Week 5

Atlas Ossification Centers: Primary -Anterior arch(?) -Lateral Masses(?)

1 2

Ossification centers- typical cervical: Primary -Body(?) -Arch(?) Secondary -Superior rim of body(?) -Inferior rim of body(?) -Tips of transverse processes(?) -Tip of spinous process(?)

1 2 1 2 2 1

Ossification Centers-C7: Primary Body(?) Secondary(?) Secondary Transverse processes(?) Superior body(?) Inferior body(?) Spinous process(?) Costal elements(?)** The seventh cervical vertebra has the typical ossification centers with the addition of separate secondary ossification centers for the costal processes.

1 2 2 1 1 1 2

Transverse Process: ? roots / bars: anterior and posterior. Anterior and posterior tubercles. Joined by intertubercular lamella (CT lamella or bar) Groove for spinal nerve and ? (?) ramus located between anterior and posterior roots. Anterior tubercles: attachment of anterior S, LC, LC Posterior tubercles extend further L and I than anterior: attachments of splenius cervicis, longissimus cervicis, iliocostalis cervicis, levator scapulae and scalenius medius and posterior.

2 costotransverse anterior ventral scalene longus colli longus capitis laterally inferiorly

Spinous Process: Short and bifid. Develops from ? secondary centers of ossification Bifid For attachment of LN and DE of the spine. ? tubercle / side often larger than the other Often deviates to ? side (not on midline) Length decreases from C? - C? then increases from C? to C?. (so C4 has S)

2 ligamentum nuchae deep extensors 1 1 C2-C4 C4-C7 shortest

Pedicles: The pedicles of typical cervical vertebrae are placed about midway between the superior and inferior margins of the vertebral body. Therefore the superior and inferior vertebral notches are of approximately equal size. The spinal nerve, surrounded by a sleeve of dura, courses just above (superior to) the pedicle of each typical cervical vertebra. The left and right transverse processes (TPs) of a typical cervical vertebra are each composed of ? roots, or bars, one anterior and one posterior. The two roots end laterally as tubercles (anterior and posterior). The two tubercles are joined to one another by an IT lamella, which is less correctly known as a CT lamella (bar). The two roots end laterally as tubercles (anterior and posterior).

2 intertubercular lamella costotransverse

Cervical Discs: No IVDs between occiput and C1 or between C1 and C2 About ?% of the height of the cervical spine is from the cervical IVDs Annulus fibrosus has lots of sensory nerve fibers, including nociceptors for pain, PC and GTO for proprioception. Nucleus Pulposus has NO nerve supply. Taller ?, shorter ?

25 pacinian corpuscles golgi tendon organs anterior posterior

Biomechanics of C0-C1 Limits: Designed for flexion and extension (combined ?? degrees) with some lateral flexion (? degrees unilateral) and rotation (? degrees unilateral) Extension limited by posterior aspect of superior articular process of C1 opposing the occiputs condylar fossa Flexion limited by soft tissue stops such as posterior atlanto-occipital membrane.

25 5 5

The dorsal and ventral roots (medially) or the spinal nerve (laterally) and the dural root sleeve account for ??% to ??% of the cross-sectional area of a typical cervical IVF. When the cervical spine is in the neutral position, the dorsal and ventral roots are located in the ? portion of the IVF at or below the disc level. Epidural fat and blood vessels are found in the ? aspect of the IVF. The dorsal root and dorsal root ganglion are located ? to and slightly A the ventral root. The dorsal root is also in contact with the ? articular process. The dorsal root ganglion is associated with a small notch on the anterior surface of the superior articular process in the cervical region. The ventral root contacts the UP, and the dorsal and ventral roots are separated from each other by adipose tissue. This adipose-filled region between the dorsal and ventral roots has been called the IR foramen or cleft and can be seen on MRI.

35 50 inferior superior posterior above superior uncinate process interradicular

Articular Processes and Z-joints: Facet joint angles = ?? degrees to the horizontal plane. Upper cervical are closer to?? degrees and lower cervical are closer to ?? degrees. Range 35-65 degrees. Superior articular processes and facets face posterior, superior and slightly ?

45 35 65 medial

Articular Processes and Zygapophysial Joints: The superior articular processes and their hyaline cartilage-lined facets face posteriorly, superiorly, and slightly medially (see Fig. 5-1), and the cervical Z joints lie approximately ?? degrees to the horizontal plane. More specifically, the facet joints of the upper cervical spine lie at approximately a ??-degree angle to the horizontal plane, and the lower cervical Z joints form a ??-degree angle to the horizontal plane.

45 35 65

Invertebral Foramina: The left and right intervertebral foramina (IVFs) in the cervical region lie between the inferior and superior vertebral notches of adjacent cervical vertebrae. They face obliquely anteriorly at approximately a ??-degree angle from the midsagittal plane for the upper and middle cervical IVFs and approximately a ??-degree angle to the midsagittal plane for the lower cervical IVFs. However, the uncinate processes, which help to form the anterior border of the IVFs, are unique to the cervical region. The cervical IVFs, as with those of the thoracic and lumbar regions, can best be considered as neural canals because they are ? to ? mm in length. They are almost oval in shape. The IVFs change dimensions with movement. Flexion of ?? degrees, ?? degrees, and full flexion from the neutral position increase the superior to inferior IVF diameter by ??%, ??%, and ??%, respectively; and extension of ?? degrees, ?? degrees, and full extension from the neutral position decreases IVF diameter by ??%, ??%, and ??%, respectively.

