DMI 403 Chapter 2: Cranium and Facial Bones

atlantooccipital joint

Occipital condyles project inferiorly to articulate with the first cervical vertebral (atlas) at the _____

3

The base of the cranium houses how many fossae?

posterosuperiorly

The squamous portion of the occipital bone curves ______ from the foramen magnum to articulate with the parietal and temporal bones

Occipital bone

_____ creates foramen magnum

Crista Galli

______ projects superiorly to act as attachment for the falx cerebri

Body, lesser wings (2), greater wings (2)

Parts of the sphenoid bone

Posterior clinoid processes

The dorsum Sellae gives rise to the ____

Tentorium cerebelli

Anterior and posterior clinoid processes serve as attachment sites for ____

Composed primarily of Frontal bone, ethmoid bone, and lesser wing of the sphenoid bone

Anterior cranial fossa (frontal fossa)

Contains frontal lobe of the brain/cerebrum, olfactory bulbs

Anterior cranial fossa (frontal fossa) contents

Formed by the tuberculum sellae

Anterior portion of the sella turcica

pterygoid (vidian) canal

At the base of the pterygoid process is the _____

Contains sella turcica and sphenoid sinuses

Body of the sphenoid

parietal eminences

Determine width of cranium by measuring distance between two _____

Spongy bone between the 2 tables of the cranium

Diploe

Sphenoid sinuses (2)

Directly below the sells turcica is the ____

Lateral occipital condyles (2), basilar, squamous portion

Division of the occipital bone

Smallest of the cranial bones and is situated in the anterior cranial fossa

Ethmoid bone

Largest ethmoid sinus

Ethmoid bulla

Located between the orbital plate, receives the cribriform plate of the ethmoid bone

Ethmoid notch

Consists of vertical and horizontal portions of skull

Frontal bone

Smooth area that joins two elevated arches (Supraciliary arches)

Glabella

Contains three foramen: rotundum, ovale , spinosum

Greater wing

Fits into the ethmoid notch of the frontal bone

Horizontal portion (Cribriform plate) of ethmoid bone

Contains many foramina for the passage olfactory nerve fibers

Horizontal portion (Cribriform plate) of ethmoid bone contents

Cribriform plate

Horizontal portion of ethmoid bone

Forms the roof over each orbit (aka orbital plate) and the majority of the anterior cranial fossa

Horizontal portion of frontal bone

8, surround and protect the brain

How many bones are in the cranium? What do they do?

Narrow groove between the uncinate process and ethmoid bulla

Infundibulum (ethmoid bone)

Sphenoid, the only bone to articulate with all other cranial bones

Keystone of cranial bones

A Squamous portion of frontal bone B Frontal sinus C Maxilla D Perpendicular plate of ethmoid E Nasal bone F Supraorbital foramen

LABEL THE FOLLOWING

A-Frontal bone B-Sella turcica C-Dorsum sella D-Frontal sinus E-Nasal bone F-Ethmoid air cells G-Inferior nasal concha H-Hard palate I-Sphenoid sinus J-Clivus of occipital bone K-Occipital bone

Label the following:

Ethmoid sinuses Sphenoid sinus Optic canal Lesser wing of sphenoid Zygoma Superior orbital fissure Sella turcica Greater wing of sphenoid Anterior clinoid process Dorsum sella Posterior clinoid processes

Label the following:

A - Coronal Suture B - Frontal Bone C - Parietal Bone D - Superior Orbital Fissure E - Temporal Bone F - Sphenoid Bone G - Zygoma H - Maxilla I - Mandible J - Vomer K - Inferior Nasal Concha L - Ethmoid Bone M - Supraciliary Arch N - Glabella O - Parietal Eminence

Label the parts on the anterior skull 3D image-

1 Coronal Suture 2 Frontal Bone 3 Pterion 4 Sphenofrontal suture 5 Sphenoid bone 6 Nasal bone 7 Ethmoid bone 8 Zygomatic arch 9 Zygoma 10 Maxilla 11 Mandible 12 Mastoid Process 13 Temporal bone 14 Occipitomastoid suture 15 Parietomastoid suture 16 Asterion 17 External Occipital Protuberance 18 Occipital Bone 19 Lambdoidal suture 20 Squamous suture 21 Vertex 22 Parietal Bone

Label the parts on the lateral skull 3D image-

hypoglossal canal

Located obliquely at the base of the occipital condyles and anterolateral to the foramen magnum are the _____

hypoglossal nerve (CN VII)

Located obliquely at the base of the occipital condyles and anterolateral to the foramen magnum are the hypoglossal canal through which the _____ courses

longer

Medial pterygoid plate section is ____ and has a hook shaped projection on its inferior end termed the pterygoid hamulus

pterygoid hamulus

Medial pterygoid plate section is longer and has a hook shaped projection on its inferior end termed the pterygoid hamulus

Formed primarily by the body of the sphenoid and temporal bones

Middle cranial fossa (temporal fossa)

houses the pituitary gland, hypothalamus, and temporal lobes of the brain, optic nerves and chiasm, cavernous sinus, trigeminal ganglion, internal carotid artery, and the following cranial nerves: trigeminal, oculomotor, trochlear, abducent, ophthalmic

Middle cranial fossa (temporal fossa) contents

Forms posterior cranial fossa and inferioposterior portion of the cranium

Occipital bone

Project inferiorly to articulate with the first cervical vertebral (atlas) at the atlantooccipital a joint

Occipital condyles

Completely contained within the lesser wing and provides a passage of the optic nerve and ophthalmic artery

Optic canal

Bony root(inferior root) that separates the optic canal from superior orbital Fissure

Optic strut

Two bones forming a large portion of the side of the cranium.

