Description

This video covers:

• Parts of the Internal Carotid Canal
• Internal Carotid Artery and its branches:
  • Anterior Cerebral Artery
  • Middle Cerebral Artery
  • Anterior Choroidal Artery
  • Posterior Communicating Artery
• Blood Supply of the Brain

Parts of the Internal Carotid Artery:

The Internal Carotid Artery is divided into four main parts:

• Cervical Part
• Petrous Part
• Cavernous Part
• Cerebral Part

Circle of Willis (Circulus Arteriosus Cerebri s. Willisi) – Thomas Willis:

A critical anastomotic system at the base of the brain that ensures collateral circulation.

• Ophthalmic Artery
• Anterior Cerebral Artery
• Middle Cerebral Artery
• Anterior Choroidal Artery
• Posterior Communicating Artery
• Posterior Cerebral Artery (Branch of Basilar Artery)

Cerebral Part of Internal Carotid Artery:

Anterior Cerebral Artery:

• Runs along the longitudinal cerebral fissure.
• Supplies the medial surface of the frontal and parietal lobes, including:
  • Superior Frontal Gyrus
  • Superior Parietal Lobule
  • Upper part of Postcentral and Precentral Gyrus
  • Gyrus Rectus (Straight Gyrus)

Middle Cerebral Artery:

• Clinical Note: Occlusion of this artery results in Middle Cerebral Artery Syndrome.
• Supplies:
  • Insula
  • Lentiform Nucleus
  • Caudate Nucleus
  • Internal Capsule
  • Superior and Middle Temporal Gyri
  • Large portions of the superolateral surface of the cerebral hemispheres

Anterior Choroidal Artery:

• Runs posteriorly to form part of the choroid plexus in the lateral and third ventricles.

Posterior Cerebral Artery:

• A branch of the basilar artery.
• Supplies:
  • Occipital Lobe
  • Inferior Temporal Gyrus

