thorax cage.pptx
- 1. Anatomy of the Thorax, Pelvis and Back 1 By Addis T.
- 2. Thorax The thorax (chest) is the superior part of the trun k between the neck and abdomen The superior thoracic a perture bordered by ver tebra TI, rib I, and the m anubrium of sternum The inferior thoracic a perture bordered by ver tebra T12, rib 12, the en d of rib 11, the costal ma rgin, and the xiphoid pro cess of sternum By Addis T. 2
- 3. The Bony Thorax (thoracic cage) Sternum Composed of Manubrium, Body, Xiphoid Process form anterior boundary with costal cartilages Ribs (12 pair) 7 pair True Ribs 3 pair False Ribs 2 pair are floating Form lateral boundaries Vertebrae Thoracic(12) Forms Posterior boundary of the cage By Addis T. 3
- 4. The Sternum Manubrium Has Jugular (sternal) notch Articulats with rib #1 & 2 Articulate with clavicle at Clavicular facets Sternal Angle –articulate 2nd rib which is a major surface landmark used by clinicians Body Articulates with ribs 2-7 Xiphosternal joint Xiphoid process Cartilage-calcifies through time Partial attachment of many muscles By Addis T. 4
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- 6. The Ribs Twelve pairs Ribs 1-7 attach directly to sternum by separate costal cartilages - true ribs Ribs 8-10 attach indirectly to sternum by attaching to costal cartilages –false immediately above Ribs 11-12 have no anterior attachments - floating ribs By Addis T. 6
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- 8. Rib Anatomy Typical Ribs (3rd-9th) Head (2 facets) Neck Tubercle Angle Shaft Subcostal Groove By Addis T. 8
- 10. Atypical Ribs (1st , 2nd , 1 0th , 11th & 12th ) 1st rib-short, wider, posse s subclavian groove , no an gle 1st , 10th, 11th -12th articul ate with only = one vertebr a (single articular facet) #11, 12 – don’t articulate with transve rse processes (not have tube rcle), or anteriorly at all, – very short neck, – poor/no angle and costal gro ove By Addis T. 10
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- 12. Vertebral Column The vertebral column the main part of the axial skeleton, which extends from the cranium (skull ) to the apex of the coccyx. Composed of:- The vertebrae, IV discs & assoc iated ligaments. The adult vertebral column is 72 -75 cm long one quarter is formed by the IV discs 12 By Addis T.
- 13. Vertebrae… The vertebral column consists of 33 vertebrae arranged in fiv e regions. 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal. Of the 9 inferior vertebrae, the 5 sacral vertebrae are fused in adults to form the sacru m after approximately age 30, the 4 coccygeal vertebrae fuse to form the coccyx. 13 By Addis T. Significant motion occurs only between 25 superior vertebrae The vertebrae gradually become larger as the vertebral colum n descends to the sacrum and then become progressively smal ler toward the apex of the coccyx
- 14. Vertebral Column By Addis T. 14
- 15. Structure and Function of the Vertebrae • Vertebras are vary in size but t heir basic structure is the same. • Classified as typical and atypic al • Typical vertebra consists of Vertebral body Vertebral arch Seven processes 15 By Addis T.
- 16. Structure and Function of the Vertebrae Vertebral body: – Massive and roughly cylindric al anterior part of the bone – The size of the vertebral bodies increases as the column descen ds, most markedly from T4 inf eriorly, as each bears progressi vely greater body weight. – Separated from above and belo w by intervertebral discs (IVD ) – Used for hematopoiesis. 16 By Addis T.
- 17. Structure and Function of the Vertebrae… Vertebral arch – Is U shaped and posterior to th e vertebral body – Formed by two pedicles and la minae Pedicles: short cylindrical proce sses, that project posteriorly f rom the vertebral body to la minae Laminae: two flat parts that co nnects the spinous process a nd the transverse process of t he vertebrae By Addis T. 17
- 18. Structure and Function of the Vertebrae… Seven processes: arise from the vertebral arch – Spinous process (1) – Transverse processes (2) – Articular processes ( 4) Function of processes Attachment for deep back muscl e Keeping adjacent vertebrae align ed, i.e. preventing one vertebra fr om slipping anteriorly on the ver tebra below. Determine type of movement & weight bearing (temporarily) 18 By Addis T.
