Respiratory System 2 Flashcards
what is pulmonary ventilation
movement of gases between atmosphere and alveoli
what is pulmonary gas exchange
exchange of gases between alveoli and blood
what is gas transport
transport of gases in blood between lungs and systemic cells
what is tissue gas exchange
exchange of respiratory gases between the blood and the systemic cells
what is eupnea
quiet breathing
what regulates breathing activity
autonomic nuclei in brainstem
explain mechanics of inspiration
diaphragm contracts and flattens downwards
external intercostals contract and elevate ribs to increase dimension of thoracic cavity
intrapleural volume increases so intrapleural pressure decreases
pleura pulls on lungs so lung volume increases
as lung volume increases, intrapulmonary pressure decreases to less than Patm
air flows in until Ppul and Patm are equal
explain mechanics of expiration
passive process where diaphragm and external intercostals relax which decreases thoracic volume
intrapleural volume decreases, pressure increases
elastic recoil pulls lungs inward which decreases intrapulmonary volume and increases intrapulmonary pressure to greater than Patm
air flows out of lungs until Ppul and Patm are equal
what are the muscles for forced inspiration
diaphragm and external intercostals
what are the muscles of deep inspiration and what do they do
sternocleidomastoid, scalenes, pectoralis minor, erector spinae, and serratus posterior superior
move ribcage up, lateral, and forward which increases thoracic volume
what are the muscles of forced expiration
accessory muscles: internal intercostals, abdominal muscles, transverse thoracics, and serratus posterior inferior
move ribcage up, medially, and posteriorly or compress abdominal contents
what causes vertical dimension changes in the thoracic cavity
diaphragm contracts down to increase dimensions or relaxes to decrease dimensions
what causes lateral dimension changes in the thoracic cavity
relaxation of all breathing muscles except for diaphragm
what causes anterior-posterior dimension changes in the thoracic cavity
relaxation of all breathing muscles except for diaphragm
explain Boyle’s Law
pressure of a gas and volume of a container are inversely related at a constant temperature
P1V1 = P2V2
what causes an air pressure gradient
when force per unit area is greater in one place than another
what is atmospheric pressure (Patm)
pressure of air in environment
does not change during breathing
760mmHg at sea level or 0mmHg for our purposes
what is intrapulmonary pressure (Ppul)
pressure within alveoli
fluctuates when breathing
what is intrapleural pressure (Pip)
pressure in pleural cavity
fluctuates when breathing
lower than intrapulmonary pressure to keep lungs inflated (4 mmHg less)
what is alveolar volume
collective volume of alveoli
explain inspiration in terms of volume and pressures
thoracic volume increases, thoracic pressure decreases
thoracic volume increase, lung volume increases and lung pressure decreases
when pressure in lungs decreases below atmospheric pressure, air flows into lungs
explain expiration in terms of volume and pressures
thoracic volume decreases, thoracic pressure increases
thoracic volume decreases, lung volume decreases and lung pressure increases
when lung pressure increases above atmospheric pressure, air flows out of lungs
explain forced inspiration in terms of volume and pressures
diaphragm and external intercostals contract more forcefully along with other accessory muscles as needed
thoracic volume increases with lung volume
intrapleural volume increases, pressure decreases
intrapulmonary volume increases, pressure decreases farther below Patm
more air comes in until pressures are equal
explain forced expiration in terms of volume and pressures
inspiratory muscles relax and respiratory muscles are recruited as needed
thoracic volume decreases with lung volume
intrapleural volume decreases, pressure increases
intrapulmonary volume decreases, pressure increases farther above Patm
air flows out until pressures are equal
what is happening in terms of volume and pressures between breaths
intrapulmonary pressures and atmospheric pressures are equal so there is no air movement, no muscle contraction
define airflow
amount of air moving in and out of the lungs with each breath
what are the two factors that airflow depends on
pressure gradient of Patm and Ppul
resistance
how are the pressure gradient and resistance related to air flow
F (airflow) = changeP/R
pressure gradient is directly related to airflow
resistance is inversely related to airflow
define pressure gradient
difference between atmospheric pressure and intrapulmonary pressure
what is the main driving force of airflow in and out of the lungs
air pressure gradient
what factors affect the resistance to airflow
bronchiole diameter
compliance in chest wall or lungs
define distensibility
ability to stretch
how are surface tension and surfactant related
inversely; less surfactant, more surface tension, less compliance, more resistance
define minute ventilation
process of moving air into and out of the lungs
amount of air moved between atmosphere and alveoli in one minute
minute ventilation = tidal volume x respiration rate
define tidal volume
amount of air per breath
define respiration rate
number of breaths per minute
define anatomical dead space
collective space that has air but that air is not exchanging respiratory gases with the blood
roughly 150 mL
define alveolar ventilation
volume of air that reaches the alveoli and participates in gas exchange per minute
AVR = (tidal volume - dead space volume) x respiratory rate
what is a spirometer
device that measures respiratory volumes
what is a spirogram
graphical representation of respiratory movements made during spirometry
define inspiratory reserve volume (IRV)
amount of air that can be forcibly inhaled beyond tidal volume
measures compliance
define expiratory reserve volume (ERV)
amount that can be forcibly exhaled beyond tidal volume
measure of elasticity
define residual volume
amount of air left in lungs after the most forceful expiration
define respiratory capacity
sum of two or more respiratory volumes
define inspiratory capacity (IC)
tidal volume + inspiratory reserve volume
define functional residual capacity (FRC)
expiratory reserve volume + residual volume
volume left in lungs after a quiet respiration
define vital capacity (VC)
tidal volume + ISV + ESV
total amount of air a person can exchange through forced breathing
define total lung capacity (TLC)
sum of all volumes
maximum amount of air the lungs can hold
define forced expiratory volume (FEV)
% of vital capacity that can be expelled in a set period of time
75-85% in healthy person
what respiratory test is used to distinguish COPD and CRPD
forced expiratory volume
define maximum voluntary ventilation (MVV)
greatest amount of air that can be taken in and then expelled from the lungs in one minute
1.)
inspiratory reserve volume
2.)
tidal volume
3.)
expiratory reserve volume
4.)
residual volume
5.)
inspiratory capacity
6.)
functional residual capacity
7.)
vital capacity
8.)
total lung capacity