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
alright guys so this video is about the
0:02
internal carotid I just want to start by
0:05
saying that everything you see in this
0:06
video was made to be schematic for you
0:09
to hopefully be able to visualize it now
0:12
essentially as the common carotid artery
0:15
ascends along the neck it will divide at
0:17
the region of the upper thyroid
0:19
cartilage into the external and the
0:22
internal carotid arteries with the
0:24
external carotid here in orange as we’re
0:26
not really going to talk about this one
Parts of the Internal Carotid Artery
0:28
now initially the internal carotid is
0:31
divided into four anatomical parts
0:33
however in a clinical setting and this
0:36
really depends on the source you’re
0:37
studying from you may find it divided
0:40
into seven anatomical segments I will go
0:43
through the four anatomical parts but I
0:45
will also show you the 7-segment scheme
0:48
later in this video so the first part is
Cervical Part
0:51
the cervical part in the neck region
0:53
hence named cervical part it goes up and
0:57
then it goes inside the carotid canal as
1:00
you see here where it now becomes the
Petrous Part
1:03
petrous part so if we take this area out
1:06
and visualize it a little bit you will
1:09
see the carotid canal here it’s
1:11
initially a canal within the petrous
1:14
part of the temporal bone so this is
1:17
just a coronal or a frontal section of
1:20
the canal now the internal carotid will
1:24
continue up through with the canal and
1:26
then it will give off some important
1:30
side branches and they’re called the
1:31
carotid code tympanic branches supplying
1:34
the the tympanic cavity or or the middle
1:37
ear now as it leaves the canal and enter
1:42
the middle cranial fossa it becomes a
Cavernous Part
1:45
cavernous part and here’s maybe a better
1:48
representation of it it goes right
1:50
through the cavernous sinus the
1:53
cavernous sinus is one of the dural
1:56
sinuses of the head they’re huge they’re
1:59
large veins draining blood from the
2:01
brain and then sending them down mainly
2:04
through the jugular vein and this is how
2:06
it um you see going through the
2:09
cavernous sinus but that is why it’s
2:11
called the cavernous part because it
2:13
through with the cavernous sinus and
Cerebral Part
2:15
then as it goes up it eventually gets
2:18
the name cerebral Park where it is
2:21
divided into five terminal branches now
2:24
I mentioned earlier that it could be
2:26
divided into seven segments and I’m not
2:29
really going to spend too much time on
7 Segment Scheme
2:31
this but I made a quick scheme of the
2:34
seven segments with the side branches of
2:36
the internal carotid
2:37
I mentioned the color to Kunta panic
2:39
branch but as you see there are specific
2:43
side branches for each segment except
2:46
the the cervical segments lacerum and
2:49
cleaner each segment
2:51
I guess c1 c3 and c5 they’re without
2:54
side branches you can just pause the
2:57
video and take a mental picture if you
2:58
want to but I essentially want to focus
3:00
on the terminal ends of this artery
3:02
because those are the most important
3:04
ones so looking at a cranial view of the
Cerebral Part
3:08
cranium we’re going to have the
3:11
ophthalmic artery going into the optic
3:13
cavity through the optic canal then
3:16
there’s the anterior cerebral artery
3:19
which communicates with the other one on
3:21
the opposite side through the anterior
3:24
communicating artery there’s the middle
3:27
cerebral artery then there’s a posterior
3:30
communicating artery which communicates
3:32
with the posterior cerebral artery here
3:35
in red the posterior cerebral artery is
3:38
a branch of the basilar artery as you
3:41
see here which initially comes from the
3:44
vertebral artery coming from the
3:46
subclavian artery so now the last branch
3:50
is the anterior caried artery which
3:53
enters the lateral ventricle and then it
3:56
forms the choroid plexus now I will try
4:00
to cover these arteries in a little more
4:02
detail or rather just enough for you to
4:05
gain a general knowledge and hopefully
4:07
pass your test without comfortable great
Circle of Willis
4:11
all of these form the so-called Circle
4:15
of Willis which supply a huge majority
4:18
of the brain with blood it’s named after
4:20
the English physician Thomas Willis who
4:23
in late 1600s researched at a gnat
4:26
of the brain and found the structure of
4:28
arteries so let’s look into each of
4:31
these again the major blood supply of
4:33
the brain comes from the cerebral part
4:35
of the internal carotid and the BET
4:37
basilar artery the ophthalmic artery
4:40
does not provide any blood supply to the
4:43
brain and so to save time I will go
4:46
through this one when I talk about the
4:48
blood supply of the eye in in a separate
4:49
video but the first one in the list is
Anterior Cerebral Artery
4:52
the anterior cerebral artery which again
4:55
has this anterior communicating artery
4:57
which communicates with the anterior
4:59
cerebral artery of the opposite side now
5:02
essentially this artery will run along
5:05
the longitudinal Ceri blow fissure as
5:07
you see here and this if you look where
5:10
the arrow is and then follow the artery
5:12
the whole purple area will be supplied
5:15
by the anterior cerebral artery and this
5:18
include the whole medial surface of the
5:21
frontal and part the lobe as you see
5:23
here and then on the superior lateral
5:26
surface the whole blue area on the top
5:29
is is supplied by this artery that
5:32
include the superior frontal gyrus the
5:35
superior parietal lobule and the upper
5:39
part of the pre and post si reblog
5:41
leaders also a little hard to see here
5:46
but it also supplies a straight gyrus or
5:49
gear deflectors on the inferior surface
5:52
so that’s this one next is the medial
Medial Cerebral Artery
5:58
cerebral artery this is a huge artery
6:01
supplying really most of the brain with
6:04
blood therefore any blockage here will
6:07
lead to something called middle cerebral
6:09
artery syndrome and this is quite
6:11
serious because you see here how it
6:13
supplies many structures in the brain it
6:15
supplies the insula the lengthy form
6:18
nucleus the cow that nuclear’s the
6:19
internal capsule along with the superior
6:22
and the middle temporal gyrus and then
6:25
the rest of the purple areas in the
6:26
brain here and that’s why the middle
6:29
cerebral artery syndrome is associated
6:31
with many symptoms like paralyzes
6:34
sensory loss and and speech problems
6:37
mainly because
6:37
Broca’s area and
6:39
areas also affected so that’s mainly
6:43
Allah had for the middle cerebral artery
6:45
next we can jump over the posterior
Posterior Communicating Artery
6:48
communicating artery because this is
6:51
this just goes back and communicates
6:53
with the posterior cerebral artery but
Anterior Choroid Artery
6:56
the anterior correlate artery is very
6:58
important and I try to visualize it here
7:01
so again here’s the internal carotid
7:04
with the anterior and the middle
7:06
cerebral arteries the anterior choroidal
7:09
arteries will go backwards to form
7:12
mainly the choroid texas in the lateral
7:15
and the third ventricle so that’s mainly
7:18
this one that’s mainly overhead for this
7:20
one now the next one is the posterior
Posterior Cerebral Artery
7:23
cerebral artery coming from the basilar
7:26
artery to supply mostly the occipital
7:28
lobe as you see here in in yellow as
7:32
well as the inferior temporal and
7:33
remember both the occipital and the
7:36
inferior temporal gyrus are both
7:38
associated with vision so any any
7:41
occlusion in the posterior cerebral
7:43
artery will result in visual defects
7:46
along with other significant things like
7:48
pain and temperature sensation loss so
7:51
that’s mainly all I had for the internal
7:55
carotid and the blood supply to the
7:56
brain I really hope this video helped
7:59
you in any way just as long as you
8:01
remember the circle of fullest
8:02
you’re already understanding a huge
8:04
majority of this topic