9/17 Repiratory physiology introduction Flashcards
what are some functions of respiratory system?
- Gas Exchange; (matabolism, acid/base balance); 2. olfaction; 3. processing inhaled air (BTPS); 4. Blood reservior; 5. filter small emboli; 6. biochemical reactions (angiotensin II from I; remove some hormones)
what does BTPS stand for in lung function
body temperature, ambient pressure, water saturated.
how much of the blood is in the pulmonary vessels?
9%
what is Pressure?
directly related to force per area over which the force is applied (F/A)
what are the common units of pressure?
Pascal (newton/m2); PSI (pounds/in2); mmHg (manometer)
ideal gas law
PV-nRT
what is a partial pressure?
the partial of a gas is the pressure that it would have if it occupied the volume of the mixture. similar to conc.
how does Partial presssure affect gass dynamics
drives the diffusion and reaction of the gasses
how is conc. of gas in solution related to the partial pressure?
Ca=Pa* solubility (directly related)
the normal range of resperatory volume in normal breathing
Tidal Volume
Total air volume forcibly expired after full inspiration.
forced vital capacity (usually measured over 3-5 sec)
the volume of air expelled from max inhale in 1 sec
Forced Voume Expired (FEV1)
the ratio of air expelled in the first second to the toal expelled over about five seconds
FEV1/FVC
what is a normal FEV1/FVC
0.7-0.8
what is a FEV1/FVC that is abnormal and indicative of asthma?
what problems whould cause a lower FEV1/FVC?
asthma and problems that cause obstructive diseases (copd etc.)
what problems would cause a greater than normal FEV1/FVC?
restrictive diseases where the lung has problems getting enough air in (Fibrosis)
what is the RV for lungs?
the reserve volume, or the air that is left in the lung after all of the air is exhaled as possilbe.
what would the purpose of the RV be for the lungs
to prevent lungs from collapsing
what is it called when you measure the volumes of air going in or out of the lungs?
Spirometry
what is the partial pressure of O / CO2 in inspired air
O is 160 mmHG; CO2 is 0