21.3 Chapter Human Structure and Function

Gross structure of lung

Cone shaped lung surrounded by pleura and connected to mediastinum by lung root, Lung surfaces close to ribs forming costal surface

Pleura

Thin, double-layered membrane that lines lungs, allows for smooth breathing

Apex of lung

narrow superior tip of lung

Base of lung

inferior surface of lung resting on diaphragm

Hilum

indention on each lung, transportation system

Lobes

Lungs divided into sections, 2 in left lung, 3 in right lung

Differences in lungs

Left lung smaller, has cardiac notch, 2 lobes, right bigger has 3 lobes

Pulmonary circulation

blood goes to lungs and is oxygenated, and then circulates out, has low pressure and high volume

Bronchial circulation

provide oxygenated blood to lung tissue, high pressure low volume

Constriction of air tubes

Parasympathetic fibers cause air tubes to constrict, increased mucous and secretion

Dilation of air tubes

Sympathetic fibers cause air tubes to dilate, more air taken in

Pleura two layers

Parietal Pleura, Visceral pleura

Parietal Pleura

Superficial layer, covers thoracic wall and superior face of diaphragm, Forms lateral walls of mediastinal enclosure, encloses lung root

Visceral pleura

Deep layer, lines fissures

Pleural fluid

Produced by pleura, between layers of pleura, reduces friction between lung tissue