Bony Thorax Notes PDF

4. Bony Thorax 111  4. The Bony Thorax Protects thoracic organs and allows respiration Supports shoulder girdle and upper limbs Provides attachment sites for muscles 112 4. The Bony Thorax ...

4. Bony Thorax 111  4. The Bony Thorax Protects thoracic organs and allows respiration Supports shoulder girdle and upper limbs Provides attachment sites for muscles 112 4. The Bony Thorax  4. The Bony Thorax Components of the bony thorax: 1. Ribs - laterally 2. Thoracic vertebrae - posteriorly 3. Sternum and costal cartilage – anteriorly Used for respiration & to accomodate pregnency 113 4. The Bony Thorax  4. Sternum 3 sections 1. Manubrium Articulates with clavicles 2. Body sides articulate with costal cartilages for ribs 2-7 3. Xiphoid process Ossifies around age 40 114 4. The Bony Thorax  Good landmarks for assg 4. Sternum Jugular notch Manubrium Sternal angle Body Xiphisternal Junction Xiphoid process Costal angle 4. The Bony Thorax 115  4. Ribs All ribs attach to vertebral column posteriorly 12 pairs of ribs, 12 thoracic vertebrae True ribs – ribs 1-7 (paired) Attach to sternum by costal cartilage False ribs – ribs 8-12 (paired) Ribs 11-12 are floating ribs 116 4. The Bony Thorax  4. Ribs True ribs – ribs 1-7 (paired) Attach to sternum by costal cartilage 117 4. The Bony Thorax  4. Ribs False ribs – ribs 8-12 (paired) Attach to sternum via rib 7's costal cartilage 118 4. The Bony Thorax  4. Ribs False ribs - ribs 11-12 are floating ribs Don't attach to sternum 119 4. The Bony Thorax  4. Ribs 120 4. The Bony Thorax  4. Ribs 121 4. The Bony Thorax  4. Ribs 122 4. The Bony Thorax  4. Ribs 123 4. The Bony Thorax  Vertebrae T2 – T9 have 2 demifacets (superior & inferior) 124 4. The Bony Thorax Vertebrae T1, T10, T11, and T12 have complete costal facets on the bodies for ribs 1 and 10-12, which articulate on the vertebral bodies instead of between vertebrae. Vertebrae T2 – T9 have 2 demifacets (superior & inferior) Vertebrae T11 and T12 have no costal facets on transverse processes. 125 4. The Bony Thorax  The placement of full vs demi costal facets Full costal facets attach with head of rib (simple joint) which is more stable at superior & inferior ends of thoracic vertebraes 2 Demi costal facets attach with head of rib (compound joint) allows for more mobility & increased breathing Do demi costal facets provide more mobility? YES! Demi-facets: Location: T2–T9 vertebrae Function: Two adjacent vertebrae articulate with 1 rib Structural impact: Distributes mechanical stress between vertebrae, providing flexibility.  That means full costal facets provide more stability! Full facets: Location: T1, T10, T11, and T12 Function: Direct articulation between 1 rib & 1 vertebrae Structural impact: Offers more stable attachment, especially in the lower thoracic region.