Description

This video covers the Veins of the Systemic Circulation, including:

• Veins of the Superior Vena Cava
• Veins of the Inferior Vena Cava
• Veins of the Heart
• The Portal System

Topography of the Dural Venous Sinuses

The Dural Venous Sinuses are located between the Periosteal and Meningeal layers of the Dura Mater. They drain venous blood from the brain into the Internal Jugular Veins.

Classification of Dural Venous Sinuses:

Midline Sinuses:

• Superior Sagittal Sinus (Sinus Sagittalis Superior): Drains into the confluence of sinuses.
• Inferior Sagittal Sinus (Sinus Sagittalis Inferior): Runs along the lower border of the falx cerebri and drains into the straight sinus.
• Straight Sinus (Sinus Rectus): Formed by the union of the inferior sagittal sinus and the great cerebral vein (Vein of Galen).
• Anterior Intercavernous Sinus (Sinus Intercavernosus Anterior): Connects the two cavernous sinuses anteriorly.
• Posterior Intercavernous Sinus (Sinus Intercavernosus Posterior): Connects the two cavernous sinuses posteriorly.
• Basilar Plexus (Plexus Basilaris): Communicates with the internal vertebral venous plexus, allowing venous drainage between the cranial cavity and vertebral column.

Lateral Sinuses:

• Transverse Sinus (Sinus Transversus): Drains the confluence of sinuses into the sigmoid sinus.
• Sigmoid Sinus (Sinus Sigmoideus): Continuation of the transverse sinus that empties into the internal jugular vein.
• Superior Petrosal Sinus (Sinus Petrosus Superior): Drains the cavernous sinus into the transverse sinus.
• Inferior Petrosal Sinus (Sinus Petrosus Inferior): Drains the cavernous sinus into the internal jugular vein.

Posterior Sinuses:

• Occipital Sinus (Sinus Occipitalis): Located along the margin of the foramen magnum, drains into the confluence of sinuses.
• Confluence of Sinuses (Torcular Herophili): Meeting point of the superior sagittal sinus, straight sinus, and occipital sinus.

Anterior Sinuses:

• Cavernous Sinus (Sinus Cavernosus): Large venous plexus around the pituitary gland that communicates with the facial vein via the ophthalmic veins.
• Sphenoparietal Sinus (Sinus Sphenoparietalis): Drains the superficial middle cerebral vein into the cavernous sinus.

Clinical Relevance:

• Cavernous Sinus Thrombosis: Infection from the face (danger triangle) can spread to the cavernous sinus via the ophthalmic veins, leading to severe complications.
• Venous Sinus Thrombosis: Can occur in conditions like hypercoagulability disorders, causing headaches, seizures, and stroke-like symptoms.
• Basilar Plexus and Vertebral Veins: Provide a route for metastases to spread between the brain and lower body.

Sources Used:

• • Memorix Anatomy (2nd Edition) – Hudák Radovan, Kachlík David, Volný Ondřej.

• Complete Anatomy by 3D4Medical.
• Biorender.
• University Notes and Lectures.

