp...
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Atlas (C1)

The atlas is the first cervical vertebra, commonly called C1. It is an atypical cervical vertebra with unique features. It articulates with the dens of the axis and the occiput, respectively allowing rotation of the head, and flexion, extension and lateral flexion of the head.  Unlike the rest o...
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Atypical cervical vertebrae

Of the cervical vertebrae, the atlas (C1), axis (C2) and vertebra prominens (C7) are considered atypical cervical vertebrae. The atlas (C1) lacks a body or spinous process. It has an anterior and posterior arches with lateral masses. Its superior articular surfaces articulate with the occiput a...
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Atypical lumbar vertebrae

Of the five lumbar vertebrae, L5 is considered atypical due to its shape. The remaining lumbar vertebrae are largely typical. For a basic anatomic description of the structure a generic vertebra, see vertebrae.
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Atypical thoracic vertebrae

T1 and T9 to T12 are considered atypical vertebrae. T1 bears some resemblance to low cervical vertebrae. T9 has no inferior demifacet. T10 often, but not always, shares features with T11 and T12.  For a basic anatomic description of the structure a generic vertebra, see vertebrae.
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Axis (C2)

The axis is the second cervical vertebra, commonly called C2. It is an atypical cervical vertebra with unique features and important relations that make it easily recognisable. Its most prominent feature is the odontoid process, which is embryologically the body of the atlas (C1) 1,2. It plays a...
Article

Batson venous plexus

Batson venous plexus (or Batson veins) is a network of veins with no valves that connect deep pelvic veins draining the bladder, prostate, and rectum to the internal vertebral venous plexus 1. These veins are important because they are believed to provide a route for spread of pelvic cancer meta...
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Block vertebra

Block vertebra is a type of vertebral anomaly where there is a failure of separation of two or more adjacent vertebral bodies. Pathology In a block vertebra, there is partial or complete fusion of adjacent vertebral bodies. Associations there is a frequent association with hemivertebrae/abse...
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Brachial plexus

The brachial plexus is a complex neural network formed by lower cervical and upper thoracic ventral nerve roots which supplies motor and sensory innervation to the upper limb and pectoral girdle. It is located in the neck extending into the axilla posterior to the clavicle. Summary origin: ven...
Article

Butterfly vertebra

Butterfly vertebra is a type of vertebral anomaly that results from the failure of fusion of the lateral halves of the vertebral body because of persistent notochordal tissue between them. Pathology Associations an anterior spina bifida, with or without an anterior meningocele can be part of...
Article

Cauda equina

The cauda equina is the collective term given to nerve roots distal to the conus medullaris, which occupy the lumbar cistern.  It is said to look like a horses tail.
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Cervical enlargement

The cervical enlargement is the source of the spinal nerves that contribute to the brachial plexus and supply the upper limbs. Gross anatomy It is one of two symmetrical enlargements which occupy the segments of the limb plexuses, the other being the lumbosacral enlargement for the lumbar and ...
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Cervical plexus

The cervical plexus is formed by the ventral (anterior) rami of the C1 to C5 nerve roots and innervates the diaphragm, provides motor supply to some neck muscles and cutaneous sensation to the skin of the head, neck and chest. Gross anatomy Roots anterior rami of C1 to C5 nerves Course runs...
Article

Cervical rib

Cervical rib is a supernumerary or accessory rib arising from the seventh cervical vertebra. They occur in ~0.5% of the population, and are more common in females. Although cervical ribs are usually asymptomatic, they are the most important anatomic rib variant clinically, because they can caus...
Article

Cervical spine

The cervical spine is the upper part of the spine extending from the skull base to the thorax at the level of the first vertebra with a rib attached to it. It normally consists of seven vertebrae. Its main function is to support the skull and maintain the relative positions of the brain and spin...
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Cervical spine ligaments

Cervical spine ligaments ordered from anterior to posterior include: anterior longitudinal ligament (ALL) anterior atlanto-occipital membrane apical ligament alar ligaments (paired) cruciate ligament of the atlas longitudinal band: joins the body of the axis to the foramen magnum transver...
Article

Coccyx

The coccyx is the series of rudimentary vertebrae forming the caudal termination of the vertebral column and is positioned inferior to the apex of the sacrum. The coccyx is one leg of the tripod formed in conjunction with the ischial tuberosities for support in a seated position. Additionally, i...
Article

