Pathology
Department of Pathology
Long jie
1. What is Pathology:
1)
Scientific study of disease
2) Investigation
of
Causes (etiology)
mechanisms (pathogenesis)
manifestation
morphology
progress
sequels
2. Status of Pathology:

a bridge
Anatomy
Histology and
embryology





Physiology
Biochemistry
Cytology
microbiology
pathology
Clinical
medicine
3. Contents of pathology
pathology
General pathology
Systemic pathology
Cell,tissue damage
Cardiovascular
system
repair
Disorders of
vascular flow
Inflammation
Neoplasm……
Respiratory
system
Digestive system……
4. Methods in pathology
1)
Autopsy
2)
Biopsy
3)
Cytology
4)
Electron-microscopy
5)
tissue and cell cultivation
6)
Animal experiment
7)
molecular biology
5. morphological observations:
1) Gross level
2) Light microscopy
Chapter
1
Cell injury and
adaptation
Introduction

Physiologic
stresses
Pathologic
stimuli
Cells maintain normal homeostasis
adaptation
Atrophy
hyperplasia
hypertrophy
metaplasia
cells
Degeneration (reversible)
injury
Cell death
(irreversible)
Adaptation（适应）
1.
2.
3.
4.
Atrophy
Hypertrophy
Hyperplasia
Metaplasia
(萎缩）
(肥大)
(增生)
(化生)
Atrophy (萎缩）
 Shrinkage
in the size of the normal cell,
tissue and organ by the loss of cell
substance.
 Decrease in Cell
size or number
Causes and types
1. Aging
(生理性~)
2. Inadequate nutrition/ diminished blood
supply
(营养不良性~)
3. Pressure
(压迫性~)
4. Reduced functional activity (废用性~)
5. Interrupted nerve supply
(去神经性~)
6. Endocrine deficiency
(内分泌性~)
Pathologic changes
Grossly:
The entire tissue or organ diminishes in
size ,weight and function.
Microscopically:
1. Organelles degradation
2. Increased autophagic vacuoles
3. Residual bodies(e.g., lipofuscin)
results

Recover
 Cell death
Hypertrophy （肥大）


Increase in the size of cells and
consequently an increase in the
size of the organ.
increase in cell size
Causes and types

Physiologic
 Pathologic
hypertrophy (生理性～）
hypertrophy （病理性～）
Hypertrophy of myocardium
Pathologic changes
Grossly:
Enlarged organ
Microscopically:
1. Increased in the size and number of
Organelles
2. Bigger cells
Physiologic hypertrophy of the uterus during pregnancy
Hyperplasia （增生）
 Increase
in the number of cells and
consequently an increase in the size of
the organ or tissue.
 Increase in cell number
Causes and types

Physiologic
hyperplasia (生理性～）

Pathologic
hyperplasia （病理性～）

Most forms of pathologic hyperplasia are
instances of excessive hormonal or growth
factor stimulation.
Pathologic changes

Microscopically:
Increased cell mitosis

Grossly:
Enlarged organ
results

Recover
 Cancerous proliferation
Metaplasia （化生）

A reversible change in which one adult
cell type( epithelial or mesenchymal) is
replaced by another adult cell type.

Change in cell type
Causes and types

Squamous

Intestinal epithelial ~

Bone or cartilage
metaplasia
~
Pathologic changes

Microscopically:
1.cell type change
2. Epithelium __ Epithelium ;
mesenchymal__ mesenchymal
3. Adult cells
results

Recover
 Induce cancer transformation
Cell injury（损伤）



causes
mechanisms
morphology
Causes

Oxygen deprivation

Chemical agents

Infectious agents

Immunologic reactions

Genetic defects

Nutritional imbalances

Physical agents

aging
Mechanisms
(self-study)

Defects in plasma membrane

Hypoxia or generation of reactive
oxygen species

Loss of calcium homeostasis

Chemical injury

Genetic variation
morphology
 Degeneration
 Cell
death
( reversible )
( irreversible )
degeneration（变性）
The injuried cell accumulate abnormal
amounts of various substance in the cell
or mesenchyma . Degeneration is always
accompanied by diminishing in function.
types
1. Cellular swelling
(细胞水肿）
2.
3.
4.
5.
6.
7.
(脂肪变性)
(玻璃样变)
(淀粉样变)
(黏液样变)
(病理性色素沉着)
(病理性钙化)
Fatty change
Hyaline change
Amyloidosis
Mucoid degeneration
Pathologic pigmentation
Pathologic calcification
Cellular swelling
Hydropic change
Vacuolar degeneration
(水变性)
(空泡变性)
morphology

Microscopically:
1. swollen cells balloon degeneration
2. Small clear vacuoles in the cytoplasm
3. Coarse granules in the cytoplasm( swollen
organells).

Grossly:
entire organ : pallor,turgor,increased weight.
气球样变性
胞浆疏松化
Cellular swelling of liver
Fatty change
Fatty degeneration
(脂肪变性)
Refer to any abnormal accumulation of triglycerides
within parenchymal cells.

Fatty change may caused by toxins,
protein malnutrition, diabetes mellitus,
obesity and anoxia.

Alcohol abuse
morphology

Microscopically:
Clear lipid vacuoles / small droplets in the
cytoplasm of parenchymal cells.

