Skull Anatomy
the lesser wings of the sphenoid bone articulate anteriorly with the orbital plane of the _____ bone
frontal
each parietal bone articulates anteriorly with the ______ _____ and posteriorly with the ______
frontal bone, occipital
each lateral portion of the occipital bone has a convex, rocklike ________ ________ on it.
occipital condyle
the ______ portion is called the perpendicular plate
vertical
the right and left lateral masses contain anywhere from ____ to ____ air cells which form the _________ ________
3 to 18, ethmoid sinuses
how many parts is the occipital bone divided into? and what are all the parts?
4 parts, Squamous, right and left lateral, and basilar
How many parts does the ethmoid bone have and what are they?
4 parts, horizontal portion, vertical portion and 2 lateral masses
what portion extends anteriorly and superiorly to articulate with the body of the sphenoid?
Basilar portion
what parts does the sphenoid bone consist of?
Body, 2 lesser wings, 2 greater wings, pterygoid processes
The _____ ______ is a triangular process that projects upward from the cribriform plate.
Crista galli
the ________ bone is a small, complex-shaped bone located on the midline of the skull between the orbits.
Ethmoid bone
what bone forms the anterior part of the cranial floor, medial wall of each orbit, lateral walls of the nasal cavity and upper part of the nasal septum?
Ethmoid bone
what bone is situated anteriorly to the sphenoid and posteriorly to the nasal bones?
Ethmoid bone
the _______ _______ is somewhat of a horse-shoe shaped opening located between the two orbital plates.
Ethmoidal notch
the crista galli extends up through the _____ _____ of the frontal bone
Ethmoidal notch
what is the large hole for which the spinal cord passes?
Foramen magnum
There are ______ or ______ that accommodate the venous sinuses of the brain
Grooves or sulci
What portion of the ethmoid bone is known as the Cribriform plate?
Horizontal portion
which portion of the ethmoid bone fits snugly in the ethmoidal notch of the frontal bone to form the anterior portion of the cranial floor and roof of the nasal cavity
Horizontal portion
there is also a _____ _____ located at the superior end of the condyle through which the 12th cranial or hypoglossal nerve is transmitted to the brain.
Hypoglossal canal
what is the palpable bump located on the midline of the squamous portion?
Inion
on the inner surface of the occipital bone there is a bump called the ____ ____ _____ that corresponds in location to its counterpart.
Internal occipital protuberance
what's another name for the right and left lateral masses?
Labyrinths
The largest air cell
Mastoid Antrum
A spike of bone positioned at the anterior end of the ethmoidal notch on the frontal bone is known as the
Nasal spine
each _____ _______ forms the roof of an orbit and the anterior aspect of the floor of the cranial fossa
Orbital plate
The orbital and horizontal portion of the frontal bone is formed by 2 flat plates of bone known as the
Orbital plates
what is the rounded tuberosity located on the lateral surface of the parietal bone?
Parietal eminence
Where do the parietal bones articulate with each other at?
Sagittal suture on the midline of the skull
the _____ _____ is a saddle shaped depression on the superior surface of the body that houses the pituitary gland.
Sella turcica
What is the largest segment of the occipital bone that curves upward from the foramen magnum to form the posterior wall and articulates with both parietal & temporal bones?
Squamous
the two lateral portions of the occipital bone are situated between the ______ and ______ portions
Squamous and basilar
what do the two parietal bones form?
The lateral walls and roof of the skull
What does the posterior aspect of the orbital portion of the frontal bone articulate with
The lesser wings of the sphenoid bone
What lines run horizontally through the occipital crest?
The superior and inferior nucal lines
the sella turcica is bordered anteriorly by the
Tuberculum sallae
A small projection known as the ____ ____ process extends from the posterior margin of each lesser wing to project posteriorly and laterally to the opening of the optic canal
anterior clinoid process
where is the basilar portion located?
anterior to the foramen magnum
What does the word "Occiput" refer to?
back of the head
the ______ ______ forms part of the base of the skull
basilar portion
the ___ part of the sphenoid forms the central portion of the bone
body
the ____ ____ is the posterior boarder of the sella turcica
dorm sallae
the body of the sphenoid is located between the ____ and _____ bones
ethmoid and occipital
what do the superior nasal concha and middle nasal concha do
filters warm and moistened inhaled air before it passes to the lungs.
each parietal bone articulates inferiorly and anteriorly with a small part of the _______ ________
greater wing of the sphenoid bone
the vertical portion projects _____ from the bottom of the cribriform plate to form the superior portion of the bony nasal septum
inferiorly
the ______ surface of the labyrinth forms the medial wall of an orbit
lateral
two _____ wings extend laterally and horizontally from the anterosuperior aspect of the body of the sphenoid.
lesser
the _____ surface of the labyrinth forms the lateral wall of the nasal cavity
medial
what bone forms the posteroinferior wall and floor of the cranium?
occipital bone
the ____ or ___ _____ is a depression that runs horizontally across the body of the sphenoid anterior to the sella turcica
optic or chiamasti groove
the greater wings of the sphenoid bone are _____ to the lesser wings
posterior
two small rounded projections known as the ____ ____ processes extend superiorly from the upper, lateral margins of the dorsum sallae.
posterior clinoid processes
the ________ are thin-walled, spongelike structures that hang from the underside of the cribriform plate on either side of the perpendicular plate.
right and left lateral masses/labyrinths
What is the tubercular sallae
small tubercle or eminence
what bone is located on the midline of the cranial floor?
sphenoid bone
which bone acts as an anchor or keystone to hold 8 cranial bones together, as it articulates with each of the other 7 bones?
sphenoid bone
what shape are the parietal bones?
square
two thin scroll-shaped structures project into the nasal cavity from the medial wall known as
superior nasal concha and middle nasal concha
the lesser wings junction at the midline is called
the sphenoid ridge