Week 4 Flashcards
What does the anterior cerebral artery supply
lower limb
What artery is the main continuation of the internal carotid artery
middle cerebral artery
where does the middle cerebral artery run
into deep part of lateral fissure, branches out into the middle of the cerebral hemisphere
what artery supplies the visual cortex
posterior cerebral artery area
what supplies the motor speech area
middle cerebral artery
what lines the cranial cavity
dura mater
what is dura mater
tough, most outer layer of the meninges
what is found between the inner and outer tables of the skull
bone marrow
how is the cranial cavity divided
anterior cranial fossa, middle cranial fossa, posterior fossa
where does the olfactory nerve come out
cribriform plate of ethmoid bone
what is the path of the olfactory nerve
lots of little nerves which come through the cribriform plate of the ethmoid bone.
join the olfactory bulb and tract
info about smell to the frontal lobe of brain
why is the anterior clinoid process useful
landmark for finding the optic nerve
what are the borders of the middle cranial fossa
lesser wing of the sphenoid bone to the superior border of the petrous temporal bone
what covers the pituitary gland
pituitary stack
where is the internal carotid artery in the cranial cavity
very close to the optic chiasm
what is an aneurysm
swelling of an artery
why might an aneurysm cause visual disturbances
swelling of the artery pressing on the optic chiasm
where is the superior orbital fissure
under the sphenoid bone
what is the path of the occulomotor nerve
- goes through the dura
- runs between the dura and bone
- comes out at the superior orbital fissure
what does the trochlear nerve supply
superior oblique muslce
what is the path of the trochlear nerve
- smallest of the cranial nerves
- through dura
- runs between dura and bone
- comes out at superior orbital fissure
where does the trigeminal nerve come out
back end of the middle cranial fosa
what is the path of the trigeminal nerve
- comes from pons
- goes into tunnel in dura
- trigeminal ganglion in meckel’s cave
what are the 3 branches of the trigeminal nerve
- opthalimic
- maxillary
- mandibular
what is the path of the ophthalmic nerve
- branches from ganglion
- goes through superior orbital fissure
- supplies skin of forehead and scalp
what is the path of the maxillary nerve
- branches from ganglion
- goes through foramen rotundum
- reaches pterygopalatine fossa
- supplies middle face, palate, siuses, nasopharynx, nose and alveolar to upper teeth
what is the path of the mandibular nerve
- branches from ganglion
- goes through the foramen ovale
- supplies the temple, jaw, chin, anteiror 2/3 tongue, floor of mouth, lower teeth and lower gingiva, lower lip
what is trigeminal neuralgia
extremely sharp pain in one of the areas of the trigeminal nerve (often maxillary)
what can trigger trigeminal neuralgia
dental treatment
how is trigeminal neuralgia treated
carbamazepine (neuro-suppressor drug) or use needle through the foramen ovale to remove cells causing the trouble
what is the path of abducens nerve
- penetrates dura, has very long course
- runs under the dura
- over the edge of the petrous temporal bone
- forwards to get to the superior orbital fissure where it leaves cranial cavity
what is the path of the facial and vestibulochlear nerve
- nerves run side by side (8th is lateral)
- go into the internal acoustic meatus
- 8th goes into ear
- 7th runs close to ear and comes out at the base of the skull
what is the path of the glossopharyngeal, vagus and cranial root of the accessory nerve
- go through jugular foramen
- 9 and 10 supply pharynx and larynx
what is the path of the spinal root of the accessory nerve
- go through jugular foramen
- comes up from spinal cord
- supplies sternocleidomastoid and trapezius
what is the spinal root of the accessory nerve derived from
the first 5 cervical (C1-C5) segments
apart from nerves what also exits the cavity through the jugular foramen
venous blood
what is the path of the vertebral arteries
- comes through dura
- into spinal cord
- through the foramen magnum
- alongside the medulla
- join together to form the bailsar artery at pons
what is the path of the hypoglossal nerve
- small bony opening just in front of the foramen magnum
- long course towards the tongue
where is the dura mater
immediately inside the vault
slightly attached to the vault
what is the large fold of dura mater called in he midline
falx cerebri
what runs inside the falx cerebri
superior sagital sinus
what are the 3 layers of meninges called
- dura mater
- arachnoid mater
- pia mater
what and where is pia mater
- deepest layer of meninges
- on surface of brain
- very thin and soft
- follows brain everywhere and covers CNS
what and where is the arachnoid mater
- lies immediately to the dura
- soft, flimsy layer
- cob-web like strands run across the sub-arachnoid space to the pia mater
what is in the sub-arachnoid space
CSF
what is the path of CSF
- made in ventricles
- escapes into sub-arachnoid space at the 4th ventricle (hind brain)
- goes down the spinal cord through the foramen magnum
what is the purpose of CSF
helps to resist movement of the brain
what are the projections of arachnoid mater called
arachnoid villi
what do the arachnoid villi do
absorb CSF into the blood stream
what happens at the superior sagital sinus
where the falx meets the tentorium
what shape is the superior sagital sinus
triangular
what is the path of the blood following the superior sagital sinus
- superior sagital sinus
- blood swings to right through right transverse sinus (makes a groove in the skull)
- sigmoid sinus at front of posterior cranial fossa
- through jugular foramen
what is the path of the blood following the straight sinus
- straight sinus
- blood swings to the left through the left transverse sinus
- sigmoid sinus
- through jugular foramen
what is the connection between the superior sagital sinus and straight sinus called
confluence of sinuses
path of venous blood from the orbit
- orbit
- opthalmic veins
- cavernous sinus
- pietrosal sinuses
- sigmoid sinus
- internal jugular vein
describe cavernous sinus thrombosis
caused by infection in upper teeth or face
results in swollen eye and fever due to blood clot
UPPER TEETH
- bacteria enters venous blood at pterygoid venous plexus
- sphenoidal emissary vein
- cavernous sinus
FACE
- bacteria enters venous blood through orbit
- at caverous sinus blood moves very slowly as lots of gaps
- bacteria multiply here
what does cavernous sinus thrombosis present as
swollen eye and fever
how quickly does blood move the cavernous sinus and why
very slowly, lots of gaps
what are the 3 types of haemorrhage called
- Extradural haemorrhage
- Subdural haemorrhage
- Subarachnoid haemorrhage
what causes an extradural haemorrhage
bursting of middle meningeal artery
where does blood gather in an extradural haemorrhage
between the dura and the bone
how quickly does a pt’s conscious level deteriorate in an extradural haemorrhage
gradually over a few hours
who tends to get extradural haemorrhages
anyone of any age
what causes a subdural haemorrhage
cerebral veins tearing where the are attached to firm dura
where does blood gather in a subdural haemorrhage
between dura and arachnoid
how quickly does a pt’s conscious level deteriorate in a subdural haemorrhage
very gradually over days weeks (venous blood is slower)
who tends to get subdural haemorrhages
elderly
what causes a subarachnoid haemorrhage
bursting of cerebral arteries (berry aneurysm around the circle of Whillis that can burst)
where does blood gather in a subarachnoid haemorrhage
on the underside of the brain
how quickly do patients level deteriorate in a subarachnoid haemorrhage
very rapidly
who tends to get a subarachnoid haemorrhage
people in mid-life
