Anatomy: Skull lecture 1

The Clovis is located on which bones?

A portion of the sphenoid and basilar part of the occipital bone

The pterion was previously?

Anterolateral fontanel

What type of joints are sutures?

Fibrous

Foramen ________ is a small opening between the frontal crest and crista galli and transmits emissary veins from the nose/nasal cavity to venous vessels of the cranial cavity.

Foramen Cecum... another route for infection of nasal cavity to go to brain --> meningitis

During birth the OBGYN uses forceps during delivery, when the baby is born and begins to cry, there is noticable asymmetry, what could have happened?

Forceps compressed the facial nerve exiting the stylomastoid foramen (between the styloid and mastoid process.

THIS lankmark is found by following the superciliary arch medially and is often used in the ER to assess the level of consciousness of patients by tapping on it.

Glabella

What are the two foramina found on the palatine bone?

Greater palatine foramen Lesser palatine foramina

What boney landmarks make up the sella turcica?

Hypophysial fossa superiorly, tuberculum sellae anteriorly, dorsum sellae posteriorly

A dentist is going to be pulling out lower teeth, what never will the dentist anesthetize?

Inferior alveolar nerve (transmitting through mandibular foramen) supplying the lower teeth

The mandibular foramen transmits what vessels?

Inferior alveolar nerve, artery and vein

Where is the jugular foramen found?

Inferior to petrous portion of the temporal bone

Where is the optic canal located?

On the sphenoid bone medial to the anterior clinoid processes

What is a sutural bone (wormian bone)?

an extra bone near the lambdoid and squamous suture due to incomplete fusion of sutures causing an extra sutural bone

anterior to the mandibular fossa is the ________ which prevents anterior dislocation of the TMJ.

articular eminence (tubercle)

The mastoid foramen transmits _______.

emissary veins

what transmits through the jugular fossa?

internal jugular vein, CN XI, X, XI

groove for superior sagittal sinus carries what?

one of the dural sinuses carrying venous blood

The internal auditory meatus transmits ___________. what bone is this structure part of?

1. CN VII and VIII and internal acoustic artery supplying inner ear 2. posterior part of the petrous portion of the temporal bone

What are the eight bones included in the Neurocranium?

1. Frontal bone (1) 2. Parietal bone (2) 3. Temporal bone (2) 4. Occipital bone (1) 5. Ethmoid bone (1) 6. Sphenoid bone (2) These cover the brain

The mylohyoid line is inside the mandible at the _____ of the mandible while the mylohyoid groove is at the ____ of the mandible.

1. body 2. ramus

The top of the skull (without the mandible and the face) is known as the _________. When the skull is turned over, the inside is called the __________

1. calvaria 2. cranial vault

The petrous part of the temporal bone contains when foramen(s)?

1. carotid canal with the carotid foramen for internal carotid artery 2. internal auditory canal transmitting CN VII and VIII and acoustic artery-->inner ear.

what forms the cruciform suture of the maxilla?

1. intermaxillary suture 2. palatomaxillary suture 3. interpalatine suture

What is a landmark used to separate the anterior from the middle interior skull base (fossa)? What is used to separate the middle from the posterior skull base?

1. sphenoid crest (posterior border of the lesser wing of the sphenoid). 2. the superior border of the petrous bone of temporal bone.

What skull bone is the pharyngeal tubercle?

Basilar part of the occipital bone

Deep to the pterion of the LEFT side of the skull is known as the __________ area. What is significant about this region if injured?

Broca's region- left hemisphere responsible for motor-speech. If middle meningeal artery ruptures, leads to extradural or epidural hematoma and compresses this part of the brain causing aphasia.

Which of the following is NOT a viscerocrainium bone A. Nasal bones B. Lacrimal bones C. Frontal bones D. Vomer E. Inferior nasal conchae F. Occipital bone G. Zygomatic bones H. Maxillae I. Mandible

C and F: these are Neurocranium bones of the skull.

The foramen magnum transmits all of the following except: A. vertebral artery B. medulla oblongata C. spinal cord D. interval vertebral venous plexus E. anterior/posterior spinal arteries

C. spinal cord. The medulla oblongata (part of the brainstem) becomes the spinal cord but it has already passed through the foramen magnum at this point as spinal cord

The occipital condyles articular with ________.

C1 vertebra

The parietal foramina transmits __________ through its foramen, what is the significance of this type of transmission?

Emissary veins allowing the external veins to travel deeper into the skull. If you have an infection of the scalp, it is possible for the infection to travel inside the cranial cavity leading to meningitis.

Why do symptoms of pneumococcal meningitis often precede a nasal cavity infection?

Emissary veins; veins traveling from the external skull to internal skull.

The external occipital protuberance is also known as the ______

Inion

The Saggital suture and lambdoidal sutures meet to form the _________.

Lambda

What small honey projection is at the margin of the mandibular foramen?

Lingula

The greater wing of the sphenoid bone forms part of which cranial fossa?

Middle Cranial fossa The lesser wing of sphenoid forms the anterior cranial fossa

What vessel does the foramen spinosum transmit?