45 55 4 6 20 30 8 10 31 20 30 10 13 20

Upper Cervical Ligaments: Transverse Ligament of C1: A strong ligament that runs from a small tubercle on the medial aspect of 1 lateral mass of the atlas to the other lateral mass. Lies in a horizontal plane Runs about ?mm inferior to attachment of A and A ligaments on the dens, in the posterior groove. Lined by a thin layer of FC, forming a D joint with odontoid Allows atlas to pivot on axis and holds atlas in position to prevent spinal cord compression during flexion Has 2 layers, superficial and deep Measure ADI (Atlanto-dental interspace) on neutral lateral cervical film. If greater than ? mm in adult or ? mm in child, indicates compromise of transverse ligament and possible upper cervical instablity Superior Longitudinal Band: From transverse ligament to anterior lip of foramen magnum (superior aspect of clivus). Between tectorial membrane and apical ligaments Holds transverse ligament of C1 in position. May limit flexion and extension of the occiput Inferior Longitudinal Band: Attaches transverse ligament of C1 to body of C2 Prevents transverse ligament from riding up the odontoid and helps limit flexion of occiput on atlas

5 alar apical Fibrocartilage diarthrodial 3 5

Congenital non-union of odontoid to C2 body: Os odontoideum: a transverse, radiolucent cleft separates as ossicle of variable size from the axis body Transverse ligament is usually intact Normal development of the dens includes a synchondrosis separating the base of the dens from the C2 vertebral body It normally ossifies to connect the odontoid to the C2 body by age ?-? years

5-7

General Cervical Info: ? CERVICAL VERTEBRAE ? CERVICAL NERVES ? ARTICULATIONS MOST MOBILE ARE OF THE SPINE SECONDARY LORDOTIC CURVE

7 8 76

The cervical spine is one of the most complicated articular systems in the body, comprising ?? separate joints. It allows more movement than any other spinal region and is surrounded by a myriad of nerves, vessels, and many other vital structures. However, such complexity can come at a high cost; more than ??% of individuals suffer from significant neck pain at some time in their lives. Some authors state that the cervical curve actually is composed of ? curves, upper and lower. The upper cervical curve is described as a distinct primary curve that extends from the occiput to the A and is concave anteriorly (kyphotic). The lower cervical curve is the classically described lordosis, but in this case begins at C? rather than C1. This description helps to explain the dramatic differences seen between the upper and lower cervical vertebrae, such as the independent movements that can occur in the two regions (e.g., flexion of the lower cervicals and simultaneous extension of the occiput on the atlas and the atlas on the axis).

76 50 2 axis C2

Cervical Curvatures: Development: -? weeks gestation -? - ? months when lifting head begins -? months when sitting upright and crawling 2 curves: -Upper cervical curve = a primary curve from occiput to A, K -Lower cervical curve = secondary lordosis from C? - C?

9 3-4 9 axis kyphotic C2-C7

Biomechanics of Lower cervical: C2-3 down to C7-T1 Combined flexion extension (?? degrees). Unilateral lateral flexion (?? degrees). Unilateral axial rotation (?? degrees) Extension usually ? than flexion. Extension limited by inferior articular process of C7 hitting a groove below the superior articular process of T1 Flexion limited by lip of anterior and inferior vertebral body of 1 cervical pressing on the anterior superior lip of the vertebral body below.

91 51 33 greater

Vertebral Foramen of C1: Large: ? diameter > ? diameter Steels rule of thirds = the division of the atlas vertebral foramen into ? Anterior 1/3 filled by O 1/3 free space (adipose tissue, blood vessels, ligaments, meninges and subarachnoid space), 1/3 SC

AP transverse thirds odontoid spinal cord

The two tubercles are joined to one another by an intertubercular lamella, which is less correctly known as a costotransverse lamella (bar). The distance between the lateral tips of the left and right TPs is greatest at C?. This same distance, although smaller, remains relatively constant from C2 through C6 and then increases greatly at C?. In the typical cervical vertebrae a gutter, or groove, for the spinal nerve is formed between the anterior and posterior roots of each TP. This groove serves as a passage for exit of the spinal nerve and its largest branch, the ? primary division (ventral ramus).

C1 C7 anterior

Typical Cervical Vertebrae: The typical cervical vertebrae are C? through C?. These are some of the smallest but most distinct vertebrae of any vertebral region. C? and C? are considered to be atypical vertebrae, and C? is unique.

C3-C6 C1 C2 C7

The anterior aspects of the TPs of C? to C? terminate in roughened tubercles that serve as attachments for the tendons of the scalenus anterior, longus colli (superior and inferior oblique fibers), and longus capitis muscles. The posterior tubercles extend further laterally and slightly more inferiorly than their anterior counterparts (except for C6, where they are level). The splenius cervicis, longissimus cervicis, iliocostalis cervicis, levator scapulae, and scalenus medius and posterior muscles attach to the posterior tubercles.

