Thrombosis在线视频

In this chapter we will introduce thrombosis

The formation of thrombus belongs to the change of blood endoplasm

So in the last lesson we introduced the change of blood volume

So like Hyperemia bleeding

In this class we will introduce the change of blood endoplasmic

First of all let's introduce thrombosis

So called thrombosis refers to the separation of some components of blood in the blood vessels of the living heart

The process of condensing into a solid mass

We call it thrombosis

And this solid mass of agglutination

We call it thrombus

Generally speaking thrombus formation is achieved under the dynamic balance of coagulation and anticoagulation

So its significance is that it can stop bleeding

At the same time vascular endothelium can prevent thrombosis from causing unnecessary damage to the body

So the two are a balanced dynamic relationship

The conditions and mechanism of thrombosis are as follows

The first is the flowing blood

Because of the activation of platelets and the activation of coagulation factors

And lead to abnormal solidification

The other three are what we call the conditions for thrombosis

Three important theories of Virchow

The first is the damage of cardiovascular intima

The second is the change of blood flow state

And finally there's an increase in blood clotting

Let's introduce one by one

First the damage of cardiovascular intima

Endothelial cells in normal cardiovascular intima

It has two functions of anticoagulation and coagulation promotion

Under physiological conditions anticoagulation is the main action

So that the blood maintains a state of flow

So let's take a look at the cell at the bottom of this diagram which is the endothelial cell of the blood vessel

Endothelial cells can release ADP enzyme prostacyclin and nitric oxide

These substances can inhibit platelet adhesion

So it plays an anticoagulant role

At the same time the endothelium can release the regulatory factors of thrombin and heparin like molecules

At the same time they can inactivate prothrombin

It has anticoagulant effect

In addition endothelial cells can release plasmin activating factors

It can degrade fibrin

It can prevent the formation and subsequent development of thrombus

These pathways are the anticoagulant mechanism of vascular endothelium in thrombosis

Now let's look at the role of endothelium in promoting coagulation

It's the reaction between them

In this image we can see

Tissue factors can be released when the vascular endothelium at the top is damaged

At the same time collagen under the endothelium can release VWF factor

All of these can induce the aggregation of platelets

The head of a thrombosis or a platelet stack

And in the process of platelet aggregation

It can release alpha particles in the cytoplasm

Producing ADP or serotonin

These substances can further induce the activation of platelets and thrombin

Overlapping of formed platelets

With fibrin adhesion

And then there's a whole process of thrombosis

So the second condition for thrombosis is the change of blood flow

The state of normal blood flow is an axial state

When they happen to have some blockage in this vein or blood vessel

This state of axial flow is broken to form turbulence

This will induce thrombosis

In addition the probability of thrombosis in the venous system is much higher than that in the arteries

The reason is that there are vein valves in the vein

When the blood flows through the valve

There's a change in the state of blood flow

The velocity of the vein is slow

It can cause transient stagnation and thrombosis

Finally the vein is located on the body surface

It's easy to get under pressure and it's holding the waste that's coming back from the blood

So its viscosity is increased

These are the main reasons why the probability of thrombosis in the venous system is higher than that in the arteries

The last cause of thrombosis

The last condition is an increase in clotting

Four points are included here

The first is an increase in platelets or clotting factors

The second is the cause of heredity

Like thrombin or protease C and so on

They have some mutations that cause an automatic increase in blood clotting

And the third is when you have surgery trauma pregnancy or cancer

It can release a large number of coagulation factors into the blood

The fourth is DIC

Blood is almost immobile

The increase of blood coagulation caused by stagnation in the capillary network

The above conditions of thrombosis often exist at the same time

But generally speaking the damage of cardiovascular intima

Is the most important and common cause of thrombosis

So let's take a look at the process of thrombosis

In fact when we just introduced the mechanism

I have introduced this part to you

The first is that platelets adhere to collagen

Vascular endothelial injury

Collagen and platelets below form adhesion

Platelets can be activated by VWF etc

Release of ADP or thromboxane

A way to activate thrombin

And then it forms a thrombus

Platelet pile platelet formation and fibrin transformation form thrombus head

Form an irreversible and firm connection

The second is due to platelets under the obstruction of thrombosis

It's blocked as it flows through the bloodstream

So platelets are in the bloodstream

To form an irregular coral like appearance

A lot of red blood cells can be filled in the middle

This is a diagram of venous thrombosis

At the top of the image we see that the venous system has valves

The leftmost part of the image

We can see that there is a turbulence in the blood as it flows through this area

It's a change in blood flow

Platelets are more likely to come into contact with the endothelium

Under the action of some tissue factors released by endothelium

It can form a platelet pile

And form a platelet beam which can trap a large number of red blood cells

Finally the head body and tail of the continuous thrombus are formed

So let's talk about the type and shape of thrombus

There are four types of thrombus

White thrombus mixed thrombus red thrombus and transparent thrombus

White thrombus is usually located in the head of thrombus in artery or heart valve area and vein system

Its general shape is mainly gray white solid closely adherent to the blood vessel wall not easy to peel off

Microscopically it is mainly composed of platelets and a small amount of fibrin

Red thrombus is usually located in the venous system

It forms the tail of a continuous thrombus

In general it's red and elastic

There is no tight adhesion with the vessel wall

You can see under the microscope that there are a lot of these red cells in the fibrin network

As for the third kind of mixed thrombus

It is between white thrombus and red thrombus in morphology and microscopic appearance

And the last transparent thrombus is often invisible to the naked eye

It needs to be observed under a microscope

Mainly in DIC

The main component of capillaries is fibrin

This image is about white thrombus

This is a white thrombus in the heart valve area or in the artery

It is mainly composed of platelets and a small amount of fibrin

This is a thrombus in a heart valve

It's a so-called mixed thrombus

Both platelets and fibrin

A large number of red blood cells were also collected

This is the main component of the mixed thrombus

This is a venous thrombus in a gross presentation

This image is a transparent thrombus in the glomerulus

There are four main outcomes of thrombus

The first is dissolution and absorption

The second point is re-engineering

The third point is that calcification forms a stone like change in the blood vessels

The fourth point is falling off

It can form a embolus to embolize the corresponding organs or tissues to cause infarction

Let's show you how it ends with a few pattern maps and histologic images

We can see it in the middle of the image

You can see a thick walled vessel like this

Inside the blood vessels are a lot of granulation tissue

This is thrombus organization

There are a lot of empty spaces in this granulation tissue

These are microvessels formed by the vascular endothelium creeping into the granulation tissue

The communication between the front and the back of thrombosis

It is a pathological feature of thrombus organization and recanalization

The difference between thrombus and clot after death

There are mainly four aspects

The first is whether they are dry or moist

A common thrombus is like a red thrombus or a common type of thrombus

It's usually dry and fragile

The clot after death is generally moist and elastic

And the clots after death do not adhere to the cardiovascular wall

And its solidified material is layered

At the top is a light yellow matrix of serum like substances

Because it is blood clotting after death

So there's no clogged appearance

So the blood clot after death is compared with thrombus

The vascular wall is a kind of appearance without swelling or fullness

There are two main aspects of the influence of thrombus on the body

Like this double-edged sword

The good thing is that when you have tuberculosis and ulcers

Thrombosis can stop bleeding in time

The downside is that it can block blood vessels and cause infarction or congestion

Or it can form the vegetations of the valve to form the valve disease

Thrombus can also cause embolism after falling off

Extensive bleeding can lead to DIC and other adverse outcomes

Thank you