Middle meningeal artery

THIS line serve as as the border between the submandibular salivary gland and sublingual salivary line (part of mandible).

Mylohyoid line

THIS is where the nasofrontal suture and internasal sutures meet on the skull.

Nasion

What cranial nerve transmits through the cribiform plate of ethmoid bone?

Olfactory nerve (CNI)

What are the paired and unpaired skull bones?

Paired: parietal bones, temporal bones, nasal bones, lacrimal bones, inferior conchae, zygomatic bones, maxillae, palatine bones Unpaired: frontal bone, occipital bone, ethmoid bone, sphenoid bone, Vomer, mandible

What bone is the external opening of the carotid canal?

Petrous portion of temporal bone

What are the boundaries of the foramen lacerum?

Petrous portion of temporal bone Pterygoid process of sphenoid bone Basilar part of occipital bone

What two bones is the jugular foramen?

Petrous portion of temporal bone and occipital bone

THIS structure occupies the Clivus of the skull base.

Pons

Where is the Hypophyseal fossa located?

Posterior to the chiasmatic sulcus on the sphenoid

Describe the location of the asterion. What was the asterion previously?

Posterolaterally located on the skull: occipital, parietal, and temporal bones meet. Previously the posterolateral fontanel

The optic nerve cross through _____ sulcus.

Prechiasmatic sulcus

In between the medial and lateral plates of the sphenoid bone lies the ______ fossa.

Pterygoid fossa two plates are locations where the two muscles of mastication attach. medial and lateral pterygoid muscles.

Describe the location of the Peterson?

Region where the 4 bones meet: frontal, parietal, temporal and sphenoid bone

What are the granular foveolae? How do they function?

Shallow depressions caused by the arachnoid granulations They return CSF to the circulation

Why will patients have blood pooling at bottom of eyes when have trauma to superciliary arches?

Skin here is very tight so will see bruising at the sight and pooling underneath eyes where connective tissue is looser.

THIS skull bone has both a greater and lesser wing.

Sphenoid bone

This fissure is formed between the lesser wing and greater wing of sphenoid bone.

Superior orbital fissure

What foramina are within the sphenoid bone?

Superior orbital fissure Foramen roundup Foramen ovale Foramen spinosum

What bone is the mandibular fossa located?

Temporal

What two processes make up the zygomatic arch?

Temporal process of zygomatic bone Zygomatic process of temporal bone

What transmits through the mental foramen?

The mental VAN

The supraorbital nerve is a branch of which cranial nerve?

Trigeminal nerve

T or F: The palatine bones are part of the Viscerocranium

True

T or F: during fetal development, the two frontal bones are paired and fuse just before birth

True If are fail to fuse at birth, will result in a METOPIC suture

T or F: the paranasal sinuses should ONLY contain air.

True, as opposed to dural sinuses like specialized vessels that carry blood.

what boney structures make up most of the nasal septum along with septal cartilage?

Vomer perpendicular plate of ethmoid

What does the zygomaticotemporal foramen transmit?

Zygomaticotemporal VAN and part of the trigeminal nerve

The crista galli is part of which bone? what structure is on either side of the crista galli?

ethmoid bone the cribiform plate (lots of tiny holes)

what transmits through the stylomastoid foramen of the skull?

facial nerve (CN VII)

T or F: all through nasal conchae (inferior, middle, and superior) are part of the ethmoid bone.

false: the inferior nasal conchae is a separate bone, the other two are part of the ethmoid bone.

T or F: the foramen lacerum transmits many different vessels.

false; it is typically covered by cartilage and is an irregular opening.

what are the 3 foramen of the sphenoid bone?

foramen rotundum, foramen ovale, foramen spinosum

Where are the primary ossification sites of the skull?

frontal and parietal eminences (will be prominent in patients with acromegaly)

The anterior cranial fossa is mostly encompassed by the _________.

frontal lobe of the brain

What passes through the infraorbital foramen?

infraorbital artery, vein, and nerve. Can anesthetize for sutures to the face or dental procedures (nerve block)

Another name for the mandibular angle is _____

gonion

What transmits through the hypoglossal canal?

hypoglossal nerve

What passes through the supraorbital foramen?

supraorbital vein, artery and nerve can be pressed to elicit pain and LOC

What kind of joint is the TMJ?

synovial joint (condyloid type)

what is the pterion? what is it's clinical significance?

the junction that connects all 4 bones (parietal, greater wing of sphenoid, temporal, and frontal bones. it is where the sphenoparietal suture, coronal suture, and squamousal suture meet. Deep within the pterion is the middle branch of the middle meningeal artery. This area of bone is very thin and prone to fracture, fracture will cause rupture of this artery leading to epidural hematoma (between dura mater and skull). If this occurs this part of the brain (on left side is Broca's region) will be compressed. Broca's area is the motor-speech area and damage to this area leads to aphasia

____ is the highest point of the skull

vertex

What is the Bregma of the skull?

where the coronal and saggital sutures meet. Former site of the anterior fontanel .