Axial Skeleton Lecture:

Responsible for the names of the bones of the skull

Crista galli: ___________________________________

Cribrofim plate: allows passage for ___________ ________________

††††††††††† Some special markings:

††††††††††† Styloid process: attachment for neck muscles

††††††††††† Mastoid process: full of air cavities (mastoid sinuses) some neck muscles attach

††††††††††† Jugular foramen: passage for jugular vein

††††††††††† Carotid canal: internal carotid artery


14 facial bones

Maxillae: sinuses drain into nasal passages

Paranasal sinuses: lighten skull bones, ____________ sounds as we speak

________ bones: form medial wall of orbits w a groove which serves as a passage for tears

Hyoid bone: ligaments anchor it to styloid, supports the tongue


Vertebral column:

7 cervical (neck)

12 thoracic

5 lumbar

1 sacrum (fusion of 5 sacral vertebrae)

Coccyx bones


Common vertebral parts:

Spinous process: pointy end, feel on your back

Laminae: fuse to give rise to spinous process (spina bifida)

Superior facets articulate with the inferior facetof the vertebra immediately superior

Pedicles: project off the lamina leading to a body

Body is separated by a fibrocartilage disc (intervertebral discs)

Vertebral foramen for the spinal cord

Transverse processes


Cervical vertebrae: have three foramen : vertebral and transverse (for arteries and veins)

Thoracic vertebrae: all 12 have rib facets on bodies and transverse processes

Lumbar vertebrae: one hole and no rib facet: equipped to bear weight due to body being big and spinous process is broad


Specialized vertebrae:

___________: supports the head, occipitalcondyles rest on the superior facets, allows you to say YES, No spinous process or body


__________: ____________ process (dens) allows the rotation of the head to say NO


Sternum: manubrium, body and xiphoid process (frequently used for biopsy of marrow)

12 pairs of ribs all posteriorly attached to thoracic vertebrae at the articulating facets of the ribs and 10 pairs are attached to costal cartilage


Normal curvatures:

4 slight curves when viewed from the side

††††††††††††††††††††††† Cervical and lumbar

††††††††††††††††††††††† Thoracic and sacral curves

Curvature increases strength, maintain balance in the upright position, absorb chock, protect from vertebral breaks


Axial skeleton disorders:

________________: results when palatine bones donít fuse to form a hard palate

††††††††††††††††††††††† Palantine bones form the roof of the mouth behind the maxilla, forming the posterior portion of the hard palate, part of the floor and the lateral wall of the nasal cavity and a small portion of the orbit


Deviated nasal septum: a septum that bends sideways from the middle of thenose, can completely block passageway , can lead to congestion, blocked sinuses, chronic sinusistis, headaches and nosebleeds

††††††††††† Nasal septum is formed by the vomer, spetal cartilage and the perpendicular plate of the ethmoid bone



Congenital defect where laminae fail to unite

††††††††††† Serious cases: meninges protrude or the cord itself may produce partial or complete paralysis, loss of urinary control and reflexes

††††††††††† Related to folic acid



Ligaments of the inerterbral discs are so weakened that the fibrocaertilage discs ruptures, herniating the material inside usually a lumbar vertebrae


Unusual curves:

_________: a crooked sideways bend if you look straight at the back

_________: exaggerated thoracic curve (elderly due to osteoporosis, rickets and posture)

_________: swayback or exaggerated lunbar curve, weight,poor posture, rickets or TB of spine)


_________: resorption outpaces deposition, causes morethan a million fractures inth eus a year causes shrinkage of vertebrae


_________: disorder where calcification fails causing bones to become soft, rubbery and easily deformed (rickets affects growing children and osteomalacia affects adults)hypocalcemia due to vit D deficiency. Vit D allows Ca to be absorbed through the gut. Need UV light to synthesize Vit D, usually due to malnutrition, bow legs, floppy baby syndrome