Anatomy 2320 - Axial Skeleton: Skull

8

How many cranial bones are there?

14

How many facial bones are there?

Calvaria

The upper dome-like portion of the skull, which forms the upper portion of the cranial cavity

Upper portion of frontal bone, parietal bones and upper portion of occipital bone

What bones form the calvaria?

Nasal septum

divides nasal cavity

mucas and cilia

What lines the hollow paranasal sinuses?

Sphenoidal, Maxillary, Frontal, Ethmoidal

The four paranasal sinuses

supraoribital margin

prominent bony ridge over orbits

supraorbital foramen

Allows for passage of nerves and blood vessels to the eyes

frontal sinuses

pair of sinuses within frontal bone

Age 6, Age 10

When do the frontal sinuses begin to appear? When do they fully develope?

frontal sinus

Which sinus has a unique pattern so it is able to be used in forensics?

Frontal crest

a midline elevation of bone on the internal anterior surface of the frontal bone

Falx Cerebri

What does the frontal crest and crista galli serve as attachments for?

Sagittal suture

What divides the two parietal bones?

Coronal suture

What separates the frontal bone from the parietal bones?

squamosal suture

What separates each parietal bone from its adjacent temporal bone?

Petrous Region

region of temporal bone that houses structures of middle and inner ear

Otitis Media

infection of the middle ear

Carotid canal

Within the petrous region of the temporal bone, allows for passage of blood vessels that supply the brain

Foramen lacerum

Located between the petrous portion of the temporal bone, sphenoid bone and occipital bone (FLOST). Closed off by connective tissue in living persons

Jugular foramen

located between the temporal and occipital bones, allows for drainage of blood from the brain via internal jugular vein

Mastoid Region

rounded portion of the temporal bone which can be easily felt as the bony knob immediately behind your earlobe

Mastoid process

location on the skull that serves as attachment for muscles that flex the neck or rotate head

Mastoiditis

Prolonged middle ear infections may spread to mastoid air cells causing...

Squamous Region

lateral flat surface of each temporal bone immediately inferior to the squamosal suture

Tympanic region

small area surrounding the outer entrance to the external auditory canal

Styloid process

serves as attachment point for muscles of tongue and ligaments connecting to hyoid bone

Lambdoidal suture

separates the occipital bone from the two parietal bones

Occipital condyles

On either side of foramen magnum, articulate with atlas. Allows head to nod "yes"

Superior nuchal line and inferior nuchal line

two prominent horizontal ridges on posterior portion of occipital bone, serve as attachment sites for neck muscles

Internal occipital crest

On the internal posterior portion of occipital bone, serves as attachment point for falx cerebri

falx cerebri

"sickle shaped" sheet of connective tissue that separate the two hemispheres of the brain

Sphenoid bone

often referred to as the bridging bone, also resembles a bat or butterfly with outstretched wings

Sphenoidal sinuses

Sinuses of sphenoid bone that drain into the nasal cavity

hollow

Because the sphenoid is ___, it may be fractured from head trauma

sella turcica

prominent depression on superior medial portion of sphenoid bone

pituitary stalk

Because the pituitary gland is so well anchored, sudden traumatic shifting may sever the...

Optic foramen

Allows passage of the optic nerve (part of sphenoid)

foramen rotundum

Allows passage of one of the three branches (second branch) of the trigeminal nerve (V) that conveys sensations from teeth and gums of maxillae

Second division nerve block

name for injection of anesthetic not far below foramen rotundum that desensitizes all upper teeth on one side of maxilla

Foramen ovale

allows passage of the third branch of the trigeminal nerve (V) that conveys sensation from the teeth and gums of the mandible

Foramen spinosum

small opening for meningeal blood vessels

Superior orbital fissure

allows passage of several cranial nerves, including first branch of trigeminal, that convey sensation the nose, forehead and anterior scalp

Cirsta galli

superior part of the ethmoid bone that exhibits a midsagittal elevation

Falx cerebri

The crista galli serves as an attachment for...

cribriform plate

immediately lateral to each side of the crista galli, has numerous foramina that allow passage for fibers of olfactory nerves (I) to travel from nose to brain

Perpendicular plate

inferior midline projection of ethmoid bone, forms superior part of nasal septum

Superior and middle nasal conchae

two projections of the ethmoid located on both lateral walls of the nasal cavity

inferior nasal conchae

Nasal conchae that is not part of the ethmoid, but are independent facial bones

mucous membrane and erectile tissue

All the nasal conchae are covered with...

Zygomatic

forms bony prominence of cheeks

lacrimal bones

paired bones that form part of the medial wall of each orbit

lacrimal groove

A small depressed inferior opening in the lacrimal bone that provides a passageway for the nasolacrimal duct, which drains tears into the nasal cavity. Explains why nose runs when you cry

Nasal bones

paired bones where your glasses would sit

vomer

a triangular bone that joins perpendicular plate of ethmoid bone to form bony part of nasal septum

Palatine bones

forms the posterior third of the hard palate and contribute to the posterior walls and floor of nasal cavity, as well as make a small contribution to floor of orbits

Craniosynostosis

the premature fusing of the skull bones

scaphocephaly, or dolicocephaly

A child with sagittal synostosis develops a very elongated, narrow skull shape called...

Plagiocephaly

term for asymmetric head shape where one part of the skull (usually the frontal or occipital region) has an oblique flattening

Infraorbital foramen

Large hole providing passage for blood vessels and nerves on the maxilla

Palletine processes

There are two ____ ____ of the maxillae that project horizontally and form anterior portion of hard palate

Cleft palate (may be accompanied by cleft lip)

The failure of the palatine processes to join during early prenatal development (about 10-12 weeks)

Maxillary sinus

Sinus lateral to nasal cavity, drains into nasal cavity through opening high and medial within sinus that exits inferior to midline of middle nasal conchae

Crepitus

Crackling sound caused by gas or grinding broken bone pieces beneath skin, can be caused by fracture of maxillary sinus

Blowout fracture

A fracture of the bone that supports the orbit causing the eye and/or eye muscles to drop down into the maxillary sinus

Occlude

Term for the teeth of the mandible and maxilla lining up properly

Mentum

The anterior point of the mandible

mandibular condyle

Name this highlighted bony landmark.

Ramus

Name this highlighted bony landmark

coronoid process

Name this part of the mandible

mandibular notch

Name this part of the mandible.

angle of the mandible

Name this bony landmark.

Mental foramen

Name this opening.

Mandibular foramen

Name this bony landmark.

Mandibular foramen

Allows passage of the third branch of the trigeminal nerve (V) on mandible, conveys sensation from the teeth and gums of the mandible

Third division nerve block

Mandibular teeth and gums can be desensitized by an injection of anesthetic near the mandibular foramen

Roof

Part of nasal complex formed by nasal bones, cribiform plate of ethmoid, and parts of frontal and sphenoid

Floor

Part of nasal complex formed by palatine processs of maxillae and horizontal plates of palatine bones

Walls

Part of nasal complex formed by ethmoid, maxillae, inferior nasal conchae, palatine bones and lacrimal bones

Nasal septum

Area formed by septal nasal cartilage, perpendicular plate of ethmoid and vomer

Humidify/warm air, give resonance to voice, and lighten skull

What are the three purposes of the paranasal sinuses that are mentioned

Bones that contribute to the oribits

What is "many people see zebras falling like elephants" a mnemonic for

Malleus, Incus, Stapes

List the auditory ossicles from superficial to deep

Fontanelles or Fontanels

Six large membranous areas of the skull providing space space between developing bones

Molding

Term for the shifting of one parietal bone over the other and the occipital sliding underneath to shrink the head during parturition

Dehydration; Meningitis and increased intracranial pressure

____ may lead to sunken fontanels. ________ may lead to bulging fontanels.

Dental attrition

Term for when teeth begin to wear down or are lost with age

The bone that covers the alveoli and roots of teeth become less prominent and eventually disapear

Explain what happens to the mandible and maxillae when a person loses some or all of their teeth

20s to 30s, 40s, late 60s or not at all

When does the coronal suture first fuse? Sagittal suture? Squamosal suture?