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Anatomy Made Easy “MSS” هذا الملف يشمل تفريغ المحاضرة الخامسة لعون وحتى اآلخر15 بدءا من الصفحة part 3 Done By :Fadi Al-Ghzawi Edited by: AWN Academic Team Vertebral column) the spine , backbone, spinal column) There are 33 vertebrae;some are typical while others are atypical. Inter-vertebral disc form 1/4 of its length. The lower aspect of the vertebral column is fused as one bone,but they are 5 sacrum bones & the 4 coccyx bones below it. New So, the total # of vertebrae during early development is 33. Then, by fusions of sacral and coccyx regions , it reduces to: Vertebral column New o consists of : a) bones ( vertebrae) b)connective tissue o function: 1) surround and protect the nervous tissue of spinal cord 2) support the head 3)point of attachment for the ribs , pelvic girdle, muscles of the back and upper limbs. New neck region posterior to the thoracic cavity Support the lower back Fused to form 1 sacram Fused to form 1 coccyx C U RVATURE S OF VERTEBRAL COLUMN Mature Vertebral column has curves, but intrauterine baby has virgula shape, After that the baby will grow, he will crawl then stand & walk. 1- Thoracic and sacral curvatures(primary): Concave anteriorly,Develop during fetal period due to the deference between ant and post Thickness of the vertebra. II. Cervical and lumbar : Concave posteriorly,develop during the fetal period due to deference in IV disc thickness. Cervical:infant hold head. Lumbar:infant walk and assume upright position, prominent in female. NORMAL vs. PATHOLOGICAL CURVATURES mainly in pregnant woman the lumbar curvature posterior convexity will increase due to the weight of the fetus. Normal:occurs Pathological: normal curvature but more prominent. NORMAL CURVATURES New • The baby in the uterus create a force of drop at the level of the abdomen; >> this bring the lumbar region forward, and help support axis of vertebral column. • It is occurs within the first semester of pregnancy . • You have to tell the pregnant women to do exercises , other wise( if the pregnant women doesn’t do exercise or walk) the lordosis will become pathologic ) PATHOLOGICAL CURVATURES abnormal increase in thoracic curvature convexity & prominent concavity, it is an erosion of anterior vertebral part. Scoliosis: abnormal lateral curvature & rotation of the back (deviation to left or right),crooked or curved back (appears between ages of 10-15). Very dangerous condition, surgeons have difficulty in repairing this condition; because the intervertebral discs are more compressed at one side than the other, so they have to replace many discs. Lordosis (hollow back):anterior rotation of pelvis, an abnormal increase in lumber curvature,could be physiological (pregnancy) or pathological, so both men & women can have lordosis. Kyphosis: Deviation from midline increase concavity of thoracic region increase concavity of thoracic region General Structure ofTypical Vertebrae 1. 2. 3. New 4. 5. 6. Body or centrum (disc shaped):weight-bearing region. Vertebral arch:composed of pedicles and laminae that along with the centrum encloses the vertebral foramen. Laminae: the flat continuation of the body posteriorly. ****laminae has anterior connection with pedicle pedicle: thick round connection between arch and body Vertebral foramina:make up the vertebral canal through which the spinal cord passes. Spinous process:2 laminae fuse together & project posterior and usually downward, some are bifid which provide muscle insertion. Just bifid in the cervical region 7. Transverse processes:pedicle meets with lamina then projects laterally. • New • • They are for muscle attachment of the back. In the cervical vertebrae, there are vertebral artery foramen through which vertebral artery pass. In thoracic vertebrae, these processes are present with facets or demi-facet (demi-facet also present on the body), facets exist on the apex of the trans. process. 8. Superior and inferior articular processes: protrude superiorly and inferiorly from the "pediclelamina" junctions. All vertebrae have 2 superior & 2 inferior articular processes except the sacrum & except coccyx bones The first sacral vertebra has superior one to actriculate with the 5th lumabar vertebra.. These processes depend on the movement range, they differ in orientation (laterally, anteriorly, more or less lateral & anterior), so they differ from region to another,to provide more movement according to that region. 