Ch. 1 - Skull Flashcards
What are the two components to the skull?
facial skeleton (viscerocranium) and cranial vault (neurocranium)
How many bones are there in the facial and cranial component of the skull?
14 facial bones, 8 cranial bones
The frontal view of the skull includes every skull bone except…
occipital and palatine bones
Which bone is the only bone not directly attached to the skull?
mandible
Which facial bone is diamond shaped?
zygomatic bone
What is the name of the process located on the maxilla and mandible?
alveolar process (contains the teeth)
What do the foramina located on the skull allow?
passage of nerves
Which bone is responsible for ethnic facial features
zygomatic bone
What makes up the zygomatic arch?
temporal process of the zygomatic bone + the zygomatic process of the temporal bone
What are the names of the two sections of the temporal bone?
squamous (flat) and petrous (rocky)
What makes up the temporal fossa?
squamous temporal bone with the greater wing of the sphenoid + lower portion of the parietal bone
Where do the frontal bone and the parietal bone meet?
coronal suture
Where do the parietal bone and the occipital bone meet?
lamboid suture
What is the name of the area where the parietal, frontal, sphenoid, and temporal bones join?
pterion
Where do the paired parietal bones unite?
sagital suture
What feature of the occipital bone is responsible for muscle attachment?
superior nuchal line
Where do the occipital condyles and the atlas articulate?
atlanto-occipital joint
Where does the spinal cord pass through?
foramen magnum
What separates the nasal choanae?
vomer bone
What is the hard palate composed of?
palatine bones posteriorly + palatine processes of the maxilla anteriorly
The pterygoid plates and the inferior orbital fissure are lateral to which feature?
choanae
What is the floor of the anterior cranial fossa made up of?
horizontal plate of the frontal bone and the cribriform plate and crista galli
What makes up the roof of the orbit?
horizontal plate of the frontal bone
Which cranial fossa is butterfly shaped?
middle cranial fossa
What is the central region of the sphenoid bone?
sella turcica (roof of sphenoid body)
Where are the optic canals located?
between the anterior clinoid processes
Which feature is anterior to the foramen magnum and runs up towards the sella turcica
clivus
What do the grooves on the wall of the fossa indicate?
the course of the transverse and sigmoid sinuses
What does the frontal bone contain?
frontal sinuses and the supraorbital notch
Which bones form the walls and roof of the cranium?
parietal bones
What are the main features of the occipital bone?
foramen magnum, hypoglossal canals, occipital condyles
The auditory tube, middle ear and inner ear are part of which bone?
temporal bone
The upper half of the temporal bone is __________ while the lower half is __________.
squamous, petrous
Which bone has a vertical and horizontal plate and two lateral masses?
ethmoid bone
These paired shell-shaped bones arise from the maxillae.
inferior concha
How many bones are present in the superior alveolar process?
16
The horizontal palatine process is the anterior _____ of the hard palate.
4/5
What are the two foramina of the maxilla
infraorbital and incisive foramina
Which bone is L shaped?
mandible or palatine
The vertical arm of the mandible is called the ______ and the horizontal arm is called the ______.
ramus, body
Where do the two halves of the mandible meet?
mental protuberance (point of the jaw)
What do the condyloid processes articulate with?
mandibular fossa of the temporal bone
Where does the nerve to the lower teeth pass through?
mandibular foramen
The horizontal plate of the palatine bone is the _____ of the hard palate.
1/5
The vertical plate of the palatine bone forms the posterior ___ of the lateral nasal wall
1/3
Where are the tear ducts located?
lacrimal bone
What shape is the vomer bone?
triangle
Which bone hangs below the floor of the mouth?
hyoid bone
What is suspended from the hyoid bone?
larynx
How many bones in the facial skeleton?
14
How many bones in the cranial vault?
8
Frontal bone
- vertical plate = forehead - horizontal plate = roof of orbit - contains frontal sinuses and supraorbital notch
Maxilla
- has zygomatic and frontal processes - makes up part of medial and inferior border of orbit - contains 2 foramina: 1. infraorbital 2. incisive
How many teeth each in the Maxilla and Mandible bones?
