8.2.3: Markings of the Cranium
- Page ID
- 53619
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Markings of the Cranium
Recall from Chapter 7: Introduction to the Skeletal System, that bones have markings including holes, passageways, basins, and projections. Before examining the specific markings of the cranium, review the pertinent types of markings we will see when we examine the cranium markings:
|
Type of Bone Marking |
Description of Bone Marking Type |
|---|---|
|
canal |
Passageway through a bone. Example: optic canal |
|
condyle |
Refers to a large rounded prominence which often provides structural support to the overlying hyaline cartilage. Examples: femoral lateral and medial condyles; tibial lateral and medial condyles; occipital condyles articulate with atlas (C1) |
|
foramen (pl. foramina) |
A hole in a bone through which nerves and blood vessels pass. Examples: foramen magnum; supraorbital foramen; infraorbital foramen; mental foramen |
|
fossa (pl. fossae) |
A shallow depression in a bone surface. Examples: trochlear fossa; posterior, middle, and anterior cranial fossae |
|
meatus (pl. meatuses) |
A tube-like channel that extends within the bone, which may provide passage and protection to nerves, vessels, and sound. Examples: external acoustic meatus; internal auditory meatus |
|
process (pl. processes) |
Bony projection, allow for muscle attachment. Examples: spinous process, acromial process, radial styloid process |
|
protuberance |
A bump or outgrowth on a bone. Example: external occipital protuberance |
Above: Markings of the cranium viewing the skull from the inferior view.
Above: Markings of the cranium viewing the skull from the superior view of the cranial cavity.
|
Marking |
Bone Marking is Part of |
Location |
Function |
|---|---|---|---|
|
carotid canal (2, one right & one left) |
temporal bones |
inferior skull |
provides passage for the right and left internal carotid arteries |
|
cribriform plate (2, one right & one left) |
ethmoid bone |
cranial cavity |
forms the superior aspect of the nasal cavities; forms part of the anterior cranial fossa; plate contains olfactory foramina where sensory neurons carrying scent information pass through from the nasal cavities towards the brain |
|
crista galli |
ethmoid bone |
cranial cavity |
located between the cribriform plates; attaches to the dura mater, one of the meninges surrounding the brain |
|
external acoustic meatus (2, one right & one left) |
temporal bones |
lateral skull |
passageways (right and left) form canals to the middle ears |
|
external occipital protuberance |
occipital bone |
posterior skull |
a minor projection on the posterior of the skull |
|
foramen lacerum (2, one right & one left) |
temporal bones |
inferior skull & cranial cavity |
mostly blocked by cartilage, but some blood vessels and nerves pass through |
|
foramen magnum |
occipital bone |
inferior skull & cranial cavity |
this is the largest foramen of the skull; provides passage for the spinal cord to attach to the brain stem |
|
foramen ovale (2, one right & one left) |
sphenoid bone |
inferior skull & cranial cavity |
these provide passage for branches of the paired (right and left) C.N. V trigeminal nerves |
|
foramen spinosum (2, one right & one left) |
sphenoid bone |
inferior skull & cranial cavity |
these provide passage for the middle meningeal arteries (right and left) which supplies blood to the dura mater of the brain |
|
hypoglossal canal (2, one right & one left) |
occipital bone |
cranial cavity |
provide passage for the pair (right and left) of C.N. XII hypoglossal nerves |
|
hypophyseal fossa |
sphenoid bone |
cranial cavity |
this fossa is the "seat" of the saddle-like sella turcica where the pituitary gland is positioned (another name for the pituitary gland is hypophysis) |
|
internal acoustic meatus (2, one right & one left) |
temporal bones |
cranial cavity |
provide passage for the right and left C.N. VIII vestibulocochlear nerves transmitting sensory information including auditory information |
|
jugular foramen (2, one right & one left) |
temporal bones |
inferior skull & cranial cavity |
provides passage for paired internal jugular veins (right and left) and right and left pairs of cranial nerves (C.N. IX, X, and XI) |
|
mandibular fossa (2, one right & one left) |
temporal bones |
inferior skull |