7.Inter-vertebral foramina:lateral openings formed from notched areas on the superior and inferior borders of adjacent pedicles. Lacated anterior to the transverse process and more or less immediately underneath the pedicle . The spinal nerves exist through it from the spinal cord. The atlas & axis vertebrae are different from all other vertebrae, although they contain same features of other vertebrae,but still they have additional processes so therefore they are considered atypical vertebrae. Sacral and coccyx vertebrae are typical;they are fused together so we don’t consider them as atypical New ** Vertebrae are the same(arch& body), but the difference from one region to another can be in: 1- the prominence of the spinous process, 2- size of the body 3- the shape in the vertebral canal. Cervical Vertebrae Seven vertebrae (C1-C 7) are the smallest & lightest vertebrae. C 3-C 7 are distinguished with an 1. Oval body. 2. Long spinous processes. 3. Large and triangular vertebral foramina. Each transverse process contains a transverse foramen which vertebral artery passes through. Superior and inferior articular facets are oriented superior & inferior. ATYPI C A L C ERV I C A L V ERTEBRAE Atlas (C 1):it is nothing but a round arch. Has no body and no spinous process. Consists of anterior and posterior arches, and two lateral masses (masses are elongated more toward lateral aspect). The superior and inferior surface of lateral masses has articular surfaces (depressions) to articulate with the occipital condyles and with the axis Lateral to the lateral masses there are transverse processes, and it has transverse foramen. 1. New Notice the anterior & posterior tubercle made by meeting of arches posteriorly & anteriorly. Atlanto-occipital joint: an important joint, only flexion & extension movement occurs ; where at the rest of the joints in vertebrae such as (atlanto-axial, axial-c3),the movement is rotation. The superior articular facets are divided into 2 facets separated by a ridge ; this ridge is important in the flex.& ext. maneuver. It will stop the posterior sliding of condyles of the occipital bone on atlas. The ridge will limit the movement anterior & posterior. With age the flex. & ext. maneuver will be reduced; because the intervertebral layer (hyaline cartilage) in the joint is eroded,it won't be moving like before, exercise will help in keeping good movement. The inferior articular facets are more rounded and more medially oriented to fit the superior aspect of the axis. On the anterior arch, notice the fovea dentis which is the facet for the dens, odontoid ligament holds the dens to lateral borders of fovea dentis. 2.Axis (C 2): The axis has a body (very small) ,spine, and vertebral arches as do other cervical vertebrae. Unique to the axis is the dens,or odontoid process,which projects superiorly from the body and is attached to the anterior surface of the arch of the atlas. The dens is a pivot for the rotation of the atlas. Transvers processes comes from similar masses (pedicles & laminae), they are very small with transverse foramen where vertebral artery passes. Masses in axis are called pedicles & laminae while in atlas called lateral masses The pedicles are more or less connected directly; because of the presence of the masses, the transverse process comes out before the pedicle,that when you go down to C 3 it is pushed anteriorly & the pedicle is more posterior. That's why we call it more or less atypical vertebra; because it doesn't present the typical aspect of any vertebra. The spinous process is posterior & it is bifidic. Irregular vertebral canal. The atlanto-occipital joint has limited movement due to the ridge on the facets & the spinous processes all the way down in the cervical region. Pivot joint: Projection (dens) of axis articulates within ring of atlas. Movements: Rotation Around one Axis. New the doctor pointed to all the labeled parts Thoracic vertebrae H ow do you know this is a thoracic vertebra? The spinous process is long & inclined inferiorly, heart shape body. The body has a mass , that is full of spongy bone). The trans. process has articular facets & the body have demi facet so that 2 demi facets of adjacent vertebrae forms one facet which articulate with the head of rib.That’s why the rib takes