Respiratory System Mechanics

Group 6

Marcelino

Mayor

Moises

Olasiman

Ong

Respiratory System• The respiratory system is situated in the thorax and is

comprises of the nose, mouth, throat, larynx, trachea, bronchi and lungs.

• The function of the respiratory system is to facilitate gaseous exchange to take place in the lungs and tissue cells of the body.

Respiration – process of transferring oxygen to and

removing carbon dioxide from cells in the body

Ventilation - physical process of moving air into and out of the lungs

Diaphragm - main muscle of breathing or ventilation

2 Phases of Ventilation:

a. Inspiration – air is taken into the lungs

- occurs as the external intercostal muscles and the diaphragm contract.

b. Expiration – air is expelled out of the lungs

-inspiratory muscles relax, causing the diaphragm to rise and the chest wall to

move inward.

Objectives

• To describe the role of muscles and volume changes in the mechanics of breathing

• To understand that the lungs do not contain muscle and that respirations are therefore caused by external forces

• To explore the effect of changing airway resistance on breathing

• To study the effect of surfactant on lung function• To examine the factors that cause lung collapse• To understand the effects of hyperventilation,

rebreathing, and breath holding on the CO2 level in the blood.

Methodology

• Use of the program Physio Ex 5.0• 5 Activities were done.

• Activity 1: Measuring Respiratory Volumes• Activity 2: Examining the Effect of Changing Airway

Resistance on Respiratory Volumes • Activity 3: Examining the Effect of Surfactant• Activity 4: Investigating Intrapleural Pressure• Activity 5: Exploring Various Breathing Patterns

Figure 1. Opening Screen of the Respiratory Volumes Experiment

Figure 2. Opening Screen of the Factors Affecting Respirations Experiment

Figure 3. Opening screen of the Variations in Breathing Experiment

Results and Discussion

Radius Flow T.V. ERV IRV RV VC FEV1 TLCPump

Rate

5.00 13,356 500 1200 3091 1200 4791 3541 5991 15

Table 1. Baseline Respiratory Values

Results and Discussion

• Minute Respiratory Volume (MRV)

- the volume of gas inhaled or exhaled from a person's lungs in one minute

- can be calculated by multiplying tidal volume by Breaths per minute (BPM)

• MRV = TV x BPM

= 7500 ml/min• It is an important parameter in respiratory medicine due

to its relationship with blood carbon dioxide levels.

Results and Discussion

Radius Flow TV ERV IRV RV VC FEV1 TLCPump

Rate

4.50 7.963 328 787 2,028 1,613 3,143 2,303 4,756 15

4.00 4,983 205 492 1,266 1,908 1,962 1,422 3,871 15

3.50 2,919 120 288 742 2,112 1,150 822 3,262 15

3.00 1,578 65 156 401 2,244 621 436 2,865 15

Table 2. Values of Airway resistance on Respiratory Volumes

2 types of Pulmonary Diseases

• Obstructive Pulmonary Disease

- characterized by chronic obstruction of the small airways.

- people having obstructive pulmonary diseases have difficulty in removing air from their lungs.

- ex. Bronchitis, Emphysema, and Asthma• Restrictive Pulmonary Disease

- restrict lung expansion, resulting in a decreased lung volume, an increased work of breathing, and inadequate ventilation and/or oxygenation.

- ex. Pulmonary Fibrosis, Pneumonia, Pulmonary Edema, or other types of inflammatory lung diseases.

Results and Discussion

RadiusPump

Rate

Surfact

ant

Pressur

e left

Pressur

e right

Flow

Left

Flow

Right

Total

Flow

5 15 5 0.53 0.53 49.69 49.69 99.38

5 15 7 0.53 0.53 69.56 69.56 139.13

Table 4. Comparison of a Normal and an Addition of Surfactant in the Lungs

Results and Discussion

• Surface tension arises because water molecules are more strongly attracted to one another than to air molecules.

• Surface tension produces an inwardly directed force that tends to reduce alveolar diameter.

• Pulmonary surfactant is a lipoprotein rich in phospholipid.

• Surface tension arises because water molecules are more strongly attracted to one another than to air molecules.

Results and Discussion

RadiusPump

Rate

Surfact

ant

Pressur

e left

Pressur

e Right

Flow

Left

Flow

Right

Total

Flow

5.0 15 5 0.53 0.53 49.69 49.69 99.38

5.0 15 5 0 0.53 0 49.69 49.69

5.0 15 5 0 0.53 0 49.69 49.69

5.0 15 5 0.53 0.53 49.69 49.69 99.38

Table 4. Investigating Intrapleural Pressure

Results and Discussion

• Intrapleural Pressure - pressure within the pleural cavity. Less than the pressure within the alveoli.

• Negative pressure caused by 2 forces:

- tendency of the lung to recoil due to its elastic properties

- surface tension of the alveolar fluid• Opening in the thoracic wall causes equalization of the

intrapleural and atmospheric pressure (Pneumothorax)• Pneumothorax allows lung collapse, a condition called

atelectasis.

Results and Discussion

Condition PCO2

Max

PCO2

Min PCO2

Pump

RateRadius Total Flow

Rapid

Breathing43.77 45.00 40.54 39.19 5.0 2,683.40

Rebreathin

g47.97 52.95 45.00 14.93 5.0 2,941.31

Breath

Holding51.86 58.00 45.00 13.87 5.0 2,950.11

Table 5. Pressure, Pump Rate and Total Flow in Various Breathing Patterns

Conclusion

• The respiratory system is important in gas-exchange and works through inspiration and expiration.

• There are factors affecting the ventilation of an organism such as surface tension and diseases

• Rapid breathing causes a decrease in PCO2 and breath holding causes an increase in PCO2