GRISTO Module 4 Anatomy: Blood Supply of the CNS

center, furthest

Arterial supply is delivered from the outside, so the ____ of the CNS is ______ from the largest vessels

segmental, regional

The arterial supply to the spinal cord is largely ________, while the blood supply of the brain is ______

arterioles and capillary beds

Anastomoses between larger arteries are limited and there are almost no anastomoses between

The internal carotid system and the vertebral system

There are two pathways of blood into the brain:

BLOOD SUPPLY OF THE BRAIN AND BRAINSTEM

BLOOD SUPPLY OF THE BRAIN AND BRAINSTEM

A. Basilar

B. Vertebral artery

C. Internal carotid artery

D. External carotid artery

E. Common carotid

F. Brachiocephalic trunk

G. Subclavian artery

Enters the skull at the opening to the carotid canal, passes through the petrous temporal bone before emerging into the middle cranial fossa, where it passes anteriorly through the cavernous sinus

The artery loops superiorly and posteriorly before dividing into its terminal branched

The internal carotid artery is a branch of the common carotid artery. The artery travels:

Anterior cerebral artery and middle cerebral artery

Terminal branches of the internal carotid artery

ascend the neck through the transverse foramina of cervical vertebrae before entering the skull at the foramen magnum

These two vessels then come together to form the basilar artery at the base of the medulla

The vertebral arteries are branches of the subclavian artery. These vessels travel:

brainstem

The basilar artery is the main blood supply to the

circle of willis

The basiler arter is connected to the carotid system via the

Circle of Willis Isolated

A. Middle cerebral artery (MCA)

B. Posterior cerebral artery

C. Superior cerebellar artery (SCA)

D. Anterior inferior cerebellar artery

E. Posterior inferior cerebellar artery (PICA)

F. Anterior spinal artery (ASA)

G. Posterior spinal artery (PSA)

H. Vertebral artery

I. Basilar artery

J. Posterior communicating artery (PCOM)

K. Internal carotid artery

L. Anterior communicating artery (ACOM)

M. Anterior cerebral artery (ACA)

A. Anterior communicating branch (ACOM)

B. Anterior cerebral artery

C. Internal carotid artery

D. Middle cerebral artery

E. posterior cerebral artery

F. superior cerebellar artery

G. Basilar artery

H. Vertebral artery

I. Anterior spinal artery

J. Posterior spinal artery

K. Posterior inferior cerebellar artery (PICA)

L. Anterior inferior cerebellar artery (AICA)

M. Posterior communicating artery (PCOM)

cerebral cortex and deep telencephalic structures like basal ganglia and internal capsule

The internal carotid system irrigates most of the

middle cerebral artery (MCA) and anterior cerebral artery (ACA)

The main branches of the internal carotid artery are the

Covers the largest territory in the brain, supplying most of the lateral frontal, parietal, and temporal lobes and insula

Branches of the MCA supply the portions of the primary motor and sensory cortices dedicated to the arm and face.

Middle cerebral artery:

will generally have paresis of the contralateral face and upper limb with sensory loss from the corresponding area

Patients with MCA strokes

ACA and PCA can NOT take over it does not anastomoses with anything

If we lose MCA

Supplies the medial surfaces of the frontal and parietal lobes. The paired anterior cerebral arteries are joined anterior to the optic chiasm by the anterior communicating artery

Branches of the ACA supply the portions of the primary motor and sensory cortices dedicated to the lower limb and perineum.

Anterior cerebellar artery:

have paresis of the contralateral lower limb and foot with sensory loss from the corresponding areas

Patients with ACA strokes will generally

the entire spinal cord, brainstem, cerebellum, thalamus, occipital lobes, and inferior aspect of temporal lobes

The vertebrobasilar system irrigates

Basilar artery terminates in two posterior cerebral arteries

The PCA supplies the medial surface of the occipital lobe (visual cortex) and the inferior and lower lateral surfaces of the temporal lobe

Posterior cerebral artery (PCA)

prominent visual deficits

Strokes to PCA results in

A. PCOM

B. PCA

C. SCA

D. AICA

E. PICA

F. ASA

PCA aa

Blood supply to the Midbrain

Basilar a.

