The tela choroidea (or tela chorioidea) is a region of meningeal

pia mater Pia mater ( or ),Entry "pia mater"
in
ependyma The ependyma is the thin Neuroepithelial cell, neuroepithelial (Simple columnar epithelium, 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 fou ...

, 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 v ...

’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 bra ...

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 par ...

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 spi ...

, and the

subarachnoid space In anatomy, the meninges (, ''singular:'' meninx ( or ), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in th ...

. 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

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

, 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 The stria terminalis (or terminal stria) is a structure in the brain consisting of a band of fibers running along the lateral margin of the ventricular surface of the thalamus. Serving as a major output pathway of the amygdala, the stria termina ...

and hippocampal fimbria in the inferior horn, and is the location of the attachment of the margins of the

. 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 v ...

. In the

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 The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...

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 medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun ...

. The ''posterior layer'' covers the antero-inferior surface of the cerebellum.

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 ...

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

{{Authority control Meninges