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Physical factors as causes
of diseases
Mechanical energy
Injuries and wounds
• injury – trauma
• wound – vulnus (pl. vulnera)
• wounds
vulnus punctum - stabbed wound
vulnus scissum - incised wound
vulnus sectum - cut wound
vulnus laceratum – lacerated wound
vulnus contusum – contused wound
vulnus sclopetarium – bullet wound
vulnus morsum – bite wound
vulnus venenatum – poisoned wound
• other injuries
commotio - concussion
contusio - contusion
ruptura – rupture, splitting
distorsio - distorsion
luxatio - dislocation of the joint
fractura – broken bone
ulcus - ulcer
dekubitus – decubitus, bed sore
Injuries and wounds
• symptoms of wound
pain – location
age
individual difference
bleeding – arterial
venous
capillary
• consequences and complications of
wounds
traumatic shock
infection – locus minoris resistentiae –
gas gangrene
tetanus – Clostridium tetani
embolia – fat (fractura), gas (lung
damage)
pneumotorax
damage of the NS – paralysis, epilepsy,
dementia
necrosis
stress – vegetative symptoms tachycardia
death – damage of brain, heart
Blast syndrome
Syndrome characterized by tissue damage induced by strong shock
(pressure) wave:
Consequences:
1. primary – the effect of pressure on tissue
- damage of the organs filled with air
bleeding to the tympanic membrane
(ear drum) and/or rupture
damage of the inner ear
damage of hollow organs (e.g. stomach, intestines)
rupture of alveoli and pulmonary capillary
2. secondary – damage caused by the flying object (flying human being
too) – wounds, fractura, commotio cerebri
3. other – fire, fall of the building, intoxication, radiation
Blast syndrome
using of the Blast syndrome in medicine
extracorporeal litotripsy – using of a shock
wave and its energy on destroying of
gallstones or kidney stones
Crush syndrome
Syndrome characterized by tissue damage induced by compression
-
compression of soft tissues – ischaemia, oedema
ischaemia-reperfusion injury – oxygen radicals
traumatic shock
-
anaerobic metabolizm  release of myoglogin from cells  cylindres of
precipitated myoglobin  damage of kidney acute renal failure 
uremia  death
Vibration, noise
vibration
- pain – spine, extremities
- osteoporosis
- Raynaud´s syndrome – vasoconstriction – pale,
cold finger, trophis changes
- neurosis, hypertension
noise
- above 50 dB
- acute very intensive noise – explosion
- short-lasting reduction of hearing
- rupture of tympanic membrane – deafness
- chronic exposure to noise
- vegetative syndromes – palpitations, nausea
- headache, insomnia, dizziness
- loss of hearing
Ultrasound
-
frequency above 18 kHz
thermal, mechanical effect
-
used in diagnosis and therapy
ultrasound dental scaler
ultrasound toothbrush
Acceleration
Acceleration–deceleration: sudden and quick changes
in movement speed or directions of the body in the space
acceleration = positive acceleration
deceleration = negative acceleration
angular acceleration – acceleration during rotation of the body
intensive acceleration upward (plane, spacecraft)
accumulation of the blood in the lower parts of body 
brain and retina deprived of blood supply  „black shield“
unconsciousness
intensive acceleration downward (plane, spacecraft)
accumulation ot the blood in the upper parts of body 
hyperaemia of brain and retina  „red shield“
Kinetosis (sea sickness)
– manifestation of vestibular system dysfunction
– dysfunction is manifested by „stormy“ reaction of
vegetative nerve system  dysbalance sympathetic
and parasympathetic nerve systems
Main symptoms:
vegetative – pallor, sweating, nausea, vomiting, abdominal pain,
hypersalivation, tachycardia, decrease of blood
pressure
sensory – dizziness
motor – hypotonia, loss of coordination
psychic – apatia, depresion, somnolence
Hypobaria and hyperbaria
Hypobaria
Atmospheric pressure on the surface of Earth – 101.3 kPa (760 torr or Hgmm)
The athmospheric pressure decreases parallel with the altitude
In high altitude (more than 3 km) – mountain disease – acute
chronic
Hypobaria (in planes) – distension of gases in hollow organs
middle ear pain
pain of perinasal cavities
pain and cramps in GIT
Hypobaria in dental medicine
- expansion of gas in carious of improperly filled teeth – pain (barodontalgia)
Decompression sickness (caisson disease)
Who is in risk?
