Presentation on theme: "CHAPTER 7 “The Axial Skeleton #2” Course objectives: Define and identify the bones of the axial skeleton."— Presentation transcript:
1 CHAPTER 7 “The Axial Skeleton #2” Course objectives: Define and identify the bones of the axial skeleton
2 Vertebral column composed of 26 irregular bones. These bones provide a solid support structure, but are also remarkably flexible.
3 Regions of the Vertebral Column Cervical − neck region 7 vertebraeThoracic – thorax region 12 vertebraeLumbar – lower back 5 vertebraeSacral – low, low back 1 vertebrae (5 fused)Coccygeal – tail bone 1 vertebrae (4 fused)
4 Spinal Curvature Thoracic and sacral are concave (i.e. backward) Primary curves since they developed first.Cervical and lumbar curves are convex (i.e. forward) and secondary curves.
6 VertebraeIndividual vertebrae are found in the cervical, thoracic and lumbar regions of the vertebral column.There are significant differences between the vertebrae in each of these regions that you should know.
7 Cervical vertebrae – C1- C7 Body is oval; spinous process is short (except C-7) and sometimes split;Large vertebral foramenTransverse foramen for vertebral artery to brainstem.C1 is Atlas articulates (atlanto-occipital joint) with occipital bone of skull-allows “yes” motion of headC2 is Axis characterized by peg-like process called “dens” or odontoid process which interlocks with atlas (atlanto-axial joint)-allows sideward rotation or “no” motion of head.
11 Thoracic vertebrae T1- T12 Body is roughly heart shapedDemifacets for rib articulationVertebral foramen are circularSpinous process long and points inferiorlyThe thoracic vertebra look like a giraffe’s head when viewed from the lateral view!
13 Lumbar Vertebrae L1-L5 Pedicles and laminae are short and thicker Spinous processes are short, flat and hatchet shapedVertebral foramen is triangularInferior and superior processes lock the adlacent vertebrae together for strength and stability.The lumbar vertebra look like a Moose’s head!
15 Sacral Vertebrae S1-S5Sacral vertebrae consists of 5 fused vertebrae fully fused by 30 years of ageWomen sacrum is shorter, wider and more curvedConnects the spine to the pelvic girdle at the sacroiliac joint.Sacral canal is continuation of vertebral canal.
21 Additional structures of the vertebral column Intervertebral discsPresent between all vertebrae C2- L5/S1;Composed of fibro cartilageTwo regions of disc:- nucleus pulposis – central core of disc- annulus fibrosis - outer covering of fibro cartilageFunction: -discs permit various movements-provide shock absorbing functions for vertebral column
24 Vertebral Ligaments(1). Anterior and posterior longitudinal ligaments hold vertebral column together along with trunk skeletal muscles-prevent hyper-extension and hyper-flexion of the vertebral column.(2). Shorter ligaments connect adjoining vertebrae together.-There are 3 of these ligaments the ligamentum flavum, the supraspinous ligaments and the interspinous ligaments.
28 Ribs1. true ribs – the first (superiormost) seven pairs of ribs R1-R7 are directly connected to the sternum via costal cartilage.- are called vertebrosternal ribs.2. false ribs – the remaining five pairs of ribs.There are two types of false ribs.vertebrochondral ribs -- rib pairs #8, #9, and #10 are connected by a single band of costal cartilage to the inferior portion of the sternum. Unlike the first seven pairs of ribs they do not have their own individual attachments.floating or vertebral ribs – rib pairs #11 and #12 are connected only to the vertebral column, they have no anterior connection to the skeleton.
29 All ribs articulate with vertebral column All ribs articulate with vertebral column. The head of the rib articulates at a demifacet on the body of the vertebrae, while the tubercle of the rib articulates at a facet on the transverse process.
30 Sternum “breast plate” Anterior central portion of thoraxOnly bony attachment of axial skeleton to appendicular skeleton via clavicle.Consists of Manubrium, Body and Xiphoid processKey landmarks: calvicular notches, jugular notch “suprasternal notch”, sternal angle.
31 SternumThe sternal foramen is an anomaly and occurs in ~ 4-10% of the population. It can be mistaken for a bullet puncture in cases of traumatic death.
32 Hyoid bone Lies inferior to the mandible Is not attached to skeleton by bony meansHelps movement of base of tongue