What is the organum Vasculosum?
What is the organum Vasculosum?
The term organum vasculosum refers to one of seven predominantly cellular structures of the anterior hypothalamic region as defined by Nissl stain. As one of the circumventricular organs, the organum vasculosum is highly vascular and lacks a blood brain barrier ( Saper-2004 ).
What is Circumventricular organ?
The circumventricular organs (CVO) are structures that permit polypeptide hypothalamic hormones to leave the brain without disrupting the blood-brain barrier (BBB) and permit substances that do not cross the BBB to trigger changes in brain function.
How many Circumventricular organs are there?
seven circumventricular organs
The seven circumventricular organs (shown as poppy-colored ovals) are the area postrema (AP), median eminence (ME), neurohypophysis (N), organum vasculosum of the lamina terminalis (OVLT), pineal (P), subcommissural organ (SCO), and subfornical organ (SFO).
What does the OVLT do?
Therefore, they function as communication sites between the blood, brain parenchyma, and cerebrospinal fluid, and are thought to be involved in water and energy metabolism, as well as immunomodulation. Among them, the OVLT is a sensory organ, which is an osmotic regulator involved in the release of vasopressin.
Where can we find the lamina terminalis?
Rhoton (1987) described the Lamina Terminalis as a triangular, transparent whitish membrane found at the base of the brain and forms the anterior wall of the third ventricle.
What is hypothalamic sulcus?
The hypothalamic sulcus defines the upper border and extends from the interventricular foramen to the cerebral aqueduct, above which lies the thalamus. The anterior border is roughly defined as a line through the anterior commissure, lamina terminalis, and optic chiasm.
Is Subfornical organ in hypothalamus?
Organum Vasculosum of the Lamina Terminalis and the Subfornical Organ. Because it lies at the rostral and ventral tip of the third ventricle, the OVLT is surrounded by cell groups of the preoptic region of the hypothalamus. Like other CVOs, the OVLT is composed of neurons, glial cells, and tanycytes.
Where is AV3V?
The OVLT and SFO are both interconnected with the nucleus medianus, and together these three structures comprise the so-called “AV3V” region – the region anterior and ventral to the third ventricle.
What do these circumventricular organs have in common?
Circumventricular organs contain capillary networks that vary between one another and within individual organs both in density and permeability, with most CVO capillaries having a permeable endothelial cell layer, except for those in the subcommissural organ.