C4 C6

Vertebral Artery: 4 parts: Subclavian to C? transverse foramen C6 transverse foramen to C? transverse foramen C1 transverse foramen to P A-O memnbrane From posterior atlanto-occipital membrane to unite as B artery

C6 C1 Posterior atlanto-occipital basilar

Transverse Foramen: Boundaries = pedicle, anterior root of TP, posterior root of TP, intertubercular lamella Vertebral artery: C? transverse foramen to C? transverse foramen. Ventral Rami pass ? to vertebral artery Vertebral Veins Plexus of S nerves

C6 C1 posterior sympathetic

Transverse Foramen: As the name implies, the foramen of the TP is an opening within the TP. This foramen is present in the left and right TPs of all cervical vertebrae. It was previously called the foramen transversarium, but the currently preferred term is simply foramen of the transverse process. The boundaries of this foramen are formed by four structures: the pedicle, anterior root of the TP, posterior root of the TP, and intertubercular lamella. The vertebral artery normally enters the foramen of the TP of C? and continues superiorly through the corresponding foramina of C5 through C1. The vertebral artery of each side loops posteriorly and then medially around the superior articular process of the atlas on the corresponding side. The artery then continues superiorly to pass through the foramen magnum. The ventral rami of the C3 to C6 spinal nerves pass directly ? to the vertebral artery. In fact, each of these rami usually rests against the artery as the ventral ramus exits the gutter (groove) for the spinal nerve of the TP Several vertebral veins on each side also pass through the foramina of the TPs. These veins begin in the atlanto-occipital region and continue inferiorly through the foramina of the TPs of C1 through C7 and then enter the SC vein. The vertebral veins receive branches from both the EV plexus and the EVV plexus.

C6 posterior subclavian epidural venous external vertebral venous

Body of C2: Inferior surface: I and communicates with ? intervertebral disc (C2 disc or C2-3 disc) Anterior hollowed out for attachment of LC muscle Anterior Longitudinal Ligament (ALL) attaches to inferior border of vertebral body Posterior longitudinal ligament (PLL) attaches to the posterior inferior border of vertebral body, superiorly called the T membrane

Indented first longus colli tectorial

Occiput: Squamous Part = ? to FM Lateral Parts Basilar Part = ? to FM

Posterior Anterior

Cervical Spinal Ligaments: Supraspinous Ligament (S to T?) becomes Ligamentum Nuchae (C7 - Occiput): connects tips of SPs Interspinous Ligaments: connects 1 SP to the next SP Intertransverse Ligaments: connects 1 TP to the next TP Ligamentum Flava: 1 on each side (right and left): connects the anterior surface of 1 lamina to the anterior surface of the next lamina. Directly posterior to the spinal cord. Posterior Longitudinal Ligament becomes Tectorial membrane (at C?): connects posterior vertebral bodies. -Posterior Atlanto-occipital membrane -C / C Ligament: Transverse ligament of C1, Superior longitudinal band, Inferior longitudinal band -Alar Ligaments -Apical Ligament -Anterior Atlanto-occipital membrane -Vertebral Bodies -Anterior Longitudinal Ligament: connects the anterior vertebral bodies.

Sacrum T1 C2 Cruciate Cruciform

External aspect of the Occipital Bone: The external aspect of the occipital bone consists of three different regions: squamous, left and right lateral, and basilar. These three regions are discussed separately.

YES

The left and right longitudinal channels of the cervical anterior internal vertebral venous plexus are kept in the most ? and ? regions of the epidural space by a thin fibrous membrane on each side of the vertebral canal. These venous channels anastomose with one another behind each vertebral body via RC veins that course between the posterior longitudinal ligament and vertebral bodies. The anterior internal vertebral veins of the upper cervical region (periodontal veins) have communications with the venous drainage of retropharyngeal structures via PV veins. These anastomoses have been implicated as a route for the spread of infection from anterior paravertebral structures to the occipital condyles and the atlas, in some cases leading to osteomyelitis affecting the upper cervical joints.

anterior lateral retrocorporeal pharyngovertebral

Lateral Parts: Occipital Condlyes: -AL aspect of the FM, -Protrude inferior, anterior, and medial -Articular facets covered with hyaline cartilage, Fit into superior articular facets of Atlas -Flexion, extension, and lateral flexion of occiput on atlas (the "Y" joint) Jugular Process: ? border of jugular groove. Attachment for Rectus capitis L muscle

anterolateral yes lateral lateralis

Ligaments: Posterior Atlanto-Occipital Membrane: Thin structure attaching the posterior arch of the A to the posterior rim of the FM Closely associated with the posterior aspect of the spinal DM Limits F of occiput on atlas Arches over the grooves for the vertebral artery (also over the vertebral veins and suboccipital nerve. Posterior ponticus = ossification of the posterior atlanto-occipital membrane, creating an A foramen through which the vertebral artery, veins and suboccipital nerve pass. Tectorial Membrane: The superior extension of the PLL. Posterior aspect of C2 vertebral body, crosses over dens, inserts on A rim of foramen magnum Has superficial and deep fibers Limits flexion and extension of the atlas and occiput

