Axial Skeleton

Vertebral Column/ Spine supports the skull /transfers weight Structure: 26 irregular bones (33 pre-birth) 7 cervical 12 thoracic 5 lumbar 1 sacrum 1coccyx

Intervertebral foramen- Between each vertebrae For spinal nerves Intervertebral discs- Cushion/absorbs shock Provides flexibility Hardens with age

Herniated Disc When the annulus wall weakens, the disc will press against the spinal nerve= PAIN

curvatures Primary curvature- It’s what you are born with Posterior = Convex Secondary curvature-It’s what develops Cervical becomes posterior concave when baby lifts its head Lumbar becomes posterior concave when baby walks

Abnormal Curvatures Scoliosis- abnormal side to side Kyphosis-Exaggerated posterior curvature of thoracic vertebrae, typical of osteoporosis Lordosis-exaggerated posterior curve of lumbar. Typical of pregnancy, pot belly

Scoliosis

Posterior View

After Surgery

New Rods

Typical Vertebrae Body- weight bearing anterior Vertebral Arch- join the laminae and pedicles posterior Vertebral Foramen- canal that the spinal cord passes through Transverse Process- 2 lateral projections from the arch

Typical vertebrae Spinal Process- single projection from posterior arch Superior and Inferior Articular Processes- paired projections lateral to the foramen, it allows the vertebrae to join each other

Cervical Vertebrae - neck C1 - ATLAS No body receives the occipital condyles Allows the “yes” nod

Cervical vertebrae C-2 - AXIS Has an upright pivot called dens or odontoid process Allows rotation- “no”

Cervical vertebrae C-3 to C- 7 Small Short bifid spinous process Transverse processes contain foramen for arteries

Thoracic Vertebrae T1 – T12 Larger heart shaped body Long spinous process-points downward 2 costal facets on either side for ribs

Thoracic Vertebrae

Lumbar vertebrae L1 – L5 Massive body Hatchet like spinous process Takes the most stress

Sacrum 5 fused vertebrae Posterior Pelvis wing like Lateral articulation with hip Medial Sacral Crest- posterior fused spinous processes

Sacrum Sacral foramina- lateral to crest Sacral Canal- down the center Sacral Hiatus- inferior opening

Coccyx 3-5 fused vertebrae tailbone

Bony Thorax Ribs Sternum Thoracic vertebrae

Sternum Manubrium- jugular notch (top) Body- sternal angle, 3rd rib (middle) Xiphoid Process- small point at bottom

Xiphoid The Xiphoid process can cause damage because of the location of the liver

Costal Cartilage The costal cartilage attaches the ribs to the sternum-hyaline cartilage

Ribs- 12 pairs True ribs-are connected to the sternum- vertebrosternal # 1-7 Posterior – attached to thoracic vertebrae 1-7 Anterior- attached to sternum

False Ribs- are not connected directly to the sternum Ribs 8-10 are called false Ribs 8-10 are called vertebrochondral Posterior- attaches to vertebrae Anterior- attaches to cartilage

Floating Ribs- ribs 11 & 12 They are not connected in the anterior, only the posterior Posterior- vertebrae Anterior- nothing

Ribs- flat bones Head- meets with the body of the thoracic vertebrae Neck- meets with the transverse process of the thoracic vertebrae Shaft- angles downward