Biomechanics Of Breathing Flashcards
What is the 5 functions of the respiratory system?
Gas exchange Filtration and destruction of venous thrombi Host defence Acid base regulation Speech
The structure of the respiratory system consists of the large airway, the small airway and the alveoli. The alveoli is made up of two cell types with differing functions. What are they?
They are called pores of Kohn
Type 1 - gas exchange
Type 2 - manufactures surfactant which covers the surface of alveoli
The structure of the respiratory system is divided into three parts consisting of the large airway, small airway and alveoli. What is the difference between the large and small airways apart from its size?
The large airway has cartilage, small airway has no cartilage
The large airway has smooth muscle lining longitudinally and mucous glands and goblet cells
Whereas the small airway has smooth muscle in helices and les mucous glands
Differences in pressures in the respiratory system enable us to breathe through areas of high and low pressure. There are three different types of pressure. What are they and where’re are they measured?
Pip is the intrapleural pressure. It is the pressure within the intrapleural cavity. It is always negative
Palv is the intraalveoli/intrapulmonary pressure. It is the pressure within the alveoli
Ptp is the transpulmonary pressure. It is the pressure across alveoli and the intrapleural pressure. It is essentially reflective of the pressure from the elastic recoil of the lungs. It is always positive
A surgical patient has had his phrenic and intercostal nerves severed. What muscles would be affected and in which phase of breathing would he be unable to carry out?
The diaphragm and external intercostal nerves would be affected. The diaphragm is innervated by the phrenic and lower intercostal and the external intercostal nerve is innervated by the intercostal nerve.
Both are responsible for inspiration
What muscles are used during forced expiration and not passive expiration?
Rectus abdominis and internal intercostal muscle. The rectus abdominis is innervated by the thoraco-abdominal nerves from T7-T12 and the internal intercostal muscles are innervated by the intercostal nerves.
During passive expiration the elasticity of the diaphragm will naturally push the air out.
Lung pulmonary compliance indicates how easy it is to stretch the lungs during inflation. What are the two factors influencing the stretch and recoil of the lungs?
Elastic fibres in the lung parenchyma (alveoli)
Surface tension of air-water surface of alveoli
Emphysema is a disease that affects which aspect of the breathing?
Emphysema affects the lung compliance
State what the following volumes represent: Tidal volume (Vt) Inspiratory reserve volume (IRV) Expiratory reserve volume (ERV) Residual volume (RV)
Volume of air normally inspired/expired
Extra volume that can be inspired
Extra volume that can be forced out
Volume remaining after forced expiration
State what the following capacities represent: Inspiratory capacity (IC) Vital capacity (VC) Functional residual capacity (FRC) Total lung capacity (TLC)
Maximum possible inspiration (Vt+IRV)
Maximum expiration after filling lungs (IRV+Vt+ERV)
Amount left in lungs after normal breathing (ERV+RV)
Maximum volume lung can hold (VC+RV)