atlas foramen magnum dura mater flexion arcuate anterior

Anterior Ligaments of C1: Anterior Atlanto-Occipital Membrane: A broad band of densely woven fibers running from superior aspect of anterior arch of A to anterior margin of FM, anterior to the A ligament Blends laterally with the C ligaments Limits ? of occiput on atlas. Runs just ? to the ALL

atlas foramen magnum apical capsular extension posterior

Basilar Part: The basilar region of the occipital bone extends anteriorly from the foramen magnum. The part of the occipital bone that forms the most anterior aspect of the foramen magnum is known as the B. The basilar region of the occipital bone meets the basilar portion of the S bone, and together the internal surface of the two basilar processes is known as the C. The superior constrictor muscle of the pharynx attaches to the distinct pharyngeal tubercle, which is located in the center of the external surface of the basiocciput. The rectus capitis anterior muscle attaches just in front of the occipital condyle, and the longus capitis muscle attaches anteriorly and laterally to the pharyngeal tubercle. The anterior atlanto-occipital membrane attaches just in front of the foramen magnum. The apical ligament of the odontoid process attaches to the rim of the foramen magnum, and the superior (upper) band of the cruciform ligament attaches to the surface of the clivus, covered posteriorly by the clival attachment of the tectorial membrane. The transition of the spinal dura to the meningeal layer of the cranial dura occurs just posterior to the tectorial membrane. The CST Pump The CranioSacral system is also a RP, like the heart and lungs. ... These tissues create a semi-closed hydraulic pump system that bathes the spinal cord and brain in cerebrospinal fluid which, like blood, provides vital nourishment and detoxification.

basion sphenoid clivus rhythm pump

C2 Inferior Articular Processes and SPs: SP is more prominently B than other cervical SPs, with many muscle attachments SP attachments Entire SP may deviate to left or right, Right and left sides of the bifid are often asymmetrical Inferior articular processes are the same as typical cervical vertebrae, arising from lamina-pedicle junction and facing anterior, inferior, and slightly lateral

bifid

C6: C6 is considered typical Anterior tubercles of the TPs are prominent and called CT. Common carotid artery lies directly ? to carotid tubercle Superior articular process is more ? than the inferior articular process Sulcus for the Dorsal primary rami of C6 is D, seen from both lateral and posterior views C6 is the last cervical vertebrae with palpable movement in ? / ?

carotid tubercles anterior anterior deep flexion/extension

Typical Cervical Vertebral Bodies: Side View Anterior body: ridges at superior and inferior borders for attachment of the ALL, creates a C body from S to I. It is C from side to side. Posterior body: slightly I, with small foramina for BV veins. PLL attaches to superior and inferior margin of post vertebral body. Anterior inferior aspect of vertebral body cups D to overlap the IVD below.

concave convex indented basivertebral down

Typical Cervical Vertebral Bodies: Superior surface (looking down from above) is C or slightly H out side to side due to uncinate processes projecting up, but C A to P due to beveling of anterior aspect. Inferior surface (looking up from below) is C from side to side and C from A to P due to anterior lip of inferior surface. Inferior surface is ? than superior surface (like a trapezoid)

concaved hollowed convex convex concave larger

Lateral Parts: The left and right lateral portions of the occipital bone are located to the sides of the foramen magnum. They include the left and right occipital C, J processes, and J notches. The two occipital condyles are convex structures located on each side of the foramen magnum. Each condyle follows the contour of the large foramen and protrudes inferiorly, anteriorly, and medially. Each possesses a hyaline cartilage-lined articular facet. The left and right occipital condyles fit snugly into the superior articular facets of the atlas, and the left and right atlanto-occipital articulations allow for flexion, extension, and lateral flexion of the occiput on the atlas.

condyles jugular jugular

Lateral Atlanto-Axial Articulations: Planar joints between inferior articular process of C1 and superior articular process of C2. Flat, but both surfaces covered with C articular cartilage. Fibrous capsule is T and L, attaching to outermost rim of articular margins. Lined by synovial membrane, with synovial folds Posteromedial accessory ligament attaches to inferior body of axis, near base of dens and runs up to lateral mass of atlas, near attachment of transverse ligament of C1. Called AAA ligament.

convex thin loose accessory atlanto-axial

(superior to inferior dimensions) of both the anterior and posterior aspects of the cervical vertebral bodies generally increase from C3 to C7 The anterior surface of the cervical vertebral body is C from side to side. However, these same surfaces are C from superior to inferior because of prominent ridges at the superior and inferior borders (discal margins) formed by the attachment sites of the anterior longitudinal ligaments. Indentations seen on the left and right of the anterior midline of the vertebral bodies are for attachment of the vertical fibers of the longus colli muscle. The posterior surface of a typical cervical vertebral body is slightly indented and possesses two or more foramina for exit of the BV veins.. The posterior longitudinal ligament attaches to the superior and inferior margins of the posterior aspect of the cervical vertebral bodies.

