Gross Brain Flashcards
What are the 3 main functions of the overall brain?
stimulates movement
maintains homeostasis
produces thought
How does the brain stimulate movement (general)
via sensory/motor input
How does the brain maintain homeostasis (general)
maintains homeostasis between internal and external environemnt
How does the brain produce thought (general)
intelligence related processes including memory
Frontal lobe main function
primary motor and personality
Parietal lobe main function
primary sensory and integration
Occipital lobe main function
primary visual
Temporal lobe main function
memory areas, auditory, speech, olfactory
Cerebellum main function
fine motor coordination
Pons main function
houses CN nuclei
Contains tracts between cerebrum and cerebellum
Medulla oblongata main function
maintain blood pressure and respiration
Where is the central sulcus?
between frontal and parietal lobes
Where is the parieto-occipital sulcus?
between parietal and occipital lobe
Where is the lateral fissure/sulcus?
between temporal and frontal lobes
Where is the longitudinal fissure?
between the 2 hemispheres
What main structures are found in medial brian?
corpus callosum thalamus hypothalamus pituitary gland pinneal gland mammillary bodies
What is the corpus callosum
fibers connecting the 2 hemispheres
What is the thalamus
relay station for all CN sensory except olfactory
What is the hypothalamsu
center for autonomics/endocrine function
What is the pituitary gland
Master gland of homeostasis
What is the pinneal gland
center for sleep-wake cycles
What are the mammillary bodies
Nuclei related to emotions
What are the 2 main systems for arterial supply to the brain?
internal carotid arterial system
vertebrobasilar arterial system
Internal carotid arterial system and vertebrobasilar arterial system are interconnected via ____
circle of willis
Circle of willis is found at the ___ of the brain
base
Internal Carotid artery ascends ___
the neck and the base of the skull
Internal Carotid artery enters ___ and makes a 90 degree turn
carotid canal
Internal carotid artery enters the carotid canal and then ____
makes a 90 degree turn
Internal carotid artery enters carotid canal, makes 90 degree turn and then ascends ____
superior foramen lacerum
Internal carotid artery enters carotid canal, makes 90 degree turn, ascends superior foramen lacerum, enters ____
cavernous sinus –> cranial cavity
What does the internal carotid artery supply (general_
anterior and middle brain
Internal carotid artery gives off ___ branch before bifurcating into terminal branches
opthalmic artery
Opthalmic artery is a branch off of ____
internal carotid artery
Before bifurcation into anterior/middle cerebral arteries
Internal carotid artery terminates as ___
middle cerebral a.
anterior cerebral a
Anteriror cerebral artery communicates via ___
anterior communicating artery
Internal carotid artery anastomoses with ____
posterior communicating artery
Vertebral arteries (R/L) ascend through _____
transverse formane of C6 and above
Vertebral arteries (R/L) ascend through transverse foramen of what vertebral levels?
C6 and above
Vertebral arteries run along ____
lateral medulla
Vertebral arteries meet at the pons and form ___
basilar artery
The basilar artery is formed by the fusing of ____. Where?
fusing of vertebral arteries @ pons
vertebral arteries give off 3 main branches
anterior spinal artery
posterior spinal artery
posterior inferior cerebellar artery
Anterior spinal artery is a branch of ____
What does it supply
branch of vertebral artery
Supplies anterior 2/3 of spinal cord
Posterior spinal artery is a branch of ___
What does it supply
branch of vertebral artery
Supplies posterior 1/3
Basilar artery gives off 4 main branches and then terminates. What are the branches?
anterior inferior cerebellar artery
labyrinthe artery
pontine arter
superior cerebellar artery
Posterior inferior cerebellar artery is a branch of ___
anterior inferior cerebellar artery is a branch of ___
posterior inferior cerebellar is from verteberal a
anterior inferior cerebellar is from basilar a
labyrinthe a supplies ___
ear
The basilar arteries terminal bifurcation results in ____
posterior cerebral arteries
What arteries are a part of circle of willis?
