2-Minute Neuroscience: The Meninges Video Lecture | A-Z Guide to Neuroscience - Personal Learning

Welcome to 2 minute neuroscience, where I
simplistically explain neuroscience topics
in 2 minutes or less.
In this installment I will discuss the meninges.
The term meninges comes from the Greek for
membrane and refers to 3 membranes that surround
the brain and the spinal cord: the dura mater,
the arachnoid mater, and the pia mater.
The meninges protect and provide structural
support for the brain as well as contain cerebrospinal
fluid.
The outermost layer of the meninges is the
dura mater, which literally means “hard
mother.”
This thick and tough layer adheres to the
skull on one side and the arachnoid mater
on the other side.
The dura provides the brain and spinal cord
with an extra protective layer, attaches the
brain to the skull and the spinal cord to
the vertebral column to keep them from being
jostled around, and provides a system of veinous
drainage through which blood can leave the
brain.
The arachnoid mater gets its name because
it has the consistency and appearance of a
cobweb.
It is much less substantial than the dura.
Strands of connective tissue called arachnoid
trabeculae stretch between the arachnoid and
pia mater.
These help to suspend the brain in place.
Between the arachnoid and pia mater there
is also an area known as the subarachnoid
space, which is filled with cerebrospinal
fluid.
The pia mater is a thin layer that closely
follows the contours of the brain.
It forms a tight membrane around the brain
and spinal cord, acting as an an additional
barrier and aiding in the secretion and containment
of cerebrospinal fluid.
Blood vessels are held against the pia mater
by connective tissue before they penetrate
the brain.
There is a space between the dura of the spinal
cord and the bone of the vertebral column
known as the epidural space; analgesics and
anesthesia are sometimes administered here.
Also, the dura and arachnoid mater extend
several vertebrae below the end of the spinal
cord, creating a cerebrospinal fluid-filled
area called the lumbar cistern where there
is no spinal cord present.
Cerebrospinal fluid can be withdrawn from
here because a needle can be inserted with
little risk of damaging the spinal cord.
Thus, the lumbar cistern is the site where
cerebrospinal fluid is aspirated in a lumbar
puncture, also known as a spinal tap.
This is done, for example, to diagnose meningitis,
a potentially life-threatening inflammation
of the meninges.