convex concave basivertebral

Atlanto-Occipital Articulation: Occipital Condyles + superior articular surfaces of C1 = E or C Articular capsules and anterior and posterior atlanto-occipital membrane surround occipital condyles and superior articular facets. Designed for ? / ?. > ? mm of A to P translation of occiput on atlas during flexion/extension = instability

ellipsoidal condylar flexion extension 2

A dural root sleeve, which surrounds each spinal nerve, and also its continuation as the EN of the ventral ramus (anterior primary division) are held to the gutter of the TP by F tissue. This strong attachment to the TP is unique to the cervical region. More specifically, the C?, C?, and C? spinal nerves and anterior primary divisions (ventral rami) are held in place to the groove for the spinal nerve by means of tough connective tissue attachments. The nerves at the other levels are not as tightly bound to the bone of the groove for the spinal nerve. Lateral traction of the dura (more specifically the "dural funnel") pulls it laterally into an intervertebral foramen (IVF) until it plugs the foramen. This prevents further traction on the nerve roots and rootlets and their attachment to the spinal cord. In addition, traction of nerves also tractions the denticulate ligament, which in turn causes the spinal cord to move laterally toward the traction force, thus removing tension on the spinal cord from the nerve roots undergoing traction. The dural root sleeves in the cervical region receive more sensory innervation than any other region of cervical dura, and the fibers innervating the dural root sleeves originate directly from the dorsal root ganglia, not the recurrent meningeal nerves. This means significant traction or compression of the cervical DRS could result in the production of pain.

epineurium fibrous C4 C5 C6 dural root sleeves

Axis -C2 = E Ossification Center (Axis): Primary Body(?) Arches(?) Lateral base of odontoid(?) Secondary Tip of the odontoid(?) Inferior vertebral body(?) Transverse processes(?) Tip of the spinous process(?)

epistropheus 1 2 2 1 1 2 1

Atlas-C1: Supports the H ? arches (anterior and posterior) + ? lateral masses (right and left) with TPs projecting laterally

head 2 2

Cervical Z-Joint Capsule: Z joint capsules: limit some HE. T, L and L than T spine or L spine. Innervation of Z joints: MR and FNE. ? branch of posterior (dorsal) rami. Usually supplied by nerve above and below.

hyperextension thinner longer looser mechanoreceptors free nerve endings medial

The Z joint capsules probably do little to limit normal motion in the cervical region: however, the anterior aspects of the capsules do restrain HE. Overall the Z joint articular capsules of the cervical region are T and are L and L than those of the thoracic and lumbar regions. Two (one arising from the anterior pole and the other from the posterior pole) Z joint synovial folds (menisci) of approximately equal size project ? to ? mm into the Z joints at all levels of the cervical spine, and together the anterior and posterior synovial folds cover approximately ? of the articular surface. The synovial folds at the C?-C? Z joint are larger than those of the other cervical Z joints, covering a higher percentage of the articular cartilage. The left and right anterior (?) C1-C2 folds are generally larger than the ? folds. The C1-C2 synovial folds have been implicated as a source of neck pain and headache following the flexion-extension injuries (i.e., whiplash-associated disorders) of automobile accidents.

hyperextension thin longer looser 1 5 one third C1-C2 anterolateral posterior

Posterior Arch: ? than anterior arch, forming ? of the ring Posterior tubercle for attachment of LN and rectus capitis posterior M muscle Lower border has attachment for right and left LF Left and Right grooves for the vertebral arteries, vertebral veins, and SO nerves Suboccipital n. = travels between VA and PA Posterior atlanto-occipital membrane attaches to the side of each groove, may ossify to create a posterior P (??% of the population have a partial pp, ?% have complete pp)

larger 2/3 ligamentum nuchae minor ligamentum flava suboccipital vertebral artery posterior arch ponticus 25 8

The jugular notch is a groove along the ? margin of each side of the occiput. This groove helps to form the large jugular foramen of the same side by lying in register with the jugular fossa of the temporal bone. The jugular notch is bounded laterally by the jugular process. The jugular process is an anterior projection on the lateral aspect of each side of the occiput. Each one helps to form the posterolateral margin of the jugular foramen of the same side. The rectus capitis L muscle, which helps to laterally flex the occiput on the atlas, attaches to this process.

lateral lateralis

Uncinate Processes: Uncinate processes = Elevations of the ? and ? rims of the superior surface of the vertebral body Function: Allow for flexion and extension, limiting some lateral flexion, & translation (stabilizing). May prevent posterior lateral IVD protrusion UC joints (Joints of VL) = Synovial joints Develop around ?-? years of age.

lateral posterior uncovertebral Von Luschka 9-10

Lamina: Narrow S to I Gap between lamina of adjacent vertebrae, filled by LF Upper border is T Anterior surface of inferior border roughened by attachment of ligamentum flavum

ligamentum Flavum thin

Biomechanics of C0-C1 Movers: FLEXORS = LC and RCA EXTENDERS = RCP major and minor, OC superior, SS capitis, L capitis, S capitis, T, SCM LATERAL FLEXORS = Rectus capitis lateralis, Semispinalis capitis, Longissimus capitis, Splenius capitis, Sternocleidomastoid, Trapezius.

longus capitis rectus capitis anterior rectus capitis posterior obliquus capitis superior semispinalis longissimus splenius trapezius sternocleidomastoid

