[B] 1.6 High temperature as cause of disease

Question 1

High temperature as a cause of a disease can be split into…

Answer 1

• Local effect of burning
• General effect - Hyperthermia

Question 2

What influences the degree of a burn?

Answer 2

• Temperature
• Duration
• Quality of substance (Parafin-water)
• Extension of the burn
• Age of the animal

Question 3

Inhalation burns

Answer 3

• Destruction of airways and lungs
• Gasses soluble in water form acids/bases because of oedema
  
  • NH₃, Cl^-, SO₂
• Pneumonitis
• Secondary infections - Loss of epithelium

Question 4

Give the appearance classifications of burns

Answer 4

• Combustio erythematosa (1st degree)
• Combustio bullosa (2nd degree)
• Combustio escharotica (3rd degree)
• Carbonisation (4th degree)

Question 5

Combustio erythematosa

Answer 5

• Hyperaemic area
• Vasodilation
• Oedema

Question 6

Combustio bullosa

Answer 6

• Vesication
• Denaturation of proteins
• Pain

Question 7

Combustio escharotica

Answer 7

• Coagulation, necrosis of the tissues
• Hemostasis
• Thrombosis
• Pale
• Insensible

Question 8

Carbonisation

Answer 8

Tissues are charred

Question 9

General effects of high temperature

Answer 9

• Circulatory disturbance, shock
• Necrosis, enzymatic lysis of proteins
• Hemoconcentration, desiccation
• Degeneration of parenchymal organs
• Hyperkalaemia
• Toxaemia

Question 10

Circulatory disturbance, shock as a result of high temperature

Answer 10

• Oedema (permeability of blood vessels)
• Pain, hypovolaemia, hyperkalaemia, autointoxication

Question 11

Necrosis, enzymatic lysis of proteins as a result of high temperature

Answer 11

Increased local osmotic pressure

Question 12

Degeneration of parenchymal organs as a result of high temperature

Answer 12

• Catabolic enzymes continue to work
• Liver, kidney, heart, bone marrow (anaemia)

Question 13

Hyperkalaemia as a result of high temperature

Answer 13

Potassium released from the cells

• 2nd day: Oliguria, anuria (degeneration of tubular cells)
• 3rd day: Polyuria (later, no water retention ability)

Question 14

Causes of hyperthermia

Answer 14

• High (and humid) environmental temperature
• High own heat production (pyrogens)
• Inhibited heat loss

Question 15

Consequences of hyperthermia

Answer 15

• Damage to the vasomotor centre
• Low BP
• spastic muscle contractions
• Kidney insufficiency
• Hyponatraemia

Question 16

Pathological findings of hyperthermia

Answer 16

• Quickly developing rigor mortis
• Incompletely clotted blood
• Early putrefaction
• Hemostasis in internal organs
• Brain oedema
• Meningeal hyperemia
• Haemorrhages in the hypothalamus

Question 17

Heatstroke is seen at which temperature?

Answer 17

>43°C

Question 18

Sunstroke/insolation

Answer 18

Infrared radiation of sunlight

• Longlasting/strong impact of sunlight
• Vasodilation in the skin of the head
• Vasodilation in the collateral brain vessels, hyperaemia
• Brain and meningeal oedema - death
• Rare in animals

Question 19

Draw the general effects of burning

Answer 19

Question 20

Lesions of high temperature

Answer 20

• Heat spasms
• Heat distress
• Heat stroke

Question 21

Heat spasms

Answer 21

Electrolyte loss (sweating)

Question 22

Heat distress

Answer 22

• Most often seen, collapse
• Failure of cardiovascular compensatory mechanisms after hypervolaemia
• Usually solved by itself

Question 23

Heatstroke

Answer 23

• Vasodialtion
• Haemostasis
• Necrosis
• DIC