Oesteology Of The Skull Flashcards
Cranium is divided into two:
List them
neurocranium and viscerocranium
Which part of the cranium contains the proximal part of cranial nerves
Neurocranium
Neurocranium is divided into what and what
a dome-like roof called the calvaria (skullcap)
•and a floor or cranial base (basicranium)
How many bones make up the neurocranium and list them
8
frontal -ethmoidal -sphenoidal -occipital 2 temporal 2 parietal
Ethmoid bone is primarily contributing to - and only minorily contributing to -
Viscerocranium
Neurocranium
How many bones are in viscerocranium
How many paired, how many single
List all
15 irregular bones
- 3 single, 6 paired
- zygomatic ;nasal;palatine;lacrimal;vomer;inferior nasal concha;maxilla, mandible;ethmoid
Which bones contributes the greatest to the upper facial skeleton
Maxilla
Mandible, maxilla
Attachement of both
fixed to the cranial base
Temporomandibular joint
Parts of mandible
condyloid process, coronoid process,Ramus, body, gonion
Parts of maxilla
infraorbital foramen, zygomatic process of maxilla, intermaxillary suture,frontal process of maxilla
Parts of frontal bone
vertical squamous part(for eyes. And forehead) , horizontal part(for nose)
Frontal bone articulates with?
-articulates with nasal bone,zygomatic bone, maxilla, sphenoid,parietal ethmoid bone , and lacrimal
Function of Supraorbital notch
for the passage of the supraorbital vessels and nerves
superior to the supraorbital margin is
superciliary arch
Between the superciliary arches is a smooth, slightly depressed area called the
Glabella
anterior most projecting part of the forehead
Glabella
Just above the glabella is
Ophyron
intersection of the frontal and nasal bones is
Nasion
Nasal septum is made up of what ?
Nasal bone
Perpendicular plate of ethmoid bone
Vomer
lateral wall of each nasal cavity has -
Conchae
Origin
Superior concha
Middle concha
Inferior concha
Ethmoid bone
Ethmoid bone
Itself
Another name for concha is?
Turbinate
Location of the mental foramina
Inferior to the second premolar teeth
base of the mandible has a midline swelling called
Mental protuberance
Lateral to the mental protuberance on either side is
Mental tubercle
Zygomatic bone is also know as - and -
Cheek bone
Malar bones
lateral aspect of zygomatic bone is a foramen called
Zygomaticofacial foramen to transmit zygomaticofacial nerve
Injury to superciliary arches can cause?
Black eye
Redness of the zygomatic eminence associated a rise in temperature in various fevers occurring with certain diseases, such as tuberculosis
Malar flush
Superior aspect of the skull is called ?
Calvaria or skull cap
Frontal bone meets parietal bones at - sutures
Parietal bones meet watch other at - sutures
Parietal bones meet occipital bones at - sutures
Coronal sutures
Saggital sutures
Lambdoid suture
junction(intersection) between the coronal and sagittal sutures is called?
Bregma
junction(intersection) between the sagittal suture and lambdoid sutures is called
Lambda
most superior point of the skull
Vertex
Sagittal suture closure begins where
And that space is called?
Suture between the parietal foramen
Obelion
Types of calvaria fractures
Linear fracture
Depressed fracture
Communited fracture
Basilar fracture
- fracture occurs at the point of direct trauma and is the most frequent type
Linea calvaria fracture
- fracture leads to depressed skull
Depressed fracture
- fracture occurs at the opposite point to the point of direct contact
Contrecoup (counterblow) fracture
- fracture leads to bone broken into several pieces
Comminuted fracture
Obliteration of sutures between bones begin at what age on the internal surface and what age on the external surface
Age 30-40
10years after internal starts
Sequential obliteration of sutures from bregma is?
Sagittal, coronal, lambdoid
Union of the mandibular bones start at what age and ends at what age
Point of fusion is called?
