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Cerebrovascular System: Anatomy

Cerebrovascular System: Anatomy

Blood supply to the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification can be divided into an anterior and a posterior circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment, which interconnect to form the circle of Willis Circle of Willis A polygonal anastomosis at the base of the brain formed by the internal carotid, proximal parts of the anterior, middle, and posterior cerebral arteries, the anterior communicating artery and the posterior communicating arteries. Subarachnoid Hemorrhage. The anterior circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment is derived from the internal carotid arteries Carotid Arteries Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery. Carotid Arterial System: Anatomy and consists mainly of the anterior and middle cerebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology. The posterior circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment is derived from the vertebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology and consists primarily of the cerebellar and posterior cerebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology. The primary venous drainage of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification occurs via the internal jugular vein Internal jugular vein Parapharyngeal Abscess.

Last updated: 7 Apr, 2022

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Contents

Arterial Supply

Arterial origin

The arterial supply of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification is derived from 2 arterial systems:

  • Internal carotid arteries Carotid Arteries Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery. Carotid Arterial System: Anatomy (anterior circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment):
    • Bifurcates from common carotid artery Common carotid artery The two principal arteries supplying the structures of the head and neck. They ascend in the neck, one on each side, and at the level of the upper border of the thyroid cartilage, each divides into two branches, the external and internal carotid arteries. Carotid Arterial System: Anatomy at the level of C4
    • Continues into brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification and becomes the middle cerebral artery
    • Anterior cerebral artery branches off the internal carotid artery Internal carotid artery Branch of the common carotid artery which supplies the anterior part of the brain, the eye and its appendages, the forehead and nose. Carotid Arterial System: Anatomy.
  • Vertebrobasilar system (posterior circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment):
    • Vertebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology arise from the subclavian arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology.
    • Vertebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology join to become the basilar artery.
    • Basilar artery bifurcates to become the posterior cerebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology.
    • Cerebellar arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology arise from the vertebral and basilar arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology.
2 sources of blood supply to the brain

Blood supply to the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification is derived from 2 sources—the internal carotid arteries Carotid Arteries Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery. Carotid Arterial System: Anatomy and the vertebrobasilar system.

Image by Lecturio.

Cerebral blood supply

  • Anterior cerebral artery:
    • Origin: smaller terminal branch of the internal carotid artery Internal carotid artery Branch of the common carotid artery which supplies the anterior part of the brain, the eye and its appendages, the forehead and nose. Carotid Arterial System: Anatomy
    • Course: occupies the longitudinal fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes and travels posteriorly, ultimately anastomosing with the posterior cerebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
    • Divisions: distributes numerous anteromedial central branches
    • Supplies:
      • Medial frontal Frontal The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the nasal bone and the cheek bone on each side of the face. Skull: Anatomy and parietal Parietal One of a pair of irregularly shaped quadrilateral bones situated between the frontal bone and occipital bone, which together form the sides of the cranium. Skull: Anatomy lobes
      • Anterior limb of internal capsule Capsule An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides. Bacteroides
      • Most of corpus callosum
  • Middle cerebral artery:
    • Origin: larger terminal branch of the internal carotid artery Internal carotid artery Branch of the common carotid artery which supplies the anterior part of the brain, the eye and its appendages, the forehead and nose. Carotid Arterial System: Anatomy
    • Course: runs through lateral fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes and posterosuperiorly on insula
    • Divisions: cortical and central branches
    • Supplies:
      • Lateral frontal Frontal The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the nasal bone and the cheek bone on each side of the face. Skull: Anatomy and parietal Parietal One of a pair of irregularly shaped quadrilateral bones situated between the frontal bone and occipital bone, which together form the sides of the cranium. Skull: Anatomy lobes
      • Portion of temporal lobes
      • Genu and posterior limb of internal capsule Capsule An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides. Bacteroides
      • Most of basal ganglia Basal Ganglia Basal ganglia are a group of subcortical nuclear agglomerations involved in movement, and are located deep to the cerebral hemispheres. Basal ganglia include the striatum (caudate nucleus and putamen), globus pallidus, substantia nigra, and subthalamic nucleus. Basal Ganglia: Anatomy
  • Posterior cerebral artery:
    • Origin: arises as terminal branches of basilar arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
    • Course:
      • Travels parallel to superior cerebellar artery
      • Receives the posterior communicating artery as it runs laterally
    • Supplies:
      • Occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy lobe
      • Posteromedial temporal lobes
      • Midbrain Midbrain The middle of the three primitive cerebral vesicles of the embryonic brain. Without further subdivision, midbrain develops into a short, constricted portion connecting the pons and the diencephalon. Midbrain contains two major parts, the dorsal tectum mesencephali and the ventral tegmentum mesencephali, housing components of auditory, visual, and other sensorimotor systems. Brain Stem: Anatomy
Lateral surface view shows the arterial supply of the brain

