Physiology 2 Flashcards
what are the 4 driving forces of air flow
atmosphere lung pressure gradient
respiratory muscles
coupling between lung and thoracic cage
resistance of airways
what is resistance and its equation
resistance is the force required to inflate or deflate lungs
R= pressure / air flow (Q)
Relationship between resistance and air flow
Relationship between resistance and diameter
inverse
inverse
respiratory pressure is always described relative to
atmospheric pressure
for air to flow inside the lungs intrapulmonary pressure must be ….. than Patm
Less
airway resistance mainly determined by
radius of conducting airway
for air to flow outside the lungs intrapulmonary pressure must be ….. than Patm
more
what controls contraction and dilation of smooth muscles in walls of bronchioles
ANS
Pulmonary ventilation or respiratory minute ventilation is
volume of air that enters lung per minute
direction of airflow is determined by difference between
atmospheric pressure and intrapulmonary pressure
number of breaths per minute RR
12
Volume of air moved per breath (tidal volume)
500
Pulmonary ventilation how is it calculated and what is the value
Tidal volume * RR = 6000 ml / min
in inspiration what muscles contracts
diaphragm and external intercostal muscles
what process of respiration is active and which one is passive
active ; inspiration
passive ; expiration
what muscle when it contracts it increases the thoracic wall superior inferior dimension
diaphragm
what muscle when it contracts it increases the thoracic wall anterior posterior dimension
external intercostal muscle
volume of thoracic cage increase and lungs expand during inspiration
true
decrease in intra pulmonary pressure to what value during inspiration
759 mmhg
increase in intra pulmonary pressure to what value during expiration
761 mmhg
negative intrapulmonary pressure pulls air into lungs during inspiration
true
relaxation of inspiratory muscles during expiration
true
volume of thoracic cavity increase during expiration
FALSE ( DECREASE)
……..intrapulmonary pressure push air out of lungs during expiration
positive
transpulmonary pressure is always
positive
at the end of inspiration and expiration
intra alveolar pressure is equal to atmospheric pressure
air will continue to flow down pressure gradient until two pressures equilibrate
throughout the cycle the intrapleural pressure is always ….. than intra alveolar pressure
less
trans mural pressure gradient always exist so lung always stretched to some degree even during expiration
true
what are the muscles of normal tidal inspiration
diaphragm
external intercostal
laryngeal muscles
accessory muscles of inspiration
sternocleidomastoid
scalene
serratus anterior
pectoralis major and minor
muscles of forced expiration
contract : internal intercostal abdominal muscles ( internal oblique , abdominal rectii and transversus abdominis ) relax : diaphragm and external intercostal
during resting expiration
relaxation of diaphragm and external intercostal
what happens to lung volume and pressure during expiration
lung volume decrease and pressure increase
what are the two modes of breathing
quiet ( eupnea ) and forced ( hyperpnea)
what is eupnea and two derivatives of it
active inhalation and passive exhalation
diaphragmatic which is deep
costal which is shallow
what is hyperpnea
active inhalation and exhalation
what is alveolar ventilation
rate at which new air reached alveoli
during inspiration what happens to alveolar pressure relative to atmospheric pressure
less than atmospheric
(pull 0.5 L in )
during expiration what happens to alveolar pressure relative to atmospheric pressure
more than atmospheric
push 0.5 L out
how to calculate alveolar ventilation and its value
RR * (tidal volume - anatomical dead space)
4200 ml
what happens to RR and TC when demand for oxygen increase
both increase
what is the difference between lung volume and lung capacity
lung volume ; directly measured by spirometer
lung capacity ; combination of different lung volumes
tidal volume value and definition
500 ml
volume of air moved in and out of lungs during single cycle at rest
inspiratory reserve volume ( IRV) value and definition
3000 ml
extra volume of air that can be inspired on top of tidal volume
expiratory reserve volume (ERV) value and definition
1000 ml to 1100 ml
extra volume of air than can be actively expired by maximal expiration
residual volume ( RV) value and definition
1200 ml
volume of air that remains in lungs after maximal expiration
inspiratory capacity ( IC) value and definition
3500 ml
maximum volume of air that can be inspired at the end of quiet expiration (TV + IRV)
functional residual volume (frv) value and definition
2200 ml to 2300 ml
volume of air that remains in lungs at the end of normal passive expiration ( ERV + RV)
Vital capacity value and definition
4500 ml
maximum volume of air that can be moved out during a single breath after maximum inspiration (TV +IRV + ERV)
total lung capacity (TLC ) value and definition
5700 ml
maximum volume of air that lungs can hold ( VC + RV)
what is forced vital capacity ( FVC)
you measure vital capacity when you forcefully exhale
what is forced expiratory volume (FEV1)
volume you forcefully exhale in one second
pulmonary function test (PFT)
you use FEV1 and FVC to diagnose respiratory diseases
when actual FVC is more than predicts and FEV 1 is more than 80 % this is a healthy individual
true
what disease a person has if FVC is less than predicted
restrictive pulmonary disease
what disease a person has if FEV1 is less than 80%
Obstructive pulmonary disease
gas laws are principles that govern the movement of gas molecules
true
inspired air is moistened and warmed and exhaled air mixes with air in anatomic dead space
true
what is BOYLE law
pressure of gas inside molecule is inversely proportional to volume of container if temp and number of gas molecules remain constant (P1V1 = P2V2)
What is DALTON law ( law of partial pressure )
p total = sum of partial pressure of each gas
what is HENRY law
solubility of gas is directly proportional to pressure applied
total atmospheric pressure is equal to and what is the % each gas makes
760 mmhg
N2= 79 % (600 MMHG)
O2 = 21% (160 MMHG)
Gas diffusion depends on
partial pressure and solubility of gas
what is the pressure of each gas in alveoli
PO2 = 104 PCO2 = 40
what is the pressure of each gas in pulmonary capillary before exchange
PO2=45
PCO2=40
what is the pressure of each gas in pulmonary capillary after exchange
PO2 = 104
PCO2=40
what is the pressure of each gas in expired air
PO2 = 120 PCO2= 27
what is the pressure of each gas in inspired air
PO2 = 160
PCO2=0.3
