Skeletal System 1/10/13

1. The skeleton is a solid, movable framework that supports the body

2. Bones work as levers to anchor plates to allow for movement

3. Bones also work for other body systems

4. The body draws from mineral stores in bones during times of shortage

Axial skeleton

Appendicular skeleton

• Skull
• Hyoid bone
• Vertebrae
• Ribs
• (superior to inferior)

Pectoral girdle

Pelvic girdle

• 33 vertebrae in 5 divisions
• Each vertebra has a letter and a number designation

• Cervical vertebrae (C1-C7)
• Thoracic vertebrae (T1-T12)
• Lumbar vertebrae (L1-L5)
• Sacral vertebrae (S1-S5) fused into sacrum
• Coccygeal vertebare (4) fused into coccyx

The higher up the injury, the more you lose.

C1 - C7

• C1 = atlas supports the skull for rotation
• C2 = axis allows the skull to pivot

• It has:
• Spinous Processes except C1 and C2-rudimentary spinous process
• Transverse Processes
• Transverse foramina are present only in the cervical vertebrae
• Corpus
• Vertebral foramen
• Intervertral foramina
• Superior articular facet
• Inferior articular facet

T1-T12

Basis for respiratory framework

Form the posterior point of attachment for the ribs of the body thorax

Correspond to each pair of ribs

Between the vertebrae are the intervertebral foramina which are formed by the inferior and superior notches of articulating vertebrae.

Superior/inferior costal facets

Larger spinous and transverse processes

L1-L5

Spinal cord ends in the lumbar

Larger muscle attachments - bigger body (corpus) walking, lifting.

Provide direct or indirect attachment for many of the back and abdominal muscles and posterior fibers of the diaphragm

Transverse spinous processes smaller

Corpus larger

• Primary:
• develop in the womb
• thoracic
• sacral

• Secondary:
• cervical-develops when the infant begins to lift his/her head

lumbar-develops when the child begins to stand and walk

Supports the upper extremities.

Clavicle

Scapula

Supports the lower extremities.

Lower extremities attach to AXIS by means of pelvic girdle.

• Llium
• Sacrum (is not part of the appendicular skeleton)
• Pubic bone
• Ischium

bone and joint disorders