the skull Flashcards
the head is composed of 4 major compartments. Name them
cranial cavity, 2 ears, 2 nasal cavities, oral cavity
Name the 2 transition areas of the head
infratemporal fossa, pterygopalatine fossa
The head area stops at which 2 bones?
the mandibular bone and the superior nuchal line
Name 4 structures that are common to the head and neck
CNS, Vessels, muscles that are in the neck and attach to the skull, the upper portion of the digestive and respiratory system
How many bones are in the skull?
22 excluding the stapes, malleus, incus
Name the only mobile joint of the skull
temporomandibular joint
The immobile joints are called?
Sutures
Name the associated bones ?
Auditory ossicles, hyoid bone
The bones of the cranium are?
occipital, parietal, frontal, temporal, sphenoid, ethmoid
The bones of the face are?
Maxillae, palatine (between the maxilla and the sphenoid bone), nasal, inferior nasal conchae, zygomatic, lacrimal, mandible, vomer (connects to zygomatic)
The skull contains?
brain, sensory organs, cranial part of digestive tract and respiratory tract
the skull can be divided into ?
neurocranium and the viscerocranium/splanchnocranium
The neurocranium is?
the upper domed part, the Calvaria or vault, and base ( the floor of the cranial cavity)
the viscerocranium is made of?
facial bones, protects and supports digestive and respiratory tract
Describe the structure of the bones of the skull
have a diploe(spongy substance) in between 2 plates of compact bone (lamina externa, lamina interna/vitrea)
What are the pneumatic bones?
they are bones that have cavities inside them. The frontal, sphenoid, ethmoid, maxilla
Name the bones that form the calvaria?
paired temporal + parietal, unpaired occipital, frontal, sphenoid
Name the bones that form the (cranial) base?
parts of the sphenoid, temporal, occipital
Name the bones forming the facial skeleton
Paired nasal bones, zygomatic bones, palatine bones, lacrimal bones, maxillae, Inferior nasal conchae
Unpaired vomer
Describe the hyoid bone
does not articulate with another bone, Anchored by narrow stylohyoid ligaments to styloid process of temporal bone
Name the different skull joints and an example of each
- Sutures (fibrous joints): cranial bones
- Synchondroses (cartilaginous joints
:Petro-occipitalis, Spheno-petrosa - Gomphosis (fibrous joints): teeth
- Condylar (synovial) : temporo-mandibular, atlanto-occipital
the neurocranium is divided into 2 portions. Name them
Membranous part: made of flat bones which surround the vault. Cartilaginous part: makes base of the skull
Detail the membranous neurocranium
it is derived from neural crest cells and paraxial mesoderm, these undergo membranous ossification, the resulting bones have needle like Spicules,
what are fontanelles?
are areas in the calvaria, in between bones, where exposed membranes are large
why are the fontanelles important?
allow for stretching and deformation of the neurocranium to accomodate the brain growth, and helps during delivery
name the fontanelles and when they close?
- The posterior fontanelle generally closes 2 to 3 months after birth;
- The sphenoidal fontanelle is the next to close around 6 months after birth;
- The mastoid fontanelle closes next from 6 to 18 months after birth; and
- The anterior fontanelle is generally the last to close between 18–24 months.
Detail the bulging fontanelles illness
crying, coughing, vomiting,
increased intracranial pressure: Hydrocephalus, meningitis, encephalitis, hypoxic-ishemic injury, intracranial hemorrhage
detail the sunken fontanelle cause?
decreased intracranial pressure and dehydration
large fontanelles or delayed closure of fontanelles can be caused by?
