Anatomy of skull Flashcards
what is cranial skeleton?
“brain box” or cranial vault 窟窿
what is facial skeleton?
bones that make up everything except the cranial cavity ( include the mandible)
what are single bones?
occupy or cross the midline
what are paired bones?
tend towards being more lateral
what does the cranial bones consist of?
external and internal tables of compact bone, and diploe
what is diploe?
a middle spongy layer, sandwiched between external and internal tables of compact bone
what is the skull covered by /lined by?
periosteum
what is the outer covering layer of the skull called?
pericranium 脑髓
what is the inner layer covering layer of the skull called?
endocranium
what are the bones that bound the cranial cavity?
- Frontal (single)
- ethmoid (single)
- sphenoid( single)
4, occipital (single)
5, temporal (paired) - parietal (paired)
what are immovable joints between most of the bones of the skull called?
sutures
what are the differences of sutures in young adults and the newborn?
sutures in young adults: irregular lines in the skulls
in the newborn: wide open( where the parietal bones meet the frontal and occipital)
what is frontanelles anterior and posterior)
the gaps between parietal bones and the frontal bones and the occipital bones behind 囟门
the intersection at each end of the saggitatal sutures
how does sutures change with age?
closure of the sutures occurs with increasing age
many fuse completely by synostosis
what is synostosis?
frontanelles become continuous bone
骨性联接
what is the shape of fontanelles in an infant?
diamond shaped
due to the fact that there are two frontal bones
what is the metopic suture?
persistent partial or complete frontal suture
额骨缝
what are sutural bones?
circumscribed bony areas
what are lower margins of orbits and upper margins of external acoustic meatuses in the same horizontal plane called?
orbitomeatal plane
听眶面
how is the base of the cranial cavity sloping?
sloping from the above at the front, downwards towards the back
what is the shape of the skull?
ovoid
wider posteriorly than in front
what are the sutures running between the parietal bones called?
the sagittal suture
what are the sutures running between the frontal bone and the two parietal bones?
coronal suture
what are the sutures between the parietal bones and the occipital bone?
lambdoid suture
where is mastoid processes of the temporal bones?
乳突
what is the external occipital protuberance?
the bulge about halfway up the posterior aspect of the occipital bone
枕外隆突
what is the superior nuchal line?
arch laterally from the occipital protuberance
mark the upper limit of the neck as a region
attachment of the sternocleidomastoid and the trapezius (斜方肌)muscles
上颈线
what is squamous temporal?
the flattish part of the temporal bone
what is zygomatic process of the temporal bone
projects forward to meet the zygomatic bone of the cheek
what form the zygomatic arch?
zygomatic process of the temporal
articular surface at the root: head of the mandible
what is mandibular fossa?
articular surface at the root of zygomatic arch with mandible
what is greater wing of the sphenoid bone?
just beneath where the frontal , parietal and squamous temporal bones all come together
sits just behind the orbit
one part of the sphenoid bone
what is role of tubercle of the root of the zygoma?
integrity and stability of the temporomandibular joint (TMJ)
What are anterior and inferior wall of the external acoustic meatus formed?
tympanic part/tympanic plate of the temporal bone
what does the mastoid part of the temporal bone have?
numerous air cells that communicate with the middle ear by mastoid antrum
what are several parts of temporal bone?
squamous
mastoid
styloid
tympanic
where is lesser wing , body and Pterygoid processes of sphenoid?
蝶骨突
what is the top part of skull called?
calvaria 颅盖
what is the petrous temporal?
solid-looking pyramidal-shaped projection of the temporal bone
most posterior part of the middle cranial fossa
chunky-looking part of the temporal bone
what lobes does the anterior cranial fossa contain?
frontal lobes of the cerebral hemispheres
what is the floor of anterior cranial fossa composed of?
- ethmoid (situated in the midline)
- frontal
- spheoid
what is the crista galli of the ethmoid?
small crest projecting upwards
on either side
what is cribriform plates of the ethmoid?
perforated
olfactory nerves (CN1) pass through
on either side of the crista galli
where is orbital plates of the frontal bone?
on either side of the ethmoid
form the roof of each orbit
in front of lesser wings of the sphenoid
sphenoidal air sinus between them
what is the middle cranial fossa formed?
by the body of the sphnoid
what is the saddle shaped recess called?
sella turcica
has four projections
what lies in sella turcica?
pituitary gland/ hypophysisi cerebri
what are the anterior clinoid processes?
anterior two processes pointing backwards over the recess
compare anterior and posterior clinoid processes?
anterior clinoid processes are wider apart than the posterior clinoid processes
describe anterior clinoid processes’ location
anterior clinoid processes project backwards from the lesser wings of the sphenoid chiasmatic groove (for optic chiasma) running transversely between the optic canals beneath the anterior clinoid processes
what is sella turcica also called?
hyperphysical fossa
what are lateral parts of the middle cranial fossa formed?
great wing of the sphenoid in front and squamous part of temporal bone behind
what are lodged in the middle cranial fossa?
temporal lobes of the cerebral hemispheres
what are lodged in posterior cranial fossa?
hindbrain: cerebellum, pons, medulla oblongata
what is posterior cranial fossa formed?
sphenoid
temporal
parietal
occipital bones
what is the clivus?
the sloping bony surface
made up from two bones that join around puberty or late teens
lower part formed by occipital bone
upper part formed by the body of the sphenoid
what flank foramen magnum on either side?
the occipital condyles
what does occipital condyle articulate with?
