Body Systems: Respiratory System (Breathing Movements) Flashcards
Breathing movements:
-Pressure difference between the atmosphere and the chest cavity determines the movement of air.
-Gases move from high to low pressure.
Inhalation:
Occurs when the pressure in the lungs is lower than the atmospheric pressure.
Exhalation:
Occurs when the pressure in the lungs is higher than the atmospheric pressure.
Diaphragm:
-Dome shaped muscle.
-Separates organs of thorax from abdomen.
-Regulates the pressure in the lungs with assistance from the intercostal muscles (muscles between ribs).
During inhalation:
-Diaphragm contracts pulling downwards.
-Intercostal muscles contract pulling the ribs up and out.
-Thoracic volume increases —> thoracic pressure decreases.
-Lungs volume increases —> pressure in lungs decreases.
-Higher pressure in the enviro than the lungs.
-Air rushes in.
During exhalation:
-Diaphragm relaxes pulling upward.
-Intercostal muscles relax and rib cage falls.
-Thoracic volume decreases —> thoracic pressure increases.
-Lung volume decreases —> Pressure in lungs increases.
-Higher pressure in the lungs than enviro.
-Air is forced out.
What are intercostal muscles?
Muscles between ribs.
Tidal volume:
Volume of air that is inhaled and exhaled in a normal breath at rest.
Inspiratory reserve volume:
Additional volume of air that can be taken into the lungs, beyond a regular or tidal inhalation.
Expiratory reserve volume:
The additional volume of air that can be forced out of the lungs beyond a regular or tidal exhalation.
Vital capacity:
The total volume of gas that can be moved into or out of the lungs. It can be calculated as tidal volume + inspiratory reserve + expiratory reserve.
Residual volume:
The amount of gas that remains in the lungs and the passageways of the respiratory system even after full exhalation. This gas never leaves, if it did, the lungs and respiratory passageways would collapse.
