Flashcards in Topic 6.4: Gas Exchange Deck (15)
What is the purpose of ventilation?
Ventilation maintains concentration gradients of oxygen and carbon dioxide between air in alveoli and blood flowing in adjacent capillaries
Ventilation: The exchange of air between the atmosphere and the lungs – achieved by the physical act of breathing
Define gas echange
Gas Exchange: The exchange of oxygen and carbon dioxide between the alveoli and bloodstream (via passive diffusion)
Define physiological respiration
Physiological respiration involves the transport of oxygen to cells within the tissues, where energy production occurs
How is air carried throughout the body?
Air is carried to the lungs in the trachea and bronchi and then to the alveoli in bronchioles
Pneumocytes (or alveolar cells) are the cells that line the alveoli and comprise of the majority of the inner surface of the lungs
What is the purpose of type I pneumocytes?
Type I pneumocytes are involved in the process of gas exchange between the alveoli and the capillaries
What is the purpose of type II pneumocytes?
Type II pneumocytes are responsible for the secretion of pulmonary surfactant, which reduces surface tension in the alveoli
What happens when the pressure in the chest is less than the atmospheric pressure?
When the pressure in the chest is less than the atmospheric pressure, air will move into the lungs (inspiration)
What happens when the pressure in the chest is greater than the atmospheric pressure?
When the pressure in the chest is greater than the atmospheric pressure, air will move out of the lungs (expiration)
What cause the pressure changes inside the thorax that forces air in and out of the lungs?
What are the two muscles responsible for inspiration?
The muscles responsible for inspiration are the diaphragm and external intercostals (plus some accessory muscles)
What are the two muscles responsible for expiration?
The muscles responsible for expiration are the abdominal muscles and internal intercostals (plus some accessory muscles)
Spirometry involves measuring the amount (volume) and / or speed (flow) at which air can be inhaled or exhaled