Column of Burdach

The column of Burdach, also known as the cuneate fasciculus or fasciculus cuneate, represents the lateral portion of the dorsal columns and carries input from between and including C1 and T6 1.  Function The cuneate fasciculus is responsible for transmitting vibration, conscious proprioception...
Article

Column of Goll

The column of Goll, also known as the gracile fasciculus or fasciculus gracilis, represents the medial portion of the dorsal columns and carries input from below and including T7 1. Function The gracile fasciculus is responsible for transmitting vibration, conscious proprioception, and fine (d...
Article

Congenital absence of a spine pedicle

Congenital absence of a spine pedicle is a rare congenital condition, but awareness of its characteristic imaging appearance is important to avoid misdiagnosis. Failure to recognise this entity can lead to misdiagnosis of unilateral facet subluxation/dislocation, leading to unnecessary treatmen...
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Congenital anomalies of the posterior atlas arch

Congenital anomalies of the posterior arch of the atlas (C1) are relatively common anomalies. They may range from partial defects presenting as clefts to complete absence of the posterior arch (aplasia). These anomalies are classified according to Currarino (see below). It should not be confuse...
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Conus medullaris

The conus medullaris is the terminal end of the spinal cord. Gross anatomy After the cord terminates, the nerve roots descend within the spinal canal as individual rootlets, collectively termed the cauda equina. The conus medullaris most commonly terminates at the L1/2 intervertebral disc leve...
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Cortical bone

The outer shell of compact bone is called cortical bone or cortex.  Gross anatomy Cortical bone contains Haversian systems (osteons) which contain a central Haversian canal surrounded by osseous tissue in a concentric lamellar pattern. Two fibrovascular layers surround the cortical bone which...
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Corticorubral tract

The corticorubral tract contains neurons that connect the primary motor and sensory areas to the red nucleus. The rubrospinal tract then descends through the spinal cord.  The tract is thought to excite flexor muscles and inhibit extensor muscles. Gross anatomy Central connections The corti...
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Cruciate ligament of the atlas

The cruciate ligament of the atlas (also known as the cruciform ligament) is an important ligamentous complex that holds the posterior dens of C2 in articulation at the median atlantoaxial joint. It lies behind a large synovial bursa (surrounded by loose fibrous capsule) and consists of two band...
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Difference in vertical mid-vertical angle (lumbar spine)

The difference in vertical mid-vertical angle is the difference in the vertical mid-vertebral angle (VMVA) between the caudal segment angle and the adjacent cephalad segment angle of the three most caudal segments of the lumbar spine as measured on a mid-sagittal MRI or a lateral radiograph. Ra...
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Disc herniation

Disc herniation refers to the displacement of intervertebral disc material beyond the normal confines of the disc but involving less than 25% of the circumference (to distinguish it from a disc bulge. A herniation may contain nucleus pulposus, vertebral endplate cartilage, apophyseal bone/osteop...
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Dorsal columns

The dorsal columns, or posterior columns, are ascending pathways primarily concerned with sensory function. They are responsible for transmitting vibration, conscious proprioception, and fine (discriminative) touch 1,2. The dorsal columns are divided two tracts, which are discussed separately 2...
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Epitransverse process of the atlas

Epitransverse process is a rare anatomical variant of the atlas, consisting of a bony exostosis which extends cephalad from from the transverse process of the atlas to articulate with the occipital bone. This process sometimes meets with a paracondylar process, forming a pseudoarthrosis at the i...
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Erector spinae group

The erector spinae group is the intermediate layer of the intrinsic muscles of the back. This group is made of three subgroups, with the group divisions occurring by location. The iliocostalis group occurs most laterally, followed by the longissimus group, and finally the spinalis as the most me...
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Facet joint

The facet (or apophyseal or zygapophyseal) joints are the articulations of the posterior arch of the vertebrae and form part of the posterior column.  Gross anatomy They are synovial-lined joints that have a fibrous capsule and connect the articular facets of the vertebrae. The superior facet ...
Article

Facet joint capsule

Facet joint capsules are the fibrous capsule that surround the vertebral facet or zygapophyseal joints. They are particularly thin and loose, attached to the margins of articular facets on adjoining articular processes. The capsules merge medially with the ligamentum flavum.  In the cervical re...
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Fifth lumbar vertebra (L5)

