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![Remember, the skull is
composed of:
1. Cranial bones (or cranium)
[these were just reviewed]
and
2. Facial bones (anterior aspect of skull)
□ Form framework of face
□ Form cavities for sense organs of sight, taste
and smell
□ Provides openings for passage of air and food
□ Hold the teeth
□ Anchor the muscles of the face](https://image.slidesharecdn.com/axialskeleton-231008153451-6eb98f23/85/axialskeleton-ppt-18-320.jpg)
axialskeleton.ppt
- 2. Table Of Context •Introduction • Skull, Cranium, Cranial bones, Temporal bones • Sutures • Composition • Vertebral Columns • Spinal Curvatures • Non Bony Parts • Structure of Typical Vertebra • Thoracic Cage • Ribs • Vertebral and Sternal Articulation • Disordered of Axial Skeleton • Fontanels • Some Abnormalities of Suture
- 3.
- 4. THE SKELETAL SYSTEM TheAxial Skeleton ■ The skeleton consists of □Bones (206) □Cartilages □ Joints – also called articulations, are the junctions between skeletal elements □ Ligaments – connect bones ■ Divided into axial and appendicular
- 5. ■ Axial skeleton- forms long axis of body □Skull □Vertebral column □Thoracic cage ■ Appendicular skeleton – appendages and what they attach to □Upper limbs (arms) □Pectoral girdle (shoulder) □ Lower limbs (legs) □Pelvic girdle
- 6. Axial skeleton Skull Vertebral column Thoraciccage Axial skeleton is shown in green
- 7. The Skull ■ Cranialbones (or cranium) □ Enclose the cranial cavity, which supports and protects the brain □ Attachment sites for some head and neck muscles ■ Facial bones (anterior aspect of skull) □ Form framework of face □ Form cavities for sense organs of sight, taste and smell □ Provides openings for passage of air and food □ Hold the teeth □ Anchor the muscles of the face
- 8. Cranium ■ Vault –“calvaria” = skullcap □ Forms superior, lateral and posterior aspects of skull, and forehead ■ Base or floor: inferior part □ Prominent bony ridges divide cranial base into 3 “fossae” (steps) – anterior, middle and posterior Anterior cranial fossa Middle cranial fossa Posterior cranial fossa (looking down on the floor of the skull)
- 9. Cranial bones ■ Frontalbone ■ Parietal bones (paired) ■ Occipital bone ■ Temporal bones (paired) ■ Sphenoid bone ■ Ethmoid bone
- 10.
- 11. Temporal bones this isthe right temporal bone looking at it from the right side
- 12.
- 13. Sutures ■ Immovable, interlockingjoints of flat bones of skull ■ Irregular, saw-toothed appearance ■ Largest 4 skull sutures: where bones articulate with parietal bones □ Coronal □ Sagittal □ Squamous □ Lambdoid (FIND THEM)
- 14. Find: coronal, squamousand lamboid sutures
- 15. Find: sagittal andlambdoid sutures
- 16. Some abnormalities (earlyfusion) of sutures: “craniosynostosis” • Metopic Synostosis and trigonocephaly • A: Preop •B: 2 years after frontal orbital advanceme nt • Sagittal synostosis and scaphocephaly • The most common suture to fuse is the middle or sagittal suture. Often the back or front of the skull will be worse but the overall shape is a long skull with a shortened distance from ear to ear. Pre-op CAT scan Diagram of surgery 2 years post-op From - http://www.ppsca.com/skull.htm
- 17. ■ Cranial “cavity”– houses brain ■ Smaller cavities □Housing middle and inner ear □Nasal cavity □Orbits □Sinuses ■ Openings (foramina, canals, fissures) for: □Spinal cord □Blood vessels □Twelve cranial nerves: I-XII
- 18. Remember, the skullis composed of: 1. Cranial bones (or cranium) [these were just reviewed] and 2. Facial bones (anterior aspect of skull) □ Form framework of face □ Form cavities for sense organs of sight, taste and smell □ Provides openings for passage of air and food □ Hold the teeth □ Anchor the muscles of the face
- 19. Facial bones ■ Mandible ■Vomer ■ Maxillae (paired) ■ Zygomatics (paired) ■ Nasal (paired) ■ Lacrimal (paired) ■ Palatines (paired) ■ Inferior nasal conchae (paired)
- 20. Facial bones: Mandible Vomer Maxillae(paired) Zygomatics (paired) Nasal (paired) Lacrimal (paired) Palatines (paired) Inferior nasal conchae (paired)
