In the city the population was spread out with 20.4% under the age of 18, 4.7% from 18 to 24, 21.3% from 25 to 44, 25.3% from 45 to 64, and 28.3% who were 65 years of age or older. The median age was 48 years. For every 100 females there were 80.5 males.
In human physiology, the muscles of respiration are those muscles that contribute to inhalation and exhalation, by aiding in the expansion and contraction of the thoracic cavity.The diaphragm and, to a lesser extent, the intercostal muscles drive respiration during quiet breathing.n human physiology, the muscles of respiration are those muscles that contribute to inhalation and exhalation, by aiding in the expansion and contraction of the thoracic cavity.
Surface tension of the pleural fluid also leads to close apposition of the lung surfaces with the chest wall. This relationship allows for greater inflation of the alveoli during breathing. The pleural cavity transmits movements of the ribs muscles to the lungs, particularly during heavy breathing.