Thoracic Cage ES 332 ? APPLIED ANATOMY Kari Kebach, ATC, MS OUTLINE Introduction Ribs Sternum Ligaments Joints of vertebral column Movements of vertebral column INTRODUCTION Thoracic cage = ribs + thoracic vertebrae + sternum + costal cartilage Functions Protection Support Muscle attachment Breathing RIBS 12 pairs of ribs + costal cartilage Attach to thoracic vertebrae posteriorly 3 types True (vertebrocostal): 1st 7 of 12 Attach directly to sternum via own costal cartilage, and attach to vertebrae False (vertebrochondral): 8th ? 10th Indirect connection to sternum via superior rib?s costal cartilage Floating (free): 11th, 12th No connection to sternum, cartilage ends in abdominal muscles RIB ? TYPICAL STRUCTURE 3rd to 9th Bowed flat bone, light From vertebra, curves laterally, anteriorly, and inferiorly Superior border of shaft = smooth Inferior border of shaft = sharp RIB ? TYPICAL STRUCTURE Head Wedge-shaped, 2 demifacets separated by crest Neck Connects head with shaft at tubercle Tubercle Articular part ? vertebral transverse process Non-articular part ? costotransverse ligament Shaft (body) Thin, flat curved Angle ? where rib turns anterolaterally Costal groove ? on internal surface ? intercostal nerves and vessels RIBS ? ATYPICAL 1st Flattened superior-inferiorly, broad, most curved Superior surface 2 grooves ? subclavian artery and vein Scalene tubercle and ridge between grooves Only 1 facet on head = articulates 1 vertebral body (as do 10th ? 12th) 2nd Thinner, less curved, longer, otherwise typical RIBS ? ATYPICAL 11th and 12th Shorter, no neck or tubercle Do not articulate with sternum COSTAL CARTILAGE Hyaline cartilage Prolongs (lengthens) rib anteriorly Adds elasticity to thoracic wall ? reduces fracture by blows to sternum Calcifies in elderly STERNUM (BREASTBONE) Flat, elongated vertically along anterior midline of thorax 3 parts Manubrium Body Xiphoid process STERNUM (BREASTBONE) Manubrium Superior, triangular, T3 ? T4 level Suprasternal (jugular) notch Superior border Palpable Clavicular notch 2, lateral to SSN Costal notch 2 full, 2 half Articulation with costal cartilage STERNUM (BREASTBONE) Body Longer, narrower, thinner than manubrium, T5 ? T9 level Costal notch 2nd ? 7th pairs Sternal angle Sagittal, between manubrium and sternum Opposite 2nd costal notch STERNUM (BREASTBONE) Xiphoid process Inferior end, T10 level Small, variable Cartilaginous in young, ossifies by age 40 LIGAMENTS Costotransverse ligament Between tubercle of rib and transverse process of vertebra Costovertebral radiate ligament Between anterior surface vertebral body and head of rib Fan-shaped LIGAMENTS Radiate sternocostal ligament Between costal cartilage and costal notch of sternum Fan-shaped SPORTS INJURIES TO RIBS Dislocation Displacement of costal cartilage from sternum (sternocostal joint) Severe pain, especially deep breathing Lump at site of dislocation Common in contact sports SPORTS INJURIES TO RIBS Separation Displacement of rib from costal cartilage (costochondral joint) 3rd ? 10th rib Tears perichondrium and periosteum, rib moves superiorly over rib above ? pain JOINTS OF THE VERTEBRAL COLUMN Vertebral body Vertebral arches Craniovertebral Costovertebral Sacroiliac (later) JOINTS OF THE VERTEBRAL COLUMN Vertebral body Intervertebral joint Symphysis Connected by fibrocartilage = IV disc Amphiarthrodial Slightly moveable Anterior and posterior longitudinal ligaments Provide additional support Vertebral arch Facet joint Superior, inferior articular facets Synovial Surrounded by joint capsule Diarthrodial Freely moveable Simple 2 articular surfaces Gliding Flat articular surfaces Shape and orientation determines movements possible JOINTS OF THE VERTEBRAL COLUMN JOINTS OF THE VERTEBRAL COLUMN Craniovertebral: Atlanto-occipital Between lateral masses of C1, occipital condyles Synovial, diarthrodial Main movement = flexion (nodding) of head + sideways tilting JOINTS OF THE VERTEBRAL COLUMN Craniovertebral: Atlantoaxial joints 2 lateral ? between lateral masses C1 and C2 1 median ? between dens C2 and anterior arch C1 Main movement = rotation (shaking) head C1 C2 JOINTS OF THE VERTEBRAL COLUMN Craniovertebral: Atlantoaxial joints Transverse ligament Strong band between medial tubercles C1 Holds dens against anterior arch C1 Longitudinal bands between TL and occipital bone (TL + LB = cruciate ligament) JOINTS OF THE VERTEBRAL COLUMN Craniovertebral: Atlantoaxial joints Alar ligament Sides of dens to lateral margins foramen magnum Checks rotation Tectorial membrane Continuation of posterior longitudinal ligament Body of C2 to internal surface occipital bone JOINTS OF THE VERTEBRAL COLUMN Costovertebral Head of rib and vertebral facet or demifacet on vertebral body Radiate ligament of head of rib JOINTS OF THE VERTEBRAL COLUMN Costotransverse Rib tubercle, vertebral transverse process Lateral, superior costotransverse ligaments Both: Synovial, diarthrodial, gliding Movements of thoracic wall associated with breathing MOVEMENTS OF THE VERTEBRAL COLUMN Flexion Extension Lateral bending/ flexion Rotation MOVEMENTS OF THE VERTEBRAL COLUMN Limits to range of motion of VC = Thickness, elasticity, compressibility of IV discs Cervical ? thick relative to vertebral body ? increased flex/ ext, lateral bending Lumbar ? thickest ? increased flex/ ext (most), lateral bending MOVEMENTS OF THE VERTEBRAL COLUMN Limits to range of motion of VC = Shape, orientation of articular facets Thorax ? Superior ? face posterior, Inferior ? face anterior no flex/ ext, restricted lateral bending Lumbar regions ? Superior ? face posteromedially, Inferior ? face anterolaterally oblique, no rotation MOVEMENTS OF THE VERTEBRAL COLUMN Limits to range of motion of VC = Tension of intervertebral joint capsules More loose in cervical region ? increased ROM Resistance of ligaments (and back muscles) Ligamentum flavum, longitudinal ligaments ? reduced ROM SUMMARY Ribs True, false, floating Sternum Manubrium, body, xiphoid process Ligaments Costotransverse, costovertebral, sternocostal Joints of vertebral column intervertebral, facet, atlanto-occipital, atlantoaxial, costovertebral, costotransverse Movements of vertebral column NEXT CLASS Upper extremity Shoulder complex
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