The tela choroidea (or tela chorioidea) is a region of
meningeal pia mater
Pia mater ( or ),[Entry "pia mater"](_blank)
in
ependyma
The ependyma is the thin neuroepithelial ( simple columnar ciliated epithelium) lining of the ventricular system of the brain and the central canal of the spinal cord. The ependyma is one of the four types of neuroglia in the central nervous syst ...
, and gives rise to the
choroid plexus
The choroid plexus, or plica choroidea, is a plexus of cells that arises from the tela choroidea in each of the ventricles of the brain. Regions of the choroid plexus produce and secrete most of the cerebrospinal fluid (CSF) of the central nerv ...
in each of the
brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a ve ...
’s
four ventricles.
''Tela'' is Latin for ''woven'' and is used to describe a web-like membrane or layer. The tela choroidea is a very thin part of the loose connective tissue of pia mater overlying and closely adhering to the ependyma.
It has a rich blood supply. The ependyma and
vascular
The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away f ...
pia mater – the tela choroidea, form regions of minute projections known as a choroid plexus that projects into each ventricle.
The choroid plexus produces most of the
cerebrospinal fluid
Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates.
CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the ...
of the
central nervous system
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all p ...
that circulates through the ventricles of the brain, the
central canal
The central canal (also known as spinal foramen or ependymal canal) is the cerebrospinal fluid-filled space that runs through the spinal cord. The central canal lies below and is connected to the ventricular system of the brain, from which it r ...
of the
spinal cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...
, and the
subarachnoid space.
The tela choroidea in the ventricles forms from different parts of the
roof plate
A roof (plural, : roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of ...
in the
development of the embryo.
Structure
![Blausen 0896 Ventricles Brain](https://upload.wikimedia.org/wikipedia/commons/d/d4/Blausen_0896_Ventricles_Brain.png)
In the
lateral ventricles
The lateral ventricles are the two largest ventricles of the brain and contain cerebrospinal fluid (CSF). Each cerebral hemisphere contains a lateral ventricle, known as the left or right ventricle, respectively.
Each lateral ventricle resemble ...
the tela choroidea–a double-layered fold of
pia mater
Pia mater ( or ),[Entry "pia mater"](_blank)
in
ependyma
The ependyma is the thin neuroepithelial ( simple columnar ciliated epithelium) lining of the ventricular system of the brain and the central canal of the spinal cord. The ependyma is one of the four types of neuroglia in the central nervous syst ...
, produces the choroid fissure (sometimes also called the choroidal fissure but this is different from the
choroidal fissure of the optic stalk). The choroid fissure is C-shaped, runs between the
fornix and the
thalamus
The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, ...
in the body of the ventricle, and between the
stria terminalis and
hippocampal fimbria in the
inferior horn, and is the location of the attachment of the margins of the
choroid plexus
The choroid plexus, or plica choroidea, is a plexus of cells that arises from the tela choroidea in each of the ventricles of the brain. Regions of the choroid plexus produce and secrete most of the cerebrospinal fluid (CSF) of the central nerv ...
.
In the choroid fissure of the lateral ventricles, the tela choroidea is a lateral extension of the tela choroidea from the
third ventricle
The third ventricle is one of the four connected ventricles of the ventricular system within the mammalian brain. It is a slit-like cavity formed in the diencephalon between the two thalami, in the midline between the right and left lateral ...
.
In the
third ventricle
The third ventricle is one of the four connected ventricles of the ventricular system within the mammalian brain. It is a slit-like cavity formed in the diencephalon between the two thalami, in the midline between the right and left lateral ...
the tela choroidea forms the roof of the ventricle. Two vascular fringes from the lower fold invaginate the roof and form the choroid plexus.
The tela choroidea of the fourth ventricle (also known as the ''triangular lamella'')
is a double layer of pia mater and ependyma, between the
cerebellum and the lower part of the roof of the fourth ventricle. The two layers are continuous with each other in front, and are mostly adherent throughout. The anterior layer of the fold, contains vascular fringes which make up the choroid plexus.
The anterior layer is continuous inferiorly with the pia mater on the
inferior cerebellar peduncle
The upper part of the posterior district of the medulla oblongata is occupied by the inferior cerebellar peduncle, a thick rope-like strand situated between the lower part of the fourth ventricle and the roots of the glossopharyngeal and vagus nerv ...
s and the closed part of the
medulla oblongata. The ''posterior layer'' covers the antero-inferior surface of the cerebellum.
Cilia on the
ependymal cell
The ependyma is the thin neuroepithelial ( simple columnar ciliated epithelium) lining of the ventricular system of the brain and the central canal of the spinal cord. The ependyma is one of the four types of neuroglia in the central nervous syst ...
s move to circulate the cerebrospinal fluid. These cilia are unusually multiple
primary cilia
The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti ...
.
[>]
Blood supply
The blood supply of these plexuses is from the
posterior inferior cerebellar artery
The posterior inferior cerebellar artery (PICA) is the largest branch of the vertebral artery. It is one of the three main arteries that supply blood to the cerebellum, a part of the brain. Blockage of the posterior inferior cerebellar artery can r ...
.
The lateral ventricles also contains the right and left
internal cerebral veins
The internal cerebral veins (deep cerebral veins) drain the deep parts of the hemisphere and are two in number; each internal cerebral vein is formed near the interventricular foramina by the union of the superior thalamostriate vein and the ...
(which drain the choroid plexuses) at its roof (the two veins unite to form the great cerebral vein).
The arteries carrying blood into the choroid plexuses are:
# 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 ...
(branch from the internal carotid).
# the
posterior choroidal artery (branch from the posterior cerebral artery).
Medial posterior choroidal branches run forward beneath the splenium of the corpus callosum, and supply the tela chorioidea of the third ventricle and the choroid plexus.
Images
File:Slide7oo.JPG, Tela choroidea
References
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Meninges