C1 Vertebra, the atlas
allow a nodding action
where does nodding occur?
atlanto-occipital joints
where does axial rotation occur?
at the C1/C2 joint
where is foramen magnum entirely within?
occipital bone
what is basilar part of the occipital bone?
the part of occipital bone anterior to the foramen magnum
rather solid-looking area
extends forward to meet the sphenoid bones
central part of the interior aspect of the skull
pharynx “hanging” from the pharyngeal tubercle
what bones can you see from the inferior aspect of the skull?
occipital
temporal bone
sphenoid bones
where are two pterygoid processes?
interior aspect of the sphenoid
project downwards
what does each pterygoid processes consist of?
two plates:
1. larger lateral plate
2, smaller medial plate
where is pterygoid fossa?
area between the plates on each pterygoid process
where is pterygoid fossa?
area between the plates on each pterygoid process
an important site of muscle attachment
what is the pterygoid hamulus?
from the inferior end of the medial pterygoid plate extends a hook-like projection
acts as a fulcrum or pulley for muscles that tense the soft palate
how does facial skeleton project?
downwards and forwards from the under-surface of the cranial part of the skull
rest on the occipital bone behind
teeth or alveolar margin of the maxillae in front
what are orbits?
two bony cavities where the eyes are situated
what is the axis of each orbit?
45 degrees laterally
how is the superior orbital margin formed?
by the frontal bone
what is supraorbital notch?
bridge over to from a foramen
what is superciliary arch?
prominent ridge of bond arching over the superior orbital margin
where is the orbital plate of the frontal bone?
at the superior orbital margin
frontal bone turns sharply backwards
what forms the greater part of the roof of the orbit?
orbital plate of the frontal bone
how is lateral orbital margin formed?
by frontal and zygomatic bones
what are the zygomatic process of the frontal and the frontal process of the zygomatic bone?
projections from each of those two bones that meet to form the lateral orbital margin
how is interior orbital margin formed?
by zygomatic bones and the maxilla
where is infraorbital foramen?
in the maxilla
just below the inferior orbital margin
how is medial orbital margin formed?
by frontal, lacrimal and maxilla
the roof of the orbit is?
orbital plate of the frontal
lesser wing of the sphenoid behind it
the roof of the orbit is?
orbital plate of the frontal
lesser wing of the sphenoid behind it
how many roots does the lesser wing of the sphenoid have at its origin?
two
what is the gap between the lesser wing of the sphenoid called?
optic canal
transmit the optic nerve and retinal artery
what is the floor of the orbit?
superior surface of the maxilla
part of the zygoma and
palatine bone
what does lateral wall of the orbit comprise?
part of the zygoma
greater wing of the sphenoid
frontal bone forms a small part
how is the medial wall of the orbit?
the thinnest wall of the orbit
almost parallel to the median plane
what are main bones forming the medial wall of the orbit?
ethmoid
lacrimal
frontal bones
how is the lacrimal sac formed by?
lacrimal bone and part of the maxilla
how is large gap in the orbit formed?
the large gap forms a diagonal or curved lien running from the apex of the orbit downwards
running laterally to the lower lateral side of the orbit
gap continuous into the orbit
open into two different area behind and below the gap
where does the superior orbital fissure open?
posteriorly into the middle cranial fossa
beneath the lesser wing of the sphenoid
lateral to the optic canal
where does the inferior orbital fissure open?
infratemporal fossa behind and below into the area deep to the zygomatic arch below the sphenoid below the maxilla lateral to the pterygoid plates
what is sphenopalatine fossa?
slit like recess
between the back of the maxilla and the pterygoid process of the sphenoid
what are three processes on zygoma?
frontal
temporal
maxxilary
where does palatine process of the maxilla extend and meet?
extends horizontally to meet its fellow of the opposite side
form the greater part of the skeleton of the hard palate
what is the main hollow body of the maxilla called?
maxillary sinus
where is the infraorbital foramen?
below the orbital rim
what is carried in the infraorbital foramen?
infraorbital nerve and artery
what are three processes of the zygoma?
- frontal
- temporal
- maxillary
what is alveolar process?
rim of the maxilla that carries the teeth of the upper jaw
what are three projections running from the back of the nasal cavity towards the front?
conchae/turbinate bones (part of the ethmoid bone)
- -superior
- -middle
- -inferior
what is the meatus?
recess beneath each turbinate
what are bony palate consisted of?
palatine processes of the maxillae (2)
horizontal plate of the palatine bone (2)
what is mylohyoid line?
roughened, slightly raised ridge on the inside of the body of the mandible
attach main muscle of the floor of the mouth
what is alveolar margin of the mandible?
the part that carries the teeth of the lower jaw
what does the foramen magnum transmit?
medulla before it becomes the spinal cord
two vertebral arteries
anterior spinal artery
spinal roots of the accessory nerve(CN12)
what does the irregular jugular foramen transmit?
internal jugular vein
cranial nerves 9,10,11
where is stylomastoid foramen?
lateral to the jugular foramen
between the mastoid process of the temporal bone and the styloid process
what does stylomastoid foramen transmit?
facial nerve (CN7)
where is carotid canal?
anterior to the jugular foramen
what does carotid canal transmit?
internal carotid artery
where is foramen lacerum?
anterior and medial to the carotid canal
petrous temporal bone meets the sphenoid
what pass through the foramen lacerum?
filed in with cartilage
no major structure passes through
interal caroid artery and some nerves pass across the top
where is foramen rotundum?
behind the superior orbital fissure
lead forwards into the pterygopalatine fossa
where is foramen ovale?
behind and a little lateral to the foramen rotundum
where is the foramen spinosum?
behind foramen ovale
much smaller
what does foramen spinosum transmit?
middle meningeal artery
where is the optic canals?
just above and medial to the superior orbital fissure
what does the optic canal transmit?
optic nerve to the eye (CN2)
what does internal acoustic meatus transmit?
vestibulocochlear nerve (CN8) facial nerve(CN7)