7.3 Atheriosclerosis

0:00

S… Speaker 1 (7.3 Atheriosclerosis)

Okay, next section,

0:00

S… Speaker 1 (7.3 Atheriosclerosis)

arteriosclerosis.

0:02

S… Speaker 1 (7.3 Atheriosclerosis)

Arterio means arteries,

0:03

S… Speaker 1 (7.3 Atheriosclerosis)

and sclerosis means hardening,

0:06

S… Speaker 1 (7.3 Atheriosclerosis)

and so in this particular set of disorders,

0:08

S… Speaker 1 (7.3 Atheriosclerosis)

what happens is we get hardening of the arterial wall.

0:11

S… Speaker 1 (7.3 Atheriosclerosis)

Now, this basically occurs due to thickening of the blood vessel wall,

0:14

S… Speaker 1 (7.3 Atheriosclerosis)

and there are three pathologic patterns.

0:17

S… Speaker 1 (7.3 Atheriosclerosis)

The first is called atherosclerosis,

0:19

S… Speaker 1 (7.3 Atheriosclerosis)

and in atherosclerosis,

0:20

S… Speaker 1 (7.3 Atheriosclerosis)

we get a thickening of the intima of the blood vessel wall.

0:24

S… Speaker 1 (7.3 Atheriosclerosis)

That's high yield.

0:25

S… Speaker 1 (7.3 Atheriosclerosis)

In atherosclerosis,

0:26

S… Speaker 1 (7.3 Atheriosclerosis)

it's the intima.

0:27

S… Speaker 1 (7.3 Atheriosclerosis)

that becomes thick,

0:28

S… Speaker 1 (7.3 Atheriosclerosis)

and this usually occurs in medium and large

0:32

S… Speaker 1 (7.3 Atheriosclerosis)

-sized vessels.

0:34

S… Speaker 1 (7.3 Atheriosclerosis)

So that's atherosclerosis.

0:36

S… Speaker 1 (7.3 Atheriosclerosis)

In arteriolosclerosis,

0:38

S… Speaker 1 (7.3 Atheriosclerosis)

the olo tells us that we're dealing with the arterioles,

0:40

S… Speaker 1 (7.3 Atheriosclerosis)

so this will occur in small blood vessels,

0:43

S… Speaker 1 (7.3 Atheriosclerosis)

and we get thickening of the wall,

0:45

S… Speaker 1 (7.3 Atheriosclerosis)

either due to a deposition of protein within the wall

0:49

S… Speaker 1 (7.3 Atheriosclerosis)

or an increase in protein within the wall.

0:52

S… Speaker 1 (7.3 Atheriosclerosis)

and that's called Heinlein arteriolosclerosis,

0:54

S… Speaker 1 (7.3 Atheriosclerosis)

or a hyperplasia of the smooth muscle of the wall,

0:57

S… Speaker 1 (7.3 Atheriosclerosis)

which is called hyperplastic arteriolosclerosis,

0:59

S… Speaker 1 (7.3 Atheriosclerosis)

but we'll give you some more details as we move forward.

1:02

S… Speaker 1 (7.3 Atheriosclerosis)

In Monckeberg medial sclerosis,

1:04

S… Speaker 1 (7.3 Atheriosclerosis)

you get calcification of the media of the blood vessel,

1:07

S… Speaker 1 (7.3 Atheriosclerosis)

and this is clinically not really significant.

1:09

S… Speaker 1 (7.3 Atheriosclerosis)

You'll hear about that at the very end of this lecture.

1:12

S… Speaker 1 (7.3 Atheriosclerosis)

So let's start with atherosclerosis.

1:14

S… Speaker 1 (7.3 Atheriosclerosis)

Again, remember,

1:15

S… Speaker 1 (7.3 Atheriosclerosis)

it's an intimal plaque that obstructs blood flow.

1:18

S… Speaker 1 (7.3 Atheriosclerosis)

So here's a blood vessel.

1:19

S… Speaker 1 (7.3 Atheriosclerosis)

And of course,

1:20

S… Speaker 1 (7.3 Atheriosclerosis)

you've got an intima,

1:20

S… Speaker 1 (7.3 Atheriosclerosis)

you've got a media,

1:21

S… Speaker 1 (7.3 Atheriosclerosis)

and an adventitia.

1:22

S… Speaker 1 (7.3 Atheriosclerosis)

Those are your three layers.

1:24

S… Speaker 1 (7.3 Atheriosclerosis)

And this is an intimal plaque in which you get obstruction of

1:28

S… Speaker 1 (7.3 Atheriosclerosis)

blood flow.

1:28

S… Speaker 1 (7.3 Atheriosclerosis)

Now, important to note that this plaque mostly consists of a necrotic

1:32

S… Speaker 1 (7.3 Atheriosclerosis)

lipid core.

1:33

S… Speaker 1 (7.3 Atheriosclerosis)

So the key component here would be cholesterol.

1:36

S… Speaker 1 (7.3 Atheriosclerosis)

And it has a fibromuscular cap,

1:40

S… Speaker 1 (7.3 Atheriosclerosis)

as I've drawn here.

1:41

S… Speaker 1 (7.3 Atheriosclerosis)

And often,

1:42

S… Speaker 1 (7.3 Atheriosclerosis)

this necrotic lipid core can undergo dystrophic calcification,

1:45

S… Speaker 1 (7.3 Atheriosclerosis)

so it's not uncommon for atherosclerosis to be calcified.

1:49

S… Speaker 1 (7.3 Atheriosclerosis)

Here's a picture of atherosclerosis.

1:50

S… Speaker 1 (7.3 Atheriosclerosis)

This would normally represent the intima with an endothelial layer

1:55

S… Speaker 1 (7.3 Atheriosclerosis)

sitting on top of a basement membrane.

1:56

S… Speaker 1 (7.3 Atheriosclerosis)

Here is the smooth muscle media.

1:58

S… Speaker 1 (7.3 Atheriosclerosis)

You can clearly see that there's expansion of the intima by this necrotic

2:03

S… Speaker 1 (7.3 Atheriosclerosis)

lipid core.

