Skull Anatomy Flashcards
The skull has how many bones?
22; 8 cranial and 14 facial
What cranial bones are paired?
Parietal and temporal
The sphenoid and ethmoid are classified as ____ bones
Cranial (floor)
What is the name of the articulation between the frontal and parietal bone?
The coronal suture
What is the name of the articulation between the parietal bone and the temporal bone?
Squamosal suture
The foramen magnum is located in which bone?
Occipital
The flattened, horizontal portion on the superior aspect of the ethmoid bone is called the:
Cribriform plate
The hard, dense bony process of the temporal bone that houses the structures of the middle and inner ear is called the:
Petrous pyramid
The mastoid air cells are located in the:
temporal bone
The rounded, articulating condyles of the mandible that help form the temporomandibular joint are called the:
condyloid processes
The superior and middle nasal conchae that serve to increase the surface area of the nasal cavities are found in the:
Ethmoid bone
Which three cranial bones articulate directly with the zygomatic bone?
Frontal, sphenoid, temporal
The only movable bone in the adult skull is the:
Mandible
Average skull, width is 75-80% of length. Angle from midsagittal plane to petrous pyramid is 47 degrees
Mesocephalic
Broad skull side to side; 80% or greater than the length
Brachycephalic
Long, narrow skull; less than 75% of the length
dolichocephalic
There are a total of _____ fontanels in an infant.
6
Which cranial bone contains the cribriform plate?
ethmoid
What is the difference, in degrees, between the infraorbitomeatal and orbitomeatal line?
7-8 degrees
A patient enters the emergency department with a possible basilar skull fracture. Which of the following skull projections would best demonstrate any blood present in the sphenoid sinus?
horizontal beam lateral
Which cranial bone possesses the zygomatic process?
temporal
What are the two most common positioning errors when it comes to headwork.
rotation and tilt
Bones of the calvarium (skullcap)
Frontal, right/left parietal, occipital
Bones of the skull floor
right/left temporal, sphenoid, ethmoid
Two main parts of the frontal bone
squamous/vertical portion (forehead); orbital/horizontal portion (superior part of orbit)
Slight depression above each eyebrow; corresponds to the floor of the anterior fossa of the cranial vault
Supraoribital groove (SOG)
Superior rim of each orbit
Supraorbital margin
Small hole/opening within the SOM slightly medial to it’s midpoint
Supraoribital notch
Four cranial bones that articulate with the frontal bone:
right/left parietals, sphenoid, ethmoid
The widest portion of the skull is located between the ________ of the two parietal bones
parietal tubercles (eminences)
five cranial bones that articulate with the parietal bones:
frontal, occipital, sphenoid, temporal, opposite parietal
Rounded external surface of the occipital bone:
Squamous portion
the prominent bump or protuberance at the inferoposterior portion of the skull:
external occipital protuberance (inion)
6 bones that articulate with the occipital bone:
two parietals, two temporals, sphenoid, atlas (first cervical vertebra)
Arch of bone extending anteriorly from the squamous portion of the temporal bone
zygomatic process
Houses the organs of hearing and equilibrium, including mastoid air cells
petrous pyramid
Cranial articulations of each temporal bone:
Parietal, occipital, sphenoid
Central depression on the body of the sphenoid bone
sella turcica
The sella turcica houses which gland?
Pituitary gland
contains many small openings or foramina through which segmental branches of the olfactory nerves (or the nerves of smell) pass.
Cribriform plate
Cranial articulations of the ethmoid bone
Frontal and sphenoid
Classification of cranial sutures
fibrous/synarthrodial
Separates the two parietal bones at the midline
Sagittal suture
Separates the two parietal bones from the occipital bone
Lambdoidal suture
What landmark corresponds with the level of the petrous ridge?
TEA
What is the largest immovable bone of the face?
Maxilla
A skull with a 47 degree angle between the petrous pyramids and the midsagittal plane is classified as:
Mesocephalic
positioning line that extends across the front (anterior face) through both eyes
IPL
Positioning line extending from the EAM to the smooth elevation between the superciliary arches
GML
Comprises most of the lateral wall of the orbital cavities.
Zygomatic bone
Forms the posterior 1/4 of the roof of the mouth
Palatine bone
Vertical portion of the mandible
Ramus
Horseshoe portion of the mandible
Body
