Human Phys Lecture 1: Pulmonary Ventilation

This set of flashcards covers key concepts related to pulmonary ventilation, including the laws governing respiration, the components of respiratory physiology, and associated definitions.

Fick’s Law of Diffusion

Describes the movement of molecules from high concentration to low concentration.

(k)(A)(P2-P1/D)

What is the rate of diffusion math formula?

Diffusion coefficient

What does the k in the diffusion rate math formula stand for? It depends on the solubility of gas and temperature

Area for gas exchange

What does the A in the diffusion rate math formula stand for?

Difference in partial pressure of gas on either side of barrier to diffuse

What does the P2-P1 in the diffusion rate math formula stand for?

Distance (thickness of barrier to diffusion)

What does the D in the diffusion rate math formula stand for?

k(cm2/s)

What changes depending on the gas?

A(cm2) and D(cm)

What changes with age, aerobic condition, fitness-level, and disease-state?

P2-P1 (mmHg)

What changes with altitude/barometric pressure?

Dalton’s Law of Partial Pressures

States that the total pressure of a gas mixture is equal to the sum of the partial pressures of its individual gases.

760 mmHg

What is composition of atmospheric air at sea level (barometric pressure)

N2

What is 78% x 760 mmHg = 593 mmHg equal to?

What is 20.94% x 760 mmHg = 159 mmHg equal?

Pulmonary Ventilation

The inflow and outflow of air between the lungs and the atmosphere.

Alveolar Air

Air present in the alveoli of the lungs where gas exchange occurs; typically has lower O2 and higher CO2 compared to atmospheric air.

O2 Transport

The movement of oxygen from the lungs to the body tissues via the bloodstream.

CO2 Transport

The movement of carbon dioxide from the tissues to the lungs to be exhaled.

Surfactant

A substance that lowers the surface tension of liquids, helping to keep alveoli open for gas exchange.

Acclimatization

Physiological changes that occur in response to high altitude exposure, enabling better oxygen utilization.

Type-I alveolar cells

Cells that line the alveoli and are primarily responsible for gas exchange.

Type-II alveolar cells

Cells that produce surfactant and reduce surface tension in the lungs.

Hypoxia

A condition in which there is a deficiency in the amount of oxygen reaching the tissues.

Dead Zone

An area at high altitudes (>8000m) where physiological challenges make survival difficult.

pCO2

Partial pressure of carbon dioxide, significant for assessing gas exchange efficiency.

pO2

Partial pressure of oxygen, crucial for evaluating oxygen availability in various conditions.