Blood Supply
to the Nervous System
Objectives





1. Describe the importance of blood circulation to the
brain.
2. List major arteries that transport blood to the
cerebrum.
3. Describe region supplied by each major artery.
4. Discuss general blood supply for brainstem,
cerebellum, and spinal cord.
5. List common points of anastomoses in the
vascular system.
Objectives


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6. Explain significance of potential collateral
circulation.
7. Describe venous-sinus system.
8. Discuss mechanism of cerebrovascular accidents.
9. Discuss common cerebrovascular accidents.
10. Describe the mechanism regulating blood flow.
11. Discuss the blood-brain barrier and its clinical
significance.
Blood Supply

Function:

Total Dependence of Nerve Cells
Oxygen Deprivation Within the
Brain

Without Adequate Blood Supply

Irreversible Damage

Site of Lesion
Metabolic Needs of the Brain

Brain’s Metabolic Needs

Blood Flow to the Brain
Drainage of Blood from the
Brain

Veins and Sinuses
Vascular Network

Blood Circulation to the Brain
Vascular Network

Large Arteries

Small arteries

Arterioles with small diameters

Capillaries
Cerebral Arteries: Lateral
Brain and Cerebellar Surface

Bhatnagar & Andy, 1995, Figure 17.4
Cerebral Arteries: Midsagittal
Brain Surface

Bhatnagar & Andy, 1995, Figure 17.3
Vascular Network

Veins

Venules
Cerebral Venous Sinuses

Bhatnagar & Andy, 1995, Figure 17.7
Cerebral Veins: Lateral
Surface

Bhatnagar & Andy, 1995, Figure 17.8A
Cerebral Veins: Midsagittal
Surface

Bhatnagar & Andy, 1995, Figure 17.8B
Cerebrovascular Supply

Two Arterial Systems:
Cerebral Arteries

Love & Webb, 1996, Figure 3-7
Cerebrovascular Supply: Carotid
and Vertebral Basilar Systems

Bhatnagar & Andy,
1995, Figure 17.1A
Cerebrovascular Supply:
Circle of Willis

Bhatnagar & Andy,
1995, Figure 17.1B
Cerebrovascular Supply:
Cerebral Arterial Structure at
Base of Brain

Bhatnagar & Andy, 1995, Figure 17.2
Cerebrovascular Supply:
Carotid System

Carotid System
Cerebral Arteries

Love & Webb, 1996, Figure 3-7
Cerebrovascular Supply: Carotid
and Vertebral Basilar Systems

Bhatnagar & Andy,
1995, Figure 17.1A
Carotid System

External Carotid Artery and its Branches

Internal Carotid Artery and its Branches
Cerebral Arteries

Love & Webb, 1996, Figure 3-7
Carotid System

Internal Carotid
Cerebrovascular Supply: Carotid
and Vertebral Basilar Systems

Bhatnagar & Andy,
1995, Figure 17.1A
Vertebral Basilar System

Two Vertebral Arteries
Cerebral Arteries

Love & Webb, 1996, Figure 3-7
Cerebrovascular Supply: Carotid
and Vertebral Basilar Systems

Bhatnagar & Andy,
1995, Figure 17.1A
Cerebrovascular Supply:
Circle of Willis

Bhatnagar & Andy,
1995, Figure 17.1B
Cerebrovascular Supply:
Cerebral Arterial Structure at
Base of Brain

Bhatnagar & Andy, 1995, Figure 17.2
Vertebral Basilar System

Branches
Cerebrovascular Supply:
Circle of Willis

Bhatnagar & Andy,
1995, Figure 17.1B
Cerebrovascular Supply:
Cerebral Arterial Structure at
Base of Brain

Bhatnagar & Andy, 1995, Figure 17.2
Vertebral Basilar System

Posterior Spinal Artery

Function:

Circulatory Disorders
Vertebral Basilar System

Anterior Spinal Artery

Pathway:

Function:

Circulatory Disorders
Corticobulbar
Tract

Bhatnagar & Andy,
1995, Figure 14.3A
Corticospinal
Tract

Bhatnagar & Andy,
1995, Figure 14.3B
Vertebral Basilar System

Posterior Inferior Cerebellar Artery

Function:
Vertebral Basilar System

Anterior Inferior Cerebellar Arteries
Vertebral Basilar System

Pontine Level
Cerebrovascular Supply:
Circle of Willis

Bhatnagar & Andy,
1995, Figure 17.1B
Vertebral Basilar System

Internal Auditory Artery

Function:
Vertebral Basilar System

Superior Cerebellar Arteries

Pathway:

Function:

Circulatory Disorders:
Circle of Willis

Shape:

Location:

Connections:
Cerebrovascular Supply: Carotid
and Vertebral Basilar Systems

Bhatnagar & Andy,
1995, Figure 17.1A
Cerebrovascular Supply:
Circle of Willis

Bhatnagar & Andy,
1995, Figure 17.1B
Cerebrovascular Supply:
Cerebral Arterial Structure at
Base of Brain

Bhatnagar & Andy, 1995, Figure 17.2
Circle of Willis

Components:

Communicating Arteries
 1.


2.
Proximal Portions of the Cortical Arteries
 1.

2.

3.
Circle of Willis

Importance:

Anastomotic Point
Circle of Willis

Two Types of Arteries:

1. Cortical (Circumferential) Arteries

2. Central (Penetrating) Arteries
Cortical Arteries

1. Anterior Cerebral Artery

Pathway:
Cerebral Arteries: Midsagittal
Brain Surface

Bhatnagar & Andy, 1995, Figure 17.3
Cortical Arteries

1. Anterior Cerebral Artery

Vascular Supply
 Regions:
Cerebral Arteries of the Lateral and
Medial Surfaces of the Left Cerebral
Hemisphere

Love & Webb, 1996, Figure 3-8
Cortical Arteries

1. Anterior Cerebral Arteries

Vascular Supply
 Interruption of Blood Circulation:

Motor Impairment:

Cognitive Impairments:

Additional Impairments:
 Decreased spontaneity
 Motor inaction
 Impaired judgment
 Limited concentration
Cortical Arteries

2. Middle Cerebral Arteries

Pathway:
Cerebral Arteries: Lateral
Brain and Cerebellar Surface

Bhatnagar & Andy, 1995, Figure 17.4
Cortical Arteries

2. Middle Cerebral Artery

Vascular Supply

Important Areas
Cerebral Arteries of the Lateral and
Medial Surfaces of the Left Cerebral
Hemisphere

Love & Webb, 1996, Figure 3-8
Cortical Arteries

2. Middle Cerebral Arteries

Vascular Supply
Cortical Arteries

2. Middle Cerebral Arteries

Interruption of Blood Supply
 Motor Impairment:

Sensory Impairment:

Other Symptoms:

Subcortical damage:
Cortical Arteries

3. Posterior Cerebral Artery

Pathway:
Cortical Arteries

3. Posterior Cerebral Artery

Vascular Supply
Cerebral Arteries of the Lateral and
Medial Surfaces of the Left Cerebral
Hemisphere

Love & Webb, 1996, Figure 3-8
Cortical Arteries

3. Posterior Cerebral Artery

Interruption of Blood Supply
 Visual Impairment:
Central (Penetrating) Arteries

Pathway:
Central (Penetrating) Arteries

Vascular Supply:

Supply the subcortical structures that include:
 Thalamus
 Hypothalamus
 Caudate nucleus
 Putamen
 Globus pallidus
 Basal ganglia
 Internal capsule
 Choroid plexus
 Other structures
Central (Penetrating) Arteries
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Interruption of Blood Supply:

Anteromedial Arteries
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Medial Striate Arteries

Anterior Choroidal Artery
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Posteromedial Arteries

Posterolateral Arteries
Collateral Circulation
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Alternative Blood Supply:

Importance in Recovery:
Cerebrovascular Supply: Carotid
and Vertebral Basilar Systems

Bhatnagar & Andy,
1995, Figure 17.1A
Cerebrovascular Supply:
Circle of Willis

Bhatnagar & Andy,
1995, Figure 17.1B
Collateral Circulation

Two Common Points of Collateral Circulation
Vascular Pathologies

Vascular Diseases of the Brain
Vascular Pathologies: Occlusive
Vascular Pathologies

Atherosclerosis
Vascular Pathologies: Occlusive
Vascular Pathologies

Ischemia

Transient Ischemic Attack (TIA)
Vascular Pathologies: Occlusive
Vascular Pathologies

Treatment

Compensation for Atherosclerosis
Cerebrovascular Disorders

Bhatnagar & Andy, 1995, Figure 17.6A, B, C
Vascular Pathologies: Occlusive
Vascular Pathologies

Embolism
Vascular Pathologies: Occlusive
Vascular Pathologies

Thrombosis
Vascular Pathologies:
Hemorrhage

Hemorrhagic Strokes
Vascular Pathologies:
Hemorrhage

Three Major Types:

1. Intercerebral Hemorrhages

2. Subdural Hematoma

3. Aneurysm
Vascular Pathologies:
Arteriovenous Malformations

Congenital Conditions
Venous Sinus System

Veins and Sinuses

Function:

Process:
Venous Sinus System: Location
of Prominent Dural Sinuses

Bhatnagar & Andy, 1995, Figure 2.42
Dural Sinuses

Structure:

Function:

Major Dural Sinuses:




1.
2.
3.
4.
Venous Sinus System

Bhatnagar & Andy, 1995, Figure 17.7
Cerebral Veins

Function:

Two Types:

1. Superficial Cerebral Veins

Three Large Superficial Veins



A.
B.
C.
Cerebral Veins: Lateral
Surface

Bhatnagar & Andy, 1995, Figure 17.8.A
Cerebral Veins

Two Types:

2. Deep Cerebral Veins

Function:
Cerebral Veins: Medial
Surface

Bhatnagar & Andy, 1995, Figure 17.8.B
Blood-Brain Barrier

Important Clinical Concept
Blood-Brain Barrier

Selective Membrane Permeability

Cortical Pathologies
Define the Following Technical
Terms:


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

Anastomose
Aneurysm
Arteriosclerosis
Arteriovenous
Malformations
Atherosclerosis
Blood-Brain Barrier
Carotid Vascular
System
Cerebrovascular
System
Circle of Willis

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
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Coagulation
Collateral Circulation
Embolism
Hemorrhage
Ischemia
Metabolism
Paresthesia
Sinus
Thrombosis
Watershed Infarction
Review Questions




1. Describe the importance of oxygen to
brain cells and how long the brain can sustain
blood deprivation.
2. Describe vascular circulation to the
brainstem and cerebellum.
3. Describe the difference between cortical
(circumferential) and central (penetrating)
arteries.
4. Describe the distribution area covered by
the anterior, middle, and posterior cerebral
arteries.
Review Questions





5. What important functional impairments
follow interruptions with blood flow in each
cortical artery?
6. Discuss the importance and mechanism of
collateral circulation.
7. Describe common vascular pathologies.
8. Describe the venous-sinus system.
9. What is the blood-brain barrier and what
are its clinical advantages?
Blood Supply
of the Nervous System
Graphics
THINGS TO DO BEFORE
LECTURE

TERMS:

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

Perfusion
 Act of pouring over or through, especially the passage of
a fluid through the vessels of a specific organ
Location of Petrous Bone
Epicritic sensation
 Cutaneous nerve fibers that serve the purpose of
perceiving fine variations of touch or temperature
Watershed region
 A ridge which directs drainage toward either side
Paresthesia
 Morbid or perverted sensation
 Abnormal sensation, as burning, prickling, formications,
etc.