1 year old,
Ends by 2nd year
Symphysis menti
Is temporal bone development complete at birth?
No.
Doesn’t have mastoid and styloid process
bones of the calvaria of a newborn infant are separated by
Fontanelles
Types of fontanelles and their orientation
Anterior fontanelle- between frontal and parietal bones; diamond or star shaped
Posterior- between parietal and occipital bone,;triangular
Sphenoid and mastoid : overlain by temporalis muscle
Original insertion of temporalis muscle
O: temporal region
I:coronoid process of the mandible
Anterior fontanelles closes by :
Frontal bone is United by :
Frontal suture is obliterated by:
18 months of age
2nd year of age
8th year of age
Persistent frontal suture is called
Metopic suture
Posterior fontanelle closes by :
First few months- ends by 1st year
Why can babies heads be molded during birth
softness of the cranial bones in infants and their loose connections at the sutures and fontanelles
What permits the cranium to enlarge during infancy and childhood
Fibrous sutures
Period of rapid cranium increase
Period of steady general inncreas
Period of final slow tiny increase
First 2 years of life
15-16 years
18-20 years
Premature closure of the cranial sutures is called
Craniosynostosis
anterior fontanelle is small or absent
When premature closure of the coronal or the lambdoid suture occurs on one side only
Premature closure of the coronal suture
Scaphoceohaly
Plagiocephaly
Oxycephaly or turricephaly
Wedge-shaped cranium
High, tower-like cranium
Scaphocephaly
Oxycephaly or turricephaly
Effect of Premature closure of cranial sutures on brain development
Nothing
Pterion area overlies the-
Middle meninges artery
Parts of temporal bone
Squamous part,zygomatic process, tympanic part,petromastoid part, styloid process,
point where the superior temporal line cuts the coronal suture is called
Stephanion
Suture between
mastoid process and parietal bone
Mastoid process and occipital bone
Parietomastoid suture
Occipitomastoid suture
Junction of parietomastoid suture, occipitomastoid suture, and lambdoid suture is called
Asterion
Along the lambdoid suture are small bones called
Sutural bones or Wormian bones
Distance between superior and inferior nuchal lines
1 inch
Extending downwards from the external occipital protuberance is
External occipital crest
Deepest and most shallow cranial fossa
Posterior cranial fossa
Anterior cranial fossa
What sits in the floor of the cranial fossas
Anterior-frontal lobe
Middle: temporal lobe
Posterior:brain stem at the front,cerebellum at the rest
Located at the midline of the middle cranial fossa is
Hypophyseal fossa that houses the pituitary gland
Canine eminence
prominence on the surface of the superior maxillary bone caused by the socket of the canine tooth.
A depression in the maxilla in which cheek muscles rest
Canine fossa
Canine fossa extends from where to where vertically and horizontally
Vertical: infraorbital margin to alveolar process below
Horizontal: zygomatic-maxillary suture to anterior nasal aperture
Nasal spine is also called?
Akanthion
Alveolar process point is also called
Prosthion
Foraminas in greater wing of sphenoid
Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen spinosum
What passes through
Foramen rotundum
Foramen ovale
Foramen spinosum
Maxillary branch of trigeminal nerve
Mandibular branch of trigeminal nerve
Middle meningeal artery and meningeal branch of mandibular nerve
What passes through superior orbital fissures
CN 3,4,5,6
Occulomotor,trochlear,opthalamic division of trigeminal nerve, and abducens nerve
Opthalamic vein
Optic canal allows passage of what
Opthalamic artery Optic nerve (CN2)
What transmits the olfactory nerve (CN1)
Cribiform plate of ethmoid’s numerous foramina
Contents of foramen magnum
Spinal cord
2 vertebral arteries
Spinal accessory nerve (CN11)
Cribiform plate forms the - of the nose
Roof of the nasal cavity
Crista galli
Extension from the cribiform plate
Hypoglossal canal transmits
Hypoglossal nerve CN12
Mastoid foramen transmits
Mastoid emissary veins
Posterior meningeal artery
Carotid canal transmits
Internal carotid artery
Internal carotid plexus
Jugular fossa transmits
CN 9,10,11
Internal jugular vein
Describe the Frankfurt plane
And it’s also called?