Blood supply to the pons

vertebral aa

Blood supply to the medulla

PCA

Blood supply to occipital lobe

PCA

Blood supply to inferior temporal lobe

PCA

Blood supply to thalamus

PICA, AICA, and SCA

Blood supply to cerebellum

vertebral artery system --> anterior and posterior spinal arteries

Blood supply to spinal cord

A. Superior cerebellar artery (SCA)

B. Anterior inferior cerebellar artery (AICA)

C. Posterior inferior cerebellar artery (PICA)

BLOOD SUPPLY OF THE SPINAL CORD

BLOOD SUPPLY OF THE SPINAL CORD

A. ASA

B. PSA

also B: PSA

A. SCA

B. Basilar artery

C. AICA

D. PICA (gives off posterior spinal a in 75%)

E. Anterior spinal a

F. Posterior spinal a. (25% of cases)

G. vertebral artery

entire spinal cord

The vertebrobasilar system supplies the

the vertebral artery

The anterior spinal artery branches directly off

PICA but can also branch off the vertebral arteries as well

The posterior spinal artery most often branches off

Supplies the ventral horn and intermediate gray areas, plus the ventral and lateral funiculi bilaterally, as well as the ventral white commissure

Along the length of the spinal cord:

The Anterior spinal artery

is bilateral. Together they supply most of the dorsal horn and dorsal column unilaterally

Along the length of the spinal cord:

The Posterior spinal artery

weakly anastomose, but this is inconsistent

ASA and PSA territories

have some serious consequences

A lesion to either the ASA or PSA can

A. Dorsal column system

B. Dorsal horn

C. Spinothalamic tract

D. Ventral horn

E. Corticospinal tract

descend

Although the ASA and PSA arteries run the length of the cord their robusticity decreases as they

medullary, great radicular artery (of adamkiewicz)

Occasionally, _______ arteries will extend to anastomose with the ASA. The largest and most discernable of these is the __________

A. Anterior spinal a.

B. Vertebral a.

C. Subclavian

D. Anterior medullary a.

E. Great radicular a.

F. Lumbar anterior medullary a.

roots

The ASA and PSA supply the cord itself but rarely reach out to supply the

segmental arteries, Radicular arteries

The roots are supplies by ____________, which branch from larger local arteries. they in turn give off ____

ventral and dorsal roots

- Very small and terminate in the roots

The radicular arteries supply the

A. Posterior spinal aa (from PICA)

B. Posterior medullary a

C. Radicular artery

D. Anterior medullary a

E. Posterior intercostal a

F. Segmental aa.

G. Segmental aa

H. Anterior spinal a

VENOUS DRAINAGE

VENOUS DRAINAGE

Cerebral

______ veins drain the brain and associated structures

dural venous sinuses (openings in the layers of the dura mater)

Cerebral veins drain into

internal jugular vein, which leaves the neurocranium

Dural venous sinuses drain predictably through the skull and coalesce to form the

A. External cerebral veins

B. Superior sagittal sinus

C. Bridging veins from external cerebral veins

Bridging veins

- if broken can cause subdural hematoma

crescent-shaped dural fold that sits in the longitudinal fissure of the cerebrum

The falx cerebri is a

the crista galli to the occiput where it connects with the tentorium cerebelli

The falx cerebri runs from

A. Superior sagittal sinus

B. Inferior sagittal sinus

C. Great cerebral vein (galen)

D. Straight sinus

E. Confluence of sinuses

F. Occipital sinus

A. Superior sagittal sinus

B. Superior ophthalmic vein

C. Cavernous sinus

D. Tentorial notch

E. Inferior sagittal sinus

F. Straight sinus

G. Confluence of sinuses

H. Transverse sinus

I. Sigmoid sinus

J. Internal jugular vein

K. Superior petrosal sinus

L. Inferior petrosal sinus

M. Falx cerebri

falx cerebri between the cerebral hemispheres

Tentorium cerebelli between occipital lobe of the cerebrum and cerebellum

Two specialized dural folds support and partition the major brain parts:

meningeal dura

The dural venous sinuses are venous channels found between layers of

internal and external veins of the brain

As well as CSF from the subarachnoid space, ultimately joining to empty into the internal jugular vein

The dural venous sinuses receive blood from the ......... as well as CSF from the ........