16
What feature makes the mandible unique?
What feature makes the mandible unique? - It is not directly attached to the skull - L shaped - vertical portion is the ramus - horizontal portion is the body
condyloid process
- articular process of mandible with mandibular fossa of temporal bone - forms temporomandibular joint
coronoid process
- gives attachment to a large muscle
mandibular foramen
- nerve to lower teeth passes through here
Zygomatic bone
- cheek bones - has frontal, maxillary and temporal processes
Hyoid bone
- hangs below the floor of the mouth supported by various muscles - larynx is suspended from it - has body and greater and lesser cornu (horns)
Alveolar process
(both maxilla and mandible have them)
Mental foramen
allow passage of nerves
Which bones make up the zygomatic arch?
Temporal process of the zygomatic bone, zygomatic process of temporal bone
Greater wing of the sphenoid bone
- contributes to the superior orbital fissure - contains foramina rotundum, ovale, spinosum
Sphenoid bone
- unpaired - shaped like big eared owl - body contains sphenoid sinuses (bone is hollow) - sella turcica on upper surface - greater wings attached to body
pterygoid process
consists of the medial and lateral pterygoid plates with pterygoid fossa between them
Temporal bone
- has upper flat squamous and petrous (not flat) sections - located by the “temple” - contains auditory tube, middle ear, and inner ear - petrous portion contains: internal and external acoustic meatuses, zygomatic, mastoid and styloid processes, part of jugular foramen, foramen lacerum and carotid canal
Which bones make up the temporal fossa?
Squamous temporal bone, greater wing of sphenoid bone, lower portion of parietal bone
Parietal bone (s)
- united by the sagittal suture - form walls and roof of cranium - articulate with frontal bone at coronal suture - articulate with sphenoid bone - articulate with occipital bone at lambdoid suture - articulate with temporal bone at squamous suture
Which bones is the coronal suture between?
Which bones is the coronal suture between? Frontal and parietal bones
Which bones is the lambdoid suture between?
between parietal bone and occipital bone
What is the Pterion?
The area where the parietal, fontal, sphenoid and temporal bones join
Occipital bone
- unpaired - forms posterior portion of the base of the skull - features: foramen magnum, hypoglossal canals, occipital condyles
occipital condyles articulate with the
atlas
spinal cord passes through:
Foramen magnum
Vomer bone
Vomer bone
palatine bones
- L shaped - horizontal plate is the posterior 1/5 of the hard palate - vertical plate forms
Palatine processes
- anterior 4/5 of the hard palate
lacrimal bone
- small bone located on medial wall of orbit - partially forms opening of nasolacrimal canal - contribute to lateral nasal wall
Hypoglossal canal (inferior view)
- in the wall of the foramen magnum
Anterior cranial fossa
- floor made up of horizontal plate of frontal bone and cribriform plate and crista galli (both of ethmoid bone) - horizontal plate is also the roof of the orbit posterior border of the fossa formed by the lesser wing and jugum of the sphenoid with the anterior clinoid processes projecting posteriorly from medial end of the wings
ethmoid bone
- makes up most of nasal skeleton and medial wall of the orbit - vertical and horizontal plate - two lateral masses - includes cribriform plate and crista galli
Lesser wing of sphenoid bone
- cenrally-located jugum - optic canals medial to clinoid processes - forms upper margin of superior orbital fissure
vertical plate of ethmoid bone
forms half of bony nasal septum
inferior nasal conchae
- paired, shell shaped - arises from MAXILLA not ethmoid bone - it is SEPARATE from the other 2 conchae - forms part of the lateral wall of nose
middle cranial fossa
- butterfly shaped - sphenoid body is the insect and greater wing and temporal bone are the wings - sella turcica in the centre with paired anterior and posterior clinoid processes bordering it - includes: optic canals, superior orbital fissures, foramina rotundum, ovale, spinosum, and lacerum
sella turcica
- roof of the sphenoid body
optic canals
- between anterior clinoid processes - connects brain case to orbit
Superior orbital fissures
- between greater and lesser wings of sphenoid
foramina lacerum
- carotid canal opens into the middle fossa just lateral to the foramen lacerum