In the anatomical position, the head is oriented in a way that the inferiorbrital margin is alighted with the superior border of the external acoustic meatus
Also called orbitomeatal plane
Boundaries of the anterior cranial fossa
Anteriorly and laterally
Posteriorly and medially
Floor
Frontal bone
Limbus of sphenoid bone
Frontal bone,ethmoid, and wings of lesser sphenoid
Describes the anterior clinoid process Frontal crest Crista galli Cribiform plate Lesser Wings of sphenoid
The rounded ends of the lesser wings
Midline of frontal bone. Attachment for falx cerebri
an upwards projection of etmoid bone, which acts as another point of attachment for the falx cerebri.
either side of the crista galli supports the olfactory bulb and has numerous foramina that transmit vessels and nerves.
Thinnest part of the anterior cranial fossa
Cribiform plate
Consequences of broken cribiform plate
Anosmia:loss of sense of smell
CSF rinorrhea: CSF comes out through the nose
3 major foramina in cranial fossa
Cribiform plate
Anterior ethmoid foramen for anterior ethmoidal VAN
Posterior ethmoidal foramen for posterior ethmoidal VAN
Boundaries of middle cranial fossa
Anteriorly and laterall Anteriorly and medially Posteriorly and laterall Posteriorly and medially Floor
Lesser wings of sphenoid bone Limbus of sphenoid bone Petrous part of temporal bone Dorsum sellae of sphenoid bone Body,greater wing,squamous, and Petrous parts of sphenoid and temporal bones
What forms the sella turica
Tuberculum sellae at the front
Hypophyseal fossa
Dorsum sellae at the back
Origin of anterior clinoid process
Origin of posterior clinoid process
Lesser wings of sphenoid bone
Posterateral part of dorsum sellae
Location of optic canals
Anterior part of Middle cranial fossa,joined together by the chiasmatic sulcus
Location of superior orbital tissue
Immediately lateral to the central part of middle cranial fossa
Foramen rotundum opens into - fossa
Foramen ovale opens into - fossa
Pterygopalatine fossa
Infratemporal fossa
Formainas of the temporal bones are?
hiatus of the greater petrosal nerve transmits the greater petrosal nerve (a branch of the facial nerve), and the petrosal branch of the middle meningeal artery.
Hiatus of the lesser petrosal nerve – transmits the lesser petrosal nerve (a branch of the glossopharyngeal nerve).
Carotid canal – located posteriorly and medially to the foramen ovale. This is traversed by the internal carotid artery, which ascends into the cranium to supply the brain with blood. The deep petrosal nerve also passes through this canal.
Foramen lacerum isfilled with cartilage
Internal acoustic meatus for CN7 and CN8 and labyrinthine artery
Borders of posterior cranial fossa Anterior medial Anterior lateral Posterior Floor
Dorsum sellae of sphenoid
Petrous part of temporal
Occipital
Mastoid of temporal, squamous,condylar,and basilar part of occipital
Foramen in occipital bone
Foramen magnum:vertebral artery, medulla of brain, spinal accessory nerve (ascending), dural veins and anterior and posterior spinal arteries.
Function of clivus
connects the foramen magnum with the dorsum sellae.
Function of sphenoid sinus
lined with cells that make mucus to keep the nose from drying out. Enlarge.