Congenital hypothyroidism, Trisomy 21, Rickets, Achondroplasia, Incresed intracranial pressure
Name the sutures
coronal (frontal-parietal), sagittal (parietal-parietal), squamous (parietal-temporal), lambdoid(parietal-occipital)
name the junctions
lambda (parietal-occipital), bregma (frontal-parietal), pterion (frontal-parietal-temporal-sphenoid), asterion (temporal-occipital-parietal), nasion (frontal-nasal), inion(edge of the occipital)
describe the frontal bone
• Upper rim, medial rim, lateral rim and roof of the orbit . • The frontal bone articulates the parietal, nasal, ethmoid, maxillary, and zygomatic bones. •
– Squama: flat portion that forms the forehead
– Superciliary arch: slight elevations – Glabella: in between arches – Supraorbital foramen (notch): blood vessels and nerves – Zygomatic process – Frontal sinuses: hollow spaces behind the squama, act as sound chambers to give the voice resonance
when looking at the frontal bone from the floor of the orbital cavity we can see ?
ethmoid notch, trochlear region, aperture of frontal sinus
describe the nasal bones
are small paired bones, and hey join with the nasion (frontal bones) and the frontal process of the maxilla
describe the zygomatic bones?
Temporal process (zygomatic arch with zygomatic process of temporal bone) • Frontal process (lateral rim of the orbit): articulates with frontal and sphenoid • Maxillary process: articulates with maxilla • Orbital surface
describe the maxillae?
alveolar process (maxillary arch) hold the upper teeth, it attaches to zygomatic bones, forms the boundrary of the roof of the mouth + floor/lateral wall of nasal cavity + wall of orbit, helps the formation of the 2 fossae and te 2 fissures (inferior orbital and pterygomaxillary), has the infraorbital foramen (from the infraorbital groove),
the largest sinus is the?
maxillary sinus, 3.3 cm long + 2.6cm wide + 3.4 cm anteroposterior
what is the mamillare tuberosity/ tuberosity of maxilla?
A protrusion of bone known as the maxillary tuberosity is the most posterior portion of the maxillary alveolar process.
what is the intermaxillary suture?
is a cranial suture which is located immediately underneath the anterior nasal spine in the middle of the right and left maxillary bones.It is the fixed joint in the middle of the two palatine processes of the maxilla
name the components of the mandible from the lateral outer view
condylar process, ramus, angle, inferior border, body, mental foramen, oblique line, anterior border, superior border
name the components of the mandible from the lateral inside view
head and neck of the condylar process, ramus, angle, rough area for attachment of medial pterygoid muscle, mylohyoid line, mylohyoid groove, lingula, mandibular foramen, coronoid process, mandibular notch
list the movements that the mandible can do
protrusion, retraction, elevation, depression
TMJ dislocation can occur by?
excessive contraction of lateral pterygoids
in the lateral portion of the calvaria we can see
?
frontal, temporal, parietal, sphenoid, occipital
from the lateral view we can see ? of the facial skeleton
nasal, maxillary, zygomatic
the temporal bone can be divided into?
squamous part, petromastoid, tympanic, styloid
the superficial temporal artery is imp because?
it may be injured during fractures of the zygomatic arch
name the distinctions of the parietal bones on the outer surface
occipital border, occipital angle (above), mastoid angle (below), parietal foramen, sagittal border, frontal angle, frontal border, sphenoidal angle, squamosal border. the sternal surface, parietal tuber, superior and inferior temporal line
name the distinctions of the parietal bones on the inner surface
galea aponeurotica, fossa temporalis, sulcus for the meningeal artery and the sigmoid sinus
the weakest point of the skull is?
the pterion
the external carotid artery divided behind the neck into the superficial temporal and the maxillary artery. This supplies the?
the scalp, face (facial artery), maxilla (maxillary artery), tongue (lingual artery), thyroid gland (superior thyroid artery)
detail the posterior inferior view of the occipital bone
squama, highest nuchal line, superior/inferior nuchal line, mastoid margin, condyloid fossa, jugular process, occipital condyle, lateral part, basilar part, foramen magnum, hypoglossal canal, external occipital crest, lambdoidal margin, external occipital protuberance(inion)
what’s the relation between the occipital bone and muscles of the neck?
the bone has an area called constrictor pharynges superior, onto which the stylopharyngeus attaches
detail the structures seen on the inner surface of the occipital bone
sulcus for sub. sagittal sinus, sulcus for transverse sinus, internal occipital protuberance, internal occipital crest, jugular process, sulcus for sigmoid sinus, jugular tubercle, occipital condyle, cerebellar fossa, cruciform eminence, cerebral fossa