2:03

S… Speaker 1 (7.3 Atheriosclerosis)

Notice all the cholesterol clefts sitting in the middle of this necrotic

2:08

S… Speaker 1 (7.3 Atheriosclerosis)

lipid core.

2:08

S… Speaker 1 (7.3 Atheriosclerosis)

And we've got this fibromuscular cap that overlies the necrotic

2:13

S… Speaker 1 (7.3 Atheriosclerosis)

lipid core.

2:13

S… Speaker 1 (7.3 Atheriosclerosis)

So again,

2:14

S… Speaker 1 (7.3 Atheriosclerosis)

intimal plaque.

2:15

S… Speaker 1 (7.3 Atheriosclerosis)

that consists of a necrotic lipid core with a fibromuscular cap.

2:19

S… Speaker 1 (7.3 Atheriosclerosis)

This involves large and medium -sized arteries,

2:22

S… Speaker 1 (7.3 Atheriosclerosis)

as I've already mentioned,

2:23

S… Speaker 1 (7.3 Atheriosclerosis)

and the four most common arteries in the body to be involved are the abdominal

2:27

S… Speaker 1 (7.3 Atheriosclerosis)

aorta, the coronary arteries,

2:29

S… Speaker 1 (7.3 Atheriosclerosis)

the popliteal artery,

2:30

S… Speaker 1 (7.3 Atheriosclerosis)

and the internal carotid arteries.

2:32

S… Speaker 1 (7.3 Atheriosclerosis)

And the idea here is that when you get involvement in these arteries,

2:35

S… Speaker 1 (7.3 Atheriosclerosis)

you're going to develop certain pathology,

2:37

S… Speaker 1 (7.3 Atheriosclerosis)

and the pathology is what we're going to discuss both in this section

2:41

S… Speaker 1 (7.3 Atheriosclerosis)

and in the cardiac section.

2:43

S… Speaker 1 (7.3 Atheriosclerosis)

So the risk factors for atherosclerosis are actually divided into two,

2:46

S… Speaker 2 (7.3 Atheriosclerosis)

modifiable and non -modifiable.

2:48

S… Speaker 1 (7.3 Atheriosclerosis)

The modifiable risk factors include hypertension.

2:51

S… Speaker 1 (7.3 Atheriosclerosis)

That's a very important risk factor for the development of atherosclerosis.

2:55

S… Speaker 1 (7.3 Atheriosclerosis)

Hypercholesterolemia,

2:56

S… Speaker 1 (7.3 Atheriosclerosis)

for example,

2:57

S… Speaker 1 (7.3 Atheriosclerosis)

LDL increases the risk,

2:59

S… Speaker 1 (7.3 Atheriosclerosis)

whereas HDL decreases the risk.

3:01

S… Speaker 1 (7.3 Atheriosclerosis)

Smoking and diabetes.

3:03

S… Speaker 1 (7.3 Atheriosclerosis)

So these are the four key modifiable risk factors that lead to

3:07

S… Speaker 1 (7.3 Atheriosclerosis)

atherosclerosis,

3:08

S… Speaker 1 (7.3 Atheriosclerosis)

and you need to memorize each of them.

3:10

S… Speaker 1 (7.3 Atheriosclerosis)

All right, so you need to know that there's four modifiable key risk factors,

3:13

S… Speaker 1 (7.3 Atheriosclerosis)

hypertension, hypercholesterolemia,

3:15

S… Speaker 1 (7.3 Atheriosclerosis)

smoking, and diabetes.

3:16

S… Speaker 1 (7.3 Atheriosclerosis)

The non -modifiable risk factors include age.

3:19

S… Speaker 1 (7.3 Atheriosclerosis)

For example,

3:19

S… Speaker 1 (7.3 Atheriosclerosis)

the number and severity of the lesions,

3:21

S… Speaker 1 (7.3 Atheriosclerosis)

they increase with age.

3:22

S… Speaker 1 (7.3 Atheriosclerosis)

Gender,

3:23

S… Speaker 1 (7.3 Atheriosclerosis)

for example,

3:23

S… Speaker 1 (7.3 Atheriosclerosis)

there's an increased risk in males and in postmenopausal females.

3:27

S… Speaker 1 (7.3 Atheriosclerosis)

Premenopausal females are relatively protected,

3:30

S… Speaker 1 (7.3 Atheriosclerosis)

and that's because estrogen is protective.

3:33

S… Speaker 1 (7.3 Atheriosclerosis)

And then there are some genetic factors.

3:35

S… Speaker 1 (7.3 Atheriosclerosis)

It's basically multifactorial,

3:37

S… Speaker 1 (7.3 Atheriosclerosis)

but important to note that family history is highly predictive of risk.

3:41

S… Speaker 1 (7.3 Atheriosclerosis)

The pathogenesis of atherosclerosis is debated,

3:44

S… Speaker 1 (7.3 Atheriosclerosis)

but one sort of theory is that you've got endothelium here.

3:48

S… Speaker 1 (7.3 Atheriosclerosis)

Of course, endothelium is sitting on top of this basement membrane,

3:51

S… Speaker 1 (7.3 Atheriosclerosis)

and the idea is that within this intima here,

3:54

S… Speaker 1 (7.3 Atheriosclerosis)

you get damage to the endothelium,

3:57

S… Speaker 1 (7.3 Atheriosclerosis)

which then results in lipid entering into the intima.

4:02

S… Speaker 1 (7.3 Atheriosclerosis)

And as lipid enters into the intima,

4:04

S… Speaker 1 (7.3 Atheriosclerosis)

the lipid then gets oxidized.

4:06

S… Speaker 1 (7.3 Atheriosclerosis)

And once it gets oxidized,

4:07

S… Speaker 1 (7.3 Atheriosclerosis)

it gets taken up by macrophages so that you get collections of macrophages

4:11

S… Speaker 1 (7.3 Atheriosclerosis)

with lipid within them.

4:12

S… Speaker 1 (7.3 Atheriosclerosis)

That forms the initial lesion of atherosclerosis,

4:16

S… Speaker 1 (7.3 Atheriosclerosis)

which is called a fatty streak.

