Advanced A&P - Study Guide: Respiratory Physiology

pulmonary ventilation

the movement of air from outside the body into the bronchial tree & alveoli , followed by a reversal of this air movement; breathing

air

mixture of gas

atmospheric pressure

relatively constant at 760 mmHg; the force that moves air into the lungs and flows from high to low pressure

resting expiration

no air moving in or out; presure inside of airways & alveoli is equal to pressure outside of thoracic wall

boyle’s law

pressure a

surfactant

keeps alveoli open and decreases surface tension; reduces alveoli’s tendency to collapse especially when lung volumes are low and eases inspiratory efforts to expand alveoli

surface tension

force that holds moist membranes together due to the attraction of water molecules

compliance

the ease with which the lungs can expand as a result of pressure changes during breathing

elastic recoil

deflates lungs back to “normal” shape

forced expiration

internal intercostal & abdominals contract

intrapleural pressure

pressure in pleural cavities, between pleural membranes should remain 4mmHg less than atmospheric pressure

pneumothorax

punctured pleural membrane; interferes with ventilation and can cause lung to collapse (atelectasis)

spirometer

device used to measure respiratory volumes & capacities, can help diagnose respiratory diseases and monitor the progression of the disease or response to treatment

Inspiration

1. the respiratory center sends an impulse via the phrenic nerves

2. the diaphragm contracts and moves downward

3. the volume of thoracic cavity increases

4. the pressure in the alveoli decreases to 758mmHg

5. air moves into the lungs

expiration

1. the respiratory stops phrenic nerve neural impulses

2. the diaphragm relaxes and moves upward

3. the thoracic volume decreases

4. the alveolar pressure increases to 762 mmHg

5. air moves out of the lung

pH

chemoreceptors monitor ____ of the brain

carbon dioxide

pH of brain is influenced by blood levels of _____ ______

cerbrospinal fluid

in the _____ _____ of the brain, water binds with carbon dioxide to form carbonic acid which quickly dissociates, releasing hydrogen ions and bicarbonate ions