A&PII Lab 9: The Respiratory System - Physiology Flashcards
Inspiration
inhalation; process by which air moves from the outside environment to the tiny alveoli within the lungs; results when respiratory muscles contract
Expiration
exhalation; occurs when respiratory muscles relax
Pulmonary ventilation
inspiration and expiration
External respiration
oxygen moving out of the alveoli and into the capillaries while carbon dioxide is moving in the opposite direction
Internal respiration
3rd step of respiration; occurs when oxygen carried in the bloodstream diffuses into surrounding body cells, and carbon dioxide moves from the cells into the bloodstream
Diaphragm
normal inhalation is caused by contraction of the respiratory muscles; the main contributor is this structure, which increases the length of the thoracic cavity when it contracts
External intercostals
during forced inhalation, these muscles participate by elevating the ribs, which increases the width of the thoracic cavity
Internal intercostals
in forced expiration, the thoracic cavity is compressed further by the contraction of these muscles
Intrapleural pressure
contraction of the diaphragm causes expansion of the thoracic cavity, which draws the attached parietal pleura outward with the thoracic wall; as a result, the pleural cavity increases in volume slightly, causing a decrease in this pressure
Intrapulmonic (alveolar) pressure
expansion of the lungs causes this pressure within the alveoli to decrease below atmospheric pressure, producing a slight gradient that pulls air into the alveoli
Bronchial sounds
sounds produced by air movement through the trachea and bronchi that sounds like the rushing of air through a narrow space
Vesicular breathing sounds
sounds like a rustling of leaves during a breezy day; produced by air rushing through bronchioles and filling the alveoli