– underwater construction workers
– deep sea divers
Mechanisms: – return too quickly to the surface causes a form of
gas embolism
– oxygen and nitrogen which are normally disolved in
the blood come out and forme tiny bubbles called
gas emboli
Consequences: – nitrogen bubbles may persist and obstruct blood
vessels gas embolism
- in muscles, joints, tendons  pain, necrosis
- cyanosis and paresthesias in the skin
- tachypnoe, substernal pain, dry cough
- bubbles in brain - unconsciousness
Hyperbaria in dental medicine
- barotrauma of n. facialis – paralysis
- barotrauma of n. trigeminus –hypoanaestesia of chin, maxillar teeth,
upper lip
hyperbaric chamber
caisson
Thermal injury
• scald (hot water)
Burns (combustio)
1.degree
2.degree
3.degree
combustio
erythematosa
combustio
vesiculosa
combustio
escharotica
4. degree - carbonisatio
2. degree
blisters
3. degree
necrosis
Complications of burns
• sepsis
• burn shock
• smoke inhalation
• burn of the upper airways
Classification of burn injuries according to
severity and range
clinical
rating
small
middle heavy
heavy
critical
%BSAB
total
<20
20 - 25
25 - 40
>40
BSAB - body surface area burned
deep
0
<10
10 - 20
>20
4.5
18
4.5
4.5
4.5
18
The rule of 9
4.5
9
4.5
1
9 9
9
4.5
18
9 9
4.5
18
1
7
7
7
Chilblain (congelatio)
1. degree - congelatio erythematosa
•
vasoconstriction – ischemia, loss of sensitivity
•
later: vasodilatation – paresthaesia (pricking)
2. degree – congelatio bullosa
•
oedema - blisters
3. congelatio escharotica
•
necrosis
Hypertermia
- warm and dry environment – dehydratation
heat cramps
heat exhaustion
-warm and wet environment – heat stroke (siriasis)
-tachycardia, tachypnoea, low blood pressure
-more than 40oC – fatigue, headache, vomitus, muscle cramps
-sunstroke (insolatio) – sunshine concentrated to the uncovered head
(children, old men)
- headache, nausea, vomitus
Hypotermia
- temperature of body core less than 35oC
-risk factors
-age – newborn babies, old people
-health status – insufficient circulation, hypothyreosis, Addison disease
-alcohol
-signs
- somnolence, rigidity of muscles
- decrease of heart and respiratory rate
- uncoscioussness
-Immersion cooling
-hyportermia in cold water
Electrical current
Damage caused by electrical current
Alternating electric current is dangerous for living organisms, only when
its parameters are - more than 50 V, more than 75 mA
Consequences:
-thermal damage  burns
due to resistance – dry skin  burns
- depolarisation of the cells 
nervous cells – brain  unconsciousness
heart cells – arrhythmia
muscles - cramps
- mechanical damage  dysruption of skin and muscles
• Ohm´s law
U
I=
R
I – intensity
U – voltage
R - reistance
• burns caused by
electrical current
Electromagnetic field
Radio waves
effects
- headache
- psychic fatigability
Microwaves
effects
- increased cell metabolism
- thermal effect – vasodilatation, hyperaemia
Infrared waves
effects
- deep thermal effect
- chronic exposure - cataract (glass-blower´s cataract
Visible light
effects
- retinal burns – blindness
Ultraviolet light
UVA - 315 - 380 nm
UVB - 280 - 315 nm
UVC – 100 - 280 nm
Effects of UV light on the skin
early – inflammation, sun tanning, sunburn, hyperplasia, synthesis of vit. D
late – ageing, sun allergy, photocarcinogenesis