The lamina terminalis is a thin sheet on the midline that forms the front wall of the third ventricle, stretching from the interventricular foramen down to the base of the optic stalk. It holds the vascular organ of the lamina terminalis, which senses and helps regulate the salt concentration of the blood. [1][2]
The 3D brain needs JavaScript. The text below still says where the lamina terminalis is and what it does.
Slice
Opens cut by a side (sagittal) slice through the lamina terminalis. Drag to turn, pinch or scroll to zoom, tap any part to name it; .
The 3D atlas draws the lamina terminalis as two halves, one on each side of the midline; both are lit, and the size line measures the two together. [3]
Takes part in: thirst — see every part of each lit together.
Where it is
It forms the middle (median) part of the front wall of the forebrain, from the interventricular foramen (foramen of Monro) to the recess at the base of the optic stalk. [1]
It holds the vascular organ of the lamina terminalis, one of the circumventricular organs of the third ventricle and one of the brain’s three sensory ones. [1][5]
The capillaries of that organ have no blood–brain barrier, so its nerve cells can respond to what circulates in the blood: they are osmoreceptors, sensitive to the sodium content and osmotic pressure of the blood. [5]
Its nerve cells signal to the supraoptic and paraventricular nuclei of the hypothalamus, which control the release of vasopressin, and to the median preoptic nucleus, which takes part in controlling thirst. [5]
With the median eminence and the subfornical organ it surrounds the third ventricle in a region called AV3V that helps regulate fluid and salt balance: thirst, sodium excretion, blood volume and vasopressin release. [5]
Connections
In the early weeks of development it is the front tip (rostral end) of the neural tube, the tube the whole brain and spinal cord grow from. [1]
It forms the commissure plate, which gives rise to the corpus callosum, the septum pellucidum and the fornix. [6]
Inside it
A thin layer of tissue; its vascular organ is covered with pia mater and lined with ependyma. [1][5]
Other names
Also called the terminal lamina. Its vascular organ is also called the organum vasculosum of the lamina terminalis (OVLT) or the supraoptic crest. [6][5]
Size
On this model the lamina terminalis (both halves the atlas draws) measures about 7 mm front to back, 12 mm top to bottom and 3 mm side to side (the box it fits in, not its volume). [3]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain.