Significance of the external

environment in the origin of

diseases

DEPARTMENT OF PATHOLOGICAL PHYSIOLOGY– 2018

Significance of the external environment in the

origin of diseases

Influence of external environmental

factors

Mechanical

Physical

Chemical

Biological

Social factors

Influence of external environmental

factors

Mechanical factors (mechanical trauma, compression and rupture of tissues and etc.)

Influence of sound vibrations and ultrasounds

Influence of atmospheric pressure (mountain sickness,caisson diseases and etc.)

Influence of heat and cold

Influence of electric current

Influence of ionizing radiation (radiation sickness)

Influence of gravitation

Influence of external environmental

factors

Influence of external environmental

factors

Noises – sound vibration or the combination of sounds may have

pathogenic effect on the organism.

Human ear perceives sound vibration of 16- 20000 cycles per second

Permissible level of noise for human ear is 40-50 decibel (during normal speech

The sound stimuli of 80-100 decibel cause pain, in the organ of hearing . More intensive noise decreases hearing and may lead to hearing loss.

Concert of rock music- 123-140db >, than noise from reactive airplane.

Prolonged noise more than 155db causes disturbance of function of organs and systems in the organism.

Sounds level more than 180db are fatal for organism.

Pathological effect of the noise depend on :

frequency of acoustic oscillations (measured in Hz )

the strength of the noise - the sound intensity (dB)

the pressure of sound vibrations - (Pa)

the duration of the effect of sound vibrations

Influence of ultrasound

Ultrasound- inaudible to the human ear waves

whose frequency is greater than 20kHz.

Ultrasound has the mechanical and thermal effects, which causes c the physical-chemical changes in the organism

Ultrasound of high intensity (3-10Wt / sm2) has a damaging effects:

disturbs the microcirculation in tissues, causes cell

injury and may lead to the local burns

Ultrazvuk- inaudible to the human ear elastic waves whose frequency is greater than 20kHz. Ultrasound has on the mechanical body tissue, thermal effect, which causes changes to the physical

Action of atmospheric pressure.Altitude, м Atmospheric pressure,

mm. Hg.

РО2, mm. Hg State of organism

0-2500 760-560 159-117 Normal

2500-4000 560-462 117-97 No changes

4000-5000 462-405 97-85 First symptoms of

mountain sickness

5000-6000 405-354 85-74 Significantly expressed

features of mountain

sickness

6000-8000 354-267 74-56 All symptoms of

mountain sickness are

expressed

>8000 < 250 < 52 This state is

incompatible with life

without oxygen

apparatus .

Action of barometric pressure.

Mountain sickness.

Mountain sickness develops in the altitude >5000м. In the

pathogenesis of mountain sickness take role the followings:

Lowered atmospheric pressure (decompression) and

decreased partial pressure of oxygen in air lead to →

extension of gases inside confined spaces oforganism(sinuses of nose, frontal sinuses, pleural andabdominal cavities), → transition of formerly dissolved

nitrogen to the gaseous state and the formation of gasembolism which leads to ischemia of tissues.

Pulmonary edema – non-cardiogenic edema of lungs,

develops as a result oh severe hypoxia → activation of sympathetic

nerves system → increasing of pressure in the capillaries of

pulmonary arterial system, increased permeability of capillary walls

Brain edema - hypoxia → activation of SNS →

increasinndповышение гидростатического давления в

микроциркуляторном русле, повышение проницаемости

сосудов, изменение- повышение проходимости

гематоэнцефаличкского барьера для брадикинина, NO-

синтазы → в сосудах образуется больше NO (оксида азота) →

расширение сосудов мозга → головная боль, тошнота и рвота

Pathogenesis of mountain sickness include

the following processes:

Hypoxemia→ hypoxia→ hyperventilation of lungs→ hypocapnia → gaseous alkalosis → decreasing of activity of respiratory center and central

nervous system which may lead to paralyses and death.

Action of elevated atmospheric pressure (hyperbarism). Caisson disease.

Hyperbaria (compression)leads to increased dissolution of gases in body fluids (saturation)

Caisson disease develops during rapid return from

elevated to normal atmospheric pressure. The gases (especially nitrogen) formerly dissolved are liberated in the form of bubbles (desaturation) and may cause gaseous embolism.

Hyperbaric oxygen therapy - breathing of oxygen under increased pressure.

Action of low temperature.

Frostbite. Hypothermia.

Frostbite – local disturbances caused

by action of cold.

Hypothermia – develops as a result of general effect of cold.

Гипотермия.

Symptoms Metabolism Consciousness Cardiovascular

and respiratory

systems

35-32°C Muscle tremors,

pain

Metabolism↑↑,

Hyperglycemia,

О2 consumption↑

Excitation

confusion

• Tachycardia,

peripheral

vasoconstriction

, increased

blood pressure

32-28°C muscle rigidity

Pupillary reflex +

Hypoglycemia

Metabolism ↓

Hallucinations,

sleepiness,

Loss of

consciousness

Bradycardia,

arrhythmias,

respiratory

depression

<28°C Wide pupils,

Pupillary reflex -

Metabolism ↓↓ Coma Fibrillation,

Asystolia

Apnea

The action of heat.

Burns (thermal)

Hyperthermia

Burns-the local changes caused by heat.

Beginning from 45-50º the thermal factors ( hot

water, heated metal, fire, etc.) causa injury of

the body.

Burn disease – develops when more than10-15%

of body surface damaged by > II degree of burn.

The following phases of burn disease are distinguished:

1.Burn shock

2. Burn toxemia

3. Burn septico-toxemia

4. Burn emaciation

5.Outcome of disease

Sunstroke - a result of exposure of UV

radiation, together with the thermal

effect of the sun's rays (infrared rays)

Effects of radiation

The forms of radiation sickness

Radiation sick

Gastrointestinal form

10-50Gy

Hematopoieticform

0,5-10Gy

Cerebral form

50-200Gy

Acute radiation sickness

Initial stage - 1-2 Gy

Moderate - 2-4 Gy

Severe - 4-6 Gy

Very severe - > 6Gy

Stages of the acute radiation sickness

Stage of initial reaction

Latent stage

Stage of marked manifestations

Recovery

Chronic radiation sickness

Occurs when the long-term exposure of

low doses those excess of permissible

standards

Electrical trauma

Burns

Disturbance of heart rhythm

Breathing arrest

internal factors

Role of internal factors in the

origin of disease

Constitution

Hereditary

Age

Sex

Reactivity and resistance

Constitutional types (by Chernorutsky)A- asthenic B- normosthenic C-hypersthenic

Constitutional types by Kretschmer:

dysplastic, pyknic, athletic, leptosomatic

Constitutional types by Hippocrates.

Phlegmatic

Melancholic

Choleric

Sanguine

Diatheses

Exsudative diatheses

Lymphohypoplastic diatheses

Spasmophilic diatheses

Astyhenic diatheses

The main cause of hereditary diseases -

mutation.

Action of mutagens → occurrence of mutations.

Mutagenic factors:

-Exogenous

-Endogenous

-Physical

-Chemical

-Biological

Hereditary diseases

Monogenic

Polygenic

gen mutations

Types of mutations chromosomal mut.

genomic murations

Types of inheritance

Autosomal dominant

Autosomal recessive

Adhesion to the X chromosome dominant inheritance

Adhesion to the X chromosome recessive inheritance

Coupling with a Y chromosome inheritance

Imprinting (Angelman syndrome, Prader-Willi syndrome)

mitochondrial inheritance

The expansion of trinucleotide repeats

Chromosomal diseases:Abnormalities of autosomal chromasomes Abnormalities of sex chromasomes

:

Down‘s syndrome Turner syndrome

Patau‘s syndrome Klinefelter‘s syndrome

Edward‘s syndrome

Klinefelter’s syndrome 47/ XXY

Terner syndrome, karyotype 45-

Х0

The syndrome of "cat cry"

Hereditary diseases. Down's Syndrome. Trisomy

of 21 chromosome 47, XX, +21

Patau Syndrome. Trisomy of 13

chromosome 47, XXX + 13.

REACTIVITY

Reactivity - the ability of organism to respond tothe factors of external and internal environment.

The Types of Reactivity

Biological reactivity

Group reactivity

Individual reactivity- physiological,

pathological (specific, nonspecific).

The Forms of Reactivity

Hyperergy

Hypergy – positive and negative

Disergy

RESISTANCE

Resistance - the ability of the organism to protect himself against to

pathogens.

The Types of Resistance

Passive

Active

Specific

Non-specific

The Factors of Nonspecific

Resistance

External barriers (skin and mucousmembranes)

Internal barriers - barriers of organs (liver,lymph nodes, spleen, bone marrow andthymus) and histohematological barriers

The Factors of Nonspecific

ResistanceThe complement system

C-reactive protein

Lysozyme

Interferons α-IFN, β-IFN, γ-IFN

Natural killer (NK- Natural Killers)

Macrophages - phagocytes, etc.

Activation of Complement System

Cells of Immune System

Phagocytes

Natural killer cells

B lymphocytes

T lymphocytes

INNATE AND ADAPTIVE IMMUNITY

HUMORAL AND CELLULAR IMMUNITY

ACTIVATION of T-CELL

Thanks for attention