the name of the above vertebrae. Superior articular facets are lateral & posterior, the inferior ones are medially & anterior. General features There are twelve vertebrae (T1-T12) all of which articulate with ribs. Major markings include two demi-facets on the heart-shaped body for the head of the rib. Circular vertebral foramen, transverse processes with articular costal facets for the rib tubercles. Long spinous process that is inclined downward. The location of the articulate facets prevent flexion and extension, but allow rotation of this area of the spine. Superior articular processes are oriented backward and laterally. Lumbar Vertebrae The five lumbar vertebrae (L1-L5) are located in the small region of the back and have an enhanced weight-bearing function. Body is large and kidney-shaped. They have short, thick pedicles and lamina. Flat hatchet-shaped spinous processes. Triangular-shaped vertebral foramen. Orientation of the sup. articular facets face medially to lock the lumbar vertebrae together to provide stability *Spinous process is more shorter and more square in shape. *The bodies are more bulky than thoracic and cervical New **Why it is a lumbar vertebrae?? 1- the spinous processes are more shorter 2- The body is more bulky **The intervertebral disc appear as a gap between the vertebrae. V ERTEBRAL C H A R A C T E R I STI CS : Below & above the 2 pedicles, there is a vertebral notch (sup & inf);it makes the intervertebral foramen between 2 vertebrae which spinal nerves exit from it. Usually (especially thoracic vertebrae) the transverse processes will grow longer,they will incline inferiorly like the wings & this resembles the ribs, it occurs mainly at the level of C 7 (you can palpate it at the end of your neck), we call it cervical rib, it will compress the nerve root leading to difficulty in moving the upper extremities. Cervical rib The arm & forearm muscles will be tired & will take their tiredness to the shoulder muscle. Cervical ribs are very common; because of the computer, games,driving & desk sitting, we compress ourselves while sitting, then the cervical rib will compress the nerve & you will have headache & shoulder stiffness. If someone told you I have headache after working,you will examine 2 things: blood pressure & x-ray of cervical region. Spinal nerves go to muscles, so any compression will lead to defects in movement skeletal muscles. Inter-vertebral discs Cushion-like pad Joint between 2 bodies of the vertebrae It’s composed of two parts 1. Nucleus pulposus: inner gelatinous nucleus that gives the disc is elasticity and compressibility 2. Annulus fibrosus:surrounds the nucleus pulposus with a collar composed of collagen and Fibro cartilage. Pathological condition Sometimes, annulus fibrosus bulge or rupture leading to movement of nucleus pulposus toward the edge,so it will exit the concentric layer of the fibrous tissue, and that's what we call herniation. Herniation varies in bulging,so bulging of annulus fibrosus can lead to reduction in distance between 2 vertebrae;because you lose the power of annulus fibrosus. The New whole vertebrae have longitudinal ligaments to hold them in place ,but they cannot help in preventing the herniation of the nucleus polposus. There are anterior and posterior longitudinal ligament; Allow them not to move in the rotational movement, instead, they will move bending left and right. Notice that the posterior ligament is anterior to the spinal cord>>> give protection Any degeneration of annulus fibrosus can lead to herniation. Spine surgeon has a ruler to measure the intervertebral discs or by naked eye, the measurement will indicate the age of compression on this disc. We have inter-spinous ligaments between the spinous processes, which hold the spinous processes in their position. M O VEM E N T S :occurs at the vertebral column level of New **when we rotate the hole vertebrae , the rotation occur at the hip joint, not within the vertebral column . In slides AT L A N TO -O C C IPITA L JOINT Often considered to be a Hinge joint because of its primary uniaxial range of movement (as in shaking your head“yes”). The atlanto-occipital joints occur between the reciprocally curved surfaces of the two occipital condyles and the articular facets on the lateral masses of the atlas. Movements: ◦ While the primary axis of movement is the nodding movements (flexion and extension of the head) in the antero-posterior plane,a small amount of side to side bending (lateral flexion),and rotation is possible at this joint surface. Ligaments of the joint: ◦ Are the fibrous membrane of the joint capsule (Ant and Post), the anterior atlanto-occipital membrane,and the posterior atlantooccipital membrane. L I G A M E N T S O F T H E JOINT In slides Most important are anterior & posterior longitudinal ligament,they will hold the atlas with the occipital bone. Anterior atlanto-occipital membrane goes from anterior arch of the atlas into the base of the occipital bone anteriorly. In slides In slides In slides Posterior longitudinal ligament doesn't appear from posterior view because it is anterior to posterior atlanto-occipital membrane & below inferior nuchal line. At the lateral aspect you will be able to see an articular capsule (image above). There is always a capsule between the 2 joints, especially synovial joints (most of joints are synovial). In slides The bodies of the vertebrae are articulated with a separate articular joint rather if you compare it with the superior & inferior articular surface,so whenever you look at any slide you will be able to see that articular capsule for the atlanto-occipital joint in the lateral aspect, because this articular capsule is surrounding the outer area of the condyles and the superior articular surface. In slides Ligaments between the atlas & the axis are important, one of them is the cruciate ligament,it has 2 branches one superior & one inferior,they are called superior & inferior longitudinal band & 2 transverse ligaments. In slides Cruciate ligament of atlas In slides In the above image we have removed the posterior aspect of the occipital bone & the spinous processes, in the posterior surface of the dens after the annular ligament of the dens you will be able to see this. Parcticaly you will be able to see the anterior arch & dens & the body of the vertebrae then posterior to that the annular ligament & posterior to that & anterior to the spinal cord you will be able to see the cruciate ligament,and lateral to it we have alar ligament. In slides Alar ligaments: ◦ They connect the sides of the dens (on the axis, or the second cervical vertebra) to the tubercles on the medial side of the occipital condyle. Legamentum flavum: ◦ They connect the laminae of adjacent vertebrae, extending from the second CERVICAL vertebra, the axis, to the first segment of the sacrum ◦ Cruciform ligament of atlas (cruciform): ◦ is a cruciate ligament in the neck forming part of the atlanto-axial joint. Cruciate = Cruciform = صليب In slides nuchae:comes from the occipital protubrance extending down till the level of the spinous process of C 7,it is a very tough membrane seperating the right & left sides of the neck Ligamentum In slides Sacrum and Coccyx Sacrum : - 5 fused bones 1 2 3 4 5 Cont Sacrum - shape the posterior wall of the pelvis - It articulates with L5 superiorly (by the only two superior processes), and with the auricular surfaces of the hip bones - Major markings include the sacral promontory, transverse lines, alae,dorsal sacral foramina, sacral canal, and sacral hiatus - Upper anterior aspect of the body protrose New anteriorly, create the concavity of sacrum convexity Anterior : - Sacral promontory -concave curve - vertebral bodies -anterior/ventral sacral foraminae - transverse lines laterally : -Ala : formed by fused transverse processes. - (here the transverse processes are more bulk and tortious compared with the thoracic one) New • the posterior aspect of ala articulate with the ilium of the hip • at the inferior part of the median crest divided into two right and left processes • Dorsal sacral foramina continuated to the anterior sacral foramina(they are lateral to the bodies). Posterior : -superior articular process ( betw S1-L5) -Sacral canal (contain fillum Terminale , open in Sacral hiatus at S5) - Median sacral crest - Lateral sacral crest Between them is : -Intermediate crest. -Dorsal Sacral foramina (betw lateral and intermediate) -sacral cornuae : belong to S4 ,near thesacral hiatus Coccyx S1 S2 S3 Coccyx (Tailbone) The coccyx is made up of four (in some cases three to five) fused vertebrae that articulate directly Superiorly with the sacrum S4 S5 Coccyx 1 2 3 4 Disk problems At the level of the vertebra : - Fractures of the vertebra At the level of the intervertebral disk : - 1.D isk Herniation - 2.D egeneration (slipped) Most common sites for disc problems: ◦ C5 - C6 ◦ L4 - L5 ◦ L5 - S1 Laminectomy ( IS a surgical removal vertebral arch by shaving laminae to access disc) Cont Disk problems At the level of the vertebra : * Fractures of the vertebra ,could be : -Fragmented & nonfragmented -Complete & incomplete - distance between the broken vertebrae and the adjacent one above or below will be minimized Cont Disk problems At the level of the intervertebral disk : - 1.Disk Herniation :complete or incomplete bulging - 2.Degeneration :degenerative changes in the structure of the annulus fibrosis Thoracic cage 1) Sternum 2) Ribs ** The thoracic cage is composed of the thoracic vertebrae dorsally,the ribs laterally,and the sternum and costal cartilages anteriorly New **The movement of thorax will be only at the anterior aspect (during respiration) by action of cartilages. But posterior part will never move ;because it linked by ligaments to the vertebrae. Thoracic cage Functions ◦ Forms a protective cage around the heart,lungs, and great blood vessels ◦ Supports the shoulder girdles and upper limbs ◦ Provides attachment for many neck,back,chest, and shoulder muscles ◦ Uses intercostal muscles to lift and depress the thorax during breathing Subcostal angle is the angle in between the two Costal margins which are the inferior borders of the 7th & false ribs costal cartilages Sternum dagger-shaped Flat bone made up of 3 parts : 1 Manubrium 2 Sternal Body 3 Xiphoid process Anatomical landmarks include the jugular (suprasternal) notch, the sternal angle,and the xiphisternal joint 1- Manubrium 1- Manubrium square shape part that has superior and inferior articular boarders Important landmarks : ** "angle of Louis“ = sternal angle **superiorly ,and lateral for clavicular sternal end **lateral,and inferior for 1st rib **Jugular notch = suprasternal notch , between the two clavicular facets used for ((tracheostomy)) cause behind it no veins or arteries, & the trachea lies directly under the skin of this region. New Sternal(lewis) angle: it lies between manubrium and body very important clinically ; because you can count the ribs from the second rib legation . 2- Sternal Body The biggest part Presents on the lateral sides depressions serves as an articulation surface for the 2nd to the 7th rib 8th to the 10th ribs are false ribs , they don’t attach to the sternal body directly . 11 and 12 are floating ribs first rib is atypical because it's surfaces orientations are different from the typical.It has superiorinferior (horizontal) rather than anterior posterior surfaces(vertical) 3- Xiphoid process Till the age of 17 to 19 it's an flexible cartilaginous & Elastic tissue Ribs (12) composed of two parts : -One anterior "the end" continues to the sternum as the costal cartilage -One posterior ,and "the head" articulate with the lateral surface "2 demifacets" on the superior and inferior boarders ofthe body of the adjacent thoracic vertebrae ,as well as the anterior part of the transverse processes for the lower vertebra articulate with the tubercale … so : the head with the body the tubercle transeverse process Ribs & sternum articulations: New All ribs are incomplete bones ; because they need cartilages to connect with lateral boarder of sternum . 1-7 ribs : articulate directly with the sternum by costal cartilages False ribs (8-12) : normal ribs but they never reach the sternum (8-10) ; adhere to the 7th cartilages (11-12) ; Floating ribs , they don't articulate with any thing anteriorly . Cont Ribs All the typical ribs are oriented anterior & inferior ribs have 2 borders & two surfaces : -One outer surface "external(lateral) surface". facing the fascia ,and One inner surface(medial) facing the pleura - The superior border is rounded ,andThe inferior border is more sharp (with subcoastal groove),contain Subcostal vein,artery & nerve from superior to inferior respectively on the internal surface (( clinically )) ,Pleural puncture we do it in the superior border ..If done on inferior border it may cause nerve injury which is called in medicine Intercostal neuralgia the head with the body the tubercle with the transeverse process So, rib= bowed, flat bone consisting of a head, neck, tubercle, and shaft Superior facet Inferior facet Articular facet of tubercle