4:17

S… Speaker 1 (7.3 Atheriosclerosis)

And where you look at a blood vessel in a very young patient,

4:21

S… Speaker 1 (7.3 Atheriosclerosis)

you could see these yellow flat streaks that are running along.

4:24

S… Speaker 1 (7.3 Atheriosclerosis)

the large blood vessels,

4:26

S… Speaker 1 (7.3 Atheriosclerosis)

and those are called fatty streaks.

4:27

S… Speaker 1 (7.3 Atheriosclerosis)

They arise early in life,

4:28

S… Speaker 1 (7.3 Atheriosclerosis)

and actually they're seen in most teenagers.

4:30

S… Speaker 1 (7.3 Atheriosclerosis)

That's how early atherosclerosis begins.

4:32

S… Speaker 1 (7.3 Atheriosclerosis)

Now eventually you get inflammation and healing and increased deposition

4:36

S… Speaker 1 (7.3 Atheriosclerosis)

of this lipid within the intima,

4:39

S… Speaker 1 (7.3 Atheriosclerosis)

and that's going to result in a thickening of this lipid layer with a

4:43

S… Speaker 1 (7.3 Atheriosclerosis)

necrotic lipid core and the formation of a fibromuscular cap.

4:47

S… Speaker 1 (7.3 Atheriosclerosis)

Now that fibromuscular cap is due to the inflammation and healing,

4:50

S… Speaker 1 (7.3 Atheriosclerosis)

which leads to deposition of extracellular matrix.

4:53

S… Speaker 1 (7.3 Atheriosclerosis)

and proliferation of smooth muscle.

4:55

S… Speaker 1 (7.3 Atheriosclerosis)

And so in the end,

4:56

S… Speaker 1 (7.3 Atheriosclerosis)

what's going to happen is that this is going to be the blood vessel,

4:59

S… Speaker 1 (7.3 Atheriosclerosis)

and you're obviously

5:00

S… Speaker 1 (7.3 Atheriosclerosis)

going to have this atherosclerotic plaque that will occlude the blood flow or

5:04

S… Speaker 1 (7.3 Atheriosclerosis)

that will decrease the blood flow

5:07

S… Speaker 1 (7.3 Atheriosclerosis)

Complications of atherosclerosis account for more than half of disease in the Western world,

5:11

S… Speaker 1 (7.3 Atheriosclerosis)

and let's walk our way through some of these now.

5:13

S… Speaker 1 (7.3 Atheriosclerosis)

The first is stenosis of medium -sized vessels,

5:16

S… Speaker 1 (7.3 Atheriosclerosis)

and here's the idea.

5:17

S… Speaker 1 (7.3 Atheriosclerosis)

If this is a blood vessel and it's going into an organ,

5:20

S… Speaker 1 (7.3 Atheriosclerosis)

you know that the medium -sized blood vessels are those vessels that feed the major organs.

5:24

S… Speaker 1 (7.3 Atheriosclerosis)

So let's say that this is the artery and this is the vein and this is the organ.

5:28

S… Speaker 1 (7.3 Atheriosclerosis)

If we get atherosclerosis here,

5:31

S… Speaker 1 (7.3 Atheriosclerosis)

then that atherosclerosis is going to cause stenosis of the blood vessel.

5:35

S… Speaker 1 (7.3 Atheriosclerosis)

i .e.,

5:35

S… Speaker 1 (7.3 Atheriosclerosis)

you've decreased the luminal caliber of that blood vessel.

5:38

S… Speaker 1 (7.3 Atheriosclerosis)

And of course,

5:38

S… Speaker 1 (7.3 Atheriosclerosis)

that can result in various signs and symptoms.

5:41

S… Speaker 1 (7.3 Atheriosclerosis)

So this can occur,

5:42

S… Speaker 1 (7.3 Atheriosclerosis)

for example, in the popliteal artery,

5:44

S… Speaker 1 (7.3 Atheriosclerosis)

resulting in peripheral vascular disease.

5:46

S… Speaker 1 (7.3 Atheriosclerosis)

It can also occur in the coronary artery,

5:48

S… Speaker 1 (7.3 Atheriosclerosis)

which would give you episodic chest pain or angina.

5:51

S… Speaker 1 (7.3 Atheriosclerosis)

And then it can also occur in the mesenteric arteries,

5:54

S… Speaker 1 (7.3 Atheriosclerosis)

which could give ischemic bowel disease.

5:56

S… Speaker 1 (7.3 Atheriosclerosis)

So that's complication number one.

5:58

S… Speaker 1 (7.3 Atheriosclerosis)

It's important to note that you usually don't get symptoms until you have greater than 70

6:02

S… Speaker 1 (7.3 Atheriosclerosis)

% stenosis.

6:03

S… Speaker 1 (7.3 Atheriosclerosis)

That's high yield.

6:04

S… Speaker 1 (7.3 Atheriosclerosis)

Greater than 70 % stenosis before you actually get complications.

6:09

S… Speaker 1 (7.3 Atheriosclerosis)

Complication number two is plaque rupture with thrombosis,

6:12

S… Speaker 1 (7.3 Atheriosclerosis)

and the idea here is you've got this blood vessel,

6:14

S… Speaker 1 (7.3 Atheriosclerosis)

and obviously this blood vessel's feeding the organ.

6:17

S… Speaker 1 (7.3 Atheriosclerosis)

Let's pretend that you've got atherosclerosis here.

6:19

S… Speaker 1 (7.3 Atheriosclerosis)

Now,

6:19

S… Speaker 1 (7.3 Atheriosclerosis)

one of the complications of atherosclerosis is that at the neck,

6:23

S… Speaker 1 (7.3 Atheriosclerosis)

this is the place where it usually ruptures,

6:24

S… Speaker 1 (7.3 Atheriosclerosis)

at the neck,

6:25

S… Speaker 1 (7.3 Atheriosclerosis)

you can get rupture,

6:26

S… Speaker 1 (7.3 Atheriosclerosis)

which would then expose all that necrotic lipid core.

6:29

S… Speaker 1 (7.3 Atheriosclerosis)

And if the necrotic lipid core and the tissue underneath it is exposed,

6:33

S… Speaker 1 (7.3 Atheriosclerosis)

that's going to result in activation of the coagulation cascade.

