W1 Skull & Meninges - ANAT3004

number of bones for skull

8 cranial, 14 facial, 1 hyoid and 6 auditory bones

cranial, single/paired?

single

temporal, single/paired?

paired

parietal, single/paired?

paired

occipital, single/paired?

single

ethmoid, single/paired?

single

sphenoid, single/paired?

single

maxilla, single/paired?

paired

zygomatic, single/paired?

paired

lacrimal, single/paired?

paired

nasal, single/paired?

paired

inferior nasal concha, single/paired?

paired

palatine, single/paired?

paired

mandible, single/paired?

single

vomer, single/paired?

single

anterior cranial fossa

formed by orbital plate of frontal and lesser wing of sphenoid

cribriform plate

perforated by small foramina to transmit olfactory nerve filaments from nose to olfactory bulb

crista galli

bony crest projects superiorly from cribriform plate as site of attachment for falx cerebri

middle cranial fossa

formed by body of sphenoid and greater wing of sphenoid with petrous and squamous temporal bones as posterolateral boundaries

hypophyseal fossa

(sella turcica) contains pituitary gland

dorsum sellae

bony ridge between the posterior clinoid processes

openings in the middle cranial fossa

optic canal, superior orbital fissure, foramen rotundum, foramen ovale, foramen spinosum and foramen lacerum

optic canal has

CN II (optic nerve)

superior orbital fissure has

CN III (oculomotor nerve), IV (trochlear nerve), V/1 (first division of trigeminal nerve) and VI (abducens nerve)

foramen rotundum has

CN V/2 (second division of trigeminal nerve)

foramen spinosum has

middle meningeal artery

foramen lacerum has

greater petrosal nerve and internal carotid traverses it

arcuate eminence

overlies the superior and anterior semicircular canals

tegmen tympani

overlies the middle ear

trigeminal impression

indentation on the posteromedial part of the middle cranial fossa on the petrous temporal bone marking position of the trigeminal ganglion

posterior cranial fossa

formed by occipital bone and petrous temporal bone

openings in the posterior cranial fossa

internal acoustic meatus, jugular foramen, hypoglossal canal and foramen magnum

internal acoustic meatus has

CN VII (facial nerve) and VIII (vestibulocochlear nerve)

jugular foramen has

CN IX (glossopharyngeal nerve), X (vagus nerve), XI (accessory nerve) and internal jugular vein drains

hypoglossal canal has

CN XII (hypoglossal nerve)

foramen magnum has

spinal cord

hard palate formed by

palatine process of maxilla and horizontal plate of the palatine bone

sutures in the hard palate

intermaxillary, palatomaxillary and interpalatine

openins in the hard palate

incisive canal and greater and lesser palatine foramina

spine of sphenoid function

attachment of sphenomandibular ligament to stabilise the TMJ, found between the foramen spinosum and carotid canal

bony nasal septum formed by

vomer posteroinferiorly and perpendicular plate of the ethmoid bone anterosuperiorly

pterygoid fossa

between pterygoid plates

scaphoid fossa

posterior end of medial pterygoid plate

choanae

posterior nasal openings

external occipital protuberance

attachment of nuchal ligament and trapezius

pharyngeal tubercle

basilar part of occipital bone for site of attachment of pharyngeal raphe and constrictor muscles

paranasal sinuses

lighten the weight of the head, support immune defence of nasal cavity, humidify inspired air, increased resonance of the voice and crumple zone protection of vital structures

dura mater layers

periosteal and meningeal

periosteal layer

firmly adherent to bone of the skull

meningeal layer

adheres to arachnoid mater, creates serveral dural folds to divide cranial cavity and function to limit the rotational displacment of the brain

dural venous sinus

space between two layers of dura mater for venous blood

meninges three layers

dura mater (outer), arachoid mater (middle) and pia mater (inner)

dura mater

adheres to skull

arachnoid mater

layer of connective tissue projections

subarachnoid space

contains CSF

pia mater

closest to surface of the brain and spinal cord which folds into sulci

falx cerebri

longitudinal fissure between hemispheres and attaches to crista galli

falx cerebelli

folds into posterior cerebellar notch and partially separates the cerebellar hemispheres and attached to the inferior surface of the tentorium cerebelli

sella diaphragm

covers the hypophyseal fossa and contains the pituitary gland with opening to accommodate infundibulum

tentorium cerebelli

between cerebellum and occpital lobes