Transcript

Introduction
0:00
[Music]
0:08
let’s go ahead and talk about the
0:09
anatomy of the dural venous sinuses and
0:12
we’re going to do that by first going
0:14
through the location of the dural
0:16
sinuses basically where they are in
0:18
comparison to the meninges
0:20
and then we’re going to visualize the
0:22
dural venous sinuses schematically so
0:25
that it’s easier to remember the dural
0:27
sciences and then in the next video
0:29
we’re going to go through the cerebral
0:31
veins and the emissary veins and the
0:33
diploic veins and then the cerebral
0:36
circulation in general
Systemic Veins
0:37
all right
0:38
so the veins of the systemic circulation
0:41
consist of four kind of systems
0:44
you have the veins of the heart
0:46
then you have the veins of the inferior
0:48
vena cava
0:49
and the veins of the superior vena cava
0:52
and then you have the portal system
0:54
so the superior venous sinuses we’re
0:57
going to go through drain into the
0:59
superior vena cava so we can start by
Location of the Dural Venous Sinuses
1:02
zooming in on this figure and then take
1:04
a small section of the skull in order to
1:06
see all the layers so these are all the
1:08
layers from the skin down to the brain
1:10
tissue so first we have the skin all the
1:13
dermal layers then underneath that we
1:15
have the skull and then the meninges and
1:18
then there’s the cerebral tissue
1:20
so the meninges are what we’re
1:22
essentially going to focus on right now
1:24
so the meninges consists of three layers
1:27
you have the pia mater which is the
1:29
thinnest most delicate layer that lies
1:33
just on top of the surface of the brain
1:34
tissue
1:36
then
1:36
superficially to that you will find the
1:39
arachnoid motor
1:40
which is slightly thicker than the pia
1:42
motor
1:43
and underneath the arachnoid motor you
1:45
will find the subarachnoid space which
1:48
contains cerebrospinal fluid and you
1:50
will notice that there are these
1:52
arachnoid granulations that take the
1:55
cerebrospinal fluid and then just pumps
1:57
them into the venous sinuses so that
1:59
they can get back into the circulation
2:01
to complete the circulation of the
2:03
cerebrospinal fluid
2:05
then superficial to the arachnoid motor
2:08
you will find the thickest meninges
2:10
called the dura mater and notice that
2:12
the dura mater inside the cranium
2:14
consists of two layers there’s first the
2:17
periosteal layer which lies very close
2:20
to the skull
2:21
and then there’s the meningeal layer
2:23
which lies very close to the arachnoid
2:25
mother and when you look at the spinal
2:27
cord you’ll notice that dura mater only
2:29
consists of one layer which is the
2:32
meningeal layer because the periosteal
2:34
layer stops at the foramen monument
2:37
notice that the periosteal layer and the
2:39
meningeal layer are bound together and
2:42
only separates when they form the dural
2:45
venous sinuses
2:47
and the dural septae
2:48
so if i would ask you between which
2:51
layers are the dural venous sinuses
2:54
located inside the head
2:57
they are located between the periosteal
2:59
and the meningeal layer of the dura
Dural Venous Sinuses
3:01
mater awesome now finally let’s go ahead
3:04
and go through the dural venous sinuses
3:07
so what we’re going to do is that we’re
3:09
going to go through all the dural venous
3:11
sciences one by one and we will use this
3:14
table to help us do that all right so
3:16
first thing is that i’ve divided the
3:18
dural venous sinuses into the ones that
3:21
are located in the midline the ones that
3:24
are located laterally the ones that are
3:26
located posteriorly and anteriorly and
3:29
you will notice that when you’re
3:30
studying the dural venous sinuses that
3:32
there are different ways to categorize
3:34
the different dural venous sciences you
3:36
can also categorize them as as paired
3:38
and unpaired for example
3:40
but i like this one we’ll stick with
3:42
that all right so first we have the
3:44
superior and the inferior sagittal sinus
3:48
then there’s a straight sinus which
3:49
connects these two or also called a
3:51
sinus rectus
3:53
laterally you will find the transverse
3:55
sinus which continues as the sigmoid
3:58
sinus and then as the internal jugular
4:01
vein
4:02
then we have the superior petrosal sinus
4:05
and the inferior petrossal sinus which
4:07
drain from the cavernous sinus and then
4:10
we have the sphenoparietal sinuses which
4:13
go along the sphenoid bone
4:16