6:36

S… Speaker 1 (7.3 Atheriosclerosis)

And so you'd rapidly develop a thrombus here,

6:39

S… Speaker 1 (7.3 Atheriosclerosis)

which could then occlude the vessel,

6:42

S… Speaker 1 (7.3 Atheriosclerosis)

creating an infarction in this organ.

6:44

S… Speaker 1 (7.3 Atheriosclerosis)

And actually,

6:45

S… Speaker 1 (7.3 Atheriosclerosis)

that's the way by which a myocardial infarction occurs.

6:47

S… Speaker 1 (7.3 Atheriosclerosis)

It's usually due to plaque rupture with thrombosis.

6:50

S… Speaker 1 (7.3 Atheriosclerosis)

So the examples would be if this occurred in the coronary artery,

6:53

S… Speaker 1 (7.3 Atheriosclerosis)

the patient would develop a myocardial infarction.

6:56

S… Speaker 1 (7.3 Atheriosclerosis)

If this occurred,

6:57

S… Speaker 1 (7.3 Atheriosclerosis)

for example, in the middle cerebral artery,

6:58

S… Speaker 1 (7.3 Atheriosclerosis)

the patient could develop a stroke.

7:00

S… Speaker 1 (7.3 Atheriosclerosis)

So that's a second complication of atherosclerosis.

7:04

S… Speaker 1 (7.3 Atheriosclerosis)

The third complication of atherosclerosis is plaque rupture with embolization.

7:08

S… Speaker 1 (7.3 Atheriosclerosis)

Now here's the idea.

7:09

S… Speaker 1 (7.3 Atheriosclerosis)

You've got this atherosclerotic plaque.

7:11

S… Speaker 1 (7.3 Atheriosclerosis)

It's possible for this plaque to break off,

7:13

S… Speaker 1 (7.3 Atheriosclerosis)

and then part of that plaque could embolize and go through the blood supply and then lodge

7:18

S… Speaker 1 (7.3 Atheriosclerosis)

in a distant site,

7:19

S… Speaker 1 (7.3 Atheriosclerosis)

and that's called embolization.

7:20

S… Speaker 1 (7.3 Atheriosclerosis)

Now that results in something called an atherosclerotic embolus,

7:24

S… Speaker 1 (7.3 Atheriosclerosis)

and remember that the hallmark of atherosclerotic emboli are the presence of

7:28

S… Speaker 1 (7.3 Atheriosclerosis)

cholesterol clefts.

7:29

S… Speaker 1 (7.3 Atheriosclerosis)

Now here's a picture of that.

7:30

S… Speaker 1 (7.3 Atheriosclerosis)

This is a blood vessel.

7:32

S… Speaker 1 (7.3 Atheriosclerosis)

This blood vessel contains an atherosclerotic embolus,

7:35

S… Speaker 1 (7.3 Atheriosclerosis)

and the way by which you know that it's an atherosclerotic embolus is because you see these

7:39

S… Speaker 1 (7.3 Atheriosclerosis)

cholesterol clefts.

7:42

S… Speaker 1 (7.3 Atheriosclerosis)

The fourth complication is weakening of the vessel wall,

7:44

S… Speaker 1 (7.3 Atheriosclerosis)

and the idea here is that,

7:46

S… Speaker 1 (7.3 Atheriosclerosis)

remember the vessel wall contains an intima,

7:48

S… Speaker 1 (7.3 Atheriosclerosis)

it contains a media,

7:49

S… Speaker 1 (7.3 Atheriosclerosis)

and it contains an adventitia.

7:50

S… Speaker 1 (7.3 Atheriosclerosis)

And of course,

7:51

S… Speaker 1 (7.3 Atheriosclerosis)

this is where the blood would be present.

7:53

S… Speaker 1 (7.3 Atheriosclerosis)

Now remember that the blood vessel wall,

7:55

S… Speaker 1 (7.3 Atheriosclerosis)

i .e.

7:56

S… Speaker 1 (7.3 Atheriosclerosis)

the intima, media,

7:57

S… Speaker 1 (7.3 Atheriosclerosis)

and the adventitia,

7:57

S… Speaker 1 (7.3 Atheriosclerosis)

these are all alive,

7:58

S… Speaker 1 (7.3 Atheriosclerosis)

and they require oxygen in order to maintain themselves and

8:02

S… Speaker 1 (7.3 Atheriosclerosis)

to be healthy.

8:03

S… Speaker 1 (7.3 Atheriosclerosis)

Now normally,

8:04

S… Speaker 2 (7.3 Atheriosclerosis)

what's nice about the blood vessel is that the blood

8:07

S… Speaker 1 (7.3 Atheriosclerosis)

carries oxygen and the oxygen from the blood actually feeds the entire vessel

8:11

S… Speaker 1 (7.3 Atheriosclerosis)

wall however if a patient gets atherosclerosis so that this intima becomes

8:15

S… Speaker 1 (7.3 Atheriosclerosis)

thick it creates a diffusion barrier so that oxygen can't feed this wall

8:19

S… Speaker 1 (7.3 Atheriosclerosis)

so this wall will become weak and will become atrophic now as the

8:23

S… Speaker 1 (7.3 Atheriosclerosis)

wall weakens what's going to happen is you're going to increase the risk of ballooning of that wall

8:27

S… Speaker 1 (7.3 Atheriosclerosis)

because now there's a weak wall with a lot of stress and so the complication of

8:31

S… Speaker 1 (7.3 Atheriosclerosis)

that would be that you would develop

8:33

S… Speaker 1 (7.3 Atheriosclerosis)

something called an aneurysm,

8:35

S… Speaker 1 (7.3 Atheriosclerosis)

which is a balloon -like dilatation of the blood vessel wall.

8:38

S… Speaker 1 (7.3 Atheriosclerosis)

This is a fourth complication of atherosclerosis,

8:42

S… Speaker 1 (7.3 Atheriosclerosis)

and it's going to be very important as we move forward in this particular chapter.

