Infarction在线视频

Next I will introduce the last part of this chapter

Infarction

Infarction refers to the ischemic necrosis of tissue caused by artery occlusion

The main causes of infarction are

Internal plug external pressure and spasm

In addition effective collateral circulation cannot be established in time

which may also cause infarction

The conditions of infarction are as follows

Interruption of arterial blood supply

types of blood supply vessels

dual or single blood circulation supply

sensitivity of local tissue to ischemia

All these factors above together determine whether the infarction occurs

Let's look at the pathological changes of infarction

and characteristics of gross specimens

There are three main aspects

shape texture and color

Let's look at the shape of the infarction

different organs have different shapes of infarction

The Infarcts of spleen kidney lung and some other organs are triangular or pyramidal

The infarct area of myocardium is in the shape of map

The infarct of intestine is segmental

These differences are related to the distribution of blood vessels

The blood vessels of the spleen kidney and lung are fan-shaped

the branches of the coronary artery of the heart are irregular

and the branches of the mesenteric artery are staggered

Therefore

different organs have different shapes of infarction

Let's look at the texture of the infarction

There are two types of infarct texture

One kind is hard which is called coagulative necrosis

It usually occurs in dense organs

such as heart spleen and kidney

The other is liquefied necrosis

It usually occurs in soft organs

as brain

According to the color of infarction

It can be divided into hemorrhagic infarction and anemia infarction

Microscopically

the main feature of infarction is necrosis of tissue and cells

In the early stage the contour of tissue and cell is preserved

and in the later stage it is replaced by granulation tissue

There are three types of infarction

anemic infarction hemorrhagic infarction and septic infarction

Now I'd like to introduce them one by one

First look at anemic infarctions

It occurs in the parenchymal organs with dense tissue structure

and inadequate collateral circulation

such as spleen and kidney

It is formed under the condition of

ischemia and anoxia of local tissues when the branches of arteries are blocked

In this picture we can see the structure of the normal spleen

The distribution of the white pulp and red pulp of the spleen is very clear

In the case of anemia infarction

although the outline of the tissue remains at the bottom of the picture

the cell components with nuclei are completely missing

instead of the only remaining cell outline

In the cytoplasm we can see the homogeneous red stained coagulative dead object

which is the common manifestation of anemia infarction under the microscope

This picture also shows the anemic infarct of the spleen

At the bottom right of the picture is the outline of the remaining cells

The nucleated cells disappear

This is also the microscopic feature of the anemia infarction

This is the gross manifestation of splenic anemia infarction

The appearance of the infarct is triangular or trapezoid

with the bottom pointing to the capsule

and the tip pointing to the hilum of the spleen

The kidney is an organ prone to anemic infarction

This picture shows the histology of the normal kidney

We can see that

the glomerulus proximal and distal convoluted tubules are in regular arrangement

After the occurrence of anemia infarction

the glomerulus and the surrounding renal tubules

all have homogeneous red stained necrosis

but the structural outline remains

and the nuclear cell components disappear

which is the microscopic feature of anemia infarction

These pictures are all anemic infarctions of the kidney

In the picture of gross specimens the infarct is triangular

and the same as the anemic infarctions of the spleen

with the bottom pointing to the capsule

and the tip pointing to the renal hilum

These pictures are the same

Next let's talk about hemorrhagic infarction

Hemorrhagic infarction usually occurs in the organs with double blood supply

The tissue structure of this organ is loose

and often has a background of high congestion

Common hemorrhagic infarction includes pulmonary hemorrhagic infarction

and intestinal hemorrhagic infarction

We can see that this is a hemorrhagic infarction of the lung

The area indicated by the green arrow

has infarction above

and congestion below

This picture is also a hemorrhagic infarction of the lung

The infarct is wedge-shaped or triangular

Both pictures show triangular infarcts at the bottom of the specimen

This is a histological picture

We can see

a hemorrhagic pulmonary infarction on the right side

There is a lot of bleeding in the alveolus cavity

The nucleated cells in the alveolus septum disappear

Septic infarction often occurs in sepsis

Embolus with bacterial clusters form abscesses in multiple organs

The common source of embolus is acute infective endocarditis

The result of infarction and its effects on the body

depend mainly on the infarction organ

the location of infarction

the area of infarction

and the tolerance of tissue to ischemia and hypoxia

The result of infarction

is generally divided into

dissolution absorption

mechanization encapsulation and calcification

That's all for this chapter

Thank you