The Skull Flashcards
What type of joint is in the skull, with the sutures?
Fibrous
How many bones are joined by sutures in the skull?
22
Cavities of the skull: (6)
Cranial
Orbits
Nasal
Oral
Ears
Paranasal sinuses
What are holes where nerves and blood vessels pass?
Foramina
Which bones directly contribute to the formation of the brain case?
Cranial bones
Which cranial bones are paired bones?
Parietal and temporal
Which cranial bones are unpaired?
Frontal
Sphenoid
Ethan oil
Occipital
Cranial bones
Frontal (1) Sphenoid (1) Ethmoid (1) Occipital (1) Parietal (2) Temporal (2)
Bones which form a foundation of the face and jaw, but do not contribute to the brain case
Facial bones
Which facial bones are paired?
Nasal
Maxillary
Zygomatic
Lacrimal
Palatine
Inferior nasal conchae
Unpaired facial bones:
Mandible
Vomer
Which bone forms the skeleton of the forehead? What does it articulate with?
Frontal bone
Nasal and zygomatic bones
What bone forms the roof of the orbit and floor of the anterior part of the cranial cavity?
Frontal bone
What is the intersection of the frontal and nasal bones?
Nasion
Supra orbital parts to the frontal bone
Supra-orbital margin
Supraorbital foramen (or notch)
What is the ridge in the frontal bone that is superior to the supraorbital margin?
Superciliary arch
The smooth area between the superciliary arches
Glabella
What bones form the prominences of the cheeks, lie on the inferolateral sides of the orbits and rest on the maxillae?
Zygomatic bones
A small _____ _____ pierces the lateral aspect of each zygomatic bone
Zygomaticofacial foramen
Paired nasal bones articulate with each other in the ______, and with the ______ bone superiorly.
Midline
Frontal
What is the anterior nasal opening of the cranium?
Piriform aperture
What can be observed, dividing the nasal cavity into right and left parts?
Nasal septum
What is paired conchae, visible through the nasal aperture
Inferior nasal conchae
Maxillae form the ____ ____ and are united at the ______ _____ in the median plane
Upper jaw
Intermaxillary suture
What part of the maxillae supports bone for the maxillary teeth?
Alveolar processes
The maxillae has connection with the _____ bones laterally and have an _____-_____ foramen inferior to each orbit
Zygomatic
Infra-orbital foramen
U-shaped bone forming the lower jaw.
Mandible
The mandible has an ______ _____ supporting the ____ ___.
Alveolar process
Lower teeth
Parts of the mandible
Body
Ramus
Condyle
Coronoid Process
Angle
Mental foramen
Mandibular foramen
Mandibular symphysis
Oblique line
Horizontal portion of the mandible- forms the chin
Body
Vertical extension of the mandibular body on either side.
Ramus
Articulation point of the mandible with the mandibular fossa of the temporal bone.
Condyle
Anterior portion of the ramus (of the mandible)- site of muscle attachment
Coronoid process
Posterior point of the mandible at which the ramus meets the body.
Angle
Where is the mental foramen located?
In the mandible between the 1st and 2nd premolars
Where is the mandibular foramen located?
On the medial aspect of the mandibular ramus
What is the purpose of the mandibular foramen?
Permits passage of the nerve involved with tooth sensation
What is the region where the two halves of the mandible fuse?
Mandibular symphysis
Where does the oblique line pass?
From inferior of the ramus onto the body of mandible
Lateral aspect of the cranium, AKA:
Norma Lateralis
The lateral aspect of the cranium is formed by both the ______ and the _____.
Neurocranium
Viscerocranium
Where is most of the temporalis muscle Located?
Temporal fossa
What are the temporal fossa boundaries?
Superior and posterior: Superior and inferior temporal lines
Anterior: Frontal and zygomatic bones
Inferior: Zygomatic arch
The zygomatic arch is formed by the union of what?
The temporal process of the zygomatic bone and the zygomatic process of the temporal bone
Parts of the temporal bone
Squamous
Zygomatic process
Tympanic part
Mastoid process
External acoustic foramen
Styloid process
What is the Squamous part of the temporal bone? What does it articulate with?
A large flat plate articulating with greater wing of the sphenoid anteriorly, and with a parietal bone superiorly.
What is the anterior bony projection from the squamous part of the temporal bone?
Zygomatic process
What does the zygomatic process articulate with?
The temporal process of the zygomatic bone to form the zygomatic arch
Where is the tympanic part of the temporal bone located?
Below the origin of the zygomatic process
Where does the mastoid process of the temporal bone lie?
Posteroinferior to the external acoustic meatus
The external acoustic foramen is the entrance to the _____ _____ ____ (__ __), which leads to the ___ ____ (____)
External acoustic meatus (ear canal)
Tympanic membrane (eardrum)
What is the slender projection of bone in the temporal bone, that lies anteromedial to the mastoid process
Styloid process
What suture joins the frontal and parietal bones?
