05 the axial skeleton english
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- 1. The axial Skeleton
2. THE AXIAL SKELETON CONSISTS OF: Skull Vertebrae Ribs Sternum Sacrum Coccyx The axial skeleton is harder to puzzle out than the appendicular, because its involved in support and protection more than movement. More memorization is required. 3. SKULL skull = cranium + mandible cranium = cranial vault +face + basicranium A vault without a face orbasicranium is called acalvarium. The splanchnocranium isanother name for the face. 4. Skull 29 bones and 32 teeth. Most joints are immovable,the exceptions being thosewith the mandible andvertebral column. The boundaries between thebones of the vault aremarked by the cranialsutures. 5. THE CRANIAL VAULT Frontal (anterior) Parietal (lateral) Temporal (lateral) Occipital (posterior) The parietal and temporalare paired (they have a leftand a right). The frontaland occipital are unpaired(theres one of each). 6. Sutures The coronal suture is parallelto the coronal plane andforms the posterior border ofthe frontal. The sagittal suture is alongthe sagittal plane. The squamosal suture isbetween the temporal and theparietal. The lambdoid suture isposterior and forms thesuperior border of theoccipital. 7. Frontal Forehead Orbits (anterior andinferior) Supraorbital torus (browridge) Coronal suture (posterior) Zygomatic process (lateral) Billowed internal surface Frontal crest (internal) 8. Parietal Deeply curved. Grooves for middlemeningeal vessels on theinside. They go back and up.The deepest is the mostanterior. It is parallel to thecoronal suture. coronal suture to anterior Sagittal suture medially Squamosal suture to inferior Lambdoid suture posterior 9. TEMPORAL External auditory meatus (earcanal) Squamosal suture superiorly Lambdoid suture posteriorly Zygomatic process to anterior Mastoid process w/ digastricgroove to posterior External auditory meatus inbetween mastoid and zygomatic Petrous process medially andinternally 10. Occipital The back of the head. External occipitalprotuberance (posterior) Lambdoid suture (anterior) Articulates with firstcervical vertebrae atoccipital condyles Foramen magnum (bighole) for spinal cord(inferior) 11. Major bones of the Face Frontal Nasal Zygomatic Maxilla 12. zygomatic Cheekbone Articulates with frontal(superiorly), maxilla(medially), and temporal(posteriorly) Contributes to orbitssuperiorly and medially 13. Maxilla Upper jaw Articulates with frontal(superiorly) and zygomatic(laterally/posteriorly) Dentition (teeth) inferiorly Maxillary sinus internally 14. Major bones of thebasicranium Occipital (posterior) Temporal (lateral) Sphenoid (midline) 15. Sphenoid Highly complex bone Contributes to vault,basicranium, and posteriorportion of the eye orbit Often recovered infragmentary state, usually inconnection with anothercranial bone To remember its anatomicalorientation, think of itresembling bat, butterfly, orowl 16. Mandible Lower jaw One of two movable jointsin the skull Articulates with thetemporals glenoid fossa Ramus Condylar process andcoronoid process 17. Vertebrae 24 vertebrae: 7 cervical, 12thoracic, 5 lumbar Cervical vertebrae arelocated in the neck Thoracic are located in thechest Lumbar are located in thelower back Ribs articulate with thethoracic vertebrae. 18. Ribs 24 ribs (12 pairs) Ribs 1, 2, 3-10, and 11-12are distinguishable withpractice Ribs articulate posteriorlyand medially with one ortwo thoracic vertebrae Articulate anteriorly andmedially with 1) the sternum2) costal cartilage thatattaches to the sternum or 3)nothing. 19. STERNUM The breastbone Three sections: themanubrium, the gladiolus(or body), and the xiphoidprocess. Can have a naturallyoccurring hole in it that ispossible to mistake for agunshot wound 20. Sacrum + Coccyx Sacrum is the posterior,medial-most part of thepelvis Sacrum follows a vertebralpattern and ossifies from fiveelements coccyx = tailbone. Veryvariable. Not alwaysrecovered. Sometimes fusedto sacrum.