The function of the respiratory system is to deliver air to the lungs. Oxygen in the air diffuses out of the lungs and into the blood, while carbon dioxide diffuses in the opposite direction, out of the blood and into the lungs.Respiration includes the following processes: Pulmonary ventilation is the process of breathingâinspiration (inhaling air) and expiration (exhaling air).xternal respiration is the exchange if oxygen and carbon dioxide between the blood and air in the lungs, and internal resparation is the exchange of gases between blood cells of the body.
Boxes can be painted or stained with a light color on the outside and left natural on the inside. Birdhouses for Eastern Bluebirds should be approximately 4 x 4 inches to 5 x 5 inches with entry holes that are either 1 inch round holes, 1 3/8 x 2 vertical oval holes or 1 1/8 inch horizontal slot entrances.
Normally, bluebirds raise two to three broods per year, often using the same nesting site each year. The female selects a proper nesting site 4 to 6 feet above the ground in a cavity or hole excavated by another animal. The nest is a neat, cup-shaped structure made of fine grass. The female lays one egg per day for 4 to 6 days in the nest, and then incubates the pale blue eggs for 12 to 14 days. Soon after hatching, the youngsters sprout feathers. They have gray backs coupled with spotted white breasts and only a hint of blue in the wing and tail feathers at this time.