The fifth lumbar vertebra (L5) is the largest of the five lumbar vertebrae and is considered an atypical vertebra due to its shape.  Gross anatomy L5 is the largest, most inferior lumbar discovertebral unit in the vertebral column, and participates in forming the lumbar lordosis (from L1 to L5...
Article

Filum terminale

The filum terminale is a filament of connective tissue that extends inferiorly from the apex of the conus medullaris. Gross anatomy The filum terminale is continuous with the pia mater and is described as having two sections: filum terminale internum: upper three quarters of the filum; covere...
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Focal fatty deposits in spinal bone marrow

Focal fatty deposits/replacement in spinal bone marrow are well-defined focal fat islands within the bone marrow of spine or other parts of axial skeleton. Epidemiology Common in older individuals, related to age and not related to sex. Pathology This process is a normal variant. Histologica...
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Hemivertebra

Hemivertebra is a type of vertebral anomaly and results from a lack of formation of one half of a vertebral body. It can be a common cause of a congenital scoliosis.  Epidemiology The estimated incidence is at ~0.3 per 1000 live births 2. Pathology It falls under the spectrum of segmentation...
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Iliolumbar ligament

The iliolumbar ligament is a strong band of connective tissue which courses from the transverse process of L5 (in over 96% of cases) to the posterior iliac wing and iliac crest. It functions to maintain the alignment of L5 on the sacrum during various movements 1, 2. It is an important landmark...
Article

Intercalary bone

Intercalary bones are common discal ossifications that are usually triangular in morphology, found in the anterior annular fibers of an intervertebral disc, and are thought to be degenerative in aetiology.  Differential diagnosis limbus vertebra flexion or extension teardrop fracture
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Intercristal line

The intercristal line (also known as Jacobys’s Line or Tuffier’s Line) is a horizontal line drawn across the highest points of both the iliac crests in an anteroposterior (AP) lumbar radiography 1,2 Intercristal line most often intersects the body of the L4 or its inferior endplate in men and t...
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Interspinous ligament

The interspinous ligaments join the spinous processes along their adjacent borders. They are composed of relatively weak fibrous tissue that fuses with the stronger, supraspinous ligaments.
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Intertransverse ligaments

The intertransverse ligaments consist of fibrous tissue joining transverse processes of adjacent vertebrae. In the cervical region, intertransverse ligaments are scattered fibres that are largely replaced by intertransverse muscles. In the thoracic region, these are fibrous cords blending with t...
Article

Intervertebral disc

Intervertebral discs are located between the vertebral bodies of C2/3 to L5/S1, totalling 23 in the conventional spine. Together they account for approximately 25% of the total height of the vertebral column. This decreases with age as disc height is lost. The upper thoracic discs are the thinn...
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Intervertebral foramen

The intervertebral foramina allow passage of structures out of and into the vertebral canal.   Boundaries Anterior- lower posterolateral aspect of a vertebral body and the intervertebral disc below in the cervical region a portion of the vertebral body below, predominately the uncinate proce...
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Intervertebral joint

There are three intervertebral joints between each adjacent vertebra from the axis to the sacrum – one between the vertebral bodies and a pair between the facets of adjoining vertebral arches (zygapophysial joints, also called facet joints). Gross anatomy Movement flexion: the anterior interv...
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Lateral corticospinal tract

The lateral corticospinal tract is formed at the level of the of the medullary pyramids when the majority (90%) of descending corticospinal tract fibres decussate – the majority of the remaining non-decussating 10% of fibres form the much smaller anterior corticospinal tract, with only a few non...
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Lateral spinothalamic tract

The lateral spinothalamic tract, also known as the lateral spinothalamic fasciculus, is an ascending pathway located anterolaterally within the peripheral white matter of the spinal cord. It is primarily responsible for transmitting pain and temperature as well as coarse touch.  The anterior sp...
Article

Ligamentum flavum

The ligamentum flavum is a paired ligament which runs between adjacent laminae of the vertebral bodies. It forms part of the posterior ligamentous complex of the vertebral column. Gross anatomy paired, yellowish, elastic ligament forms part of the posterior border of the spinal canal relativ...
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Ligamentum nuchae

