VENTILATION AND RESPIRATORY VOLUMES Flashcards
(33 cards)
the process of moving air into and out
of the lungs
Ventilation (breathing)
the movement of air into the lungs
Inspiration (inhalation)
the movement of air out of the lungs
expiration (exhalation)
Inhaling requires a set of muscles called the
muscles of inspiration
a large dome of skeletal muscle that separates the thoracic cavity from the abdominal cavity
diaphragm
Forceful exhalation requires a set of muscles called the
muscles of expiration
Two physical principles govern the flow of air into and out of the lungs:
- Changes in volume result in changes in pressure
- Air flows from an area of higher pressure to an area of lower pressure.
the air pressure within the alveoli
alveolar pressure
the air pressure outside the body
atmospheric pressure
the tendency for an expanded lung to decrease in size
lung recoil
exists because the oppositely charged
ends of water molecules are attracted to each other
surface tension
Two factors keep the lungs from collapsing:
(1) surfactant and
(2) pressure in the pleural cavity.
a mixture of lipoprotein molecules produced by secretory cells of the alveolar epithelium
surfactant
the pressure in the pleural cavity, is less
than alveolar pressure, the alveoli tend to expand
-keeps the alveoli expanded
pleural pressure
the process of measuring volumes
of air that move into and out of the respiratory system
spirometry
the device that measures these respiratory volumes
spirometer
measures of the amount of air movement during different portions of ventilation
respiratory volumes
sums of two or more respiratory volumes
respiratory capacities
The four respiratory volumes and their normal values for a young adult male
Tidal volume
Inspiratory reserve volume
Expiratory reserve volume
Residual volume
the volume of air inspired or expired
with each breath. (500ml)
tidal volume
the amount of air that can be inspired forcefully beyond the resting tidal volume (3000mL)
inspiratory reserve volume
the amount of air that can be expired forcefully beyond the resting tidal volume (1100mL)
expiratory reserve volume
the volume of air still remaining in the
respiratory passages and lungs after maximum expiration (1200mL)
residual volume
Values of respiratory capacities, the sum of two or more pulmonary volumes:
- Functional residual capacity
- Inspiratory capacity
- Vital capacity
- Total lung capacity