Lateral surface view shows the arterial supply of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification:
Note the distribution of the anterior cerebral artery supplying the anteromedial surface, the middle cerebral artery supplying the lateral surface, and the posterior cerebral artery supplying the posterior and inferior surfaces.

Image by Lecturio.
Medial view shows the arterial supply of the brain

Medial view shows the arterial supply of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification:
Note the distribution of blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure. The anterior cerebral artery is in purple and the posterior cerebral artery in pink.

Image by Lecturio.

Cerebellar blood supply

The cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy is supplied by branches of the vertebral and basilar arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology.

  • Superior cerebellar artery:
    • Origin: arises from distal aspect of the basilar artery
    • Supplies: 
      • Superior cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy
      • Pineal body
  • Anterior inferior cerebellar artery:
    • Origin: arises from proximal aspect of the basilar artery
    • Supplies:
      • Anterior inferior surface of cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy
      • Inferolateral aspect of the pons Pons The front part of the hindbrain (rhombencephalon) that lies between the medulla and the midbrain (mesencephalon) ventral to the cerebellum. It is composed of two parts, the dorsal and the ventral. The pons serves as a relay station for neural pathways between the cerebellum to the cerebrum. Brain Stem: Anatomy
  • Posterior inferior cerebellar artery:
    • Origin: arises from vertebral artery Vertebral artery The first branch of the subclavian artery with distribution to muscles of the neck; vertebrae; spinal cord; cerebellum; and interior of the cerebrum. Lateral Medullary Syndrome (Wallenberg Syndrome)
    • Supplies:
      • Posterior inferior surface of cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy
      • Choroid Choroid The thin, highly vascular membrane covering most of the posterior of the eye between the retina and sclera. Eye: Anatomy plexus of 4th ventricle
Blood supply to the cerebellum

The cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy is supplied by the superior cerebellar artery, anterior inferior cerebellar artery, and posterior inferior cerebellar artery.

Image by Lecturio.

Circle of Willis Circle of Willis A polygonal anastomosis at the base of the brain formed by the internal carotid, proximal parts of the anterior, middle, and posterior cerebral arteries, the anterior communicating artery and the posterior communicating arteries. Subarachnoid Hemorrhage

The circle of Willis Circle of Willis A polygonal anastomosis at the base of the brain formed by the internal carotid, proximal parts of the anterior, middle, and posterior cerebral arteries, the anterior communicating artery and the posterior communicating arteries. Subarachnoid Hemorrhage is an interconnected network of arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology within the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification. The circle of Willis Circle of Willis A polygonal anastomosis at the base of the brain formed by the internal carotid, proximal parts of the anterior, middle, and posterior cerebral arteries, the anterior communicating artery and the posterior communicating arteries. Subarachnoid Hemorrhage represents the collateral pathways of arterial blood, and it has many anatomical variants. The circle is formed via anastomoses between the anterior and posterior arterial systems that supply blood to the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification. This duality provides a safety net if 1 of the systems fails via occlusion, trauma, or a neoplastic process. Vessels comprising the circle of Willis Circle of Willis A polygonal anastomosis at the base of the brain formed by the internal carotid, proximal parts of the anterior, middle, and posterior cerebral arteries, the anterior communicating artery and the posterior communicating arteries. Subarachnoid Hemorrhage include:

  • Components of anterior circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment: 
    • Left and right internal carotid arteries Carotid Arteries Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery. Carotid Arterial System: Anatomy 
    • Horizontal segments of the left and right anterior cerebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
    • Single anterior communicating artery
  • Posterior circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment: 
    • Left and right posterior communicating arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
    • Horizontal segments of the left and right posterior cerebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology, arising from the single basilar artery
Components of the circle of willis

The circle of Willis Circle of Willis A polygonal anastomosis at the base of the brain formed by the internal carotid, proximal parts of the anterior, middle, and posterior cerebral arteries, the anterior communicating artery and the posterior communicating arteries. Subarachnoid Hemorrhage has 5 components, including the anterior communicating artery, the anterior cerebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology, the internal carotid artery Internal carotid artery Branch of the common carotid artery which supplies the anterior part of the brain, the eye and its appendages, the forehead and nose. Carotid Arterial System: Anatomy, the posterior communicating artery, and the posterior cerebral arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology.