Lateral lips (uncinate processes) project from the superior surface of each typical cervical vertebra. These structures arise as elevations of the lateral and posterior rims on the top surface of the vertebral bodies. The posterior components of the uncinate processes tend to become more prominent in the ? cervical vertebrae. Normally the uncinate processes allow for flexion and extension of the cervical spine and help to limit LF. In addition, the uncinate processes serve as barriers to posterior and lateral IVD protrusion. The uncinate processes of one vertebra may articulate with the small indentations found on the inferior surface of the vertebra above by means of small S joints. These joints are sometimes called the UV joints (of VL). The higher uncinate processes at C?-? and the longer nerves in this region may help to explain the higher incidence of neural compression syndromes associated with the C4-6 vertebral levels.

lower lateral flexion synovial uncovertebral von Luschka C4-C6

Transverse Processes of C1: Large, palpable between M process and angle of M Transverse Foramen contains vertebral artery and vertebral veins and sympathetic nerve plexus Muscles attaching to C1 TP = rectus capitis lateralis, obliquus capitis superior and inferior, levator scapulae, splenius cervicis, scalenius medius C1 spinal nerve exits above the posterior arch -Dorsal rami of C1 = SO nerve motor innervation to suboccipital muscles -Ventral rami of C1 passes laterally around the lateral mass to join the CP

mastoid mandible suboccipital cervical plexus

Lateral Masses: superior articular process + inferior articular process + transverse process Superior articular process: anterior aspect more ? positioned than posterior. Irregular shaped. C. Anterior aspect: RCA m. Inferior Articular process / facet is F & O shaped. Faces slightly ?. Articulates with superior articular facet of C2.

medially concave rectus capitis anterior flat oval medially

Laminae: The laminae of the cervical region are fairly N from superior to inferior. Therefore a gap can be seen between the laminae of adjacent vertebrae in a dried specimen (see Fig. 5-2, C). However, this gap is filled by the ligamentum flavum in live persons. The upper border of each cervical lamina is thin, and the anterior surface of the inferior border is roughened by the attachment of the LF.

narrow ligamentum flavum

Intervertebral Foramen (IVF): Borders: Face O and A, slightly I. Oval shaped, ? - ? mm long Flexion ? the S to I diameter, Extension ? the S to I diameter. Rotation to same side N the foramen Extension ? the pressure in the IVF and abduction of the upper limb ? pressure in the IVF (Bakody's sign / test) Contents: Dorsal and Ventral rootlets, Spinal nerve with the dural root sleeve (? portion) Epidural fat and blood vessels (? portion) Dorsal root ganglia is in a small notch on the ? surface of the superior articular process

oblique anterior inferior 4-6 increases decreases narrows increases decrease inferior superior anterior

C2 Superior Articular Processes: Smoothed out regions of the left & right P. Do not project S, even with pedicles Loose articular capsule and superior articular process orientation for greatest range of rotation between C? and C? C with a transverse ridge running from medial to lateral, allowing both anterior and posterior aspects of superior facets to slope ? C1-2 facet is more ? than other cervical facets, so do not form part of the articular pillar

pedicles superiorly C1 C2 Convex inferiorly anterior

Median Atlanto-Axial Articulation: P or trochoid joint Dens and a ring created by the anterior arch of atlas and T ligament of C1. Hyaline articular cartilage on atlas and dens are oval, with C1 orientated horizontally and C2 orientated vertically. Posterior facet of dens articulates with transverse ligament of C1 and is also oval, but orientated L Both have synovial lined fibrous capsules attaching to outer edge of articular cartilages. Slack allows for movement. Anterior joint usually has a synovial fold projecting into the ? half of the joint for lubrication and cushioning Posterior joint cavity is ? than anterior and often continuous with the atlanto-occipital joints. Sometimes has bursa associated with it.

pivot transverse longitudinally superior larger

C2 TPs: Small, without distinct anterior and posterior tubercles. Develop from ? roots only. Face obliquely ? and ?, with a foramen for the vertebral artery. Foramen is a canal with an inferior and lateral opening to point the vertebral artery more laterally toward the more lateral transverse foramen of C1 Attachments of levator scapula, scalenus medius, splenius cervicis, intertranversarii

posterior superiorly laterally

Squamous Part: The squamous part of the occipital bone (occipital squama) is located ? to the foramen magnum. The part of the occipital bone that forms the most posterior aspect of the foramen magnum is known as the O. The most prominent feature of the occipital squama is the E. This mound, whose summit is known as the I, serves as the attachment site for the medial insertion of the T muscle. The external occipital crest extends inferiorly from the EOP. The squamous part of the occipital bone also has several markings formed by muscular and ligamentous attachments. Extending laterally from the EOP are two pairs of N lines. The first is present only occasionally and is known as the highest (supreme) nuchal line. The second is almost always present and is known as the superior nuchal line. The highest nuchal line, when present, extends superiorly and laterally from the EOP. It is formed by attachment of the occipital belly of the OF (epicranius) muscle. The superior nuchal line extends almost directly laterally from the EOP and is formed by the attachment of the T and SCM muscles. A third nuchal line called the inferior nuchal line extends laterally from the external occipital crest approximately midway between the EOP and foramen magnum. Several muscles attach above and below the inferior nuchal line.The posterior atlanto-occipital membrane attaches to the most inferior aspect of the occipital squama, which is the posterior border of the foramen magnum.

