The anterior cerebral artery (ACA) is one of a pair of
cerebral arteries
The cerebral arteries describe three main pairs of arteries and their branches, which perfuse the cerebrum of the brain.
The three main arteries are the:
* '' Anterior cerebral artery'' (ACA)
* ''Middle cerebral artery
The middle cerebral arte ...
that supplies oxygenated blood to most midline portions of the
frontal lobe
The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a groove betwe ...
s and
superior medial parietal lobes of the brain
The lobes of the brain are the major identifiable zones of the cerebral cortex, and they comprise the surface of each hemisphere of the cerebrum. The two hemispheres are roughly symmetrical in structure, and are connected by the corpus callosum. ...
. The two anterior cerebral arteries arise from the
internal carotid artery
The internal carotid artery (Latin: arteria carotis interna) is an artery in the neck which supplies the anterior circulation of the brain. In human anatomy, the internal and external carotids arise from the common carotid arteries, where these b ...
and are part of the
circle of Willis
The circle of Willis (also called Willis' circle, loop of Willis, cerebral arterial circle, and Willis polygon) is a circulatory anastomosis that supplies blood to the brain and surrounding structures in reptiles, birds and mammals, including huma ...
. The left and right anterior cerebral arteries are connected by the
anterior communicating artery
In human anatomy, the anterior communicating artery is a blood vessel of the brain that connects the left and right anterior cerebral arteries.
Anatomy
The anterior communicating artery connects the two anterior cerebral arteries across the comm ...
.
Anterior cerebral artery syndrome
Anterior cerebral artery syndrome is a condition whereby the blood supply from the anterior cerebral artery (ACA) is restricted, leading to a reduction of the function of the portions of the brain supplied by that vessel: the medial aspects of the ...
refers to symptoms that follow a
stroke
A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...
occurring in the area normally supplied by one of the arteries. It is characterized by
weakness
Weakness is a symptom of a number of different conditions. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, i ...
and sensory loss in the lower leg and foot opposite to the lesion and behavioral changes.
Structure
The anterior cerebral artery is divided into 5 segments. Its smaller branches: the callosal (supracallosal) arteries are considered to be the A4 and A5 segments.
*A1 originates from the internal carotid artery and extends to the ''anterior communicating artery'' (AComm). The ''anteromedial central'' (medial lenticulostriate) arteries arise from this segment as well as the AComm, which irrigates the
caudate nucleus
The caudate nucleus is one of the structures that make up the corpus striatum, which is a component of the basal ganglia in the human brain. While the caudate nucleus has long been associated with motor processes due to its role in Parkinson's di ...
and the anterior limb of the
internal capsule
The internal capsule is a white matter structure situated in the inferomedial part of each cerebral hemisphere of the brain. It carries information past the basal ganglia, separating the caudate nucleus and the thalamus from the putamen and the g ...
*A2 extends from the AComm to the bifurcation forming the ''pericallosal'' and ''callosomarginal arteries''. The ''
recurrent artery of Heubner
The recurrent artery of Heubner, Heubner's artery or distal medial striate artery is an artery in the head. It is named after the German paediatrician Otto Heubner. It is a branch of the anterior cerebral artery. Its vascular territory is the ant ...
'' (distal medial striate artery), which irrigates the internal capsule, usually arises at the beginning of this segment near the AComm. Two branches arise from this segment:
**''Orbitofrontal artery'' (medial frontal basal): Arises a small distance away from the AComm
**''Frontopolar artery'' (polar frontal): Arises after the ''orbitofrontal'', close to the curvature of A2 over the
corpus callosum
The corpus callosum (Latin for "tough body"), also callosal commissure, is a wide, thick nerve tract, consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental mam ...
. It can also originate from the ''callosal marginal''.
*A3, also termed the ''pericallosal artery'', is one of the (or the only) main terminal branches of the ACA, which extends posteriorly in the pericallosal sulcus to form the ''internal parietal arteries'' (superior, inferior) and the ''precuneal artery''. This artery may form an
anastomosis
An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection m ...
with the ''
posterior cerebral artery
The posterior cerebral artery (PCA) is one of a pair of cerebral arteries that supply oxygenated blood to the occipital lobe, part of the back of the human brain. The two arteries originate from the distal end of the basilar artery, where it bifur ...
''.
**''Callosal marginal artery'': A commonly present terminal branch of the ACA, which bifurcates from the ''pericallosal artery''. This artery in turn branches into the ''medial frontal arteries'' (anterior, intermediate, posterior), and the ''paracentral artery'', with the
cingulate
Cingulata, part of the superorder Xenarthra, is an order of armored New World placental mammals. Dasypodids and chlamyphorids, the armadillos, are the only surviving families in the order. Two groups of cingulates much larger than extant arm ...
branches arising throughout its length. Depending on
anatomical variation
An anatomical variation, anatomical variant, or anatomical variability is a presentation of body structure with morphological features different from those that are typically described in the majority of individuals. Anatomical variations are categ ...
, the ''callosal marginal artery'' may be none discrete or not be visible. In the latter case, the branches mentioned will originate from the ''pericallosal artery''. In a study of 76 hemispheres, the artery was present in only 60% of the cases. Angiography studies cite that the vessel can be seen 67%
[ or 50%] of the time.
Development
The anterior cerebral artery develops from a primitive anterior division of the internal carotid artery
The internal carotid artery (Latin: arteria carotis interna) is an artery in the neck which supplies the anterior circulation of the brain. In human anatomy, the internal and external carotids arise from the common carotid arteries, where these b ...
that initially supplies the optic and olfactory regions. This anterior division, which appears at the twenty-eighth day of development, also forms the middle cerebral artery
The middle cerebral artery (MCA) is one of the three major paired cerebral artery, cerebral arteries that supply blood to the cerebrum. The MCA arises from the internal carotid artery and continues into the lateral sulcus where it then branches an ...
and the anterior choroidal artery
The anterior choroidal artery originates from the internal carotid artery. However, it may (rarely) arise from the middle cerebral artery.
