RA 1 Chap 2 Flashcards
The skull functions as the skeleton of the head and composed of 2 sections: cranium (8) and face (14) bones.
The head is the skull with the fleshy parts added. The skull is the bony framework of the head.
Purpose of Skull
Protect the brain
Support the jaws
Serve as an attachment for muscles
Give form to the head
The geometric form of the skull is an oval from a front, side, or top view, there are variations.
Bones of the Cranium: Occipital 1 Parietal 2 Temporal 2 Frontal 1 Ethmoid 1 Sphenoid 1
Male Skull Size - Relatively large Frontonasal angle - Sharp angular Supraorbital ridges - Prominent Forehead - Slopes backward Surface cheekbone - Rough concave Mandible tip (chin) - Squarer Foramen magnum - Large long Mastoid processes - Large
Female Skull Size - Relatively small Frontonasal angle - Smooth curve Supraorbital ridges - Poorly developed Forehead - Nearly vertical Surface cheekbone - Smooth flat Mandible tip (chin) - Pointed Foramen magnum - Small round Mastoid processes - Small
Surface Bones of the Head (6/8)
Frontal Occipital Parietal 2 Temporal 2 Ethmoid - non surface Sphenoid - non surface
Anterior 1/3 of cranium forming the forehead, part of eye socket. Most of the anterior of the cranial floor.
Frontal
Comprised of 2 planes vertical (make up the forehead) and horizontal/crown (make up superior part of the cranium.
Frontal
Frontal Bone Eminences RA significance
Frontal Eminences (2) Supraorbital Margin (2) Superciliary arches (2) Glabella (1)
Rounded prominences on either side of the median line and a little inferior to the center of the frontal bone.
Frontal Eminences (2)
Warm-color area of the face, appears asymmetry
Frontal Eminences (2)
Superior rim of the eye socket (behind eye brows)
Supraorbital Margin (2)
Inferior part of the forehead just Superior to the medial ends of the eyebrows.
Superciliary arches (2)
Elevation located between the superciliary arches on the Inferior part of the frontal bone immediately above the root of the nose.
Glabella (1)
Point at which the two nasal bones touch the frontal bone that is inferior to the glabella.
Root
Frontal bone Articulates with
Parietal bones at the Coronal Suture
The lowest most posterior part of the back and base of the cranium that acts as a Cradle for the brain.
Occipital
Occipital Bone Eminences RA significance
Occipital Protuberance
Foramen Magnum
Opening in the occipital bone through which the spinal cord, spinal arteries, and nerves pass
Foramen Magnum
Located between 2 Mastoid Processes and assist in securing the head to the body in a decapitation death
Foramen Magnum
the prominence at the center of the external surface of the occipital bone.
Occipital protuberance
Occipital bone Articulates with
Parietal bone at Lambdiodal Suture
Temporal bone at the Squamosal Suture
Forms superior portion of the sides and back of the cranium and posterior 2/3 of roof of cranium
Parietal
Parietal Bone Eminences RA significance
Parietal eminence
Vertex
Crown
Marked convex on the outer surfaces of the parietal bones. Widest part of the cranium.
Parietal eminence
Highest part of the cranium
Vertex
Area at the top/above of the cranium delineated by connecting four points together.
Crown
Where the king’s crown would rest on the 2 frontal eminences & 2 parietal eminences
Four Points
Parietal bone Articulates with
Occipital bone at Lambdiodal Suture
Temporal bone at the Squamosal Suture
Frontal bone at Coronal Suture
Opposite side parietal at Sagittal Suture
Inferior portion of the sides and base of the cranium located inferior to parietal bones and anterior to occipital bone
Temporal
Parietal Bone Eminences RA significance
Squama Zygomatic arch (2) Mandibular fossa (2) External auditory meatus (2) Mastoid process (2)
like fish scale its the thin superior part of the temporal bone
Squama
Its immediately lateral (outside) the Squama and house the Temporalis muscle. In elderly emaciate case atrophy and dehydrate cause it to shrink as sunken temples and require tissue builder only after consulting a photograph
Temporal Cavity
long thin arched process extending anteriorly from the squama to the zygomatic bone.
Zygomatic Arch (2)
Lies above the external auditory meatus and divides the length of the ear in half. Widest part of face
Zygomatic Arch (2)
Small oval depression or socket on the underside of the temporal bone where Condyle of the Mandible articulates in this depression.
Mandibular fossa (2)
Lies anterior to the external auditory meatus
Mandibular fossa (2)
Opening of the ear passage located in front of the mastoid process
External Auditory Meatus (2)
Rounded projection of the interior portion of temporal bone just media to the lobe of the ear.