The ligamentum nuchae is a large median ligament composed of tendons and fascia located between the posterior muscles of the neck. It covers the spines of C1 to C6 vertebrae. It is a superior and posterior extension of the supraspinous ligament. It rises from the spinous process of C7 to the ini...
Article

Lumbar cistern

The lumbar cistern refers to the subarachnoid space in the lower lumbar spinal canal. The cistern is an enlargement of the subarachnoid space in the dural sac, distal to the conus medullar is. It contains cerebrospinal fluid and the nerve roots of the cauda equina. As the conus (usually) termin...
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Lumbar enlargement

The lumbar enlargement of the spinal cord corresponds to the mild increase in cross sectional area of the cord from the T11 level to the conus medullaris. It is enlarged due to the present of spinal nerve anterior rami which contribute to the lumbar and sacral plexuses.
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Lumbar plexus

The lumbar plexus is a complex neural network formed by the lower thoracic and lumbar ventral nerve roots (T12 to L5) which supplies motor and sensory innervation to the lower limb and pelvic girdle. Summary origin: ventral rami of T12 to L5 course: formed within the substance of the psoas ma...
Article

Lumbar rib

Lumbar (or 13th) ribs are a rare anatomical variant and represent transitional vertebrae at the thoracolumbar junction with a prevalence of ~1% 1. It presents as an additional rib coming off T13 or L1 (depending on numbering classification) and may be unilateral or bilateral. Lumbar ribs are mos...
Article

Lumbar spine

The lumbar spine consists of five adjacent vertebrae of the mid-lower vertebral column. They participate in the lumbar lordosis, a natural curve in the spine, that is convex anteriorly.  Articulations of the facet (zygapophyseal) joints permit flexion/extension and abduction movements. Rotation...
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Lumbosacral transitional vertebra

Lumbosacral transitional vertebrae (LSTV) are a relatively common variant and can be seen in ~25% (range 15-35%) of the general population 1-3. Non-recognition of this variant and/or poor description in the report can lead to operations or procedures performed at the wrong level.  Depending on ...
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Movements of the spine

Movements of the spine are possible due to intervertebral discs, and with the fulcrum of movement occurring primarily around the nucleus pulposus. Specialized motion occurs at the atlanto-occipital and atlantoaxial joints, which do not contain a disc. The spine (vertebral column) forms the cent...
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Neurenteric canal of Kovalevsky

The neurenteric canal or canal of Kovalevsky is the transient communication of the amnion through notochordal canal to the yolk sac during notochordal formation at day 16-17. Abnormalities during this stage produce the neurenteric cyst spectrum.
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Nucleus pulposus

The nucleus pulposus is the central part of each intervertebral disc. Gross anatomy It is located within the annulus fibrosus and between the vertebral body endplates. It is composed of a thin lattice of collagen fibres (type II) which traverse though hydrophilic glycosaminoglycans.  With age...
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Occipital vertebrae

Occipital vertebrae is a very rare anatomical variant and results from incomplete or aberrant fusion of occipital bone ossification centres. There is a broad spectrum of occipital vertebrae variations and the four most common include: third condyle (condylus tertius) basilar process paracondy...
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Oppenheimer ossicle

Oppenheimer ossicles are accessory ossicles associated with the facet joints found in ~4% (range 1-7%) 1 of lumbar spines.  Oppenheimer ossicles are thought to arise as a result of non-union of a secondary ossification centre of the articular process. They predominantly occur as a single, unila...
Article

Os odontoideum

Os odontoideum is an anatomic variant of the odontoid process of C2 and needs to be differentiated from persistent ossiculum terminale and from a type 2 odontoid fracture. It can be associated with atlantoaxial instability.  Although it was originally thought to be a congenital lesion due to a ...
Article

Ossification centres of the vertebral column

Ossification of the vertebral column is complex but an overview of primary and secondary ossification centres is given below: Primary ossification centres The C3-L5 vertebrae typically have three primary ossification centres that start appearing at 9 weeks in utero and finish primary ossificat...
Article

Paracondylar process

Paracondylar process is a rare anatomical variant of the occipital bone, where a bony exostosis extends caudally from the paracondylar region (lateral to the native occipital condyles), typically articulating with the superior surface of a transverse process of the atlas. This may be unilateral ...
Article

Perivertebral space

The perivertebral space is one of the seven deep compartments of the head and neck. Gross anatomy The perivertebral space is a cylinder of soft tissue lying posterior to the retropharyngeal space and danger space surrounded by the prevertebral layer of the deep cervical fascia and extends from...
Article

