Applied Physio lectures 32 and 33 (exam 3)

These flashcards cover key terms and definitions related to the mechanics of breathing, focusing on the physiology and functions of the respiratory system.

Alveoli

Small air sacs in the lungs where gas exchange occurs.

Surfactant

A lipoprotein that lowers surface tension and stabilizes alveoli, reduces the work of breathing

Pleural fluid

Fluid that reduces friction and connects the lungs to the chest wall. helps sliding of two surfaces and reduces friction. helps maintain lung volume

Tidal Volume (TV)

The amount of air inhaled or exhaled during normal respiration.

Inspiratory Reserve Volume (IRV)

The maximum amount of additional air that can be inhaled after a normal inhalation.

Expiratory Reserve Volume (ERV)

The maximum amount of additional air that can be exhaled after a normal exhalation.

Residual Volume (RV)

The amount of air remaining in the lungs after a forced exhalation. cannot be measure by spirometry

Vital Capacity (VC)

The maximum amount of air that can be exhaled after a maximum inhalation.

IRV + TV + ERV

Total Lung Capacity (TLC)

The total volume of air in the lungs after maximal inhalation.

IRV + TV + ERV + RV

Forced Vital Capacity (FVC)

The total volume of air that can be forcefully exhaled after full inhalation.

Alveolar ventilation (QA)

The flow of fresh air that reaches the alveoli and participates in gas exchange.

Qa = Ve (respiration rate) x (Vt - tidal volume - Vd(anatomic dead space) )

Respiratory exchange ratio (R)

The ratio of CO2 produced to O2 consumed during metabolism.

R = QCO2/QO2

Henry’s Law

Relates the concentration of a gas in liquid to its partial pressure.

[A] ( concentration of dissolved gas) = Alpha(a) (solubility of gas) x Pa (partial pressure of gas)

Dead space

The part of the respiratory system where gas exchange does not occur.

Bronchodilation

Widening of the bronchi, allowing for increased airflow.

Bronchoconstriction

Narrowing of the bronchi, which can reduce airflow.

Respiration rate (RR)

The number of breaths taken per minute.

Law of Laplace

A principle that describes the relationship between pressure, surface tension, and radius in alveoli, influencing their stability and inflation.

P (pressure) = 2 y( or T surface tension)/ r (radius)

Functional residual capacity (FRC)

The volume of air remaining in the lungs after a passive exhalation, which includes the residual volume and expiratory reserve volume.

RV + ERV

Pulmonary Ventilation

rate at which air moves out of lungs. increases 15 fold during exercise

Qv = RR x TV

Pulmonary fibrosis

stiff lungs

Reynolds number

predicts laminar or turbulent flow

Re = 2aV(average velocity)p(density of air)/n(viscosity) or 2aQv/A(area)n

above 2500 is turbulent and below 2000 is laminar

BTPS to STPD conversion

Vbtps = 1.2104 Vstpd