Parietal bone

Central prominent bulge on outer surface of each parietal bone

Parietal eminence

Formed by the occipital and temporal bones; contains the cerebellum and brainstem (pons, medulla oblong at a, midbrain), and the following cranial nerves: facial, vestibulocochlear, glossopharyngeal, vagus, accessory, hypoglossal

Posterior cranial fossa (infratentorial fossa)

2 scroll shaped processes: Superior and middle nasal conchae (turbinates) and uncinate process

Projections from the lateral masses

Butterfly shaped bone, extends across the floor of the middle cranial fossa

Sphenoid bone

Two air filled cavities directly below the sella turcica

Sphenoid sinuses

Triangular shaped opening located between the lesser and greater wings that allows for the transmission other oculomotor, trochlear, abducens, and ophthalmic division of the trigeminal nerve as well as the superior ophthalmic vein

Superior orbital Fissure

Located in the superior portion of each orbit, exists for the passage of the supraorbital nerve

Supraorbital foramen or notch

basilar portion

The ____ forms the anterior margin of the foramen magnum and slopes superiorly and anteriorly to meet with the dorsum sella of the sphenoid bone to form the clivus

pterygoid plates

The ____ serve as attachment site for the pterygoid muscles used in the movements of the lower jaw

squamous portion

The _____ of the occipital bone curves posterosuperiorly from the foramen magnum to articulate with the parietal and temporal bones

foramen magnum

The basilar portion forms the anterior margin of the ____ and slopes superiorly and anteriorly to meet with the dorsum sella of the sphenoid bone to form the clivus

dorsum sella

The basilar portion forms the anterior margin of the foramen magnum and slopes superiorly and anteriorly to meet with the ____ of the sphenoid bone to form the clivus

clivus

The basilar portion forms the anterior margin of the foramen magnum and slopes superiorly and anteriorly to meet with the dorsum sella of the sphenoid bone to form the ____

Formed by the dorsum sellae

The posterior portion of the sella turcica

pterygoid muscles

The pterygoid plates serve as attachment site for the ____ used in the movements of the lower jaw

lower jaw

The pterygoid plates serve as attachment site for the pterygoid muscles used in the movements of the _____

vomer

The pterygoid processes articulate with the Palentine bones and ____ to form part of the nasal cavity

nasal cavity

The pterygoid processes articulate with the Palentine bones and vomer to form part of the ____

Palentine bones

The pterygoid processes articulate with the ____ and vomer to form part of the nasal cavity

Sphenoid boneThis bone forms the majority of the base of the skull and articulates with the occipital, temporal, parietal, frontal, and ethmoid bones

This bone forms the majority of the base of the skull and articulates with the occipital, temporal, parietal, frontal, and ethmoid bones

Superior point between the parietal bones, the highest point of the cranium

Vertex

Project inferiorly from the cribriform plate to form a portion of the bony nasal septum

Vertical portion (perpendicular plate) of the ethmoid bone

Forms the forehead and anterior vault of the cranium

Vertical portion of frontal bone (squamous portion of frontal bone)

Contains frontal sinuses, lying on either side of the midsagittal plane

Vertical portion of frontal bone (squamous portion of frontal bone) contents

perpendicular plate

Vertical portion of the ethmoid bone

Parietal(2), frontal, ethmoid, sphenoid, occipital, and temporal (2)

What are the bones in the cranium?

Compact tissue known as the internal/inner and external/outer tables

What are the cranial bones composed of?

Anterior, middle, posterior cranial fossae

What are the three cranium base fossae called?

Lateral masses (labyrinth) incorporate thin-walled orbital plates (lamina papyracea)

What creates a portion of the medial orbits?

Cancellous tissue or Spongy bone called Diploe

What is located between the two tables of compact tissue?

Medial pterygoid plate

____ section is longer and has a hook shaped projection on its inferior end termed the pterygoid hamulus

Anterior and posterior clinoid processes

____ serve as attachment sites for Tentorium cerebelli

Two Sharp points of the lesser wing

anterior clinoid processes

Bony projection stemming from the midline of the cribriform plate

crista galli

connective tissue that anchors the brain to the anterior cranial fossa

falx cerebri

Large oval aperture located at the junction of the brainstem and spinal cord

foramen magnum

Housed within the deep depression of the sella turcica

hypophysis/pituitary gland

Infundibulum

landmark of the paranasal sinuses

Ethmoid air cells (ethmoid sinuses)

lateral masses of ethmoid bone contents

Triangular shaped, attaches to the superior aspect of the body and forms anterior clinoid processes

lesser wings of sphenoid

cube shaped bone can be divided into four parts: horizontal portion, vertical portion, into lateral masses/labyrinth

parts of the ethmoid bone

Opening for the passage of the petrosal nerve

pterygoid (vidian) canal

Hook shaped projection which provides an anchor for gliding motion for the muscle responsible for opening the Eustachion tube

pterygoid hamulus

Eustachion tube

pterygoid hamulus (Hook shaped projection) provides an anchor for gliding motion for the muscle responsible for opening the ____

Extends from the inferior surface of each greater wing and is divided into medial and lateral Pterygoid plates

pterygoid process of sphenoid bone

medial and lateral pterygoid plates

pterygoid process of sphenoid bone extends from the inferior surface of each greater wing and is divided into _____