anterior communicating a anterior cerebral a internal carotid middle cerebelra posterior communcating a posterior cerebral
anterior cerebral a. supplies ___ brain
anterior and medial cerebrum
middle cerebral a. supplies __ brain
anterior and lateral cerebrum
posterior cerebral a. supplies ___ brain
posterior inferior cerebrum
What 3 bones contribute to the anterior cranial fossa?
frontal, ethmoid, sphenoid
What part of the sphenoid contributes to the anterior cranial fossa?
lesser wing
Anterior cranial fossa:
what is the anterior clinoid process?
hangs off of the sphenoid bone
What are the foramen on the ethmoid bone found in the anterior cranial fossa?
cribiform plate
foramen cecum
anterior ethmoidal foramen
posterior ethmoidal foramen
Anterior cranial fossa:
What is transmitted through the cribiform plate
CN 1 fibers
Anterior cranial fossa
what is transmitted through foramen cecum?
emissary veins going form nasal cavity to the superior sagittal sinus
emissary veins going form the nasal cavity to the superior sagittal sinus go through what foramen
what cranial fossa is this in?
foramen cecum of the ethmoid bone
this is anterior cranial fossa
Anterior ethmoidal foramen and posterior ethmoidal foramen transmit ____
anterior ethmoidal and posterior ethmoidal a., n., v.
Anterior / posterior ethmoidal foramen are best seen through what view?
the orbit
What 3 bones contribute to the middle cranial fossa?
sphenoid, temporal, parietal
The middle cranial fossa runs from ___ of the sphenoid bone to the ___ of temporal bone
lesser wing of sphenoid to the petrous portion of the temporal bone
MIDDLE CRANIAL FOSSA:
What is the chiasmatic sulcus?
where the optic chiasm sits (just above the sella turcica)
MIDDLE CRANIAL FOSSA:
What is the optic canal?
immediately lateral to the chiasmatic sulcus
transmits CN 2
MIDDLE CRANIAL FOSSA:
What is the hypophyseal fossa
aka sella turcica aka pituitary fossa
this is where the pituitary gland sits
What structures of the ethmoid bone are noticeable in teh anterior cranial fossa?
crista galli and cribiform plate
superior portions
MIDDLE CRANIAL FOSSA:
What is the dorsum sellae?
posterior to pituitary fossa, raised piece of bone
MIDDLE CRANIAL FOSSA:
What is the superior orbital fissure?
transmits CN 3, 4, 6 and opthalmic v
MIDDLE CRANIAL FOSSA:
What is the foramen rotundum?
transmits CN V2 maxillary
MIDDLE CRANIAL FOSSA:
What is the foramen lacerum?
internal carotid transmits superior to this
covered by fibrocartilage plug
MIDDLE CRANIAL FOSSA:
What is foramen ovale?
Transmits V3
MIDDLE CRANIAL FOSSA:
What is foramen spinosum?
for middle meningel a.
The posterior cranial fossa runs from __ to __
from petrous portion of temporal bone to occipital bone
POSTERIOR CRANIAL FOSSA:
What is transmitted through the internal acoustic meatus?
CN 7, 8
POSTERIOR CRANIAL FOSSA:
What is transmitted through jugular foramen?
CN 9, 10, 11, internal jugular vein
POSTERIOR CRANIAL FOSSA:
What is transitted through foramen magnum?
spinal cord and vertebral vessels
POSTERIOR CRANIAL FOSSA:
What is transmitted through hypoglossal canal?
CN 12
Describe the dura mater
outer tough layer
2 layers: periosteal layer and meningeal layer
Describe the periosteal layer of the dura mater
rough outer layer that is adherent to the skull
forms the endocranium
Describe the meningeal layer of the dura mater
smooth inner layer covering the arachnoid layer
Describe the arachnoid
intermediate web-like membrane
Describe the pia mater (general)
inner delicate layer
Middle meningeal arteries supply what
dural vasulature anteriorly
anterior meningeal artery is a branch off of __
anterior ethmoidal artery
Middle meningeal artery of dural supply branches into 2:
frontal branch and parietal branch
What happens if middle meningeal artery is injured?
