Brain anatomy Flashcards
what artery sits infront of the brainstem on a sagittal view
basillar
where is the fourth ventricle on a sgaittal image of brain
between midbrain and cerebellum
what is a cistern
expansions of the subarachnoid space, filled with cerebrospinal fluid (CSF), located between the arachnoid and pia mater of the brain and spinal cord. They act as reservoirs for CSF and allow it to circulate freely between different compartments. T
what sits between the pre and post central gyri
central sulcus
where is the limbic lobe
collection of stuctures
on a saggital view - beneatgh paritetal and frontal lobes, above corpus callosul
pineal galnd
circadium rhythm
behind hypothlaaums
mammillary bodies
a pair of small, round brainstem nuclei located in the hypothalamus and are crucial for memory, particularly spatial and episodic memor
arnold chiari malformation
condition affecting the rbian, constsists of a downward displacement of the cerebellar tonsils through the foramen magnum causing non-communication hydrocephalus as a result of obstruction of CSF outflow
fucntion of cerebellar tonsil
coordinate movement
parasagittal hyperdense mass
meningioma
beingin and slow growing
most common primary brain tumour in adults
overall - meningiioa
malignant - glioblastoma
mets more common
most common primary brain tumour in children
astrocystoma
malignant - medulloblastoma - cerebellum
whwre do meningiomas arise from
arachnoid cap cells from the arachnoid villi
precentral gyrus
motor cortex
post cental gyrus
sensory cortex
hounculus medial to lateral
toe, leg, trunk, shoulder, arm, face, mouth, tongue, larynx and pharynx
genitals most medial for sensory (post central)
what layer of meninges is a meningioma attached to
dura
meninges layers
out to in
dura
arachnoid
pia
flow of csf
lateral ventricle - interventricular oframen (monroe) - third ventricle - cerebral aquaduct (sylvius) - fourth ventricle - lateral (luschka) and medial (magendie) - subarachnoid space - spinal cord/arachnoid villi (superior sagittal sinus)
how much csp produced a day
400-600ml
how much csf present at any given time
150ml
what is the circle of willis?
anastomosis at the base of the brain between 2 internal carotid and 2 vertebral arteries
what is the circle of willis formed by
anterior communicating
anterior cerebral
internal carotid
posteiror communicating
posterior cerebral
termination of basillar arteries
brances of ICA
middle cerebral
anterior cerebral
posterior communicatinf
anterior choroidal
opthalmic
what does the circle of willis supply
corpus striatum
internal capsule
diencephalon
midbrain
what is the basal ganglia
primarily function in motor control, acting as a gatekeeper for voluntary movements by selecting and inhibiting actions.
corpus striatum is main component
what is the internal capsule
structure made of white matter that relays info between cerebral cortex and the rest of the brain/spinal cord
white vs grey matter
grey - most of the cerebral cortex. made up of dendrites and gial cells. pursose is the porcess information and make decisions
white matter is made up of myelinated axons responsible for transmitting infdiormation
diecephalon
deeper, central part of the forebrain located between the telencephalon and the midbrain, containing structures like the thalamus and hypothalamu
vertebral arteries
enter the cranium vis foramen magnum
lie in the subarachnoid space
ascend on the anterior surface of the medulla
unite to form the basillar artery at the base of the pons
branches:
anterior and posterior spinal
Posterior infereior cerebellay
basillar artery branches
anterior inferior cerebeallar
pontine
labrinthine
superior cerebellar posterior cerebral
internal carotid artery branches
posterior communicating
middle cerebrak
anterior cerebral
ophthalmic
anterior choroid
entry of vertebral artery into the skull
vertebral artery enters the skull through the foramen magnum
crosses transversely across the posterior arch of the atlas
vertebral artery course
inside the skull, the 2 vertebral arteries pass upwards, forwards and medially in the subarachnoid space to reach the anterior aspect of the medulla. they then unit at the base of the pons to form the basillar artery
what do the vertebral and basillar arteries supply in the brain
medulla
cerebellum
pons
midbrain
thalamus
occipital cortex
which vein drains the dangerous area of the face
inferior ophthalmic
where does the ICA enter the skull and what is its course
travels int he cartid sheath in the neck, enters through the carotid canal in the petrous part of the temporal bone, traverses the foramen lacerum, through the cavernous sinus, gives off the opthalmic artery near the sphenoid bone/clinoid then gives off the posterior communcating artery as it terminates into the middle and anterior cerebral arteries
what branch is given off byt he ICA before ACA and MCA
ophthalmic
what is a berry aneurysm and what would a rupture cause
saccular aneurysm ofeten found at junctions of arteries. common in circle of willis. would cause SAH
signs of an MCA infarct
hemiplegia lower 1/2 contralateral face
hemiplegia contralateral side
aphasia if dominant hemisphere
why are some patients asymptomatic from a carotid occlusion
intact circle of willis allows contrallateral spply
anterior attachment of tentorium cerebelli
petrous temporal bone
vessel supplying inner table of temporal bone
middle meningeal artery
penetrated with a pre-central gyrus tumous
pareital
aggressive form of glioma
glioblastoma multiforme
relationship between ICP and occulomotor
increase in ICP = occulomotor nerve palsy = dilated pupil
muscles supplied by the occulomotor nerve
superior rectum
inferior rectum
medial rectus
inferior oblique
sphincter pupillae
mullers muscleu (sympathetic fibres)
mullers muscle
The superior tarsal muscle, also known as the Müller muscle, is an accessory smooth muscle that allows for the retraction and elevation of the upper eyelid
affected in horner’s syndrome
horner’s syndrome
Horner syndrome is a rare condition classically presenting with partial ptosis (drooping or falling of the upper eyelid), miosis (constricted pupil), and facial anhidrosis (absence of sweating) due to a disruption in the sympathetic nerve supply.
paralysis of occulomotor nerve
eye is displaced downward and outwards
LR maintains tone (CNVI)
SO maintains tone (CN4)
ptosis
mydriasis
what structure is the occulomotor nerve pressed against
superior anterir portion of petrous part of temporal bone, where the tentorium cerebelli attaches
structures passing through superior orbital fissue
III
IV
V1 ( opthalmic - lacrimal, frontal, nasociliary)
VI
opthalmic veins superior and inferior
