Physiology of Respiratory System Flashcards
External respiration consists of (2):
- pulmonary ventilation/breathing
- gas exchange in pulmonary capillaries of the lungs
Internal respiration consists of:
- systemic tissue gas exchange
- cellular respiration
metabolic reactions that consume oxygen and give off CO2 during the production of ATP
cellular respiration
2 phases of pulmonary ventilation/breathing:
inspiration/inhalation: moves air into the lungs
expiration/exhalation: moves air out of the lungs
the rate of airflow and amount of effort needed for breathing are influenced by _________, ________, and ________.
- alveolar surface tension
- compliance of the lungs
- airway resistance
air flows from ____ pressure to _____ pressure.
high pressure to low pressure
alveolar pressure (PA) < atmospheric pressure (PB) =
inspiration
alveolar pressure (PA) > atmospheric pressure (PB) = expiration
expiration
pressure gradients are established by changes in the size of the thoracic cavity, produced by ____ and ______ of respiratory muscles
contraction and relaxation
Law: the pressure of a gas in a closed container is inversely proportional to the volume of the container
Boyle’s Law
_____ is important for understanding the pressure changes that occur in the lungs and thorax during the breathing cycle
Boyle’s Law
______:
expansion of the thorax –> decreased alveolar pressure –> air flows in to lungs
inspiration
most important muscle of respiration is the ______. Contraction of this muscle causes it to flatten and increase the vertical diameter of the thoracic cavity
diaphragm
the 2nd most important muscle of respiration are the ______ . When they contract, the ribs elevate increasing the anteroposterior and lateral diameters of the chest cavity
external intercostals
contraction of the ______ is responsible for about 25% of the air that enters the lungs during normal respiration
intercostals
expansion of the thorax results in _______ alveolar pressure.
decreased
Air moves into the lungs when alveolar pressure…
drops below atmospheric pressure
a passive process that begins when inspiratory muscles are relaxed, decreasing the size of the thorax
There is no active muscle movement
quiet expiration
at max inspiration, the atmospheric pressure and alveolar pressure are ____, meaning no more movement of air
equal
decreasing thoracic volume ____ alveolar pressure above atmospheric pressure –> air moves out of the lungs
increases
tendency of pulmonary tissues to return to a smaller size after having been stretched during inspiration
elastic recoil
how much effort is required to stretch the lungs and chest wall
compliance
lungs and chest wall expand easily
high compliance
lungs and chest wall resist expansion
low compliance
the 2 principle influences on compliance:
elasticity
surface tension
Surfactant reduces the pressure difference needed to allow the lung to inflate. The lung’s compliance decreases and ventilation decreases when lung tissue becomes _______ and _____.
diseased and fibrotic
Airway resistance:
Normal inspiration:
- bronchioles __#1___ because their walls are pulled outward in all directions
- __#2____ resistance
Normal exhalation:
- brochioles return to resting diameter with __#3___ of lungs
- ___#4___ resistance
- enlarge
- decreased resistance
- elastic recoil
- increased resistance
any condition that narrows or obstructs airways _____ resistance. i.e. asthma, emphysema, chronic bronchitis, COPD
increases
Respiratory muscles for inspiration (7)
- diaphragm
- external intercostals
mm that aid in forced inspiration:
- scalenes
- SCM
- Trapezius
- Pectoralis Major
- Pectoralis Minor
Respiratory muscles for forced exhalation (5)
- internal intercostals
- rectus abdominus
- external oblique
- internal oblique
- transverse abdominus
the amounts of air moved in and out of the lungs and remaining in them
pulmonary volumes
instrument used to measure volume of air exchanged in breathing
spirometer
amount of air inhaled and exhaled in normal breathing
tidal volume (TV)
when you take a deep breath, more than 500mL of air is inhaled. This additional air is the _________.
inspiratory reserve volume (IRV)
Tidal volume = the volume of one breath averages about ____mL of air into and out of the lungs
500mL
IRV is approximately ____mL in an adult male and ___mL in an adult female
- 3100
- 1900
amount of air that can be exhaled after normal exhalation
expiratory reserve volume (ERV)