locations where the mandible articulates with the temporal bone creating hinges between the jaw and the rest of the skull; the condylar processes of the mandible (right and left) are positioned in these fossae |
|
mastoid process (2, one right & one left) |
temporal bones |
inferior skull & lateral skull |
location where neck muscles attach including the right and left sternocleidomastoid muscles |
|
middle nasal concha (2, one right & one left) |
ethmoid bone |
anterior skull, nasal cavities |
create passages for airflow through right and left nasal cavities |
|
occipital condyle (2, one right & one left) |
occipital bone |
inferior skull |
this pair of condyles is where the skull articulates with C1, the first cervical vertebra, also known as atlas |
|
olfactory foramina or cribriform foramina (many, found in right & left cribriform plates) |
ethmoid bone |
cranial cavity |
provides passage for axons of olfactory sensory neurons from the nasal cavities to the olfactory cranial nerves (C.N. I) in the cranial cavity; enables transmission of scent information to the brain |
|
optic canal (2, one right & one left) |
sphenoid bone |
anterior skull, posterior orbits & cranial cavity |
these provide passage for the paired C.N. II optic nerves (right and left) to pass from the eyes to the brain carrying sight information |
|
perpendicular plate |
ethmoid bone |
anterior skull, superior nasal septum |
creates the superior part of the nasal septum separating the nasal cavities into right and left |
|
pterygoid process (2, one right & one left) |
sphenoid bone |
inferior skull |
pterygoid muscles attach to these processes connecting with the mandible to move the mandible for chewing |
|
sella turcica |
sphenoid bone |
cranial cavity |
a saddle-like structure creating a basin (fossa) where the pituitary gland is located; the "seat" of the sella turcica saddle is called the hypophyseal fossa (another name for the pituitary gland is hypophysis) |
|
styloid process (2, one right & one left) |
temporal bones |
inferior skull & lateral skull |
thin and narrow inferior-pointing projections (right and left) where neck muscles and ligaments attach |
|
stylomastoid foramen (2, one right & one left) |
temporal bones |
inferior skull |
provides passage for the right and left C.N. VII; each of these foramina are located between the styloid process and the mastoid process on that side of the skull |
|
superior nasal concha (2, one right & one left) |
ethmoid bone |
inside the superior nasal cavities |
create passages for airflow through right and left nasal cavities |
|
superior orbital fissure (2, one right & one left) |
sphenoid bone |
anterior skull, posterior aspect of the orbits |
paired cranial nerves (right and left) pass through to control eye movements (C.N.III, IV, part of V, and VI) |
|
supraorbital notch/foramen (2, one right & one left) |
frontal bone |
anterior skull, superior to orbits |
passage for blood vessels and nerves |
|
zygomatic process (of temporal bones) (2, one right & one left) |
temporal bones |
lateral skull & inferior skull |
creates a bridge-like structure that connects the temporal bone with the zygomatic bone forming part of the zygomatic arch |
Above: Markings of the cranium with the following views: (A) anterior view, (B) lateral view of the left side of the skull, (C) posterior view, and (D) lateral view of the right side of the skull.
Attributions (All Skull Sections)
- "Anatomy 204L: Laboratory Manual (Second Edition)" by Ethan Snow, University of North Dakota is licensed under CC BY-NC 4.0
- "Anatomy and Physiology" by J. Gordon Betts et al., OpenStax is licensed under CC BY 4.0
- "Anatomy and Physiology Lab Reference" by Laird C Sheldahl, OpenOregonEducational Resources, Mt. Hood Community College is licensed under CC BY-SA 4.0
- "BIOL 250 Human Anatomy Lab Manual SU 19" by Yancy Aquino, Skyline College is licensed under CC BY-NC-SA 4.0
- "BodyParts3D/Anatomography" by The Database Center for Life Science is licensed under CC BY-SA 2.1
- "Ethmoid.png" by Life Science Databases(LSDB) is licensed under CC BY-SA 2.0
- "Gray151.png" by Henry Vandyke Carter is in the Public Domain
- "Human Skeleton Upper Body Posterior View.jpg" by Andrewmeyerson is licensed under CC BY-SA 3.0
- "Rotation ethmoid.gif" by Life Science Databases(LSDB), animated by was a bee is licensed under CC BY-SA 2.0
- "Sphenoid bone - animation 02.gif" by Database Center for Life Science (DBCLS) is licensed under CC BY-SA 2.1