posterior opisthion EOP inion trapezius nuchal occipitofrontalis trapezius sternocleidomastoid

Alar ligaments: Left and Right. Originate from PL portion of dens, passes laterally to attach to ? surface of occipital condyles Width of a P and strong Limits C-L R. AKA C ligaments May be torn if axial rotation is combined with ? in a trauma (MVA) Apical ligament of the Odontoid Process: From posterior and superior aspects of dens to anterior wall of foramen magnum (with the fibers from the superior longitudinal band of the cruciate ligament). T about ? cm long . Develops from the core of C of the proatlas and contains remnants of the NC. Prevents some V translation and A shear of the occiput

posterior lateral medial pencil contra-lateral rotation check flexion thin 2.5 centrum notochord vertical anterior

Vertebral Prominens-C7: Spinous Process: The most prominent SP in cervical region Projects directly ? Not Bifid. Funicular portion of ligamentum nuchea attaches to tip. Attachments: Trapezius, rhomboid minor, serratus posterior superior, splenius capitis, spinalic cervicis, semispinalis thoracis, multifidus thoracis, interspinales

posteriorly

Vertebral Bodies: Each cervical vertebra consists of a vertebral body and a posterior arch. The vertebral bodies of the cervical spine are small and are more or less R in shape when viewed from above, with the transverse (left-to-right) diameter greater than the anteroposterior diameter Because of the "inferior lip" of the anterior aspect of the inferior vertebral margin, the anteroposterior distance is greater at the ? than the ? aspect of the vertebral bodies. The exception to this is C?, where the anteroposterior distance is approximately equal at the superior and inferior vertebral margins. The transverse and anterior-to-posterior diameters both increase from C2 to C7 with the T increasing more than the anteroposterior diameters. This allows the lower vertebrae to support the greater weights they are required to carry. In addition, the vertebral bodies of males have been found to be larger than those of females. The thickness of the outer cortex of the superior and inferior aspects of the vertebral bodies increases from C3 to C7. In addition, the superior aspect of each C3-7 vertebral body (superior bony end plate) is thickest ? and thinnest ?; the opposite is true for the inferior end plate (i.e., thickest ?). The center of the ? bony end plate also is thicker than the center of the ? bony end plate in the C3-7 vertebrae. Finally, the heights (superior to inferior dimensions) of both the anterior and posterior aspects of the cervical vertebral bodies generally increase from C3 to C7.

rectangular inferior superior C7 transverse posteriorly anteriorly anteriorly inferior superior

Typical Cervical Vertebrae: VERTEBRAL BODY: Small, R, Wider T than A to P, VERTEBRAL FORAMEN / CANAL: L and T TRANSVERSE PROCESSES: Transverse Foramen, Anterior and Posterior Tubercles ARTICULAR PROCESSES/ FACETS: ?? - ?? degrees (av. ??), Oblique Superior facets face postero-superior-medial SPINOUS PROCESSES: Short & Bifid

rectangular transverse large triangular 35-65 45

Coupled Motion: Lateral flexion of the cervical spine (C2-7) is always accompanied by R of the vertebral bodies to the same side as the lateral flexion. Coupled motion is due to the orientation of the F; superior articular facets face S and are angled slightly M

rotation facets superiorly medially

Atlanto-Axial Joints: Atlanto-axial joint = Median = R, T joint Lateral = PD (typical z-joint) Joint capsule is L, so ? degrees of rotation is allowed in either direction

rotation trochoid planar diarthrodial looser 45

The superior and inferior surfaces of the vertebral bodies typically are described as being sellar or S shaped. More specifically, the superior surface is concave from left to right as a result of the raised lateral lips (uncinate processes). The superior surface is also convex from front to back because of the beveling of its anterior aspect. The inferior surface is C from left to right and C from anterior to posterior. Much of the concavity is created by the anterior lip of the inferior surface. The anteroinferior aspect of each vertebral body usually protrudes inferiorly to overlap the anterior portion of the intervertebral disc (IVD) and occasionally the vertebra below. When the latter occurs, the anterosuperior aspect of the vertebra below is more beveled than would otherwise be the case. This increased beveling allows the vertebra to receive the projecting portion of the body above during flexion of the cervical spine.

saddle convex concave

C7 TPs: Anterior tubercle is S, costal element Posterior tubercle is L, making the entire TP quite large. Intertubercular lamella is grooved by ? rami of C7 SP membrane (aka C) of the apical pleura of the lungs attaches to the posterior tubercle of C7 TP. Transverse foramen are small and do NOT transmit the vertebral artery, but may contain branches of the S ganglion as well as A arteries and veins

short large ventral suprapleural cupola stellate accessory

Spinous Process: The spinous process of a typical cervical vertebra is S and B posteriorly. It is bifid because it develops from two separate ? centers of ossification. This morphology is unique to cervical spinous processes. The "terminal tubercles" of the bifid spinous process are frequently of unequal size and allow for attachment of the LN and many of the deep extensor muscles of the spine (semispinalis thoracis and cervicis, multifidi cervicis, spinalis cervicis, and interspinalis cervicis muscles). The length of the spinous processes decreases from C? to C? and then increases from C? to C?.

