Ministry of Public Health of Ukraine M. Gorky Donetsk National Medical University
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Ministry of Public Health of Ukraine M. Gorky Donetsk National Medical University BASIS STAGES OF BREATHING. MECHANISMS OF INSPIRATION AND EXPIRATION. PROCESSES OF GAS EXCHANGE IN THE LUNGS AND TISSUES. Methodical instructions for students Donetsk 2009 BASIS STAGES OF BREATHING. MECHANISMS OF INSPIRATION AND EXPIRATION. PROCESSES OF GAS EXCHANGE IN THE LUNGS AND TISSUES. Actuality of subject: Importance of studying gas exchange and transport of gases consists in the understanding physiological processes absorption by the organism of O2 and excretion of CO2, which is gas exchange. This processes is based on the aerobic oxidation, which provides energy metabolism in the organism. Respiration happens by way of interaction between respiratory organs system, cardiovascular system and blood, which forms functional systems. Impairment pulmonary ventilation can lead to different pathologic states (for example, hypoxia, hypoxemia, hypercapnia) and diseases. The knowledge of ventilation mechanism of lung and gas exchange is necessary for further use in therapeutic clinic. Common purpose: To be able to interpret the mechanisms of lungs ventilation, to base the importance of gas exchange and of gases transfer in organism for further use in clinic of internal diseases. ^ To be able to:
You must decide some tests in order to reveal your initial level of knowledge-skill: ^ Task # 1. During examination under microscope the respiratory tracts preparation segmental epithelium with a large quantity of ciliary and goblet cells was determined. What was the basic function of these cells?
Task # 2. In consequence of the disease a patient has indurations of all the costal joints. What occurs with breathing?
Task # 3. During the experiment one rat’s lung was treated by elastase, which destroyed elastic fibers. How does change the elastic draught of lung?
If you decide previous tests then you must decide following tests independently. Task # 4. A 44 year old man is the thickness of alveolo-capillary membrane increased. Change of which index of breathing did this lead to?
Task # 5. During the experiment at examination of human respiratory muscles state, rhythmic, intensive contraction of abdominal wall muscles was revealed. Which phase of breathing did this correspond?
Task # 6. During open pneumothorax at an old age, as compared with young age, the degree of alveoli collapse decreases. What does explain such age peculiarity?
Basic theoretical questions.
LiteratureTextbook of medical physiology /Arthur C. Guyton, John E. Hall – 2001, 432-472; Lectures; Methodical recommendation for students. The educational tasks. Task # 1. In the puerperal room in the new-born the first cry didn’t arise and child dead. After death was revealed that the lungs didn’t smooth out but respiratory tracts was free. What was the cause of this?
Task # 2. A patient arbitrary delayed breathing for 50 seconds. What changes took place in blood after such breath holding?
Task # 3. It was determined that an important role in transportation of CO2 by blood took part carbonic angidrase. Where was situated this ferment?
If you decide previous tests then you must decide following tests independently. Task # 4. After the operation on abdominal cavity a 48 year old patient is at rest at a horizontal position. Contractions of which muscles provides inspiration in this position?
Task # 5. Some time a patient lived in mountainous place with low partial pressure of O2. What led to resistance increasing of this patient to conditions of the hypoxia?
Task # 6. During examination of the respiratory functions in 55 year old woman it was necessary to determine, what part of the alveolar air renewed during each breath? What index was necessary for determination of this function?
Approximate basic of work. ^ Spirometry is carried out with help of a dry spirometer. Before beginning the work a tip to be attached to the spirometer and disinfected by 96% ethyl alcohol. Turning the glass cover, put marks opposite zero mark on the dial-plate of scale. Measuring of breathing volume (BV). The spirometer must be set to the initial position . Doing quiet breaths through the nose, do several quiet expirations through the mouth in to the spirometer. With the help of scale determine volume of expired air and divide it by the numbers of expirations. Find proper BV, use the tables for this, make conclusion. ^ The spirometer to the initial position, after a quiet breath do in the spirometer as a deep expiration as possible. Take reading spirometer and subtract from of breathing volume exponent this index, find ERV, make conclusion. Measuring of vital capacity (VC). Spirometer leads to point of departure. Do a maximum breath and, closing nose, do the deep most expiration in the spirometer, and fix index and compare it with the physiological index. Make conclusion. ^ Inspiratory reserve volume can be calculated subtracting the sum of breathing volume and expiratory reserve volume from the value, determined during the definition of VC. Find proper index. Make conclusion. Laboratory work # 3. Determination of gas partial pressure by its percentage maintenance in alveolar air (with demonstration of Haldane gas analyzer). Laboratory work # 4. Determination of breath holding in rest, after strained muscular work, after hyperventilation. Laboratory work # 5. Determination of arterial blood saturation by oxygen with the help of oxyhemography method. ^ Task It was known that in surface layer of liquid which covered alveolus, surfactant was contained .What functions did this substance carried out? A. Preservation of straightened form of alveolus. B. It improved gas exchange during deep breathing. С.Periodical turn off part of alveolus. D. Increasing of alveolus stretching. E. Decreasing of evaporation with alveolus surface. ^ After organization part , in the beginning of study, after actualisation of topic pay attention to necessity to be able to interpret the mechanisms of pulmonary ventilation, gas exchange on the different stages of breathing for value of human functional possibilities. After this the teacher ascertains initial level of knowledge-skill which received before. After decision of teaching tasks students independent interpret physiologic properties of gas exchanging and pulmonary ventilation external breathing. During this students use table-train, graf logical structure of topic (addition 1). After this students decide teaching tasks which they receive from teacher. Students with teacher modulate situation tasks on these topics. Teacher corrects mistake students’ actions. Students carry out laboratory works independent. For consolidate the topic students see education film. After this students decide control tasks. Sum up of study and announcement marks. ^
Addition 1. Graf logical structure of topic “External respiration. Gas exchange and transport of gases”. Gas exchange and transport of gases ^ Carbohemoglobin Transport of О2 Diffusion of О2 and СО2 through pulmonary capillary membraneArea of alveolar surfaceThickness of pulmonary membrane ^ Diffusion coefficient for various gases Transporte of СО2 Physical soluble О2 Oxyhemoglobin Physical soluble Factors which influence on gas transport form рН Т0 рСО2 Carbonic angidrase 2,3 DPG                    ^ | ||||||||||||||||||||||||||||||||||||||||||||