8:47

S… Speaker 1 (7.3 Atheriosclerosis)

Now the second type of arteriosclerosis,

8:49

S… Speaker 1 (7.3 Atheriosclerosis)

remember arteriosclerosis is the global term that refers to these three

8:53

S… Speaker 1 (7.3 Atheriosclerosis)

mechanisms by which we can create thickening of the blood vessel wall.

8:57

S… Speaker 1 (7.3 Atheriosclerosis)

So the second type of arteriosclerosis is arteriolosclerosis,

9:03

S… Speaker 1 (7.3 Atheriosclerosis)

implying that we're dealing with the small blood vessels.

9:05

S… Speaker 1 (7.3 Atheriosclerosis)

Now what happens here is you get thickening of the wall of the small blood vessels,

9:09

S… Speaker 1 (7.3 Atheriosclerosis)

which then narrows those small blood vessels and then creates complications

9:13

S… Speaker 1 (7.3 Atheriosclerosis)

downstream.

9:15

S… Speaker 1 (7.3 Atheriosclerosis)

Arteriolosclerosis comes in two flavors.

9:17

S… Speaker 1 (7.3 Atheriosclerosis)

Number one,

9:18

S… Speaker 1 (7.3 Atheriosclerosis)

highline arteriolosclerosis,

9:20

S… Speaker 1 (7.3 Atheriosclerosis)

and number two,

9:20

S… Speaker 1 (7.3 Atheriosclerosis)

hyperplastic.

9:21

S… Speaker 1 (7.3 Atheriosclerosis)

In highline arteriolosclerosis,

9:24

S… Speaker 1 (7.3 Atheriosclerosis)

you get proteins leaking into the vessel wall.

9:27

S… Speaker 1 (7.3 Atheriosclerosis)

This produces vascular thickening,

9:29

S… Speaker 1 (7.3 Atheriosclerosis)

and you see it on microscopy as pink highline within the blood vessel.

9:33

S… Speaker 1 (7.3 Atheriosclerosis)

So here's what it looks like.

9:35

S… Speaker 1 (7.3 Atheriosclerosis)

This is obviously a blood vessel here,

9:37

S… Speaker 1 (7.3 Atheriosclerosis)

and you can see that the wall of this blood vessel is relatively thick,

9:40

S… Speaker 1 (7.3 Atheriosclerosis)

and what's thickening it here is the presence of this pink Heinlein

9:45

S… Speaker 1 (7.3 Atheriosclerosis)

material.

9:45

S… Speaker 1 (7.3 Atheriosclerosis)

And so this is an example of Heinlein arteriolosclerosis.

9:49

S… Speaker 1 (7.3 Atheriosclerosis)

Very important to note that it arises due to two things.

9:54

S… Speaker 1 (7.3 Atheriosclerosis)

You have to know this.

9:55

S… Speaker 1 (7.3 Atheriosclerosis)

This is super high yield.

9:56

S… Speaker 1 (7.3 Atheriosclerosis)

It's going to be something that we're going to hear about regularly as we move through pelvic

10:00

S… Speaker 1 (7.3 Atheriosclerosis)

floor.

10:00

S… Speaker 1 (7.3 Atheriosclerosis)

pathology.

10:00

S… Speaker 1 (7.3 Atheriosclerosis)

Number one,

10:01

S… Speaker 1 (7.3 Atheriosclerosis)

benign hypertension.

10:02

S… Speaker 1 (7.3 Atheriosclerosis)

Patients who have long -standing benign hypertension,

10:05

S… Speaker 1 (7.3 Atheriosclerosis)

they get highline arteriolosclerosis.

10:08

S… Speaker 1 (7.3 Atheriosclerosis)

And the idea here is that the high blood pressure forces protein into the

10:12

S… Speaker 1 (7.3 Atheriosclerosis)

wall, giving us this change.

10:13

S… Speaker 1 (7.3 Atheriosclerosis)

And number two,

10:15

S… Speaker 1 (7.3 Atheriosclerosis)

we see it in diabetics.

10:16

S… Speaker 1 (7.3 Atheriosclerosis)

So patients who have diabetes,

10:18

S… Speaker 1 (7.3 Atheriosclerosis)

they get non -enzymatic glycosylation of the basement membrane,

10:22

S… Speaker 1 (7.3 Atheriosclerosis)

which then makes this blood vessel wall leaky,

10:25

S… Speaker 1 (7.3 Atheriosclerosis)

and then protein begins to leak in,

10:27

S… Speaker 1 (7.3 Atheriosclerosis)

giving us highline

10:30

S… Speaker 1 (7.3 Atheriosclerosis)

I cannot emphasize this enough.

10:32

S… Speaker 1 (7.3 Atheriosclerosis)

It's so high yield.

10:33

S… Speaker 1 (7.3 Atheriosclerosis)

It will come up over and over again in our discussions of pathology.

10:36

S… Speaker 1 (7.3 Atheriosclerosis)

Highline arteriolosclerosis is a consequence of

10:40

S… Speaker 1 (7.3 Atheriosclerosis)

two things.

10:41

S… Speaker 1 (7.3 Atheriosclerosis)

Number one,

10:41

S… Speaker 1 (7.3 Atheriosclerosis)

benign hypertension.

10:42

S… Speaker 1 (7.3 Atheriosclerosis)

Number two,

10:43

S… Speaker 1 (7.3 Atheriosclerosis)

diabetes.

10:45

S… Speaker 1 (7.3 Atheriosclerosis)

Now, the consequence of highline arteriolosclerosis is that you're going to get a reduced

10:49

S… Speaker 1 (7.3 Atheriosclerosis)

vessel caliber,

10:50

S… Speaker 1 (7.3 Atheriosclerosis)

which is then going to result in end organ ischemia.

10:52

S… Speaker 1 (7.3 Atheriosclerosis)

This can occur throughout the body,

10:54

S… Speaker 1 (7.3 Atheriosclerosis)

but it classically occurs within the kidney,

10:56

S… Speaker 1 (7.3 Atheriosclerosis)

producing glomerular scarring.

10:58

S… Speaker 1 (7.3 Atheriosclerosis)

And here's the idea.

10:59

S… Speaker 1 (7.3 Atheriosclerosis)

It's very high yield to be aware of.

11:01

S… Speaker 1 (7.3 Atheriosclerosis)

You've got this glomerulus here,

11:03

S… Speaker 1 (7.3 Atheriosclerosis)

okay?

11:04

S… Speaker 1 (7.3 Atheriosclerosis)

and there's an afferent arteriole here,

11:07

S… Speaker 1 (7.3 Atheriosclerosis)

and there's an efferent arteriole here.

11:09

S… Speaker 1 (7.3 Atheriosclerosis)

Imagine if you get highline arteriolosclerosis so that you get thickening

11:13

S… Speaker 1 (7.3 Atheriosclerosis)

of the blood vessel wall.

11:14

S… Speaker 1 (7.3 Atheriosclerosis)

As you thicken the blood vessel wall,

11:15

S… Speaker 1 (7.3 Atheriosclerosis)

slowly over time,

11:16

S… Speaker 1 (7.3 Atheriosclerosis)

you're slowly going to decrease the amount of blood that's actually supplying this glomerulus.

11:21

S… Speaker 1 (7.3 Atheriosclerosis)

This glomerulus will then scar.

11:23

S… Speaker 1 (7.3 Atheriosclerosis)

and you'll get something called glomerular scarring.

11:26

S… Speaker 1 (7.3 Atheriosclerosis)

So this is a key consequence of highline arteriolosclerosis.

11:30

S… Speaker 1 (7.3 Atheriosclerosis)

And in fact, this is the reason why patients with diabetes and patients with high blood

11:35

S… Speaker 1 (7.3 Atheriosclerosis)

pressure, they get chronic renal failure because over time,

11:38

S… Speaker 1 (7.3 Atheriosclerosis)

they develop this glomerular scarring due to the highline

11:42

S… Speaker 1 (7.3 Atheriosclerosis)

arteriolosclerosis.

11:43

S… Speaker 1 (7.3 Atheriosclerosis)

And that's what I've stated here in your text where I say that it classically produces

11:48

S… Speaker 1 (7.3 Atheriosclerosis)

glomerular scarring.

11:49

S… Speaker 1 (7.3 Atheriosclerosis)

Now when it produces glomerular scarring,

11:51

S… Speaker 1 (7.3 Atheriosclerosis)

we call that arteriolo.

11:54

S… Speaker 1 (7.3 Atheriosclerosis)

nephrosclerosis, arteriolo,

11:55

S… Speaker 1 (7.3 Atheriosclerosis)

small arterioles.

11:57

S… Speaker 1 (7.3 Atheriosclerosis)

Nephro,

11:58

S… Speaker 1 (7.3 Atheriosclerosis)

kidney, sclerosis,

11:59

S… Speaker 1 (7.3 Atheriosclerosis)

you get sclerosis of both the glomeruli as well as those small

12:03

S… Speaker 2 (7.3 Atheriosclerosis)

blood vessels.

12:04

S… Speaker 1 (7.3 Atheriosclerosis)

And of course,

12:05

S… Speaker 1 (7.3 Atheriosclerosis)

this is how we get to chronic renal failure in patients with long -standing

12:09

S… Speaker 1 (7.3 Atheriosclerosis)

hypertension and in patients with diabetes.

12:11

S… Speaker 1 (7.3 Atheriosclerosis)

Now,

12:12

S… Speaker 1 (7.3 Atheriosclerosis)

of course, as you get this...

12:15

S… Speaker 1 (7.3 Atheriosclerosis)

glomerular scarring,

12:16

S… Speaker 1 (7.3 Atheriosclerosis)

you're going to shrink the kidney,

12:18

S… Speaker 1 (7.3 Atheriosclerosis)

so the kidney will become shrunken.

12:19

S… Speaker 1 (7.3 Atheriosclerosis)

And on top of that,

12:20

S… Speaker 1 (7.3 Atheriosclerosis)

you'll see the scarring on the surface of the kidney.

12:22

S… Speaker 1 (7.3 Atheriosclerosis)

Now, when you look at the outside of the kidney,

12:24

S… Speaker 1 (7.3 Atheriosclerosis)

you're really getting a look at the cortex.

12:25

S… Speaker 1 (7.3 Atheriosclerosis)

So the outside represents the cortex.

12:29

S… Speaker 1 (7.3 Atheriosclerosis)

The surface of the kidney is really up against the cortex,

12:31

S… Speaker 1 (7.3 Atheriosclerosis)

basically.

12:32

S… Speaker 1 (7.3 Atheriosclerosis)

And so this is a classic example of arteriolonephrosclerosis.

12:40

S… Speaker 1 (7.3 Atheriosclerosis)

The other type of arteriolosclerosis is called hyperplastic arteriolosclerosis.

12:45

S… Speaker 1 (7.3 Atheriosclerosis)

And again, this is going to involve the small blood vessels,

12:47

S… Speaker 1 (7.3 Atheriosclerosis)

and we're gonna get thickening of the small blood vessels.

12:50

S… Speaker 1 (7.3 Atheriosclerosis)

However, instead of the thickening being due to this protein

12:54

S… Speaker 1 (7.3 Atheriosclerosis)

that's leaking into the vessel wall,

12:56

S… Speaker 1 (7.3 Atheriosclerosis)

we get hyperplasia of the smooth muscle that results in that thickening,

13:00

S… Speaker 1 (7.3 Atheriosclerosis)

which then gives something called an onion skin appearance.

13:02

S… Speaker 1 (7.3 Atheriosclerosis)

So here's the classic image,

13:04

S… Speaker 1 (7.3 Atheriosclerosis)

and this is again a small blood vessel or an arteriole.

13:07

S… Speaker 1 (7.3 Atheriosclerosis)

and we've got thickening of the arterial,

13:09

S… Speaker 1 (7.3 Atheriosclerosis)

and you can see that there's too many muscular cell layers

13:14

S… Speaker 1 (7.3 Atheriosclerosis)

here, and that's producing layer after layer of smooth muscle,

13:17

S… Speaker 1 (7.3 Atheriosclerosis)

which then is called onion skinning because each layer looks like the skin of

13:21

S… Speaker 1 (7.3 Atheriosclerosis)

an onion.

