Case Study

Case 1.
A group of tourists came under heavy rain. A day later, one of them developed pneumonia.

Questions:

1. What causes inflammation of the lungs in a tourist? What was the condition for the occurrence of the disease
2. Define the causes and conditions of the disease
3. Give the characteristics of causes of diseases
4. What is the role of the causes and conditions in disease occurance. Give the characteristics of monocausalism and conditionalism

Case 2

A Child of 14 years, entered the hospital with tuberculous gonitis (inflammation of the knee joint). Onset of the disease is associated with knee injury. The child is often sick with colds. Living conditions are below average.
1. What was the cause of the child's illness? What was the condition of this disease?
2. Define the causes of disease and conditions
3. Describe the causes of the disease
4. What is the role of the causes and conditions in disease occurance. Give the characteristics of monocausalism and conditionalism

Case 3

A mouse is put in a small pressure chamber. Then, during 2-3 min air is pumped out of it to decrease the pressure in the chamber down to 170-180 mm Hg. After 0.5-1 min in the hypobaric conditions the mouse shows signs of anxiety: running over, scratching its face. Two or three minutes later clonic and tonic seizures develop; the mouse is lying on its side, urinates; terminal breathing ("gasping") develops. Soon afterwards, breathing stops, and the mouse dies. The overall time of the mouse's life in the hypobaric atmosphere is 3-4 min.

Questions:

What factors affect the mouse in this experiment?

Which of these factors could be considered the leading cause of the pathologic process - hypobaric hypoxia?

How can you experimentally check your presumptions about the nature of the pathologic process?

Case 4

Air is pumped out of the pressure chamber to bring the barometric pressure to approximately 20-30 mmHg. Then the chamber is filled with pure O₂ up to normal atmospheric pressure 750 mm Hg. A mouse is carefully put in the chamber so that the barometric pressure inside remains unchanged. The mouse is then observed as in the previous experiment. At first, seeking behavior is seen. Later the mouse is sitting quietly, showing no signs of pathology. Within approximately 10 minutes after the start of the experiment the mouse is taken out of the chamber, and its normal behavior and state is established. Questions:

1. Taking into account the results of this test what can you say about the pathologic factors which caused death of the mouse in the previous experiment?

Case 5

A pressure chamber is filled with a mixture of gases consisting of 95% N₂ and of 5% O₂. Barometric pressure inside the chamber is maintained equal to normal atmospheric pressure. A mouse is put in the chamber. A thin jet of the same gas mixture is being passed through the chamber. Partial pressure of O₂ in this gas mixture is about 37 mm Hg. After staying in the chamber for 10-15 min the mouse develops seizures and then dies.

Considering the results of all 3 experiments, answer the following questions: