Skull Anatomy PDF

GENERAL ANATOMY PRACTICAL BONES OF THE HEAD AND NECK 1  THE SKULL The skull is formed of twenty two bones. Twenty one bones are immovable connected mainly by sutures & only one bone is movable “the mandible”. The immovable bone are: Five sin...

GENERAL ANATOMY PRACTICAL BONES OF THE HEAD AND NECK 1  THE SKULL The skull is formed of twenty two bones. Twenty one bones are immovable connected mainly by sutures & only one bone is movable “the mandible”. The immovable bone are: Five single bones: -Frontal -Ethmoid -Sphenoid -Vomer -Occipital Eight paired bones: -Lacrimal -Nasal -Inferior concha -Zygomatic -Maxillary -Palatine -Parietal -Temporal Subdivision of the skull: The cranial bones (neurocranium): Bones that surround and protect the brain. The facial bones (viscerocranium): bones that form the face. 2 3 4  NORMA VERTICALIS The superior aspect of the skull NORMA VERTICALIS: I- Bones: a-Anteriorly: Frontal bone b-Laterally: Rt & Lt parietal bones c-Posteriorly: Occipital bone II- Sutures: a-Coronal suture: separates the frontal from the two parietal bones b-Sagittal suture: separates the right and left parietal bones c-Lambdoid: separates the two parietal from occipital bones III- Important features: a-Bregma: is the point of meeting between coronal and sagittal sutures. At birth it was the site of the anterior fontanelle which ossified at the age of 1 years and 6 months b-Lambda: is the point of meeting between lambdoid & sagittal sutures. At birth it was the site of the posterior fontanelle which ossified at the age of 6 months c-Vertex: It is most convex point of skull vault. It lies between bregma and lambda. d-Parietal foramen: Is present on each side of the sagittal suture through which passes parietal emissary vein that connects veins of scalp with superior sagittal sinus e-Parietal eminence: It is the most prominent part of the parietal bone. 5 6 NORMA FRONTALIS The anterior aspect of the skull 7 NORMA LATERALIS The lateral aspect of the skull 8 TEMPORAL FOSSA AND INFRATEMPORAL FOSSA 9 NORMA OCCIPITALIS The posterior aspect of the skull 10 NORMA BASALIS EXTERNA The inferior aspect of the skull seen from outside (The anterior part of norma basalis externa) Hard palate is formed by: -Its anterior 3/4: Is formed by the palatine process of maxilla -Its posterior 1/4: Is formed by the horizontal plate of palatine bone 11 NORMA BASALIS EXTERNA The inferior aspect of the skull seen from outside 12  NORMA BASALIS INTERNA The inferior aspect of the skull seen from inside [Seen after removal of skull cap (vault)] Ethmoid bone Sphenoid bone 13 The Mandible 14 15 CERVICAL VERTEBRAE C1 (Atlas) 16  C2 (Axis) Typical cervical vertebra C3, 4, 5 & 6 C7 17 HYOID BONE 18