- 19. Vertebral foramen Bounderis: anteriorly by the posterior surf ace of the vertebral body laterally and posteriorly: the v ertebral arch. Contains the spinal cord and the roots of the spinal nerves 19 By Addis T. Structure and Function of the Vertebrae…
- 20. Structure and Function of the Vertebrae… Vertebral notches •are indentations(concavities) on the s uperior surface and inferior surface of the pedicle on each side of a vertebra • The superior and inferior vertebral notches of adjacent vertebrae and th e IV discs connecting them form the intervertebral foramina, in which t he spinal nerves emerge from the ver tebral column with their accompanyi ng vessels. By Addis T. 20
- 21. Structure and Function of the Vertebrae… In general vertebral column Support the body's weight Protection Plays an important role in posture and locomoti on By Addis T. 21
- 22. Regional Characteristics of the Vertebrae • Each of the 33 vertebrae is unique. • However, most of the vertebrae have characteristic features identifying the m as belonging to one of the five regi ons of the vertebral column • e.g. Cervical vertebrae have foramin a in their transverse processes 22 By Addis T.
- 23. Cervical Vertebrae • Cervical vertebrae form the skeleton of the nec k. • Smallest of the 24 moveable vertebrae • are located between the cranium and the thorac ic vertebrae. • they bear less weight than do the larger inferio r vertebrae. • Although the cervical IV discs are thinner than those of inferior regions • Thickness of the disc & horizontal orientation of the articular facet , small amount of surroun ding body mass, give high mobility. 23 By Addis T.
- 24. Cervical Vertebrae • The most distinctive feature of each cervical v ertebra is a foramen on transverse process cal led foramen transversarium (transverse fora men). • The vertebral arteries and their accompanyin g veins pass through the transverse foramina, except those in C7, which transmit only small accessory veins. • The transverse processes has two projections: – anterior tubercle and – posterior tubercle By Addis T. 24
- 25. Cervical Vertebrae • The tubercles provide attachment f or a laterally placed group of cervi cal muscles (levator scapulae and sc alenes). • The anterior rami of the cervical s pinal nerves course initially on th e transverse processes in grooves f or spinal nerves between the tube rcles. By Addis T. 25
- 26. Cervical Vertebrae • There are 4 typical – (C3-C6) and • 3 atypical – C1(atlas), C2(axis) and C7 • Typical cervical vertebra – Has a bifid spine – Have foramina in their transverse processes. – Transverse process has an anterior tubercle and a posterior tubercle. 26 By Addis T.
- 27. C1 (Atlas) • The Atlas is ring-shaped and supports the s kull • No a body & spinous process • has paired lateral masses that serve the pla ce of a body by bearing the weight of the cr anium • superior articular surfaces articulate with t wo large cranial protuberances called the o ccipital condyles and form atlanto-occipita l joint • Inferior articular surfuces articulate with b elow vertebra and form atlanto axial joint 27 By Addis T.
- 28. C2 (Axis) • is the strongest of the cervical vertebr ae • C1, carrying the cranium, rotates on C2 (e.g., when a person turns the hea d to indicate “no”). • Has superior articular facets, on whi ch the atlas rotate • Has blunt tooth-like dens (odontoid process) which projects superiorly fro m its body. 28 By Addis T. • Both the dens and the spinal cord are encircled by the atlas. • The dens lies anterior to the spinal cord transverse ligamen t of the atlas is a ligament which passes between the dens a nd spinal cord • It has a large bifid spinous process
- 29. Atypical Cervical vertebrae C7 long spinous process. Small transverse foramen Has prominent unbifid spinous used to count ve rtebrae 29 By Addis T.
