Physiology Unit 5: Lung Structure & Function

What are the roles and components of the conducting respiratory system being upstream of the lung’s exchange interface with atmospheric air?

The conducting respiratory system upstream includes nasal cavity, Pharynx, Larynx, Trachea, Bronchi, and Bronchioles. No gas exchange happens but air movement and conditioning. The functions conducts air into and out of the lung, and warm, filter and humidify air. It protects the lungs by the mucus.

How the total cross-sectional area of pulmonary capillaries greatly aids in gas exchange?

Pulmonary capillaries have a very large cross sectional area so as the cross sectional area increases, the velocity decreases. This have the effect of slower blood flow so it gives more time for gas exchange and improves diffusion of oxygen and carbon dioxide.

What are the structures of the respiratory system that are supported by cartilage?

Trachea and Bronchi

What are the structures of the respiratory system that are supported by smooth muscle?

Bronchioles and Terminal bronchioles

What are the structure called that doesn’t have cartilage and smooth muscle and are thin walls for gas exchange?

Alveoli

How the conduction of air through the respiratory system resembles the arterial side of the circulation during inspiration?

Air moves from large tubes to smaller branches like arterial flow. The flow is directed outward into many small pathways.

How the conduction of air through the respiratory system resembles the venous side during expiration?

Air moves from small spaces to large tubes like venous flow. The flow is collected back toward a central exit

What are the three primary cell types in the alveolus and each of their roles?

Type 1 Alveolar cells function is gas exchange. Type 2 Alveolar cells function is secrete surfactant. Alveolar macrophages function is immune defense.

What is the Visceral Pleura?

The pleural membrane that cover the lung surface

What is Parietal pleura?

the pleural membrane that lines thoracic cavity

What is the pleural cavity?

Space between layers of the lung that contains pleural fluid

What is the function of pleural fluid?

Lubricates the lung to reduce friction and have negative pressure that keeps the lung expanding

What is the interfaces of the parietal pleura?

Diaphragms (Inferior) → Mediastinum (medial) → Rib cage and Intercostal muscles (lateral)