then we have the anterior and the
4:18
posterior inter-cavinus sinuses which
4:22
connect the two cavernous sinuses
4:25
and then we have the basilar plexus and
4:28
you know plexus just means a network of
4:31
structures and the basilar plexus are
4:34
just a plexus of veins that connect
4:37
different
4:38
adjacent structures together at the
4:40
basal region of the skull so it connects
4:44
with the cavernous sinuses it connects
4:47
with the superior and the inferior
4:49
petrossal sinuses and it also goes down
4:52
and connects with the vertebral veins
4:54
then we have the occipital sinus which
4:56
is the smallest sinus and then when the
5:00
occipital sinus the superior sagittal
5:03
sinus and the straight sinus meets
5:06
they form the confluence of sciences so
5:10
those are the main dural venous sinuses
5:13
that i want you to know so let’s go
5:14
ahead and go through them in detail
5:17
first we have the superior sagittal
5:19
sinus which remember is the largest
5:22
dural sinus it starts at the foramen
5:24
cecum in the anterior part of the
5:27
cranial cavity and then goes along the
5:30
superior margin of the falx cerebri and
5:33
then goes back to drain into the
5:35
confluence of sinus
5:37
then we have the inferior sagittal sinus
5:40
the inferior sagittal sinus goes along
5:43
the inferior edge of the flux cerebri
5:46
and it receives mainly tributaries from
5:48
the fox itself as well as some small
5:51
veins from the medial surface of the
5:52
cerebral hemispheres
5:54
the straight sinus drains the inferior
5:57
sagittal sinus into the confluence of
6:00
sciences
6:01
more anteriorly we will find the
6:03
anterior and the posterior intercavenous
6:06
sinuses which just connects the right
6:08
and the left cavernous sinus together
6:11
and notice that i’ve put in brackets
6:13
variable here because depending on your
6:15
source they can be anterior or posterior
6:18
or even in fear of your inter cavernous
6:20
sciences but the functions are the same
6:22
it just connects the two cavernous
6:24
sinuses together
6:25
then we have the basilar plexus which
6:28
remember just connects regional venous
6:30
structures
6:32
then the transverse sinus drains the
6:35
confluence of sinuses into the sigmoid
6:38
sinus
6:39
the sigmoid sinus is a continuation of
6:41
the transverse sinus and it actually has
6:44
a pretty cool s-shaped form as it goes
6:47
towards the jugular bulb of the inferior
6:50
jugular vein
6:51
then we have the superior and the
6:53
inferior petrossos which drain the
6:56
cavernous sinus into the sigmoid and the
7:00
internal jugular vein then we have the
7:02
occipital sinus and the occipital sinus
7:05
is the smallest sinus we have and as you
7:08
see it connects with the confluence of
7:10
sinuses and the sigmoid sinus
7:13
then we have the confluence of sciences
7:16
the confluence of sinuses is not really
7:19
a structure in itself
7:21
rather it’s just a connecting point of
7:24
the superior sagittal sinus the straight
7:27
sinus and the occipital sinus so when
7:29
these three sinuses meet they form the
7:31
confluence of sinuses
7:34
then we have the cavernous sinus
7:36
and the cavernous sinus is actually
7:39
divided by fibrous septae
7:42
into small caves and that’s where the
7:45
word cavernous sinus comes from it comes
7:48
from the word cave
7:49
and if you look at this picture you will
7:51
see that there are different structures
7:53
that passes within the cavernous sinus
7:56
because the carbon sinus is divided into
7:59
these caves there’s this mnemonic for
8:01
all of all the structures that go
8:03
through the cavernous sinus which is o
8:05
tone cats so o stands for the oculomotor
8:09
nerve which is the third cranial nerve t
8:11
for the chocolate the fourth cranial
8:13
nerve
8:14
then o and m stands for the ophthalmic
8:18
and the maxillary branch of the
8:20
trigeminal nerve
8:21
c stand for internal carotid artery
8:24
a for the abducent nerve the six cranial
8:26
nerve and t is just a filler in order to
8:29
complete the mnemonic oh tomcats
8:32
so that was this one
8:34
the last one is the sphenoparietal
8:37
sinuses which receives tributaries from
8:39
the adjacent lobes and then drains them
8:42
into the cavernous sinus to then be
8:44
drained through the
8:47
superior and the inferior petroleum
8:49
sinuses and then into the internal
8:51
jugular vein
8:52
so that was everything i had about dural
8:55
venous sinuses in the next video we’re
8:57
going to go through the branches of
8:59
these dural sinuses