Case 1 anatomy Flashcards
what does the tentorium cerebelli separate?
occipital lobes from the cerebellum
what is the diaphragmatic sellae?
a sheet of dura mater which attaches to the clinoid process of sphenoid bone - it covers the pituitary gland and contains an opening through which the infudibulum and hypophysial veins pass
does the subarachnoid space contain arteries/veins?
yes, even though the arachoid mater itself is avascular
what is the most important artery supplying the dura mater? how does it get to the dura mater?
middle meningeal artery (branch of maxillary artery) - enters skull via foramen spinosum
what is the innervation of the dura mater?
innervated by branches of the vagus, trigeminal and first three cervical nerves
where does the lumbar cistern extend from and to? what is it?
L2-S2
enlargement of subarachnoid space, caudal to the conus medullaris, containing CSF and the cauda equina
what’s the denticulate ligament?
fibrous sheet of pia mater which suspends the spinal cord in the dural sac - it extends laterally from the spinal cord and attaches to the inner surface of the dural sac
where does the spinal cord terminate?
L1
where do the spinal dura and subarachnoid mater, and subarachnoid space terminate?
S2
where is a lumbar puncture usually inserted?
between L3 and L4 (or L4 and L5)
what is the supracristal plane?
spinous process of L4 is determined by this plane with transects the highest points of the iliac crests
what is secretes CSF?
group of specialised ependymal cells, choroid plexus, within each ventricle
(ependymal cells secrete it)
how are the lateral ventricles connected to the third ventricle? how are they in relationship to each other?
interventricular foramen
third ventricle within the C of the lateral ventricles
how are the third and fourth ventricles connected?
cerebral aqueduct
what’s in the middle of the spinal cord?
central/CSF canal
how is CSF returned to the venous system?
via the arachnoid villi - sections of arachnoid mater which project into the dural venous sinuses
what are cisterns? where are the different cisterns?
greater amounts of subarachnoid space
- Pontocerebellar (pontine) cistern – lies anterior to the pons
- Quadrigeminal cistern (cistern of the great vein) – located between the posterior part of the corpus callosum and the cerebellum, contains part of the great cerebral vein and the pineal gland
- Interpeduncular (basal) cistern – located between the cerebral peduncles (not cerebellar) of the midbrain
- Cerebellomedullary cistern (cisterna magna) – the largest cistern, located between the cerebellum and the medulla – receives CSF from the median and lateral apertures
- Cisterna ambiens – located on lateral aspect of the midbrain, it is continuous with quadrigeminal cistern
- Chiasmatic cistern – lies inferior and anterior to the optic chiasma, contains the decussation of the optic nerve fibres
where are the dural venous sinuses - what makes them?
space in between the periosteal and meningeal layers of the brain
which sinuses form the internal jugular vein?
sigmoid sinus and inferior petrosal sinus
where are the petrosal sinuses?
super and inferior are between cavernous sinus and sigmoid sinus
where is the confluence of sinuses?
where the superior sagittal, straight and transverse sinuses meet
what connects cavernous sinuses?
anterior and posterior intercavernous sinuses
how does cavernous sinus differ from other dural venous sinuses? what traverses through the sinus and where? what is it in direct communication with?
- it’s traversed by a number of trabeculae - give it sponge-like appearance - flow therefore quite slow
- abducens nerve and internal carotid artery traverse through the sinus
- oculomotor, trochlear, ophthalmic and maxillary lie in its lateral wall
- superior and inferior ophthalmic veins and pterygoid plexus
what does the internal carotid artery pass through to get into the skull?
carotid canal (passes along superior surface of foramen lacerum but does not traverse it)
what are the cerebellar arteries?
- superior cerebellar
- anterior inferior cerebellar
- posterior inferior cerebellar
what are the veins of the brain and what do they unite with? what are they like? what do they pass through?
- thin walled and valveless
- pass through arachnoid mater and meningeal layer of dura mater to empty into dural venous sinuses
- great cerebral vein (of Galen) unites with inferior sagittal sinus (which is above it) to form the straight sinus
- superior cerebral veins drains into the superior sagittal sinus
is the ethmoid bone part of the neurocranium?
yes
how many palatine bones are there?
2
how many maxilla bones are there?
2
what are the bones of the viscerocranium?
- Palatine (x2)
- Nasal (x2)
- Inferior nasal concha (x2)
- Maxilla (x2)
- Zygomatic (x2)
- Vomer (x1)
- Mandible (x1)
- Lacrimal (x2)
what are sutures?
immovable fibrous joints
- Most of the bones of the skull articulate with each other at immovable fibrous joints = sutures
- The only exception to this is the temporomandibular joint
what are intersections between sutures called? name them.
fontanelles
- Anterior = bregma
- Posterior = lambda
- Anterolateral = pterion
- Posterolateral = asterion
what type of the joint is the TMJ?
synovial, modified hinge joint
what are the superior articulating surfaces of the TMJ?
mandibular fossa and the articular tubercle of the temporal bone
what is unusual about the TMJ?
unlike many synovial joints, the articular surfaces of the TMJ are not covered with hyaline cartilage but with fibrocartilage
describe the TMJ
- The joint cavity is divided into superior and inferior articular cavities by a fibrocartilaginous disc
- In order for the jaw to fully open, the head of the mandible has to slide forward from the mandibular fossa onto the articular tubercle - this movement is termed translation and it occurs in the superior articular cavity
- In the inferior articular cavity the head of the mandible rotates around a transverse axis (??)
- The joint capsule is thickened laterally to form the lateral temporomandibular ligament which strengthens the joints and helps prevent posterior dislocation
- The stylomandibular and sphenomandibular ligaments are also associated with the TMJ
which cranial fossa is the pituitary gland in?
middle
which cranial fossa is the pons and medulla in?
posterior
what are the boundaries of the temporal fossa?
- Superior – inferior temporal line
- Anterior – frontal process of zygomatic bone
- Medial – parietal & temporal bone
- Lateral – zygomatic arch
- Inferior – infratemporal crest of sphenoid
- Posterior – inferior temporal line
what are the boundaries of the infratemporal fossa?
- Superior – greater wing of sphenoid
- Anterior – maxillary tuberosity
- Medial – lateral pterygoid plate
- Lateral – ramus & coronoid process of mandible
what are the boundaries of the pterygopalatine fossa?
- Superior – inferior surface of body of sphenoid
- Anterior – maxillary tuberosity
- Medial – vertical plate of palatine bone
- Lateral – pterygomaxillary fissure
- Inferior – pterygopalatine canal
- Posterior – pterygoid process of sphenoid
where is the mandibular foramen? symphysis?
inside on the ramus
line of junction when the two lateral halves of mandible typically fuse at an early period of life
what bone is the infraorbital groove in?
maxilla
where’s the basiocciput?
immediately in front of the foramen magnum - basilar part of occipital bone
where’s the mandibular fossa?
on the zygomatic arch
what’s the sella turcica?
saddle-shaped depression in the sphenoid bone - the pituitary gland is located within the most inferior aspect
where are the foramen rotundum, ovale and spinosum situated?
in the greater wing of the sphenoid bone
what are landmarks of the ethmoid bone?
- Crista Galli
- Cribriform plate
- Perpendicular plate – descends from under surface of cribriform plate, and assists in forming septum
- Superior & middle nasal conchae