Image by Lecturio.

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Venous Drainage

Venous drainage of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification occurs via the cerebral veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology, which ultimately drain into the straight sinus, transverse sinus, and finally the sagittal Sagittal Computed Tomography (CT) sinus before reaching the internal jugular vein Internal jugular vein Parapharyngeal Abscess and traveling back to the heart. 

  • Venous drainage of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification occurs via the superficial and deep venous systems:
    • The 2 systems are connected via anastomoses and drain via the dural venous sinuses Venous sinuses Veins: Histology and, ultimately, to the internal jugular vein Internal jugular vein Parapharyngeal Abscess.
    • Unlike all other veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology of the body, cerebral veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology do not have valves.
  • Superficial venous system:
    • Composed of cortical veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology
    • Drains the cerebral cortex Cerebral cortex The cerebral cortex is the largest and most developed part of the human brain and CNS. Occupying the upper part of the cranial cavity, the cerebral cortex has 4 lobes and is divided into 2 hemispheres that are joined centrally by the corpus callosum. Cerebral Cortex: Anatomy
  • Deep venous system:
    • Divisions:
      • Deep cerebral veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology
      • Straight sinus
      • Transverse sinus
      • Sagittal Sagittal Computed Tomography (CT) sinuses
    • Drains the deep brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification structures
  • Dural venous sinuses Venous sinuses Veins: Histology:
    • Drain blood from the cerebral veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology, orbits, and skull Skull The skull (cranium) is the skeletal structure of the head supporting the face and forming a protective cavity for the brain. The skull consists of 22 bones divided into the viscerocranium (facial skeleton) and the neurocranium. Skull: Anatomy 
    • Empty into the internal jugular veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology
Sagittal view through the skull illustrating the venous drainage system

Sagittal Sagittal Computed Tomography (CT) view through the skull Skull The skull (cranium) is the skeletal structure of the head supporting the face and forming a protective cavity for the brain. The skull consists of 22 bones divided into the viscerocranium (facial skeleton) and the neurocranium. Skull: Anatomy illustrating the venous drainage system:
The arrows demonstrate the flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure of blood from the cerebral veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology and sinuses to the confluence of sinuses, ultimately returning to the jugular vein via the sigmoid Sigmoid A segment of the colon between the rectum and the descending colon. Volvulus sinus.

Image: “Blood drains from the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification through a series of sinuses that connect to the jugular veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology” by OpenStax College. License: CC BY 4.0
Venous sinuses that drain blood from the cerebral veins

A transverse view of the cerebral deep venous system, specifically the sigmoid Sigmoid A segment of the colon between the rectum and the descending colon. Volvulus and transverse sinuses