13:22

S… Speaker 1 (7.3 Atheriosclerosis)

Now, this reduces the luminal caliber,

13:25

S… Speaker 1 (7.3 Atheriosclerosis)

which then decreases the blood flow going to the end

13:29

S… Speaker 1 (7.3 Atheriosclerosis)

organ.

13:29

S… Speaker 1 (7.3 Atheriosclerosis)

All right,

13:30

S… Speaker 1 (7.3 Atheriosclerosis)

once you've understood the histology,

13:31

S… Speaker 1 (7.3 Atheriosclerosis)

then the next question is,

13:32

S… Speaker 1 (7.3 Atheriosclerosis)

what does this process do to?

13:34

S… Speaker 1 (7.3 Atheriosclerosis)

And it's very important to note that this process is a consequence of malignant

13:38

S… Speaker 1 (7.3 Atheriosclerosis)

hypertension.

13:39

S… Speaker 1 (7.3 Atheriosclerosis)

Malignant hypertension.

13:41

S… Speaker 1 (7.3 Atheriosclerosis)

And so the idea here is that when you get super high blood pressure,

13:44

S… Speaker 1 (7.3 Atheriosclerosis)

sort of the smooth muscle begins to respond by hyperplasing,

13:48

S… Speaker 1 (7.3 Atheriosclerosis)

almost trying to contain that high blood pressure.

13:51

S… Speaker 1 (7.3 Atheriosclerosis)

And so that's called hyperplastic arteriolosclerosis.

13:57

S… Speaker 1 (7.3 Atheriosclerosis)

Now, of course,

13:58

S… Speaker 1 (7.3 Atheriosclerosis)

the luminal narrowing that's going to occur here is going to result in

14:02

S… Speaker 1 (7.3 Atheriosclerosis)

reduced vessel caliber,

14:03

S… Speaker 1 (7.3 Atheriosclerosis)

and so we'll get end -organ ischemia.

14:04

S… Speaker 1 (7.3 Atheriosclerosis)

Now that high blood pressure can also result in fibrinoid necrosis.

14:08

S… Speaker 1 (7.3 Atheriosclerosis)

Remember from chapter one when we talked about necrosis,

14:10

S… Speaker 1 (7.3 Atheriosclerosis)

we said that when you get death of the blood vessel wall,

14:13

S… Speaker 1 (7.3 Atheriosclerosis)

that's called fibrinoid necrosis,

14:15

S… Speaker 1 (7.3 Atheriosclerosis)

and we see that in two circumstances.

14:16

S… Speaker 1 (7.3 Atheriosclerosis)

We see that in malignant hypertension,

14:19

S… Speaker 1 (7.3 Atheriosclerosis)

and we see that in vasculitis.

14:21

S… Speaker 1 (7.3 Atheriosclerosis)

So this is an example of where we might get fibrinoid necrosis of the blood vessel

14:25

S… Speaker 1 (7.3 Atheriosclerosis)

wall.

14:25

S… Speaker 1 (7.3 Atheriosclerosis)

Now the classic finding is also present within the kidney when patients

14:29

S… Speaker 1 (7.3 Atheriosclerosis)

have

14:31

S… Speaker 1 (7.3 Atheriosclerosis)

highline arteriolosclerosis,

14:32

S… Speaker 1 (7.3 Atheriosclerosis)

and that is that they get acute renal failure with something called a flea bitten

14:36

S… Speaker 1 (7.3 Atheriosclerosis)

appearance to the kidney.

14:37

S… Speaker 1 (7.3 Atheriosclerosis)

The acute renal failure,

14:39

S… Speaker 1 (7.3 Atheriosclerosis)

again, is because you're getting acute damage due to the very high blood pressure to the

14:43

S… Speaker 1 (7.3 Atheriosclerosis)

kidney, and at the same time,

14:44

S… Speaker 1 (7.3 Atheriosclerosis)

you get this flea bitten appearance because on the surface of the kidney,

14:47

S… Speaker 1 (7.3 Atheriosclerosis)

you have these little pinpoint hemorrhages where you've had,

14:50

S… Speaker 1 (7.3 Atheriosclerosis)

you know,

14:51

S… Speaker 1 (7.3 Atheriosclerosis)

blowing out of the blood vessels,

14:52

S… Speaker 1 (7.3 Atheriosclerosis)

for example,

14:53

S… Speaker 1 (7.3 Atheriosclerosis)

which then results in hemorrhage.

14:55

S… Speaker 1 (7.3 Atheriosclerosis)

So this is a very high yield principle to be aware of.

14:59

S… Speaker 1 (7.3 Atheriosclerosis)

Now let me just summarize this because this is,

15:01

S… Speaker 1 (7.3 Atheriosclerosis)

the entire discussion is so central to so much of pathology.

15:05

S… Speaker 1 (7.3 Atheriosclerosis)

So basically what we've said so far in these few slides that we've covered are

15:09

S… Speaker 1 (7.3 Atheriosclerosis)

that you can get thickening of the blood vessel wall,

15:11

S… Speaker 1 (7.3 Atheriosclerosis)

and when you have thickening of the blood vessel wall,

15:13

S… Speaker 1 (7.3 Atheriosclerosis)

that's called arteriosclerosis.

15:15

S… Speaker 1 (7.3 Atheriosclerosis)

If you get thickening of the large or medium -sized blood vessels with

15:20

S… Speaker 1 (7.3 Atheriosclerosis)

an intimal plaque,

15:21

S… Speaker 1 (7.3 Atheriosclerosis)

that's called atherosclerosis,

15:23

S… Speaker 1 (7.3 Atheriosclerosis)

and that will have four complications,

15:25

S… Speaker 1 (7.3 Atheriosclerosis)

which we've already discussed.

15:26

S… Speaker 1 (7.3 Atheriosclerosis)

And then the other possibility is that you can get thickening of the small arterioles,

15:31

S… Speaker 1 (7.3 Atheriosclerosis)

and that's called arteriolosclerosis.

15:34

S… Speaker 1 (7.3 Atheriosclerosis)

Arteriolosclerosis can be divided into two types,

15:36

S… Speaker 1 (7.3 Atheriosclerosis)

hyperplastic and highline.

