Online Collaborative NeuroKnowledge Base
Purkinje cells, or Purkinje neurons, are GABAergic neurons located in the cerebellum, and named after Czech anatomist Jan Evangelista Purkyně, who first described the cells in 1839. They are some of the largest neurons in the human brain (Betz cells being the largest), with an tortuously elaborate dendritic arbor, characterized by a large number of…
The olfactory system is not of major importance in neurologic diagnosis, however certain clinical information would be useful, and therefore a basic knowledge of the anatomy of the olfactory pathways, and especially their relationship with the surrounding neural structures is required. Basic Anatomy The olfactory nerves or nerves of smell are distributed to the mucous…
The anterior choroidal artery arises from the internal carotid artery, near the posterior communicating artery, and rarely from the middle cerebral artery.[1] Passing backward and lateral ward between the temporal lobe and the cerebral peduncle, it enters the inferior horn of the lateral ventricle through the choroidal fissure and ends in the choroid plexus. It…
Temporopolar: The artery extends from the sphenoidal segment of the MCA via the inferior surface of the operculum and supplies the polar and anterior lateral portions of the temporal lobe. The vessel can be identified in 52% of normal angiograms Anterior temporal: This artery extends in the similar fashion as the temporopolar artery and vascularizes…
Anterior parietal: This artery usually originates from the anterior or middle MCA trunk. In some cases it branches from the rolandic artery or from the posterior parietal artery. It extends the length of interparietal sulcus and descends slightly posteriorly. Posterior parietal: Emerges from the posterior end of the Sylvian fissure and extends first posteriorly, and…
Lateral frontobasal (orbitiofrontal): This artery branches out anteriorly, superiorly and laterally to vascularize the inferior frontal gyrus. It “competes” in size with the frontal polar branch of the anterior cerebral artery Prefrontal arteries: These arteries fan out over the insula and exit to the cortex via the medial surface of the frontal operculum. The arteries…
M4: These finer terminal or cortical segments of the middle cerebral artery, irrigate the cortex. They begin at the external of the Sylvian fissure and extend distally away on the cortex of the brain.
M3: The opercular segments of the middle cerebral artery, and extends laterally exteriorly from the insula towards the cortex. This segment is sometimes grouped as part of M2.
M2: Extending anteriorly on the insula, this segment in known as the insular segment of the middle cerebral artery. It is also known as the Sylvian segment when the opercular segments are included. The MCA branches may bifurcate or sometimes trifurcate into trunks in this segment which then extend into branches that terminate towards the…
M1: The sphenoidal segment, of the middle cerebral artery, so named due to its origin and loose lateral tracking of the sphenoid bone. Although known also as the horizontal segment, this may be misleading since the segment may descend, remain flat, or extend posteriorly the anterior (dorsad) in different individuals. The M1 segment perforates the…