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Clinical Relevance

  • Intracranial aneurysms: A cerebral, or intracranial, aneurysm Aneurysm An aneurysm is a bulging, weakened area of a blood vessel that causes an abnormal widening of its diameter > 1.5 times the size of the native vessel. Aneurysms occur more often in arteries than in veins and are at risk of dissection and rupture, which can be life-threatening. Thoracic Aortic Aneurysms is an abnormal dilation of a local area of the artery wall in the CNS. These aneurysms most often occur at junction points of the major arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification, usually around the circle of Willis Circle of Willis A polygonal anastomosis at the base of the brain formed by the internal carotid, proximal parts of the anterior, middle, and posterior cerebral arteries, the anterior communicating artery and the posterior communicating arteries. Subarachnoid Hemorrhage. They can either compress adjacent structures or rupture and cause a hemorrhagic stroke Hemorrhagic stroke Stroke due to rupture of a weakened blood vessel in the brain (e.g., cerebral hemispheres; cerebellum; subarachnoid space). Subarachnoid Hemorrhage.
  • Arterial dissections: The vertebral and carotid arteries Carotid Arteries Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery. Carotid Arterial System: Anatomy are vital components of the blood supply to the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification. Arterial dissections occur when the integrity of the arterial wall structure fails, usually abruptly, resulting in an intramural hematoma Intramural hematoma Dissection of the Carotid and Vertebral Arteries formation and a false lumen False lumen Aortic Dissection between the tunica media Tunica media The middle layer of blood vessel walls, composed principally of thin, cylindrical, smooth muscle cells and elastic tissue. It accounts for the bulk of the wall of most arteries. The smooth muscle cells are arranged in circular layers around the vessel, and the thickness of the coat varies with the size of the vessel. Arteries: Histology and adventitial layers. This process may result in aneurysm Aneurysm An aneurysm is a bulging, weakened area of a blood vessel that causes an abnormal widening of its diameter > 1.5 times the size of the native vessel. Aneurysms occur more often in arteries than in veins and are at risk of dissection and rupture, which can be life-threatening. Thoracic Aortic Aneurysms, stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS), or occlusion. Presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor is typically with unilateral head or neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and/or stroke-like symptoms.
  • Subclavian steal syndrome Subclavian steal syndrome A clinically significant reduction in blood supply to the brain stem and cerebellum (i.e., vertebrobasilar insufficiency) resulting from reversal of blood flow through the vertebral artery from occlusion or stenosis of the proximal subclavian or brachiocephalic artery. Common symptoms include vertigo; syncope; and intermittent claudication of the involved upper extremity. Subclavian steal may also occur in asymptomatic individuals. Subclavian Steal Syndrome: occurs when narrowing/occlusion of the subclavian artery proximal to the origin of the vertebral artery Vertebral artery The first branch of the subclavian artery with distribution to muscles of the neck; vertebrae; spinal cord; cerebellum; and interior of the cerebrum. Lateral Medullary Syndrome (Wallenberg Syndrome) causes a reversal of blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure in the ipsilateral vertebral artery Vertebral artery The first branch of the subclavian artery with distribution to muscles of the neck; vertebrae; spinal cord; cerebellum; and interior of the cerebrum. Lateral Medullary Syndrome (Wallenberg Syndrome) to continue perfusing the ipsilateral arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy. The most common cause of subclavian steal syndrome Subclavian steal syndrome A clinically significant reduction in blood supply to the brain stem and cerebellum (i.e., vertebrobasilar insufficiency) resulting from reversal of blood flow through the vertebral artery from occlusion or stenosis of the proximal subclavian or brachiocephalic artery. Common symptoms include vertigo; syncope; and intermittent claudication of the involved upper extremity. Subclavian steal may also occur in asymptomatic individuals. Subclavian Steal Syndrome is atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis. Symptoms are rare, but when they occur, they are usually triggered by physical exertion of the arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy and subsequent hypoperfusion of the arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy or brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification.
  • Stroke: The 2 types of stroke are ischemic and hemorrhagic. Risk factors include hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, cerebral amyloid angiopathy Amyloid angiopathy A heterogeneous group of sporadic or familial disorders characterized by amyloid deposits in the walls of small and medium sized blood vessels of cerebral cortex and meninges. Clinical features include multiple, small lobar cerebral hemorrhage; cerebral ischemia; and cerebral infarction. Cerebral amyloid angiopathy is unrelated to generalized amyloidosis. Amyloidogenic peptides in this condition are nearly always the same ones found in alzheimer disease. Alzheimer Disease, neoplastic diseases, and cerebral aneurysms. Strokes can be diagnosed with brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification CT or MRI, and treatment is geared toward reperfusing the ischemic area or stopping the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification hemorrhage.

References

  1. Barshes, N. R. (2019). Overview of upper extremity peripheral artery disease. UpToDate. Retrieved February 15, 2021, from https://www.uptodate.com/contents/overview-of-upper-extremity-peripheral-artery-disease
  2. Spittell, P. C. (2019). Subclavian steal syndrome. UpToDate. Retrieved February 15, 2021, from https://www.uptodate.com/contents/subclavian-steal-syndrome
  3. Edwardson, M. A. (2021). Overview of ischemic stroke prognosis in adults. UpToDate. Retrieved August 5, 2021, from https://www.uptodate.com/contents/overview-of-ischemic-stroke-prognosis-in-adults
  4. Oliveira-Filho, J., Mullen, M. T. (2021). Initial assessment and management of acute stroke. UpToDate. Retrieved August 1, 2021, from https://www.uptodate.com/contents/initial-assessment-and-management-of-acute-stroke
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