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- 31. The thoracic vertebrae • are in the upper back and provide attachment for the ribs • the primary characteristic features of thoracic vertebrae are – the costal facets on the body of the vertebrae for articula tion with ribs. – The middle four thoracic vertebrae (T5–T8) demonstrate all the features typical of thoracic vertebrae. – The articular processes of thoracic vertebrae extend verti cally – This arc permits rotation and some lateral flexion of the vertebral column in this region. – The T1–T4 vertebrae share some features of cervical vert ebrae, eg. horizontal spinous process that may be nearly as prominent as that of the C7. – T1 also has a complete costal facet for the 1st rib and a d emifacet for the 2nd rib By Addis T. 31
- 32. Thoracic Vertebrae… • Body – Heart shaped – one or two costal facets for artic ulation with head of rib • Vertebral foramen – Circular and smaller than those of cervical and lumbar vertebrae • Transverse processes – Long and strong and extend pos terolaterally – length diminishes from T1 to T1 2 – have facets for articulation with tubercle of rib By Addis T. 32
- 33. Thoracic Vertebrae • Articular processes – Superior facets directed po steriorly and slightly latera lly – inferior facets directed ant eriorly and slightly mediall y • Spinous processes – Long, slope posteroinferior ly – tips extend to level of verte bral body below By Addis T. 33
- 34. Thoracic Vertebrae Typical: T5-T8 – Body is larger than cervical ; heart shaped – Spinous process is long an d sharp, projects inferiorly – Vertebral foramen is circul ar – Contains all the features ty pical of thoracic vertebrae 34 By Addis T.
- 35. Lumbar Vertebrae • The lower back between the thorax & sacrum. • Large and kidney shaped body when viewed superiorly • Vertebral foramen is triangular; larger than in thoracic vert ebrae and smaller than in cervical vertebrae • The transverse processes project posterosuperiorly as well a s laterally. • On the posterior surface of the base of each transverse proce ss is a small accessory process, which provides an attachme nt for the intertransversarii muscles. 35 By Addis T.
- 36. Lumbar Vertebrae… • Articular processes - The superior articular process directed medially and the inferior articular facets directed laterally. • On the posterior surface of the superior articular processes a re mammillary processes, which give attachment to both the multifidus and intertransversarii muscles of the back. • Spinous processes is short thick, and broad • Vertebra L5 - is the largest of all vertebra. • It has massive body and transverse processes By Addis T. 36
- 37. Sacrum • Triangular bone • Formed by the union of 5 sacral vertebrae • Indicated as a S1-S5. • The fusion of the sacral vertebra e begins ages 20yrs. • It provides strength and stability to the pelvis • Transmits the weight of the body to the pelvic girdle 37 By Addis T.
- 38. Sacrum • Contains Sacral canal is the conti nuation of the vertebral canal in t he sacrum. • Sacral canal contains the bundle of spinal nerve roots known as th e cauda equina • Sacrum also contains four pairs of sacral foramina for the exit of the posterior and anterior rami of the spinal nerves By Addis T. 38
- 39. Sacrum • The pelvic surface of the sacru m (ventral surface) is smooth a nd concave • Four transverse lines on this s urface from adults indicate wh ere fusion of the sacral vertebr ae occurred. By Addis T. 39
- 40. Sacrum • The base of the sacrum is forme d by the superior surface of the S1 vertebra • The anterior projecting edge of t he body of the S1 vertebra is the sacral promontory • The apex of the sacrum, its taper ing inferior end, has an oval face t for articulation with the coccyx. • Female sacrum are shorter, wid er and more curved between S2 and S3 than a male sacrum • But the body of the S1 vertebra i s usually larger in males. 40 By Addis T.
- 41. Sacrum • Dorsal surface which is rough an d convex • Contains:- median sacral crest, int ermediate sacral crest & lateral sa cral crest • the median sacral crest, represent s the fused rudimentary spinous processes of S1-S4; S5 has no spin ous process. • The intermediate sacral crests rep resent the fused articular processe s • The lateral sacral crests are the tip s of the transverse processes of th e fused sacral vertebrae. 41 By Addis T.