short bifid secondary ligamentum nuchae C2 C4 C4 C7

Anterior Arch: ? than posterior arch. Anterior tubercle for attachment of Anterior longitudinal ligament (ALL) and LC muscles Facet for D. Covered by hyaline cartilage, articulates with anterior surface of dens via a DA/T joint (synovial pivot)

smaller longus colli dens diarthrodial trochoid

The proposed normal functions of the Z joint synovial folds include lubricating the Z joints, acting as passive SF in the Z joints, and possibly serving joint-stabilizing and force-dissipating roles. When the individual vertebrae are united, the articular processes of each side of the cervical spine form an articular pillar that bulges ? at the pediculolaminar junction of each vertebra. This pillar is conspicuous on lateral x-ray films. The cervical articular pillars (left and right) help to support the weight of the head and neck. Therefore, weight bearing in the cervical region is carried out by a series of ? longitudinal columns: one anterior column, which runs through the vertebral bodies; and two posterior columns, which run through the right and left articular pillar. Consequently, loss of intervertebral disc height (e.g., disc height loss as a result of intervertebral disc degeneration) usually results in ? loads being placed on the cervical articular facets. The medial branch of the ? primary division (dorsal ramus) of the spinal nerve provides sensory innervation by means of both mechanoreceptors and free nerve endings to the Z joint capsule. The cervical Z joints receive innervation from ? branches of two adjacent spinal segments, with the exception of the C2-C3 Z joint, which receives innervation from only the TO nerve (through a communication to the C2 posterior primary division) This indicates that the Z joint capsules are important for providing information on both joint position and tissue damage to the central nervous system. The Z joints are a source of pain in a substantial number of both acute and chronic neck pain patients, and are estimated to be a source of pain in approximately ?% of those with chronic neck pain.

space fillers laterally 3 increased posterior medial third occipital 50

Basilar Part: Forms the basion. Meets the basilar portion of the S bone to form C P tubercle on the midline(externally) for superior pharyngeal constrictor muscle and LC muscles Rectus capitis A muscle attaches just in front of occipital condyles Anterior Foramen Magnum = Anterior atlanto-occipital membrane & A ligament Superior band of C ligament attaches to surface of clivus, under T membrane

sphenoid clivus pharyngeal longus capitus anterior apical cruciate tectoral

Pedicles: Small, project posterolaterally from vertebral bodies. Form medial border of Vertebral foramen Midway between superior & inferior vertebral body endplates, so superior and inferior vertebral notches similar in size. Spinal nerve, within its dural sleeve, runs just ? to its corresponding pedicle. The spinal nerve exits ABOVE its corresponding vertebrae. --Occupies approximately?(book, 1/3-1/2) of the IVF

superior 1/2

Pedicles and Lamina of C2: PEDICLES: T from medial to lateral and superior to inferior May be asymmetrical in width and angle of attachment to C2 vertebral body Inferior vertebral notches are ?, Superior vertebral notches are almost N-E LAMINA: T and T than other cervical lamina. Strong to transmit forces. Forces (weight of H) to inferior articular process are transmitted through the lamina

thick large non-existent taller thicker head

DENS= Odontoid Process: Anterior hyaline cartilage lined facet to articulate with anterior arch of atlas Posterior groove for TA ligament, forms a synovial joint Trochoid or pivot diarthrodial (synovial) joint allows ?? degrees of left and right rotation Sides are flat for attachment of A ligaments

transverse atlantal 45 alar

Squamous Part: Opisthion-posterior of FM EOP (inion) for T muscle Supreme nuchal line for OF muscle Superior Nuchal lines for T and SCM extend out laterally from EOP. Inferior nuchal line: Splenius capitis, Semispinalis capitis, Superior oblique, Rectus capitis posterior major and minor. Posterior border of FM: posterior atlanto-occipital membrane

trapezius occipitofrontalis Trapezius

Vertebral Canal: A vertebral foramen of a typical cervical vertebra is T (trefoil) in shape. It is also large, allowing it to accommodate the cervical enlargement of the spinal cord. The vertebral canal is fairly large in the upper cervical region but narrows from C? to C?. More specifically, the transverse (left-to-right) dimension remains relatively constant at approximately ? mm. However, the sagittal dimension becomes smaller; therefore the shape of the trefoil becomes relatively wider as one descends the vertebral canal in the cervical region. In fact, the spinal cord occupies ?% of the space available within the vertebral canal at the C6 level. The volume of cerebrospinal fluid in the subarachnoid space in the cervical vertebral canal is least in ? and greatest in ?, and the total change in volume of the cervical subarachnoid space (C2 to C7 levels) during full extension to full flexion is approximately ? ml.

triangular C3-C6 24.6 75 extension flexion 1.9

Vertebral Foramen and Canal: T shaped. L. Borders: -Lamina/ ligamentum flavum -Pedicles -Vertebral bodies and intervertebral discs Contents: EA tissue, internal vertebral venous plexus, spinal cord covered by meninges and CSF, spinal nerve roots Volume of CSF in subarachnoid space is greatest in ? and least in ?

triangular large epidural adipose flexion extension

Typical Cervical Vertebral Bodies: Increase in W (AP and Transverse), Increase H as descend inferiorly. Also increase in C thickness as descend

width height cortical