Mechanics of Breathing

These flashcards cover key concepts related to the mechanics of breathing and the respiratory system, including functions, laws of gas, anatomical structures, and physiological conditions.

What are the four main functions of the respiratory system?

1. Exchange of gases between the atmosphere and the blood 2. Homeostatic regulation of body pH 3. Protection from inhaled pathogens and irritating substances 4. Vocalization

What drives respiratory bulk flow?

Flow occurs from regions of higher to lower pressure created by a muscular pump that generates pressure gradients.

What are the three types of gas exchange in respiration?

1. Atmosphere to lung (ventilation) 2. Lung to blood 3. Blood to cells.

What does the pleural sac do?

The pleural sac forms a double membrane surrounding the lung, lowering friction between membranes and adhering lungs to the thoracic wall.

Which muscle contracts during inspiration?

The diaphragm and intercostal muscles contract to increase the thoracic cavity volume.

What is tidal volume?

The volume of air that typically moves in and out with each breath.

Define vital capacity.

The maximum volume of air that can be moved in plus the maximum amount that can be moved out during one breath.

Describe Boyle's Law in relation to respiration.

Boyle's Law states that pressure and volume are inversely related; as the volume of the thoracic cavity increases during inspiration, the pressure decreases, allowing air to flow in.

What is the role of surfactant in the lungs?

Surfactant reduces surface tension in the alveoli, making it easier for the lungs to expand during breathing.

What is compliance in lung mechanics?

Compliance is the ability of the lungs to stretch; high compliance means easy expansion, while low compliance requires more force.

What physiological condition might result from inadequate surfactant production in premature babies?

Newborn respiratory distress syndrome.

What characterizes obstructive lung diseases?

Airway obstruction leading to difficulty in exhaling; includes conditions like asthma and emphysema.

Explain the concept of ventilation-perfusion mismatch.

A condition when certain parts of the lung receive oxygen but do not have enough blood flow to transport it, or vice versa, resulting in inefficient gas exchange.

What factors can affect airway resistance?

Factors include length of the airways, viscosity of air, and the diameter of airways.

During which phase of breathing is intrapleural pressure most negative?

During inspiration, when the diaphragm contracts and thoracic volume increases.