15:38

S… Speaker 1 (7.3 Atheriosclerosis)

In highline arteriolosclerosis,

15:40

S… Speaker 1 (7.3 Atheriosclerosis)

you get leaking of protein across the blood vessel wall,

15:43

S… Speaker 1 (7.3 Atheriosclerosis)

which thickens the blood vessel wall,

15:44

S… Speaker 1 (7.3 Atheriosclerosis)

giving it a pink appearance.

15:46

S… Speaker 1 (7.3 Atheriosclerosis)

And of course,

15:46

S… Speaker 1 (7.3 Atheriosclerosis)

the two ways by which you can get highline arteriolosclerosis are hypertension,

15:51

S… Speaker 1 (7.3 Atheriosclerosis)

which squeezes protein across that blood vessel wall,

15:54

S… Speaker 1 (7.3 Atheriosclerosis)

and diabetes,

15:55

S… Speaker 1 (7.3 Atheriosclerosis)

in which you get non -enzymatic glycosylation of the basement membrane of

15:59

S… Speaker 1 (7.3 Atheriosclerosis)

the vessel wall,

16:00

S… Speaker 1 (7.3 Atheriosclerosis)

which then allows protein to leak in.

16:02

S… Speaker 1 (7.3 Atheriosclerosis)

So Heinlein arteriolosclerosis,

16:03

S… Speaker 1 (7.3 Atheriosclerosis)

benign hypertension,

16:05

S… Speaker 1 (7.3 Atheriosclerosis)

and diabetes.

16:05

S… Speaker 1 (7.3 Atheriosclerosis)

The other way by which you can get arteriolosclerosis of a small blood vessel

16:10

S… Speaker 1 (7.3 Atheriosclerosis)

wall would be hyperplastic arteriolosclerosis.

16:13

S… Speaker 1 (7.3 Atheriosclerosis)

This is where you get thickening of the blood vessel wall due to hyperplasia of the smooth muscle,

16:17

S… Speaker 1 (7.3 Atheriosclerosis)

and it's classically seen with malignant hypertension.

16:20

S… Speaker 1 (7.3 Atheriosclerosis)

You've got to have all that summary very well established in your minds

16:25

S… Speaker 1 (7.3 Atheriosclerosis)

to be able to understand the discussions that we're going to have as we move forward.

16:29

S… Speaker 1 (7.3 Atheriosclerosis)

Now the third way by which you can have arteriosclerosis

16:33

S… Speaker 1 (7.3 Atheriosclerosis)

would be a disease or a disorder called Monckeberg's medial calcific sclerosis.

16:38

S… Speaker 1 (7.3 Atheriosclerosis)

And the idea here is that you get calcification of the media.

16:40

S… Speaker 1 (7.3 Atheriosclerosis)

That's why it's called media,

16:42

S… Speaker 1 (7.3 Atheriosclerosis)

and that's why it's called calcific,

16:43

S… Speaker 1 (7.3 Atheriosclerosis)

calcification of the media.

16:46

S… Speaker 1 (7.3 Atheriosclerosis)

This is non -obstructive,

16:47

S… Speaker 1 (7.3 Atheriosclerosis)

and therefore it's not clinically significant.

16:49

S… Speaker 1 (7.3 Atheriosclerosis)

And it's seen as an incidental finding on x -ray or mammography.

16:53

S… Speaker 1 (7.3 Atheriosclerosis)

This is what the histology looks like.

16:56

S… Speaker 1 (7.3 Atheriosclerosis)

You see a blood vessel wall.

16:57

S… Speaker 1 (7.3 Atheriosclerosis)

This layer here represents the intima.

16:59

S… Speaker 1 (7.3 Atheriosclerosis)

You can see the intima is right up against the

17:02

S… Speaker 1 (7.3 Atheriosclerosis)

smooth muscle media as it should be.

17:04

S… Speaker 1 (7.3 Atheriosclerosis)

And then within the media,

17:05

S… Speaker 1 (7.3 Atheriosclerosis)

you can see that you've got this area of calcification.

17:08

S… Speaker 1 (7.3 Atheriosclerosis)

So this is Monckeberg's medial calcific sclerosis.

17:11

S… Speaker 1 (7.3 Atheriosclerosis)

Again, it does not alter the luminal caliber,

17:14

S… Speaker 1 (7.3 Atheriosclerosis)

and therefore it does not affect blood flow,

17:16

S… Speaker 1 (7.3 Atheriosclerosis)

and therefore it is not clinically significant.

17:19

S… Speaker 1 (7.3 Atheriosclerosis)

The only reason you need to know about it is because it can show up on x -ray,

17:22

S… Speaker 1 (7.3 Atheriosclerosis)

in particular on mammography.

17:24

S… Speaker 1 (7.3 Atheriosclerosis)

Now, you know that on mammograms,

17:25

S… Speaker 1 (7.3 Atheriosclerosis)

you're classically looking for calcification as a sign of cancer.

17:28

S… Speaker 1 (7.3 Atheriosclerosis)

Remember,

17:29

S… Speaker 1 (7.3 Atheriosclerosis)

that's one of the things that we screen for is the presence of calcifications.

17:32

S… Speaker 1 (7.3 Atheriosclerosis)

And so it's important to note that you can also get calcifications of the blood

17:36

S… Speaker 1 (7.3 Atheriosclerosis)

vessel wall.

17:37

S… Speaker 1 (7.3 Atheriosclerosis)

And so this is an example of a calcification that's running in a vascular

17:41

S… Speaker 1 (7.3 Atheriosclerosis)

pattern.

17:41

S… Speaker 1 (7.3 Atheriosclerosis)

And so this is called Monckeberg's medial calcific sclerosis.

17:45

S… Speaker 1 (7.3 Atheriosclerosis)

It's important to note that that would then result in

17:48

S… Speaker 1 (7.3 Atheriosclerosis)

incidental calcifications on for example a mammogram and

17:52

S… Speaker 1 (7.3 Atheriosclerosis)

that closes off this particular section

7.3 Atheriosclerosis

خلاصه

از هوش مصنوعی در مورد این رونوشت بپرسید