Mechanics of Breathing Flashcards

Vocabulary flashcards for reviewing the mechanics of breathing, covering key terms and definitions from the lecture notes.

External Respiration

Gas exchange between air in alveoli and blood in pulmonary capillaries.

Internal Respiration

Gas exchange between tissue cells and blood in systemic capillaries.

Boyle's Law

P1V1 = P2V2; If Volume increases, Pressure must decrease.

Intra-alveolar Pressure

Pressure within the alveoli of the lungs (760 mm Hg).

Intrapleural Pressure

Pressure within the pleural cavity (758 mm Hg).

Eupnoea

Normal quiet breathing.

Inspiration

Active process of breathing in air.

Expiration

Passive process of breathing out air.

Transmural Pressure Gradient

Pressure gradient across the lung wall that holds the thoracic wall and lungs in close apposition.

Phrenic Nerve

Innervates the diaphragm (C3,4,5).

Inspiratory Stridor

Noisy breathing due to paralysis of abductors of vocal cords.

Intrapulmonary Pressure

Pressure within the lungs.

Valsalva Maneuver

Forced expiration against a closed glottis.

Muller’s Maneuver

Forced inspiration against a closed glottis.

Emphysema

Loss or decrease in lung elasticity, leading to expansion of the thoracic cage.

Pneumothorax

Air in the pleural cavity, leading to collapse of the lung.

Tidal Volume (TV)

Normal volume of air inspired or expired during quiet breathing (500 ml).

Inspiratory Reserve Volume (IRV)

Extra volume of air inhaled after tidal volume by maximum inspiratory effort (3000 ml in adult male).

Expiratory Reserve Volume (ERV)

Extra volume of air that can be exhaled after tidal volume by maximum expiratory effort (1100 ml in a normal adult male).

Residual Volume (RV)

Volume of air left in the lungs after forceful expiration (1200 ml).

Inspiratory Capacity (IC)

Maximum volume of air that can be inspired after normal tidal expiration (TV + IRV = 3500 ml).

Expiratory Capacity (EC)

Maximum volume of air that can be expired after normal tidal inspiration (TV + ERV = 1600 ml).

Functional Residual Capacity (FRC)

Volume of air remaining in the lungs after normal tidal expiration (ERV + RV = 2300 ml).

Vital Capacity (VC)

Maximum amount of air expelled after deepest possible inspiration (TV + IRV + ERV = 4600 ml).

Total Lung Capacity (TLC)

Volume of air present in the lung after maximum inspiration (VC + RV = 5800 ml).

Timed Vital Capacity (FVC)

Volume of air that can be expired rapidly with maximum force following a maximum inspiration.

FEV1

Volume of air expired in the first second of FVC (normally 80%).

Minute Ventilation

Volume of air inspired or expired per minute (TV * RR = 6000 ml).

Maximum Breathing Capacity (MVV)

Maximum volume of air that can be ventilated voluntarily for a given interval of time.

Breathing Reserve/Pulmonary Reserve (PR)

Maximum amount of air above the PV that can be inspired or expired in one minute (MVV – PV).

Dead Space

Volume of air that does not participate in gaseous exchange.

Airway Resistance

Resistance to airflow in the airways, depends primarily on the radius of the conducting airways.