The Airways and Blood Vessels
The Protective System of Respiration
The airway epithelium
:secretes watery fluid mucus
macrophages
a second protective mechanism against infection
Site of Gas Exchange :The Alveoli
open ends are continuous with the lumens of the airways
alveolar wall
the air in two adjacent alveoli is separated
interstitial space
loose meshwork of connective tissue
Expiration
primary changes in the dimensions of the thoraxduring expiration force virtually identical changes in the dimensions of the kungs
air flows from the alveoli through the airways out into the atmosphere
expiration of larger volumes by contraction of intercostal muscles and the abdominal muscles
Inspiration
contraction of the diaphragm and the “inspiratory”intercostal muscles located between the ribs
contraction of these muscles upsets the stability
Relation of the Lungs to the Thoracic Wall
thorax
the compartment of the body between the neck and the abdomen
bounded at the neck by muscles and connective tissue
diaphragm completely separated from the abdomen
The wall of the thorax
elastic connective tissue
The relationship between a lung and its pleural sac can be visualized when push a fist into a balloon