Phys: Respiratory Phys Flashcards
fxn of lungs?
gaseous exchange
pH balance
what is gaseous exchange dependent on?
ventilation- amount of gas delivered by the lungs
perfusion- amount of blood delivered by the heart to the lungs
diffusion- amount of gas that passes thru the air-blood barrier
perfusion is greatest?
base- wasted perfusion
ventilation is highest?
apex- wasted ventilation
air- blood barrier is made up of?
capillary endothelium, basement membrane, type I pneumocyte
what are type II pneumocyte fxn?
make the surfactant, which reduces the surface tension in the alveoli
what is ficks law?
rate of diffusion through a membrane is inversely proportional to the thickness of the membrane
ventilation/perfusion rate is?pulmonary BF rate is?
4 L/min; 5 L/min- 4L/5L=0.8
highest is Apex -3
lowest in Base - 0.6
what is meant by “a shift to the right” regarding oxygen
decrease Hb affinity for O2, therefore O2 is released
what are the 4 factors for a shift to the right
acidosis
CO2 increase
temp inc
2,3 DPG
97% of the oxygen in blood is carried by?
hemoglobin
CO2 is transported by?
70% bicarbonate
23% attached to hhemoglobin as cardaminohemoglobin
7% dissolved in plasma
what does lipoprotein do?
keeps lung exoanded by dec surface tension
what is partial pressure?
O2 conc. in the alveoli
controlled by:
rate of absorption of O2 in blood
rate of entry of new O2 into lungs bu breathing
on inspiration the diaphragm does what?
contracts
when pressure dec. - air moves into lungs
TV is?
tidal volume
500 mL
volume of a normal breath
IRV is?
inspiratory reserve volume
3100 mL
volume inspired above TV
ERV is?
expiratory reserve volume
1200 mL
volume expired after normal breath
RV is?
residual volume
1200 mL
what resides in the lungs
IC is?
inspiratory capacity
3600 mL
IRV+TV=IC
FRC is?
functional resdiual capacity
2400 mL
air left in lungs after normal expiration
ERV+TV=FRC
VC is?
Vital capacity
4800 mL
volume expired after maximal inspiration
ERV+IRV+TV=VC
TLC is?
total lung capacity
5-6 L
IRV+ERV+TV+RV=TLC
pneumotaxic center does?
turns off inspiratory center before overexpansion of lungs occur
herring -breuer reflex is?
stretch receptors- bronchi PREVENT over stretching of lungs
apneustic center does?
prevents turn off of inspiratory center
Bohr effect is?
CO2 enters blood stream, causing O2 disassociation from hemoglobin
haldene effect does?
CO2 combines with hemoglobin to form more bicarbonate ions
what is the major determinant of breathing?
conc. of CO2 in the blood
arterial Pco2=?
40 mmHg
Cheyne-stokes breathing is?
periods of rapid breathing w/ increasing then decreasing TV followed by apnea (seen in CHF)
Kussmaul breathing is?
deep rapid regular breathing
diabetic ketoacidosis
Biot’s respiration is?
bouts of irregularly irregular breathing and apnea
brain stem compression