tearing leads to quick epidural (extradural) and hematoma (bleeding between dura and skull)
Define a hematoma
bleeding between dura and skull
An expanding hematoma leads to ___
increased and fatal pressure to the brain
What is the most common way for middle meningeal artery to be perforated?
fracture to PTERION tears frontal branch of middle meningeal artery which crosses pterion
If the pterion is broken, what dural supply branch is hit?
frontal branch of middle meaningeal artery
Dura innervation is supplied by ___
trigeminal branch and C2-3 branches
___ branch of CN V1 supplies dural innervation
___ branch of CN V2 supplies dural innervation
___ branch of CN V3 supplies dural innervation
anterior ethmoidal branch from CN V1
and tentorial nerve (recurrent, posterior)
meningeal branch of CN V2
meningeal branch of CN V3
What is the anterior ethmoidal nerve a branch of? What does it supply?
CN V1, supplies anterior cranial fossa DURA
What is tentorial nerve a branch of? What does it supply?
CN V1 recurrent branch
supplies more posterior aspects of DURA
C2-C3 supply dural innervation to ____
posterior cranial fossa floor
Dural folds are made up of ____ layer
meningeal layer of dura mater
2 layers each
What are the main 4 dural folds
falx cerebri
falx cerebelli
tentorium cerebelli
diaphargma sellae
What is falx cerebri?
a dural fold between the 2 cerebral hemisphers
What is falx cerebelli?
a dural fold between the 2 cerebellar hemispheres
What is tentorium cerebelli?
a dural fold between the cerebellum adnd cerebrum
What is diaphragma sellae?
a dural fold between the brain and pituitary gland
When 2 dural layers split this becomes =
dural venous sinus
Dural venous drainage comes from what veins?
emissary veins, cerebellar veins, cerebral veins, diploic veins
What course do sinuses drain in?
anterior to posterior
The superior sagittal sinus joins with the straight sinus to drian into ___
the confludnce of sinus
the inferior sagittal sinus is located ____
at the inferior margin of falx cerebri
The inferior sagittal sinus joins with great cerebral veins to drain into ____
straight sinus
What drains into straight sinus?
inferior sagittal sinus
and great cerebral veins
Straight sinus joins with ___ to drain into the confludnce of sinus
superior sagittal sinus
Sphenoparietal sinus is located __
between sphenoid and parietal
Cavernous sinus is located where?
1 on each side
lateral to the pituitary gland
The 2 cavernous sinuses are interconnected via ___
intercavernous sinus
What is located within the cavernous sinus?
internal carotid artery and CN 6
What is sheathed within the walls of the cavernous sinus?
CN 3, 4, V1, V2
If the cavernous sinus ruptures, what is the most adverse affect?
then ICA ruptures which would result in an ARTERIOVENOS FISTULA
What is the most common way to get an arteriovenous fistula?
damage to the base of the skull ruptures cavernous sinus (and ICA within)
Superior and inferior petrosal sinuses are found ____
superior and inferior to the dorsum sella in the middle cranial fossa
Confluence of sinuses gets drainage from ____
superior sagittal sinus and straight sinus
Confluence of sinus drains out the ___
transverse sinus
Transverse sinus drains out the ___
sigmoid sinus
Arachnoid mater is vascularized or nonvascularized?
non vascularized
Arachnoid mater and pia mater both cover ____
all surfaces of fissures and sulci on the brain
___ in a web-like process extending downward
arachnoid mater
deep to arachnoid mater is
subarachnoid space
Subarachnoid space contains ___
CSF
how does subarachnoid space act as a shock absorber?
because it forms a fluid cushion over the gyri and sulci
What vessels are found in the subarachnoid space?
cerebral and cerebellar arteries/veins
Where are arachnoid granulations found?
in the subarachnoid space
What are arachnoid granulations?
projections of arachnoid into the superior sagittal sinus
they drain CSF into the venous system
Drainage at the arachnoid granulations occurs via ____
passive pressure gradient
Pia mater is pierced by ____
vessels that supply the brain