Resp S1 - Intro Flashcards
What is Charles’ law?
Pressure is proportional to absolute temperature as the kinetic energy of molecules increases with temperature
What is Boyle’s law?
Pressure is inversely proportional to volume - if a given amount of gas is compressed into a smaller volume, pressure will rise..
What is a partial pressure?
The proportion of pressure exerted by one gas in a gaseous mixture (it’s the same proportion of the total pressure as the volume fraction of the gas in the mixture)
What is SVP?
Saturated vapour pressure, the maximum pressure that water in equilibrium with a gas exerts. It’s only dependent on temperature.
How do gases behave in water?
Gas molecules will enter the liquid until an equilibrium is established between the solution and dissolution of the gas
What is the partial pressure of gases in water?
The pressure or tension exerted by a gas has reached equilibrium in water. This is usually the same as the partial pressure in the gas phase. Shows how likely the gas is to escape from solution and is dependent on the solubility of the gas with the liquid.
Describe the structure of the airways
1 trachea branches into two bronchi, which branch into about 200,000 terminal bronchioles, which each lead to many alveoli.
The whole system is designed to have massive surface area in order to maximise gas exchange between inhaled air and capillary blood
What is average pulmonary arterial pressure?
Mean: 14-18
Systolic: 20-25
Diastolic: 4-12
In mm Hg
What is normal hydrostatic pressure in pulmonary capillaries?
9mm Hg
What is normal pulmonary venous pressure?
1-10mm Hg
What is the function of pulmonary resistance vessels?
To control the distribution (NOT the total flow) of blood flowing through the pulmonary capillaries
What forces affect fluid formation in the lung?
Capillary pressure, Gravity and colloid oncotic pressure.
Capillary pressure is always higher than oncotic pressure so fluid isn’t usually formed, except at the base of the lungs, where gravity can increase hydrostatic pressure to cause tissue fluid formation
What type of epithelium covers the respiratory tract?
Alveoli and bronchioles: simple squamous
The rest: ciliated pseudostratified columnar
How do the air spaces of the respiratory tract remain open?
Trachea and bronchi have cartilaginous framework to keep them open
There is also smooth muscle within the walls to control constriction
The smaller air spaces are held open by the elastic pull of the rest of the lung
What is the purpose of the conducting part of the respiratory tract?
Primarily to conduct air to the lung
To filter, humidify and warm the air before it reaches the lung
