Flashcards in Anatomy of Chest Wall and Mechanics of Breathing Deck (25):
What is Boyle's law?
States that the pressure exerted by a gas is inversely proportional to its volume
What is Dalton's law?
States that the total pressure of a gas mixture is the sum of all the pressures of each individual gases
What is Charles law?
States that the volume occupied by a gas is directly related to the absolute temperature
What is Henry's law?
States that the amount of gas dissolved in a liquid is determined by the pressure of the gas and its solubility in the liquid
What is pleurisy?
Inflammation of the pleura, characterised by pain while breathing as the pleural membranes grate over each other
What causes pneumothorax?
introduction of air into the pleural cavity, causing the uncoupling of the lungs to the chest wall. This leads to an increase in intrapleural pressure
What is the pressure of the pleural cavity normally when compared to atmospheric pressure?
What muscles are used during inspiration?
What muscles are used in active expiration?
Accessory muscles in severe respiratory distress?
What are the accessory muscles of respiration?
The accessory inspiratory muscles are the sternocleidomastoid, the scalenus anterior, medius and posterior, the pectoralis major and minor, the inferior fibres of serratus anterior and latissimus dorsi, the serratus posterior anterior may help in INSPIRATION
What movement of the ribcage increases the anterior-posterior dimensions of the ribcage, dependent on the intercostal muscles?
Pump handle movement
Pulls ribcage forward
What movements of the ribcage influences the lateral dimensions of the ribcage, dependent on the intercostal muscles?
Bucket handle movement
Increases lung volume at the sides
Over reactive constriction of the bronchial smooth muscle, increasing resistance of airflow, and makes expiration difficult
Does asthma make inspiration or expiration difficult?
Expiration, which is why wheeze is normally most noticeable on expiration in asthma
Describe intrathoracic (alveolar) pressure
Pressure inside thoracic cavity, can be positive or negative
Describe intrapleural cavity
Pressure inside pleural cavity, always negative
Describe transpulmonary pressure
Difference between Pa and Pip (Pa-Pip)
Always positive in health, as Pip is always more negative than Pa.
How much pleural fluid is normally found in the pleural cavity?
What is the function of pleural fluid?
Lubricates membranes to allow them to glide over each other without causing pain
Prevents separation of membranes
What are the symptoms of pneumothorax?
Sudden onset sharp pain
Usually one sided pain
What movement are the internal intercostal muscles responsible for during expiration?
Move ribs and sternum down and inwards
What are the abdominal muscles responsible for in expiration?
Reducing volume of the abdominal cavity (oppose diaphragm effects)
What are the external intercostal muscles responsible for in inspiration?
Move sternum and ribs forwards and up, as well as outwards
What is the diaphragm responsible for in inspiration?
Increasing lung volume