the skull simply, amazing!. most complex bony structure 22 bones in all mostly flat bones, but not...
Post on 03-Jan-2016
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Functions of Cranial Bones
• Enclose and protect the fragile brain and furnish attachment sites for head and neck muscles
Functions of Facial Bones
• 1. form framework of face
• 2. contain cavities for special sense organs
• 3. openings for food/air passage
• 4. secure the teeth
• 5. anchor the facial muscles of expression
THE CRANIUM (8)
1 frontal bone
2 parietal bones
2 temporal bones
1 occipital bone
1 sphenoid bone
1 ethmoid bone
Parietal Bones and Major Associated Sutures
• Four sutures mark the articulations of the parietal bones – Coronal suture – articulation between
parietal bones and frontal bone anteriorly– Sagittal suture – where right and left parietal
bones meet superiorly– Lambdoid suture – where parietal bones
meet the occipital bone posteriorly– Squamosal or squamous suture – where
parietal and temporal bones meet
Occipital Bone and Its Major Markings
• Forms most of skull’s posterior wall and base
• Major markings include the posterior cranial fossa, foramen magnum, occipital condyles, and the hypoglossal canal
Figure 7.2b
Temporal Bones
• Form the inferolateral aspects of the skull and parts of the cranial floor
• Divided into four major regions – squamous, tympanic, mastoid, and petrous
• Major markings include the zygomatic, styloid, and mastoid processes, and the mandibular and middle cranial fossae
Temporal Bones
• Major openings include the stylomastoid and jugular foramina, the external and internal auditory meatuses, and the carotid canal
Sphenoid Bone• Spans the width of the middle cranial
fossa. Has a butterfly like shape.
• Articulates with all other cranial bones.
• Markings and regions to know:• Sphenoid sinuses• Hypophyseal fossa: a snug enclosure for
the pituitary gland.• Greater and Lesser Wings• Optic Canals: (opening for optic nerves)• Superior Orbital fissures: long slit
between greater and lesser wings, allows cranial nerves to control eye movement.
• Pterygoid processes: anchors muscles used in chewing
• Foramen rotundum and Foramen ovale
Ethmoid Bone
• Lies between the sphenoid and nasal bones of the face. Most deeply situated.
• Markings/Regions• Cribriform plates: help form roof of nasal
cavities and cranial fossa.• Olfactory foramina: allow olfactory nerves
to pass from nasal cavities to the brain.• Crista galli• Ethmoid sinuses
Maxillary Bones
• Medially fused bones that make up the upper jaw and the central portion of the facial skeleton
• Facial keystone bones that articulate with all other facial bones except the mandible
• Their major markings include palatine, frontal, and zygomatic processes, the alveolar margins, inferior orbital fissure, and the maxillary sinuses
Zygomatic bones
• Paired bones aka Cheek bones
• Form prominences of the cheeks and parts of the inferolateral margins of orbits.
• Articulates with temporal, frontal, and maxillary bones.
Lacrimal Bones
• Located in the medial wall of the orbits.
• Articulates with the frontal, ethmoid, and maxillary bones.
Palatine Bones
• Complete the posterior part of the hard palate.
• Forms part of the posterolateral walls of the nasal cavity.
• Small part of the orbits.
The Inferior Nasal Conchae
• Thin curved bones in the nasal cavity.
• Forms the lateral wall of the nasal cavity.
Application Question
• Mr. and Mrs. Walkabots have recently given birth to a beautiful baby girl, Zeplin. After a few months of great joy they notice that their daughter vomits often, sleeps a lot, is irritable all the time and cannot look them in the eye. Zeplin does not meet developmental milestones over the next six months. HELP!
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