Coronal suture
What suture joins the parietal and occipital bones?
Lambdoid suture
An H-shaped formation of sutures that unite the frontal, parietal, sphenoid (greater wing), and temporal bones.
Pterion
The pterion bone is thin and overlies what?
The anterior division of the middle meningeal artery
Occipital aspect of the cranium, AKA:
Norma occipitalis
What is the Norma occipitalis formed by?
Occipital bone, parts of the parietal bones, and parts of mastoid of the temporal bone
Elevation in the median plan of the norma occipitalis
External occipital protuberance (EOP)
What extends laterally from each side of the EOP?
Superior nuchal line and inferior nuchal line (less distinct)
What is the lambda of the norma occipitalis formed by?
The intersection of the Sagittal and lambdoid sutures
Superior aspect of the cranium, AKA:
Norma vericalis
The norma vericalis broadens ______ and the _____ ____
Posterolateral
Parietal eminences
What suture unites the frontal and parietal bones?
Coronal suture
What suture unites the right and left parietal bones
Sagittal suture
What suture unites the occipital bone with the right and left parietal and temporal bones?
Lambdoid suture
What is the landmark formed by the intersection of the Sagittal and coronal sutures?
Bregma
What is the vertex?
The superior part of the cranium, near the midpoint of the Sagittal suture
The alveolar arch of the maxillae surround and support the _____ _____.
Maxillary teeth
What forms the hard palate anteriorly?
Posteriorly?
Anteriorly- palatine process of the maxillae
Posteriorly- Horizontal plates of the palatine bones
What are the three foramina open on the oral aspect of the hard palate?
Incisive fossa
Lesser palatine foramen
Greater palatine foramen
Where is the incisive fossa located?
Posterior to the central incisor
Where is the lesser palatine located?
On the posterolateral part of the hard palate
Where is the greater palatine foramen located?
On the posterolateral part of the hard palate, posterior to the lesser palatine foreamen
What is the thin flat bone that forms a part of the bone nasal septum?
Vomer
Choanae, AKA:
Posterior nasal apertures
What separates the choanae from each other?
The vomer
Where is the sphenoid bone located?
Between the frontal, temporal, and occipital bones.
What are the three pairs of processes of the sphenoid bone?
Greater wing of sphenoid bone
Lesser wing of sphenoid bone
Pterygoid process
The pterygoid processes extend _______ on each side of the _____ from the:
Inferiorly
Sphenoid
Junction of the body and greater wings
The pterygoid processes constitute of :
Medial and lateral pterygoid plates
Where is the pharyngotympanic (auditory) tube located?
Medial to the spine of the sphenoid, inferior to the junction of the greater wing of the sphenoid and the petrous part of the temporal bone
_______ foassae, depressions in the ____________ accommodate the heads of the mandible
Mandibular fossa
Squamous part of the temporal bone
Where is the foreamen magnum located?
Within the occipital bone
How does the cranium articulate with the vertebral column?
With occipital condyles
What is the large opening between the occipital bone and the petrous part of the temporal bone
Jugular foramen
The carotid canal is anterior to the:
Jugular foramen
Where is the stylomastoid foramen located?
Between the styloid and mastoid processes
What are the three depressions in the internal surface of the cranial base?
Anterior cranial fossa
Middle cranial fossa
Posterior cranial fossa
What is the anterior cranial fossa formed by?
Anteriorly- frontal bone
Centrally- ethmoid bone
Posteriorly- body and lesser wings of the sphenoid
What are the features of the anterior cranial fossa?
Orbital plates of the frontal bone (forms roof of the orbits)
Frontal crest (median bony extension of the frontal bone)
Crista Galli (median ridge of bone that projects superiorly from the ethmoid)
Cribriform plate of the ethmoid (each side of the cristal galli)
The middle cranial fossa is ______-shapes. It is formed By:
Butterfly
The greater wings of the sphenoid, squamous parts of the temporal bones laterally, and petrous parts of the temporal bones posteriorly
Features of the middle cranial fossa (8)
Sella turcica
Superior border of the petrous part of the temporal bones
Sphenoidal crests
Foramen lacerum
Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen spinosum
The sells turcica, on the body of the _____ is surrounded by:
Sphenoid
The anterior and posterior clinoid processes
What does the superior border of the petrous part of the temporal bones form?
The lateral boundaries between the middle and posterior cranial fossa
What are the sharp posterior margins of the lesser wings of the sphenoid bones?
Sphenoidal crests
The sphenoidal crests end ________ by forming:
Medially
Anterior clinoid processes
The foramen lacerum lies where?
Posterolateral to the hypophyseal fossa
What is the opening between the greater and lesser wings that communicates with the orbit?