Grossly:
liver ----- enlarge, become yellow, soft and
greasy.
heart ----- tigered effect
虎斑心
Fatty change of liver
Hyaline change
Hyaline degeneration
(透明变性)
morphology

Microscopically:
1. Homogeneous, pink, refractile(折光）,
hyaline protein accumulation
2. Occure in the cytoplasm, connective tissue,
and walls of arteriole, the mechanisms are different.
amyloidosis
Amyloid deposition
Amyloid degeneration
morphology

Microscopically:
1. Homogeneous, pink, proteinglycosaminoglycan accumulation;
2. Occur in the extracellular tissue,
basement membrane of blood vessels.
E.M.:
closely packed interlacing fibrils
Pathological
pigmentation
Colored substances that are either
exogenous
or
endogenous
accumulate in /out the cell.
types
1. Hemosiderin
(含铁血黄素）
2. lipofuscin
3. melanin
……
(脂褐素)
(黑色素)
hemosiderin
 hemoglobin-derived

granular pigment
 golden-yellow to brown
 Accumulates in tissues when there is
local or systemic excess of iron.
lipofuscin

wear-and-tear pigment

insoluble,brownish-yellow , granular

Accumulates in variety of tissues
(heart,liver and brain) as a function of
age or atrophy.
melanin

Endogenous, brown-black pigment

formed by melanocyte

occur when the enzyme tyrosinase
catalyzes the oxidation of tyrosine to
dihydroxyphenylalanine
Pathological
calcification
The abnormal deposition of
calcium salts in a wide variety of
tissues except bone and teeth.
types
1. Dystrophic calcification
(营养不良性钙化）
2. Metastatic calcification
(转移性钙化)
morphology
 Microscopically:
Intracellular and /or extracellular
basophilic deposits.
 Grossly:
white granules or clumps, felt as gritty
deposits.
Cell death（细胞死亡）
when the nuclear is severly injuried , the
cell show irreversible changes
including cell cessation of metabolic
versatility,damage of structure and
loss of function.
types
1. necrosis
(坏死)
2. apoptosis
(凋亡)
necrosis
A sequence of morphologic changes
that follow partial cells death in
living tissue.
microscopically:

Increased eosinophilia
homogeneous

Cytoplasm becomes
appears moth-eaten
Nuclear
,more
vacuolated
glassy
and
changes:
pyknosis
（核固缩）
karyorrhexis（核碎裂）
karyolysis
(核溶解）
types
Caseous necrosis
(干酪样坏死)
Coagulative ~
(凝固性坏死）
Dry~(干性坏疽)
gangrene
(坏疽)
Liquefactive ~
(液化性坏死)
Fibrinoid ~
(纤维素样坏死)
Moist ~(湿性坏疽)
Gas ~(气性坏疽)
Coagulative
necrosis
Preservation of the basic structural outline
of the cell or tissue by denaturation of
proteins in the dead cell.
grossly:
The necrosis area become swollen,
firm ,dull, and lustreless, yellowish.
坏
死
区
microscopically:

Nuclei change

Cytoplasm is granular, take up more
eosin than normal

Outline of
recognised
necrosis
cells
can
be
Caseous necrosis

tuberculous infection;

Cheesy, white gross appearance;

Microscopially, structureless ,
amorphous granular debris; the tissue
architecture is completely obliterated.
gangrene

Necrotic lesion + infected by
organisms which cause putrefaction;

grossly:
brown,green or black
discolouration of the tissue;
Dry gangrene:

skin surface

Following arterial obstruction

Liable to affect the limbs (e.g. toes脚趾）

dry

Mild infection

Clear borderline
moist gangrene:

Splanchnic organs

Venous congestion + arterial obstruction

Liable to affect bowel, gall bladder,
uterus,lung e.t.

moist

severe infection

unclear borderline
gas gangrene:

Deep ,open wound

Infected with clostridial organisms.

gas

Alveolate tissue

toxicosis
liquefactive
necrosis
The enzymes decompose the necrosis
tissue into fluid.
grossly:
The necrosis area become sofen, and
turns into turbid fluid.
(brain, spinal cord)
microscopically:

Profound loss of the previous
histological architecture.
Types (self-study):

Fat necrosis
 Purulence
 Lytic necrosis
(脂肪坏死)
(化脓)
(溶解性坏死)
Fibrinoid
necrosis
Commen feature of
connective
tissue
collagen or
diseases
accelerated hypertention.
and
microscopically:


The necrosis tissue is filamentous or
granule , brightly eosinophilic fibrinoid
substance .
Collagen
 Immunoglobulin
 fibrin
Sequels of necrosis






Autolyze
Dissolved and absorbed
Expelled
Organization
Encapisulation
Undergo dystrophic calcification
(自溶)
(溶解吸收)
(分离排出)
(机化)
(包裹)
(钙化)
Terms:

Erosion
 Ulcer
 Sinus
 Fistula
 Cavity
(糜烂)
(溃疡)
(窦道)
(瘘管)
(空腔)
apoptosis
Programmed cell death
 dying cell: Shrink and compact
 Affect single cell
 form apoptotic bodies
 no inflammatory reaction

凋亡小体