ACOS OBJ 6 Identify Bones that compose the Skeletal System Introduction The skull is made up of 22 bones total 8 Cranial Bones 13 Facial Bones The Mandible The Main function of the skull is to protect the Brain ID: 461530
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Slide1
The Skull
ACOS OBJ 6.) Identify Bones that compose the Skeletal SystemSlide2
Introduction
The skull is made up of 22 bones total8 Cranial Bones
13 Facial BonesThe Mandible
The Main function of the skull is to protect the Brain
Except for the lower jaw all bones in the skull are interlocked along lines called
sutures
. Slide3
Cranium
Protects the BrainProvides attachment for musclesContains air-filled sinuses to allow it to be light weight.Slide4Slide5
Bones Located in the Cranium
1. Frontal Bone: Includes frontal sinuses. One located above each eye.2. Parietal Bones: 1 located on each side of the skull just behind the frontal bone.
Fused at the sagittal sutureMeets the frontal bone at the coronal sutureSlide6
3. Occipital Bone: Joins Parietal Bones along
lambdoidal suture.Forms the back of the skull & the base of the cranium.Contains a large opening (
Foramen Magnum) where the nerve fibers from the brain pass through & enter the vertebral canal to become part of the spinal cord.Occipital Condyles
: Located on each side of the foramen magnum.
Articulate w/ the first vertebra ( Atlas)Slide7
4. Temporal Bones: located on each side of the skull.
Joins parietal bone @ squamosal suture.Forms parts of the sides & base of the cranium.
Inferior margin: an opening (external auditory meatus) that leads to the ear.Mandibular
fossae
articulate with
condyles
of the mandible.Slide8
Below external auditory
meatus are 2 projections.1. Rounded mastoid process- provides an attachment for certain muscles of the neck.2. Styloid
Process- anchors muscles associated with the tongue & pharynx.- Zygomatic Process: projects anteriorly from the temporal bone.
Joins
zygomatic
bone & helps form prominence of the cheek.Slide9
5. Sphenoid Bone- Anterior portion of the cranium.
Composed of a central part & 2 wing like structuresHelps form the base of the cranium, side of the skull, & floors and sides of the orbits.Contains 2
sphenoidal sinusesMidline portion of bone indents to form saddle-shaped Sella
Turcica
( where pituitary gland is located)Slide10
6.
Ethmoid Bone- Located in front of the Sphenoid bone.Consists of 2 masses (1 on each side of the nasal cavity)2 masses are joined horizontally by
cribriform plates(form part of the roof of the nasal cavity)Crista Galli- triangular process located between
cribriform
plates & forms most of the nasal septum.
Superior & Middle Nasal
Concha
-
Project inward from lateral portions of the
ethmoid
bone toward the perpendicular plate.Slide11Slide12Slide13Slide14
Facial SkeletonSlide15Slide16
1. Maxillae- Form the upper jaw.
-Portions of these bones make up the anterior roof of the mouth ( Hard Palate), floors of orbits, & sides and floor of the nasal cavity. - Contain sockets of the upper teeth
-dense connective tissue binds teeth to bony sockets.
During Development the Palatine Process grows & fuses together to form the anterior port of the hard palate.Slide17
2. Palatine Bones- L shaped
Located behind the maxillaeHorizontal portions form the posterior section of the hard palate & floors of the nasal cavity. Perpendicular portions
help form lateral walls of the nasal cavity.Slide18
3. Zygomatic
Bones- form prominences of cheeks below & to the sides of the eyes.Consists of temporal processes which join zygomatic
process and form the zygomatic archSlide19
4. Lacrimal
Bones- Thin scale-like structures located in the medial wall of each orbit.Between the ethmoid bone & maxillaSlide20
5. Nasal Bones- Long, thin, and nearly rectangular.
Lie side by side and fused at the midline where they form the bridge of the nose.Slide21
6. Vomer
Bone- Thin, Flat, & located along the midline within the nasal cavity.Posteriorly joins perpendicular plate of the ethmoid
bone (Together they form the nasal septum)Slide22
7. Inferior Nasal
ConchaeFragile, Scroll-shaped Attached to the lateral walls of the nasal cavitySupport mucous membranes within the nasal cavity.Slide23
8. Mandible- Horseshoe shaped body with a flat portion projecting upward at each end.
Divided into 2 processes:1. Posterior Mandibular Condyle
: Articulate w/ mandibular fossae of temporal bones.2. Anterior
Coronoid
Process: Provides attachments for muscles used in chewing.
Superior Border of Mandible (Alveolar Arch)- Contains hollow sockets that bear the lower teethSlide24