Blood-brain barrier
Updates to Article Attributes
The blood brain barrier (BBB) forms a physical resistance to the passage of lipophobic substances formfrom cerebral capillaries into the brain and is a key reason why there is no CSF enhancement following IV contrast media in CT and MR imaging.
Gross anatomy
ItThe BBB is formed by a combination of endothelial endothelial cells, pericytes, and astroglial and perivascular macrophages along the cerebral capillary walls.
In general, capillary walls in the human body can comprise of three different types:
- continuous: present in areas which have a BBB
- continuous interendothelial tight junctions
- no pinocytosis
- no fenestrations
- fenestrated: present in areas which lack the BBB
- sinusoidal: not found in the brain
In the brain, the majority of capillary walls are of the continuous type with tight junctions and a continuous basement membrane
Areas which have fenestrated capillaries and thus lack the blood brain barrier are:
Generally lipophilic solutes can cross the BBB which include:
- caffeine
- ethanol
- radiopharmaceuticals used in PET and SPECT imaging
- CO2
- O2
- nicotine
Hydrophilic solutes in general on the other hand are unable to cross it
-
e, e.g. water soluble CT/MR contrast media
Related pathology
There are a multitude of conditions that are associated with disruption of the BBB. They include:
- temporal lobe epilepsy (TLE) 1
- posterior reversible encephalopathy syndrome (PRES)
- hypoxia, ischaemia and infarction
- tumours
- inflammatory conditions, e.g. meningitis
- trauma
- intracranial irradiation
- multiple sclerosis
- progressive multifocal leukoencephalopathy: the JC virus can cross the BBB
-<p>The <strong>blood brain barrier (BBB) </strong>forms a physical resistance to the passage of lipophobic substances form cerebral capillaries into the brain and is a key reason why there is no CSF enhancement following IV contrast media in CT and MR imaging.</p><p>It is formed by a combination of endothelial cells, pericytes, and astroglial and perivascular macrophages along the cerebral capillary walls.</p><p>In general, capillary walls in the human body can comprise of three different types:</p><ul>- +<p>The <strong>blood brain barrier (BBB) </strong>forms a physical resistance to the passage of lipophobic substances from cerebral capillaries into the brain and is a key reason why there is no CSF enhancement following IV contrast media in CT and MR imaging.</p><h4>Gross anatomy</h4><p>The BBB is formed by a combination of endothelial cells, pericytes, and astroglial and perivascular macrophages along the cerebral capillary walls.</p><p>In general, capillary walls in the human body can comprise of three different types:</p><ul>
-<li> <a title="circumventricular organs" href="/articles/circumventricular-organs">circumventricular organs</a> (CVO):<ul>- +<li> <a href="/articles/circumventricular-organs">circumventricular organs</a> (CVO):<ul>
-<li><a title="Dura mater" href="/articles/dura-mater">dura mater</a></li>- +<li><a href="/articles/dura-mater">dura mater</a></li>
-</ul><p>Hydrophilic solutes in general on the other hand are unable to cross it</p><ul><li>e.g. water soluble CT/MR contrast media</li></ul><p>There are a multitude of conditions that are associated with disruption of the BBB. They include:</p><ul>- +</ul><p>Hydrophilic solutes in general on the other hand are unable to cross it, e.g. water soluble CT/MR contrast media. </p><h4>Related pathology</h4><p>There are a multitude of conditions that are associated with disruption of the BBB:</p><ul>
Sections changed:
- Anatomy
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