Persistent ossiculum terminale

The ossiculum terminale appears as a secondary ossification centre of the dens between 3-6 years and normally fuses by 12 years. Failure of fusion results in a persistent ossiculum terminale (also called Bergmann's ossicle or ossiculum terminale of Bergmann) and is considered a normal anatomical...
Article

Posterior atlanto-occipital membrane

The posterior atlanto-occipital membrane attaches the upper border of the posterior arch of the atlas (C1) to the outer margin of the foramen magnum. It is continuous with the posterior atlantoaxial membrane and ligamentum nuchae and lies immediately posterior to the dura. Posteriorly lie the su...
Article

Posterior ligamentous complex

The posterior ligamentous complex acts to stabilise the vertebral column and is made up of the following structures: facet joint capsule ligamentum flavum interspinous ligament supraspinous ligament In particular, it acts to hold the facet joints of the neighbouring vertebrae in fixed relat...
Article

Posterior longitudinal ligament

The posterior longitudinal ligament (PLL) arises from the back of the axis (C2) body and travels downward and posterior to the vertebral bodies (attached loosely) and intervertebral discs (firmly attaching to the posterior annulus), attaching to the back of the sacrum. It narrows as it travels d...
Article

Posterior spinal arteries

The posterior spinal arteries are a pair of arteries that supply the respective ipsilateral grey and white posterior columns of the spinal cord. Gross anatomy The posterior spinal arteries arise from either the posterior inferior cerebellar or vertebral arteries (V3 or V4 segments) and runs t...
Article

Quadratus lumborum

The quadratus lumborum muscle is an irregular quadrilateral muscle that forms part of the posterior abdominal wall. Summary location: dorsal abdominal wall attachments: medial half of inferior margins of 12th ribs and upper four lumbar transverse processes blood supply branches of the lumba...
Article

Retrodural space of Okada

The retrodural space of Okada is a wishbone-shaped potential space which links the facet joints to each other at a single level across the midline, and thus acts as a potential pathway for the spread of injected material (contrast, air, steroid, local anaesthetic) as well as infection.  Gross a...
Article

Rubrospinal tract

The rubrospinal tract contains neurons that carry signals from the corticorubral tract. The tract is thought to excite flexor muscles and inhibit extensor muscles. Gross anatomy Central connections The magnocellular portion of the red nucleus gives rise to the rubrospinal tract. It decussates...
Article

Sacral hiatus

The sacral hiatus corresponds to the posterior caudal opening at the end of the sacral canal, which usually occurs at the fifth sacral vertebra (S5), at the posterior surface of the sacrum. Gross anatomy Location Commonly, the sacral hiatus corresponds to the non-formation of S5 spinous proce...
Article

Sacroiliac joint

The sacroiliac (SI) joint is a synovial and fibrous joint between ilium and the sacrum. It has little movement and its main function is to transfer weight between the axial and lower appendicular skeletons. The SI joint is a symmetrical joint (i.e. is paired) with an oblique coronal orientation ...
Article

Sacrum

The sacrum is the penultimate segment of the vertebral column and also forms the posterior part of the bony pelvis. It transmits the total body weight between the lower appendicular skeleton and the axial skeleton. Gross anatomy The sacrum is an irregularly-shaped bone, roughly an inverted tri...
Article

Sesamoid ossicles of the nuchal ligament

Sesamoid ossicles of the nuchal ligament are a relatively common anatomical variant that are usually asymptomatic and most commonly occur at the C5/6 or C6/7 vertebral levels.  Epidemiology They occur in ~7.5% of the population, with a male predominance of 3:1 1.  Radiographic features Plain...
Article

Spinal anatomy

Spinal anatomy encompasses the anatomy of all osseous and soft tissue structures of the spine and its immediate surroundings. However, the structures related to the spinal cord are covered in our neuroanatomy section. Overview The spine is located in the midline posteriorly, extending from the...
Article

Spinal cord

The spinal cord is the part of the central nervous system that is found within the vertebral canal of the vertebral column.  Gross anatomy It measures approximately 42-45 cm in length, ~1 cm in diameter and 35 g in weight.  It is divided into cervical, thoracic and lumbar parts and terminates...

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