Attachments and function of
Temporalis Masseter SCM posterior belly of digastric muscle Splenius capitis
squamous part of temporal-mastication
Lateral zygomatic of temporal-mastication
Mastoid process-flexing and rotating of head
Mastoid process- for swallowing
Mastoid process for-shaking the head
What passes through Foramen caecum
Emissary veins from nose to superior sagitta sinus
T or F on Foramen Cecum
- Is located in the anterior cranial fossa of the calvaria
- transmits veins involved in spread of infections
- Found in 1% of people
- Is located posterior to the frontal crest
- Is a foramen on the _________ bone of the skull
- transmits veins whose destination is in the inferior sagittal sinus
- Lies posterior to the ethmoid bone
- Is the most anterior of all foramina in the base of the skull
- Contains nasal emissary veins
- Varies in size in different people
- Is frequently impervious
- Lies at the apex of the frontal crest of the frontal bone
- Lies anterior to crista galli of frontal bone
- When opened serves as a connection between extracranium and intracranium
- Provides a passage for veins ONLY
1F 2T 3F 4T 5Frontal 6F 7F 8T 9T 10T 11T 12F 13F 14T 15T
T or F on CRIBRIFORM FORAMINA
- They are small holes located in the anterior cranial fossa
- They are of the ________ bone
- Transmits the first cervical nerve called the olfactory nerve
- Allows passage of nerve cell bodies from the olfactory epithelium of the nose to the intracranium
- Located in the crista galli of ethmoid bone
- Passage of nerves through this hole allows for communication with the olfactory bulb on top of the cribriform plates
- Is located medial to the crista galli
- Is located medial to the frontal bone in the calvarium
1) T
2) ethmoid
3) F
4) F
5) F
6) T
7) F
8) F
T or F on OPTIC CANAL
- Transmits the olfactory artery
- Transmits the supraorbital artery
- Transmits the optic nerve, cervical nerve 1.
- Located in the anterior cranial fossa of calvarium
- Transmits a large ophthalmic artery to the nose
- The first cervical nerve is transmitted through this foramen
- It is located directly lateral to the prechiasmatic groove of sphenoid bone
- Located between the lesser and greater wings of sphenoid
- Transmits sympathetic nerve fibres
- Is intimately related to lesser wing of temporal bone
1) F
2) F
3) F
4) F
5) F
6) F
7) T
8) F
9) T
10) F
Branches of opthalmic division of trigeminal nere
Facial, lacrimal, nasociliary nerve
Branches of the maxillary division of the trigeminal nerve
Infraorbital nerve
Zygomatic nerve
Superior orbital fissure serves as a connection between the ———- and the ——-
Cavernous sinus and apex of orbit
T or F on SUPERIOR ORBITAL FISSURE
- It is located posterior to the middle cranial fossa
- It lies posterior and lateral to the optic canal
- It contains all branches of cranial nerves 3-6
- It contains the superior ophthalmic vein but doesn’t contain the inferior ophthalmic vein
- It is located just directly posterior to the limbus of sphenoid bone
- It contains lacrimal and frontal nerves
- Sympathetic fibres are a content
- The branch of the trigeminal nerve that passes through this fissure is the ophthalmic nerve, V2
- A content is the nasociliary nerve
- Occulomotor, trochlear and ophthalmic nerves are nerves that do not pass through this foramen
- Contains 4 cervical nerves
- Abducens nerve, cranial nerve V1, passes through this fissure
- 2 tributaries to the cavernous sinus are located in it
- It is located on the sphenoid bone only
- It separates the greater and lesser wing of sphenoid.
1) F
2) T
3) F
4) F
5) F
6) T
7) T
8) F
9) T
10) F
11) F
12) T
13) T
14) T
15) T
Zygomatic bones are triangular in shape
T/F
F
What shape is zygomatic bone
Diamond shape
Pneumatization of cranial bones decrease with age.
T/F
F. It increases
What is pneumatization of bones
presence of air spaces within bones
Bones get lighter as they age.
T/F
T
Examples of pneumatized bones?
Frontal
Ethmoidal
Sphenoidal
Temporal
The ascending cervical artery is a small branch which arises from the ——-as it passes behind the——- and runs medial to the ——?
inferior thyroid artery
carotid sheath
Phrenic nerve
