CSF and Blood SUpply Flashcards
brain and spinal cord are critically dependent on an
uninterrupted supply of oxygenated blood
VASCULAR SUPPLY OF THE BRAIN
About _____ of the total blood volume in the body circulates
in the brain, which accounts for about 2% of the body
weigh
18%
named after the English neuroanatomist Sir Thomas
Willis) is a hexagon of vessels that gives rise to all of the
major cerebral arteries
CIRCLE OF WILLIS
CIRCLE OF WILLIS is fed by the paired_________ and the _______.
paired internal carotid arteries and the basilar
artery
may be large on one
or both sides (embryonic type)
Posterior communicating
arteries
thin
on the first stretch
Posterior Cerebral Artery
may be absent, double or thin
Ant. Communicating Artery
Initial Strethc of Large Arteries:
Ventral to the brain in a
relatively small region
A border zone separates from other
territories when a major artery supplies a certain territory
Water Shed Areas:
arterial blood for the brain enters the cranial cavity by way
of two pairs of large vessels:
internal carotid arteries & vertebral arteries
supplies:
brain stem, cerebellum, occipital lobe, and parts of the
thalamus, and the carotids normally supply the
remainder of the forebrain
Vertebral Arterial System
interconnected via the anterior cerebral arteries and the
anterior communicating artery
Carotid Arteries
terminates in the interpeduncular cistern in a bifurcation as
the left and right posterior cerebral arteries.
Basilar Artery
This forms Carotid Siphon before reaching the brain.
Internal Carotid Artery:
First Branch:
Ophthalmic Artery
The ___________________ usually meet over a short distance in midplane to form a short but functionally important anterior
communicating artery. (1 Acom A)
two anterior cerebral arteries
carries blood to the choroid plexus of lat. ventricles as well to
adj. brain structures.
Ant. Choroidal Artery:
Supplies the cortical areas essential for speech in the left
hemisphere
Middle Cerebral Artery:
Left MCA:
Artery of speech.
supply the
anterior frontal lobe and medial aspect of the hemisphere.
Anterior Cerebral Artery
supplies mainly the occipital lobe, the choroid plexuses of thethird and lateral ventricles and the lower surface of the
temporal lobe
Posterior Cerebral Artery:
Predict the deficits caused by a stroke affecting the territories
irrigated by each of these arteries
.CORTICAL SUPPLY
venous drainage of the brain and coverings includes:
the veins of the brain
the dural venous sinuses
the dura’s meningeal veins,
diploic veins between the tables of the skull
-drain from the scalp, through the skull, into
the larger meningeal veins and dural sinuses
Emissary veins
have no valves and
seldom accompany the corresponding cerebral arteries
cerebral veins
with their tributaries, the septal, thalamostriate, and
choroidal veins–empty to this vein.
Internal Cerebral Veins
which wind (one right and one left) around the side of the
midbrain, draining the base of the forebrain
Basal Veins of Rosenthal
- form the straight sinus
- venous drainage of the base of the cerebrum is also into the
deep middle cerebral vein (coursing in the lateral fissure) and
then to the cavernous sinus.
Precentral Vein:
generally into the nearest large vein or sinus,
confluence of the sinuses, and ultimately to the internal
jugular vein
CORTICAL VEINS
run upward on the
hemisphere’s surface to the superior sagittal sinus,
generally passing under any lateral lacunae.
6 to 12 superior cerebral veins
Most of the inferior cerebral veins end in the superficial
middle cerebral vein.
CORTICAL VEINS
these connect the deep middle cerebral vein with
the superior sagittal sinus or transverse sinus
Anastomotic veins
Venous channels lined by mesothelium lie between the inner
and outer layers of the dura
dural sinuses
All sinuses ultimately drain into the ________
internal jugular veins or
pterygoid plexus
between the falx and the inside of the
skull cap
Superior sagittal sinus:
in the free edge of the falx
Inferior sagittal sinus
in the seam between the falx and the tentorium.
Straight sinus
between the tentorium and its attachment
on the skull cap.
Transverse sinuses:
S-curved continuations of the transverse
sinuses into the jugular veins; a transverse and a sigmoid sinus
together form a lateral sinus.
Sigmoid sinuses
drain the deep middle cerebral veins
into the cavernous sinuses.
Sphenoparietal sinuses:
on either side of the sella turcica. receive drainage from multiple sources,
including the ophthalmic and facial veins.
Cavernous sinuses:
- most common cause of neurologic disability in
adults - the third most common cause of death in our society
CEREBROVASCULAR DISORDERS
result of its high metabolic rate and limited energy reserves,
the central nervous system (CNS)
. ISCHEMIC CEREBROVASCULAR DISEASE
surrounding the area of infarction (metabolically
compromised and electrically silent)
Penumbra
The rupture of a blood vessel is often associated
with hypertension vascular malformations or with trauma.
Hemorrhage
often accompanied by contralateral weakness or sensory loss.
CAROTID ARTERY DISEASE
CAROTID ARTERY DISEASE: If the dominant hemisphere is involved there will be?
Aphasia or Apraxia
- regulates the extracellular milieu and protects the central
nervous system - formed primarily in the ventricles and then circulates through
the ventricles and into the subarachnoid space
CSF System