Structure
The anterior choroidal artery originates from the distal carotid artery 5 mm after the origin of ...
. The anterior cerebral arteries grow toward each other and form the anterior communicating artery
In human anatomy, the anterior communicating artery is a blood vessel of the brain that connects the left and right anterior cerebral arteries.
Anatomy
The anterior communicating artery connects the two anterior cerebral arteries across the comm ...
at the 21–24 mm stage of the embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
.
Variation
The anterior cerebral artery shows considerable variation. In a study made using MRA, the most common variation was an underdeveloped A1 segment (5.6%), followed by the presence of an extra A2 segment (3%). In 2% of cases there was only one A2 segment.
Function
The anterior cerebral artery supplies a part of the frontal lobe, specifically its medial surface and the upper border. It also supplies the front four–fifths of the corpus callosum
The corpus callosum (Latin for "tough body"), also callosal commissure, is a wide, thick nerve tract, consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental mam ...
, and provides blood to deep structures such as the anterior limb of the internal capsule
The internal capsule is a white matter structure situated in the inferomedial part of each cerebral hemisphere of the brain. It carries information past the basal ganglia, separating the caudate nucleus and the thalamus from the putamen and the g ...
, part of the caudate nucleus
The caudate nucleus is one of the structures that make up the corpus striatum, which is a component of the basal ganglia in the human brain. While the caudate nucleus has long been associated with motor processes due to its role in Parkinson's di ...
, and the anterior part of the globus pallidus
The globus pallidus (GP), also known as paleostriatum or dorsal pallidum, is a subcortical structure of the brain. It consists of two adjacent segments, one external, known in rodents simply as the globus pallidus, and one internal, known in rod ...
.
Clinical significance
Occlusion
Stroke
A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...
s that occur in a part of the artery prior to the anterior communicating usually do not produce many symptoms because of collateral circulation
Collateral circulation is the alternate circulation around a blocked artery or vein via another path, such as nearby minor vessels. It may occur via preexisting vascular redundancy (analogous to engineered redundancy), as in the circle of Wil ...
. If a blockage occurs in the A2 segment or later, the following signs and symptoms may be noted:
* Paralysis
Paralysis (also known as plegia) is a loss of motor function in one or more muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, roughly 1 in 50 ...
or weakness of the foot and leg on the opposite side, due to involvement of leg part of the motor cortex
The motor cortex is the region of the cerebral cortex believed to be involved in the planning, control, and execution of voluntary movements.
The motor cortex is an area of the frontal lobe located in the posterior precentral gyrus immediately a ...
* Cortical sensory loss Many types of sense loss occur due to a dysfunctional sensation process, whether it be ineffective receptors, nerve damage, or cerebral impairment. Unlike agnosia, these impairments are due to damages prior to the perception process.
Vision loss
...
in the opposite foot and leg
* Gait apraxia
Bruns apraxia, or frontal ataxia, is a gait apraxia found in patients with bilateral frontal lobe disorders. It is characterised by an inability to initiate the process of walking, despite the power and coordination of the legs being normal when te ...
(impairment of gait and stance)
* Abulia
In neurology, abulia, or aboulia (from grc, βουλή, meaning "will"),Bailly, A. (2000). Dictionnaire Grec Français, Éditions Hachette. refers to a lack of will or initiative and can be seen as a ''disorder of diminished motivation'' (''DDM'' ...
, akinetic mutism, slowness and lack of spontaneity
* Urinary incontinence
Urinary incontinence (UI), also known as involuntary urination, is any uncontrolled leakage of urine. It is a common and distressing problem, which may have a large impact on quality of life. It has been identified as an important issue in geria ...
which usually occurs with bilateral
Bilateral may refer to any concept including two sides, in particular:
* Bilateria, bilateral animals
*Bilateralism, the political and cultural relations between two states
*Bilateral, occurring on both sides of an organism ( Anatomical terms of ...
damage in the acute phase
* Frontal cortical release reflexes: Contralateral grasp reflex
Palmar grasp reflex (or grasp reflex) is a primitive and involuntary reflex found in infants of humans and most primates. When an object, such as an adult finger, is placed in an infant's palm, the infant's fingers reflexively grasp the object. ...
, sucking reflex, paratonic rigidity
Additional images
File:Circle of Willis 5.jpg, Anterior cerebral artery
File:Sobo 1909 3 548.png, Cerebral arteries seen from beneath. Anterior cerebral artery visible at centre.
File:Circle of Willis en.svg, The arterial circle and arteries of the brain (inferior view). The anterior cerebral arteries (top of figure) arise from the trifurcations of the internal carotid arteries
The internal carotid artery (Latin: arteria carotis interna) is an artery in the neck which supplies the anterior circulation of the brain. In human anatomy, the internal and external carotids arise from the common carotid arteries, where these ...
.
See also
* Cerebral circulation
Cerebral circulation is the movement of blood through a network of cerebral arteries and veins supplying the brain. The rate of cerebral blood flow in an adult human is typically 750 milliliters per minute, or about 15% of cardiac output. Arterie ...
* Middle cerebral artery
The middle cerebral artery (MCA) is one of the three major paired cerebral artery, cerebral arteries that supply blood to the cerebrum. The MCA arises from the internal carotid artery and continues into the lateral sulcus where it then branches an ...
References
External links
*
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* http://neuroangio.org/anatomy-and-variants/anterior-cerebral-artery/
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{{Authority control
Arteries of the head and neck