HOW BLOOD IS RETURNED TO THE INTERNAL JUGULAR

HOW BLOOD IS RETURNED TO THE INTERNAL JUGULAR

falx cerebri

The superior sagittal sinus arises in the roof of the

deeply placed great cerebral vein to form the straight sinus

The inferior sagittal sinus arises in the inferior free edge of the falx cerebri and joins the

superior sagittal sinus and the small occipital sinus which runs in the small falx cerebelli, at the confluence of sinuses

The straight sinus courses through the midline of the tentorium cerebelli before uniting with the

two transverse sinuses which run lateralward and forward in the attached margin of the tentorium cerebelli

The confluence of sinuses drains into the

Common superior ophtalmic vein, which in turn drains into the centrally located cavernous sinus

Meanwhile:

Blood from the orbit and face (mainly via the supraorbital and supratrochlear veins and nasal veins) drains into the

superior ophthalmic vein, which in turn drains into the centrally located cavernous sinus

The cavernous sinus is emptied by the

transverse sinus to form the S-shaped sigmoid sinus

The superior petrosal sinus units with teh

the internal jugular vein

The inferior petrosal sinus joins with the sigmoid sinus to form

A. Optic Chiasm

B. Internal carotid artery

C. CN III

D. CN IV

E. CN VI

F. CN V1

G. CN V2

H. Cavernous sinus

I. Pituitary

cool arterial blood entering the cranium

The cavernous sinus helps

nasal cavity

Across many heat adapted mammalian species, heat is dissipated through the vessels in the

cavernous sinus

The cool venous blood returns to the skull and drains into the

cools the arterial blood as it enters the cranium, thus aiding in maintaining brain thermodynamics

The internal carotid artery runs through the cavernous sinus. This cool venous blood of the cavernous sinus surrounds the carotid artery and

A. Ophthalmic vein

B. Cavernous sinus

C. Drains the forehead

D. Drains the nose

E. Drains the lips

Bacterial infection that spreads from the face such as sinusitis, infection of the nasal sinuses

Or

Facial acne which can become infected or introduce infections into the bloodstream if punctured

Cavernous sinus thrombosis is often caused by

region from which blood drains from the face via the superior ophthalmic vein into the cavernous sinuse

This is the way these infections can spread to the dural sinuses

The Danger Triangle of the face is the

QUIZ QUESTIONS

QUIZ QUESTIONS

False

True or false? There are many anastomotic connections between the arteries of the brain

Vertebral

Indicate the systemic origin (carotid versus vertebral)

Basilar artery

Vertebral

Indicate the systemic origin (carotid versus vertebral)

AICA

Vertebral

Indicate the systemic origin (carotid versus vertebral)

Posterior spinal artery

Carotid

Indicate the systemic origin (carotid versus vertebral)

Anterior cerebral artery

Carotid

Indicate the systemic origin (carotid versus vertebral)

Middle cerebral artery

Vertebral

Indicate the systemic origin (carotid versus vertebral)

Posterior cerebral artery

Vertebral

Indicate the systemic origin (carotid versus vertebral)

PICA

Vertebral

Indicate the systemic origin (carotid versus vertebral)

Anterior spinal artery

Vertebral

Indicate the systemic origin (carotid versus vertebral)

Superior cerebellar artery

Posterior communicating artery

What is the name of the artery that connects the vertebral and carotid systems

Lateral cerebrum (UL & head motor and sensory cortex and insula)

Match the artery with its general territory:

MCA