Session 1: Cranium, Meninges and Brain Flashcards
What is another name for the facial skeleton?
Visceroskeleton
What are the two parts of the cranium?
Vault and Base
Name all the cranial bones.
Frontal, Parietal, Temporal, Occipital, Sphenoid, Ethmoid
Name all the facial bones.
Mandible, Maxilla, Zygomatic, Nasal, Lacrimal, Inferior Nasal Concha, Vomer, Palatine
What are the gaps between the bones in the skull during development called?
Fontanelles
What is the shape of the sphenoid bone and what its two parts?
Butterfly shaped – it has a greater and lesser wing
Which bone has the upper teeth attached to it?
Maxilla
What is another name for the conchae and what is their role?
Turbinate Bones – they increase the surface area of the upper respiratory tract
What are the tough fibrous joints between bones in the skull called?
Sutures
What are the three parts of the ethmoid bone?
Orbital Plate Middle Nasal Concha Perpendicular Plate
What is the name of the hole in the mandible through which a branch of the inferior alveolar nerve and vessels pass?
Mental Foramen
What are the two foramina found above and below the orbit?
Supraorbital Foramen Infraorbital Foramen
Which bones form the medial part of the orbit?
Orbital plate of ethmoid Frontal process of maxilla Lesser wing of sphenoid Lacrimal
What are the parts of the temporal bone?
Squamous Tympanic (external acoustic meatus) Zygomatic Process Mastoid Petrous
How can the cranial base be divided?
Anterior, Middle and Posterior Cranial Fossae
Which layer of the meninges goes in and out of the sulci?
Pia Mater
What are the two layers of dura in the cranium?
Periosteal and Meningeal
What difference between the cranial dura and spinal dura allows for an epidural space?
At the foramen magnum the dura goes from having two layers (periosteal and meningeal) to just one layer (equivalent of the meningeal layer). This means that there is an epidural space.
What drains into the venous blood filled spaces between dural layers?
CSF via the arachnoid villi
Describe the arrangement of dural venous sinuses and the direction of blood flow.
There is a separation between the dural layers at the top of the falx cerbri forming the superior sagittal sinus. There is another separation at the bottom of the falx forming the inferior sagittal sinus. The inferior sagittal sinus drains into the straight sinus, which then joins the superior sagittal sinus, and the two transverse sinuses at the confluence of sinuses. The blood drains to the confluence of sinuses and then along the transverse sinuses to the sigmoid sinus, which then forms the internal jugular vein.
What flat sheet of dura (with a small hole in it) keeps the pituitary gland in the sella turcica?
Diaphragma sellae
List three different types of brain herniation and their consequences.
Subfalcine – part of the frontal lobe goes under the falx cerebri Uncal – medial part of the temporal lobe goes under the tentorium cerebelli – which affects the midbrain and can cause unconsciousness Tonsilar – cerebellar tonsils go through the foramen magnum – this can affect the medulla and cause cardiorespiratory failure
Which two main vessels supply the circle of Willis?
Vertebral arteries and internal carotid arteries
There is a weak point in the skull behind which you find the largest artery entering the skull. Name the part of the skull in question and the artery.
Pterion – middle meningeal artery
What is the clinical relevance of this arrangement?
This is a possible site for extradural haemorrhage
Which veins drain into the cavernous sinus?
Superior and inferior ophthalmic veins There is also communication with the pterygoid plexus
Which vein is joined to the end of the straight sinus at the pointwhere the inferior sagittal sinus joins the straight sinus?
Great cerebral vein
What is the pterygoid plexus?
A venous plexus of considerable size that is situated between the temporalis muscle and lateral pterygoid muscle, and partly between the two pterygoid muscles
Which sinus connects the two inferior petrosal sinuses?
Basilar Sinus
Name three structures found within the cavernous sinus.
Internal carotid artery Various cranial nerves (occulomotor, trochlear, trigeminal (ophthalmic and maxillary divisions) and abducens) Pituitary Gland
What are the different tissue layers of the scalp?
Skin Connective Tissue Aponeurosis Loose Areolar Tissue Periosteum
What type of intracranial haemorrhage is associated with damage to the middle meningeal artery?
Epidural Haemorrhage
What is the tentorial notch and what is its clinical significance?
Tentorial notch is a triangular opening in the tentorium cerebelli through which the brainstem extends from the posterior to the middle cranialfossa. In the case of increased intracranial pressure, part of the temporal lobe could be pushed through this opening.
List the three branches of the trigeminal nerve and the foramina through which they pass
Ophthalmic – Superior Orbital Fissure Maxillary – Foramen Rotundum Mandibular – Foramen Ovale
Which vessel passes through the jugular foramen?
Sigmoid Sinus –> Internal Jugular Vein
Which foramen do the spinal roots of the accessory nerve pass through?
Foramen Magnum
What goes through carotid canal
Internal carotid artery
What goes through internal acoustic meatus
Facial nerve Vestibulucochlear nerve Labyrinthine artery
What goes through jugular foramen
Glossopharyngeal nerve Vagus nerve Accessory nerve Sigmoid sinus
What goes through hypoglossal canal
Hypoglossal nerve
What goes through foramen magnum
Vertebral arteries Medulla of brain Spinal roots of accessory nerve
What goes through foramen spinosum
Middle meningeal artery and vein
What goes through foramen lacerum
Internal carotid artery
What goes through foramen ovale
V3 of trigemimal
What goes through foramen rotundum
V2 trigemimal
What goes through superior orbital fissure
Occulomotor nerve Trochlear nerve V1 of trigemimal Abducent nerve Superior opthalmic vein
What goes through optic canal
Optic nerve Opthalmic artery Central artery of retina
What leaves cribriform plate
Olfactory nerve fibres
Division between middle and posterior fossa
Superior part of Petrus part of temporal bone
Division between anterior and middle cranial fossa
Sphenoidal crest
What forms after posterior fontanelle
Lambda
What forms after anterior fontanelle
Bregma
Posterior coronal suture
Lamboid
Name of fontanelles and when they seal
Anterior 18-24 Posterior 2-3
