A&PII Ch.23 Respiratory System prt. 2 Flashcards
An air pressure gradient exists when ________ per unit area is _________ in one place than another
- force, greater
- if the two places are interconnected, air flows from high to low pressure until pressure is equal
Determinants of Gas Pressure
- Amount of Gas Particles
- Temperature
- Volume of Space
If the # of gas particles in a given volume increases pressure _________.
increases
If the volume increases while all other factors remain the same, pressure __________.
decreases
How to calculate airflow…
F=deltaP/R
F= Flow
DeltaP= difference in pressure between atmosphere and intrapulmonary pressure= pressure gradient= Patm-Palv
R= Resistance
Boyle’s law formula..
P1V1=P2V2
If temperature increases while all other factors remain the same, pressure __________.
increases
Facts about airflow
- flow is directly related to pressure gradient and inversely related to resistance
- if pressure gradient increases, airflow to lungs increases
if resistance increases, airflow lessens
F=
(Patm - Palv)/R
Compliance
ease with which the chest wall and lungs expand
Surfactant
reducessurface tension within alveoli
True or False? All pressure in the lungs are the same.
FALSE There are DIFFERENT pressures in the lungs
Atmospheric Pressure (Patm)
pressure in the atmosphere that surrounds the body
Transpulmonary Pressure
pressure differential between intrapulmonary and intrapleural pressures; represents force that tends to collapse the lungs
Intrapleural Pressure
pressure in the space between the visceral and parietal pleura
Intrapulmonary Pressure
same as intra-alveolar pressure (pressure in the alveoli)
Where is the visceral pleura located
directly touching and surrounding the outside of the lung
Resting breathing relies on _______ and ________ pressures.
Atmospheric and Intrapulmonary pressure
Prior to inspiration, atmospheric pressure..
= pulmonary pressure
Steps in the process of ventilation: resting breathing
0) Atmospheric pressure = intrapulmonary pressure
1) Lungs begin to expand, so intrapulmonary pressure DECREASES
2) Air moves from atmosphere to lungs
3) Pressures return to equilibrium
4) During expiration, thoracic volume decreases causing intrapulmonary pressure > atmospheric pressure
5) Air moves out of the lungs until pressure equilibrates again
What are the 5 non-breathing air movements?
1) Coughing and Sneezing; clear irritants from airways
2) Yawn; deepest possible breath
3) Hiccup: spasm of diaphragm causing rapid bursts of air through vocal cords
4) Laughing/ Crying: when emotional states drive the ventilatory pattern
5) Valsalva Maneuver: attempt to exhale against a closed airway
Inspiration
bringing air into the lungs
If the volume of the lungs increases _________ will decrease
pressure
When Alveolar type II cells are stimulated to produce more surfactant, this will ___________ compliance, thereby ___________ resistance and __________ overall airflow.
increase, reducing, increasing
Partial Pressure
represents the contribution of any gas in a mixture to the mixture’s total pressure
Partial Pressure =
Total Pressure x Fraction of Gas (decimal form of percentage)
Diffusion is based on the _____ ________ __________
gas’ partial pressures