Mastoid Process (2)
attaches to the mastoid process and the widest part of the neck measured by a straight line extending between the midpoint of the bellies of these 2 muscles
Sternocleidomastid Muscles
2 non-surface bones of the head
Ethmoid
Sphenoid
horizontal plate that forms the roof of the nasal cavity and closes the anterior part of the base of the cranium.
Ethmoid
located at the anterior part of the base of the skull and binds the other cranial bones together
Sphenoid
Temporal bone Articulates with
Parietal bone at Squamosa Suture
Occipital bone at Lambdoidal Suture
Greater wing of the Sphenoid bone
Surface bones of the Face
Nasal (2)
Zygomatic (2)
Maxilla (2)
Mandible
Lies directly inferior to the glabella and form the bridge of the nose and dome over the superior portion of the nasal cavity
Nasal
Nasal Bone Eminences RA significance
Nasal Cavity
orifice/opening in the face bounded by the margins of the nasal bones and the maxilla.
Nasal Cavity
made of 2 irregular-shaped spaces separated by a cartilage that makes up small part of the septum.
Nasal Cavity
Used as a hidden injection point for tissue building the face
Nasal Cavity
Nasal bone Articulates with
Each other forming bridge of nose
Frontal bone forming root of nose
Diamond shaped bones that form the cheekbones
Zygomatic (2)
located on the frontal and lateral planes of the face and form part of the inferior and lateral surfaces of the orbital cavity
Zygomatic (2)
Zygomatic Bone Eminences RA significance
widest part of the anterior plane of the face that measured by a straight line from midpoint of zygomatic bone to midpoint of opposite zygomatic bone. Acts as Area for Rouge Cosmetics
Zygomatic bone Articulates with
Temporal process of Zygomatic
Zygomatic Arch
(3 primary ossification centers which grow together to form the arch which completely fused it has 3 parts from anterior to posterior 1. Zygomatic bone 2. Temporal Process of Zygomatic 3. Zygomatic Process of Temporal that completes the arch attaching to the Temporal bone)
bones of the upper jaw
Maxilla (2)
form the skeleton base for most of the superior portion of the face, anterior roof of mouth, sides and floor of nasal cavity, and floor of orbits
Maxilla (2)
Maxilla Bone Eminences RA significance
Frontal Eminences/processes Alveolar process Palatine process Zygomatic process Dental prognathism (Buck teeth)
the ascending part of upper jaw that gradually protrudes as it rises beside the nasal bone to meet the frontal bone
frontal processes of maxilla -
ridge of thick spongy bone surrounding the alveoli of the teeth
Alveolar process
forms anterior part of the hard palate of the mouth, nasal cavity, orbital cavity
Palatine process
where temporal bone joins the zygomatic bone
Zygomatic process
where 2 maxilla meet and form sharp bony process and creates the inferior border of the nasal skeleton
Nasal spine
Maxilla bone Articulates with
Each other at midline forming the nasal spine (small bony process)
horseshoe shaped bone forming the lower jaw. consist of the body and ramus
Mandible
curve shaped horizontal lowest part of lower jaw that contains alveolar processes for the teeth
Body
vertical portion of mandible that wide flat and quadrilateral in shape
Ramus
Mandible Bone Eminences RA significance
Mental eminence Incisive fossa Coronoid process Condyle Angle of the mandible Bimandibular Width
triangular projection on the inferior of the anterior mandible
Mental eminence
area between the mental eminence and the inferior incisor teeth
Incisive fossa
thin flattened process projecting from the anterior portion of the upper border of the ramus.
Coronoid process
serves as the insertion of the Temporalis muscle of mastication (chewing) from the temporal cavity above which may need injections of tissue builder
Coronoid process
rounded eminence at the articulating posterior process of the ramus that’s associated with a dislocated jaw.
Condyle
angle formed by the junction of the posterior edge of the ramus and the inferior surfaces of the body of the mandible.
Angle of the mandible
Influences the form of the head from a frontal view
Angle of the mandible
measured by a straight line between the 2 angles of the mandible and is used in photographic analysis for restoration.
Bimandibular Width
compared to the Bizygomatic width and the Biparietal width and length of the head in order to produce, in wax, the correct geometric head shape
Bimandibular Width
Mandible bone Articulates with
Mandibular fossa of temporal bone
3 non-surface bones of face
Vomer
Lacrimal
Palatine
single bone along midline within the nasal cavity that forms part of the septum of the nose
Vomer
thin and bent slightly to one side or the other making the nasal chambers of unequal size
Vomer
2 bones located medial wall of each orbit between ethmoid and maxillary bones that resemble fingernail shape
Lacrimal
2 bones located back part of nasal cavity behind maxillae.
Palatine
help form back part of roof of mouth, part of the floor and outer wall of nasal cavity and very small portion of floor of the orbit
Palatine