Cell injury. (Subject 2)

Conception of cell injury

Cell
Adaptation

Pathological
process

Disease

Pathological
reaction

Influences
Stresses

Cell Injury

The relationships among cell states

(Hypertrophy)

Myocardial fiber

Hypertension

Ischemia (short time)

Ischemia (long time)

Injury From Physical Agents

Causes:
Mechanical forces - trauma.
Extremes of temperature –

Other causes of cell damage

Chemicals – substances or their metabolites
Hypoxia –

Types of Cell Injury

Acute
(strong irritants)

Chronic
(moderate irritants)

Reversible
(angina pectoris)

Irreversible
(myocardial infarction)

Non-specific
(hypoxic injury)

Specific
(immune

Signs of Cell Injury

Morphological

Functional

changes of shape and color
swelling or shrinking

General Principles of Cell Injury

Factors, which determine cell response
Kind, severity, and

Major Processes of Cell Injury

Decreased ATP production
Injury by toxic oxygen radicals
Disturbances

Example test

Chose the example of specific cell injury from listed below:
myocardial

Example test

Which factors determine the type of cell’s response to injuring

Example test

Patient was made blood biochemical test in order to confirm

Major Types of Cell Injury

Hypoxia

Chemicals

Free radicals

Reversible Hypoxic Injury

Lack of oxygen

Decreased ATP formation

failure of ATP
dependent Na/K

Irreversible Hypoxic Injury

↑ membranes
permeability

Irreversible
mytochondrial
dysfunction

↓ intracellular pH

loss of proteins,
essential

Mechanisms of membranes damage

Progressive loss of membrane phospholipids
Cytoskeletal abnormalities

Reperfusion injury

Neutrophiles

Calcium ions

Blood stream

Toxic
oxygen radicals

Cell damage

Cytokines

Enzymes activation

Cell Death

Example test

Disturbance of which process is primary observed in hypoxic injury:
detachment

Example test

Which factor directly causes the decrease of intracellular pH in

Example test

Which process is initiated by calcium in hypoxic cell injury?
detachment

Example test

Which process determines irreversibility of hypoxic injury?
inability to reverse mitochondrial

Example test

Which tissue cells are most sensitive to hypoxic injury?
skeletal muscles
smooth

Sources of free radicals

Reactive oxygen species

Superoxide O2-

Hydroxyl radical OH-

Hydrogen peroxide
H2O2

The effects of free radicals

Positive: phagocytosis, energy production
Negative:
Lipid peroxidation of membranes
Nonperoxidative

Antioxidative substances

Enzymatic antioxidants
Thioredoxin system
Glutathione system
Superoxide dismutase
Catalase

Non-enzymatic

Example test

Choose the effect which IS NOT directly caused by free

Chemical injury mechanisms
Direct cytotoxic effect
mercury damages GIT and kidneys
cyanide breaks

Outcomes of cell injury

Cell death

Necrosis - death of a cell due to external forces
Apoptosis

Physiological apoptosis

Frog

plants

amphibia

human

Morphological signs of apoptosis

Shrinkage of the cell.
Condensation of chromatin around

Necrosis and apoptosis

Example test

Give the correct definition of apoptosis. Apoptosis is…
a process of

Example test

Which from the following is the most typical morphological sign

Example test

Every day, blood cells in our body become senescent and

Cell Adaptation to Injury

compensation of energy metabolism disturbance
protection of cells membranes
compensation

Compensation of energy metabolism disturbance

increased ATP formation, transport and effectiveness of

Protection of cells membranes

activation of antioxidants action
activation of cells buffer system
activation

Compensation of water-ion disbalance

activation of ion “pumps” energy supply
increase of ion-transporting

Mechanisms of cell genome repair

revealing and elimination of damaged DNA fragment
replacement

The types of cellular adaptations

Causes of atrophy

decreased workload,
loss of innervation,
diminished blood supply,
inadequate

Hypertrophy

increase in the size of cells
REASONS:
increased functional demand
specific hormonal

Hyperlasia

increase in the number of cells
It occurs in tissues where

Metaplasia

one adult cell type (epithelial or mesenchymal) is replaced by

Dysplasia

Deranged cell growth of a specific tissue that results in cells

Example test

Cells may adapt to external and internal stimuli by undergoing

Example test

Cells may adapt to external and internal stimuli by undergoing