- 42. Coccyx (Tail bone ) • Triangular bone formed by fusion of the four rudimentary coccygeal vertebrae. • The pelvic surface is concave and relatively s mooth • Coccygeal cornua is rudimentary articular pr ocess which articulate with the sacral cornua. • Co1 is the largest and broadest of all the cocc ygeal vertebrae 42 By Addis T. Rudmentery tran sverse proces • Not Participate in support of the body weight during standing. • Provides attachments for muscle and ligaments.
- 43. Curvatures of the Vertebral Column • Vertebral column in adults has fo ur curvatures: cervical, thoracic, l umbar, and sacral. • During fetal development, the ve rtebral column shows a C-shape d concavity to the ventral • This persists in adults only in the thoracic and sacral regions • Two type of curvature – Primary curvature – Secondary curvature 43 By Addis T.
- 44. Curvatures of the Vertebral Column Primary curvatures • Seen in the thoracic and sacral curvature s . • They are primary curvatures that develo p during the fetal period in relationship to the fetal position • the primary curvatures are in the same direction as the main curvatures of the fe tal vertebral column and they retained t hroughout life 44 By Addis T.
- 45. Curvatures of the Vertebral Column Secondary curvatures • Occur after birth on the cervical and lumba r vertebrae • that result from extension from the flexed f etal position. • Cervical curvature begins to appear when t he infant starts to raise the head. • The lumbar curvature observed when the in fant starts to walk • The secondary curvatures begin to appear b efore birth but well observed after birth 45 By Addis T.
- 46. PelvicGirdle • Basin-shaped ring of bones that connects the vertebral co lumn to the femurs in the thighs • Functions Bear the weight of the upper body when sitting and st anding Transfer the weight of the upper body from the axial t o the lower appendicular skeleton for standing and wa lking Provide attachment for the powerful muscles Contain and protect the pelvic viscera and the inferior abdominal viscera 46
- 47. The bony pelvis is formed by 4 bones united by 4 joints Bones: 2 hip bones, sacrum and coccyx Joints: 2 sacroiliac joints, pubic symphysis and sacrococc ygeal joint 47
- 48. Hipbones The two hip bones are joined at the pubic symphysis anteri orly and to the sacrum posteriorly at the sacroiliac joints to form a bony ring, the pelvic girdle Each hip bone is formed by 3 bones fusing at the acetabul um (a cup-like articular depression on lateral aspect for the head of the femur) by a y-shaped cartilage Begin to fuse at 15-17 years and complete at 20-25 years o f age • The 3 bones are: Ilium Ischium Pubis 48
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- 50. Ilium The superior, flattened, fan-shaped part of the hip bone Located superior to the acetabulum Body forms the superior part of the acetabulum joins ischium and pubis at acetabulum Ala (wing) bordered superiorly by iliac crest dorsum feature:- anterior, posterior and inferior glute al lines (origins of gluteus minimus, medius and max imus muscles) 50
- 51. Landmarks of ilium: Anterior superior ili ac spine Anterior inferior ili ac spine Posterior superior il iac spine Posterior inferior ili ac spine Greater sciatic notc h 51
- 52. Ischium • posteroinferior part of hip bone • has a body and a ramus • Body – forms the posterior part of the acetabulum – joins ilium and superior ramus of pubis to form acetabu lum • Ramus – fuses with the inferior ramus of pubis – forms part of the inferior boundary of the obturator fora men 52
- 53. • Landmarks ischial tuberosity • large posteroinferior protuberance of the is chium • supports body during sitting ischial spine • small pointed posteri or projection near the junction of the ramus and body lesser sciatic notch 53
- 54. Pubis • anteromedial part of hip bone • Forms anterior part of the acetabulum • angulated bone; has two rami (inferior & superior) and body Body – has a symphyseal surface for articulation with the contral ateral pubis Rami – superior pubic ramus: forms anterior part of acetabulum – inferior pubic ramus: forms part of the inferior boundary of the obturator foramen 54
- 55. Landmarks Pubic crest • thickening on the anterior part of the body o f the pubis • ends laterally as a swelling - pubic tubercle Pubic arch (sub pubic angle) • formed by the ischiopubic rami (conjoined infe rior rami of the pubis and ischium) of the two s ides • these rami meet at the pubic symphysis • their inferior borders define the subpubic angle 55