8 bones of the cranium: 1 frontal bone 2 parietal bones 1 occipital bone 2 temporal bones 1 sphenoid bone 1 ethmoid bone 1

Cranium Forehead Roof of nasal cavity Roofs of orbits Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Frontal Bone (1) Forehead Roof of nasal cavity Roofs of orbits contains frontal sinuses (above each eye) Supraorbital foramen on the upper margin of each orbit; allows blood vessels and nerves to pass to tissues of the head. Articulates to parietal bones at the coronal suture Starts as two bones…the two halves of the frontal bone fuse together by the about the sixth year

Cranium side walls of cranium one on either side Parietal Bones (2) side walls of cranium one on either side fused at midline along sagittal suture articulate with frontal bone at coronal suture

Cranium Back of skull Base of cranium Occipital Bone (1) Back of skull Base of cranium Foramen Magnum = a large opening where the spinal cord connects to the inferior part of the brain stem; articulates with vertebrae Lambdoid suture connects the parietal and temporal bones with the occipital bone. Occipital Condyles: where most superior vertebrae articulates

Cranium Floor of cranium Floors and sides of orbits Temporal Bones (2) Side walls of cranium Floor of cranium Floors and sides of orbits Squamous suture connects it to the parietal bone External acoustic meatus Styloid process Anchors muscles for tongue Zygomatic process Mastoid process Mandibular fossa

Cranium Base of cranium Sides of skull Floors and lateral Sphenoid Bone (1) Base of cranium Sides of skull Floors and lateral sides of orbits Sphenoidal sinuses Sella turcica: pituitary gland

Roof and walls of nasal cavity Floor of cranium Wall of orbits Ethmoid Bone (1) Roof and walls of nasal cavity Floor of cranium Wall of orbits Nerves associated with smell pass through olfactory foramen in this bone Also has a feature called the crista galli:attach the membrane sac that encloses the brain Forms most of nasal septum and nasal concha that serve to support mucous membrane of nose Ethmoidal sinuses

Cranium Coronal suture Temporal bone Parietal bone Frontal bone Squamous suture Sphenoid bone Frontal sinus Lambdoid suture Nasal bone Occipital bone Ethmoid bone Crista galli Internal acoustic meatus Cribriform plate Perpendicular plate (nasal septum) Inferior nasal concha Styloid process Maxilla Sphenoidal sinus Palatine bone Vomer bone Mandible 8

Sinuses Frontal sinus Ethmoidal sinuses Sphenoidal sinus Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Frontal sinus Ethmoidal sinuses Sphenoidal sinus Maxillary sinus

Facial Skeleton form the 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 10

Facial Skeleton There are 14 bones in the face ( + 8 in the cranium = 22 in the total skull) I am only going to hold you responsible for the details of these 7: Zygomatics(2) Mandible (1) Maxillae (2) Nasals (2) The OTHER Facial Bones are: Vomer (1), Palatines (2), Inferior nasal conchae (2), Lacrimals (2)

Facial Skeleton AKA “Maxillae” forms: upper jaw Maxillary Bones (2) AKA “Maxillae” forms: upper jaw Hard palate: anterior roof of mouth floors of orbits sides and floors of nasal cavity Incisive foramen: brain freeze cure contains maxillary sinuses Hold the teeth in dental alveoli

Facial Skeleton forms: lateral walls of orbits floors of orbits Zygomatic Bones (2) forms: lateral walls of orbits floors of orbits includes the temporal process provides for the prominences of cheeks…they are the “cheekbones”

Facial Skeleton forms forms: bridge of nose medial walls of orbits Lacrimal Bones (2) forms medial walls of orbits Has nasolacrimal ducts (tear ducts) that deliver tears to nose Nasal Bones (2) forms: bridge of nose

Facial Skeleton forms: Lower jaw Ramus Mandible Bone (1) forms: Lower jaw Ramus Mandibular condyle (where it articulates with mandibular fossa of temporal bones) Mandibular foramen (blood vessels and nerve to supply roots of lower teeth) Mental foramen (blood vessels and nerve supply to chin) Facial Skeleton

Facial Skeleton Dental alveoli: border for teeth sockets Mandible Bone (1) Dental alveoli: border for teeth sockets Facial Skeleton

Infantile Skull Fontanels – fibrous membranes Frontal suture Frontal bone Anterior fontanel Sagittal suture Posterior fontanel (b) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Infantile Skull Anterior fontanel Parietal bone Coronal suture Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Anterior fontanel Parietal bone Coronal suture Posterior fontanel Frontal bone Zygomatic bone Occipital bone Maxilla Mastoid fontanel (posterolateral fontanel) Sphenoid bone Temporal bone (a) Sphenoidal fontanel (anterolateral fontanel) Mandible 18