Superior orbital fissure
What is the circular foramen located posterior to the medial end of the superior orbital fissure?
Foramen rotundum
What is the oval foramen located posterolateral to the foramen rotundum?
Foramen ovale
Where is the foramen spinosum located?
Posterolateral to the foramen ovale
What is the largest and deepest of the cranial fossae?
Posterior cranial fossa
A marked incline behind the sella turcica which leads to the foramen magnum
Clivus
What are the features of the posterior cranial fossa? (5)
Clivus
Internal occipital crest
Transverse and sigmoid sinuses
Internal acoustic meatus
Hypoglossal canals
The internal occipital crest begins posterior to the ____ _____ and end superiorly in the _____ ____ ____.
It divides the posterior part of the fossae into:
Foramen magnum
Internal occipital protuberance
Two cerebellum fossae
Transverse and sigmoid sinuses form ___ ____ that continues with the ______ _____.
Broad grooves
Jugular foramen
Where is the internal acoustic meatus located?
Anterosuperior to the jugular foramen
The hypoglossal canals lie where?
Superior to the anterolateral margin of the foramen magnum
What are the auditory ossicles?
Malleus
Incus
Stapes
What is the purpose of the auditory ossicles?
To form a mobile chain of small bones across the tympanic cavity from the tympanic membrane to the oval window
The malleus is attached to the _____ ____. It has ___, ___, and _____.
Tympanic membrane
Head, neck, and handle
(The head of the malleus articulates with the incus)
Where is the incus located? What is the purpose?
Between the malleus and the stapes and articulates with them
The ______ is the smallest ossicles. It attaches to:
Stapes
Margins of the oval window
The hyoid bone is _______-shapes with a ___ and two pairs of ______
Horseshoe
Body
Horns (or cornua)
What is the location of the hyoid bone?
In the anterior midline of the neck between the chin and the thyroid cartilage at the level of the C3 vertebra
Purpose of hyoid bone?
Does not articulate with any other bone
Functionally serves as an attachment for anterior neck muscles to keep airway open
3 parts of the hyoid bone:
Body
Greater horn
Lesser horn
The body is the _____ part of the hyped bone. It has an ______ ____ surface and a _____ ______ surface
Central
Anterior convex
Concave posterior
The greater horn of the hyoid projects from each end of the body in a ______, ______ and ______ direction. It acts as:
Posterior, superior and lateral
A site of attachment for numerous neck muscles
The lesser horn of the hyoid bone arises from the _____ aspect of the bone, near the:
It projects:
Superior
Origin of the greater horn
Superoposteriorly (toward the styloid process of the temporal bone)
Where does the stylohyoid ligament attach?
To the apex of the lesser horn
What is the highest point of the skull?
Vertex
What is the junction of the greater wing of the sphenoid bone, the squamous portion of the temporal bone, the frontal bone and the parietal bone?
Pterion
Where is the lambda located?
Where the Lambdoidal and Sagittal sutures meet
What is the bregma?
The union of the coronal and Sagittal sutures
What is the Glabella?
The most anterior part of the forehead
Formed by the junction of the inferior frontal bone and the root of the nose
What is the most prominent point of the external occipital protuberance?
Union
The Nasion is marked by:
The union of the frontonasal and internasal sutures
Foramen in the anterior cranial fossa
Cribiform foramina in cribiform plate
Anterior and posterior ethmoidal foramina
What are the contents of the cribiform foramina
Olfactory nerves (CNI)
Contents of the ant. And post ethmoidal foramina
Vessels and nerves with same nerves as foramina
Foramina in the middle cranial fossa
Optic canals
Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen spinosum
Foramen lacerum
Groove or hiatus of greater petrousal nerve
Contents of the optic canals
Optic nerves (CN II) and ophthalmic arteries
Contents of the superior orbital fissure
Ophthalmic veins; ophthalmic nerve (CN V2)
CN II, IV and VI
Sympathetic fibers
Contents of the foreamen rotundum
Maxillary nerve (CN V2)
Contents of the foramen ovale
Mandibular nerve (CN V3) and accessory menindeal artery
Contents of the foramen spinosum
Middle meningeal artery and vein and meningeal branch of CN V3
Contents of the groove/hiatus of the greater personal nerve
Greater petrosal nerve and petrosal branch of middle meningeal artery
Foramina in the posterior cranial fossa
Foramen magnum
Jugular foramen
Hypoglossal canal
Stylomastoid foramen
Contents of the foramen magnum
Medulla and meninges
Vertebral arteries
CN XI
Contents of the jugular foramen
CN IX, X, and XI
Inferior petrosal and sigmoid sinuses
Contents of the hypoglossal canal
Hypoglossal nerve (CN XII)
Contents of the stylomastoid foramen
Facial nerve (VII)