- 27. Mandible (lower jaw) Maxilla(there are 2 which fuse, forming the upper jaw)
- 28. Nasal cavity ■ Ofbone and cartilage ■ Roof is ethmoid’s cribriform plate ■ Floor formed by palatine processes of the 2 maxillae and horizontal plates of palatine bones □ These nasal-floor structures form roof of the mouth, called the hard palate nasal bone ethmoid inf nasal concha vomer (part of slide 18) maxilla
- 29. Nasal cavity To left,bones forming the left lateral wall of the nasal cavity (nasal septum removed) To right, nasal cavity with nasal septum in place, showing how the ethmoid bone, septal cartilage, and vomer make up the septum
- 30. Orbit Cone-shaped bony cavitiesholding the eyes, muscles that move the eyes, some fat and tear- producing glands; you don’t need to know all these bones that form it, just realize how complex it is and recognize the optic canal (optic nerve passes out through it) (right orbit shown)
- 31. Paranasal sinuses ■ Air-filledsacs in the bones ■ “Paranasal” because they cluster around and connect to the nasal cavity
- 32. Hyoid bone ■ Onlybone which does not articulate with any other bone ■ Moveable base for the tongue ■ Points of attachment for neck muscles that raise and lower the larynx during swallowing
- 33. Remember that theAxial skeleton includes: Skull Vertebral column Thoracic cage Axial skeleton is shown in green
- 34. The Vertebral Column ■Fetus and infant: 33 separate bones, or vertebrae ■ Adult: 24 vertebrae □Inferior 9 have fused forming ■ The sacrum (5) and ■ The coccyx (4)
- 35. Vertebrae ■ Cervical –7 ■ Thoracic - 12 ■ Lumbar - 5 ■ Sacrum (5 fused) ■ Coccyx (4 fused)
- 36. Spinal curvatures ■ Cervicaland lumbar are concave posteriorly* (lordosis) ■ Thoracic and sacral are convex posteriorly* (kyphosis) ■ Abnormal (see lab book p120): □ Too much of either □ Scoliosis (more than 10 degrees of lateral curvature) *when viewed from the side
- 38.
- 39. Non-bony parts ■ Intervertebral discs □anulus fibrosis and nucleus pulposus) ■ Anterior longitudinal ligament ■ Posterior longitudinal ligament ■ Ligamentum flavum
- 40. Anterior longitudinal ligament:wide, strong and attaches to vertebrae as well as discs (prevents hyperextension) Posterior longitudinal ligament: narrow and relatively weak, attaching only to discs Note “intervertebral foramen” vs “vertebral foramen” on next slides *
- 41. Structure of atypical vertebra
- 42. Cervical vertebrae (C1-C7) C1(atlas) C2 (axis)
- 43. ■ ■ ■ ■ Smallest Lightest Most flexible Triangular vertebral foramen Transverse processeshave foramina (transverse foramen) Spinous process bifid (forked) except for C7 ■ ■ Cervical Vertebrae
- 44. ■ Heart shaped body ■Additional small costal facets (costal=ribs) ■ Round or oval vertebral foramen ■ Form posterior part of rib cage Thoracic Vertebrae T1- T12
- 45. ■ Massive blocklike bodies ■ Short,thick hatchet-shaped spinous processes ■ Limited mobility Lumbar Vertebrae L1- L5
- 46. Shapes posterior wallof pelvis The Sacrum Composite bone of 5 fused vertebrae Sacral foramina allow passage of vessels & nerves Coccyx (the tailbone)
- 47. Remember that theAxial skeleton includes: Skull Vertebral column Thoracic cage Axial skeleton is shown in green
- 48.
- 49. Sternum Ribs ■ Manubrium ■Body ■ Xiphoid process ■ True ribs 1-7 ■ False ribs 8-12 ■ Floating ribs 11,12
- 50.
- 51. Vertebral and SternalArticulations
- 52.
- 54. Disorders of theaxial skeleton ■ Scoliosis (over 10% curvature) ■ Kyphosis ■ Lordosis ■ Vertebral compression fractures ■ Spinal stenosis
- 55.
- 56. Fontanels ■ Unossified remnantsof membranes ■ Present at birth ■ Anterior fontanel largest ■ Called “soft spots” ■ Ossify by 1 ½ - 2 years Continue to ossify into adulthood; the sutures can become fused in old age
- 57. I highly recommendProfessor Wissman’s sites ■ For bones: http://homepage.smc.edu/wissmann_paul/bones/EBbonestuto ■ Check out all his links: http://homepage.smc.edu/wissmann_paul/anatomy1/ Also check out: ■ Site for xrays & other diagnostic procedures: http://www.radiologyinfo.org/en/sitemap/category.cfm
- 58. T H AN K O Y U